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Commit | Line | Data |
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ca6c03ca JH |
1 | /* Control flow graph manipulation code for GNU compiler. |
2 | Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, | |
d9221e01 | 3 | 1999, 2000, 2001, 2002, 2003, 2004 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: | |
bc35512f | 26 | - Basic CFG/RTL manipulation API documented in cfghooks.h |
5f0d2358 | 27 | - CFG-aware instruction chain manipulation |
ca6c03ca | 28 | delete_insn, delete_insn_chain |
bc35512f JH |
29 | - Edge splitting and committing to edges |
30 | insert_insn_on_edge, commit_edge_insertions | |
31 | - CFG updating after insn simplification | |
32 | purge_dead_edges, purge_all_dead_edges | |
33 | ||
34 | Functions not supposed for generic use: | |
5f0d2358 | 35 | - Infrastructure to determine quickly basic block for insn |
ca6c03ca | 36 | compute_bb_for_insn, update_bb_for_insn, set_block_for_insn, |
5f0d2358 | 37 | - Edge redirection with updating and optimizing of insn chain |
bc35512f | 38 | block_label, tidy_fallthru_edge, force_nonfallthru */ |
ca6c03ca JH |
39 | \f |
40 | #include "config.h" | |
41 | #include "system.h" | |
4977bab6 ZW |
42 | #include "coretypes.h" |
43 | #include "tm.h" | |
ca6c03ca JH |
44 | #include "tree.h" |
45 | #include "rtl.h" | |
46 | #include "hard-reg-set.h" | |
47 | #include "basic-block.h" | |
48 | #include "regs.h" | |
49 | #include "flags.h" | |
50 | #include "output.h" | |
51 | #include "function.h" | |
52 | #include "except.h" | |
53 | #include "toplev.h" | |
54 | #include "tm_p.h" | |
55 | #include "obstack.h" | |
0a2ed1f1 | 56 | #include "insn-config.h" |
9ee634e3 | 57 | #include "cfglayout.h" |
ff25ef99 | 58 | #include "expr.h" |
ca6c03ca | 59 | |
ca6c03ca | 60 | |
ca6c03ca JH |
61 | /* The labels mentioned in non-jump rtl. Valid during find_basic_blocks. */ |
62 | /* ??? Should probably be using LABEL_NUSES instead. It would take a | |
63 | bit of surgery to be able to use or co-opt the routines in jump. */ | |
ca6c03ca JH |
64 | rtx label_value_list; |
65 | rtx tail_recursion_label_list; | |
66 | ||
d329e058 AJ |
67 | static int can_delete_note_p (rtx); |
68 | static int can_delete_label_p (rtx); | |
69 | static void commit_one_edge_insertion (edge, int); | |
d329e058 AJ |
70 | static rtx last_loop_beg_note (rtx); |
71 | static bool back_edge_of_syntactic_loop_p (basic_block, basic_block); | |
72 | basic_block force_nonfallthru_and_redirect (edge, basic_block); | |
73 | static basic_block rtl_split_edge (edge); | |
f470c378 | 74 | static bool rtl_move_block_after (basic_block, basic_block); |
d329e058 | 75 | static int rtl_verify_flow_info (void); |
f470c378 | 76 | static basic_block cfg_layout_split_block (basic_block, void *); |
d329e058 AJ |
77 | static bool cfg_layout_redirect_edge_and_branch (edge, basic_block); |
78 | static basic_block cfg_layout_redirect_edge_and_branch_force (edge, basic_block); | |
79 | static void cfg_layout_delete_block (basic_block); | |
80 | static void rtl_delete_block (basic_block); | |
81 | static basic_block rtl_redirect_edge_and_branch_force (edge, basic_block); | |
82 | static bool rtl_redirect_edge_and_branch (edge, basic_block); | |
f470c378 ZD |
83 | static basic_block rtl_split_block (basic_block, void *); |
84 | static void rtl_dump_bb (basic_block, FILE *, int); | |
d329e058 | 85 | static int rtl_verify_flow_info_1 (void); |
ff25ef99 | 86 | static void mark_killed_regs (rtx, rtx, void *); |
f470c378 | 87 | static void rtl_make_forwarder_block (edge); |
ca6c03ca JH |
88 | \f |
89 | /* Return true if NOTE is not one of the ones that must be kept paired, | |
5f0d2358 | 90 | so that we may simply delete it. */ |
ca6c03ca JH |
91 | |
92 | static int | |
d329e058 | 93 | can_delete_note_p (rtx note) |
ca6c03ca JH |
94 | { |
95 | return (NOTE_LINE_NUMBER (note) == NOTE_INSN_DELETED | |
969d70ca | 96 | || NOTE_LINE_NUMBER (note) == NOTE_INSN_BASIC_BLOCK |
750054a2 | 97 | || NOTE_LINE_NUMBER (note) == NOTE_INSN_UNLIKELY_EXECUTED_CODE |
f87c27b4 | 98 | || NOTE_LINE_NUMBER (note) == NOTE_INSN_PREDICTION); |
ca6c03ca JH |
99 | } |
100 | ||
101 | /* True if a given label can be deleted. */ | |
102 | ||
103 | static int | |
d329e058 | 104 | can_delete_label_p (rtx label) |
ca6c03ca | 105 | { |
5f0d2358 RK |
106 | return (!LABEL_PRESERVE_P (label) |
107 | /* User declared labels must be preserved. */ | |
108 | && LABEL_NAME (label) == 0 | |
109 | && !in_expr_list_p (forced_labels, label) | |
6a58eee9 | 110 | && !in_expr_list_p (label_value_list, label)); |
ca6c03ca JH |
111 | } |
112 | ||
113 | /* Delete INSN by patching it out. Return the next insn. */ | |
114 | ||
115 | rtx | |
d329e058 | 116 | delete_insn (rtx insn) |
ca6c03ca JH |
117 | { |
118 | rtx next = NEXT_INSN (insn); | |
119 | rtx note; | |
120 | bool really_delete = true; | |
121 | ||
122 | if (GET_CODE (insn) == CODE_LABEL) | |
123 | { | |
124 | /* Some labels can't be directly removed from the INSN chain, as they | |
f87c27b4 | 125 | might be references via variables, constant pool etc. |
ca6c03ca JH |
126 | Convert them to the special NOTE_INSN_DELETED_LABEL note. */ |
127 | if (! can_delete_label_p (insn)) | |
128 | { | |
129 | const char *name = LABEL_NAME (insn); | |
130 | ||
131 | really_delete = false; | |
132 | PUT_CODE (insn, NOTE); | |
133 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED_LABEL; | |
134 | NOTE_SOURCE_FILE (insn) = name; | |
135 | } | |
5f0d2358 | 136 | |
ca6c03ca JH |
137 | remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels); |
138 | } | |
139 | ||
140 | if (really_delete) | |
141 | { | |
cda94cbb RH |
142 | /* If this insn has already been deleted, something is very wrong. */ |
143 | if (INSN_DELETED_P (insn)) | |
144 | abort (); | |
ca6c03ca JH |
145 | remove_insn (insn); |
146 | INSN_DELETED_P (insn) = 1; | |
147 | } | |
148 | ||
149 | /* If deleting a jump, decrement the use count of the label. Deleting | |
150 | the label itself should happen in the normal course of block merging. */ | |
151 | if (GET_CODE (insn) == JUMP_INSN | |
152 | && JUMP_LABEL (insn) | |
153 | && GET_CODE (JUMP_LABEL (insn)) == CODE_LABEL) | |
154 | LABEL_NUSES (JUMP_LABEL (insn))--; | |
155 | ||
156 | /* Also if deleting an insn that references a label. */ | |
9295a326 JZ |
157 | else |
158 | { | |
159 | while ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)) != NULL_RTX | |
160 | && GET_CODE (XEXP (note, 0)) == CODE_LABEL) | |
161 | { | |
162 | LABEL_NUSES (XEXP (note, 0))--; | |
163 | remove_note (insn, note); | |
164 | } | |
165 | } | |
ca6c03ca JH |
166 | |
167 | if (GET_CODE (insn) == JUMP_INSN | |
168 | && (GET_CODE (PATTERN (insn)) == ADDR_VEC | |
169 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)) | |
170 | { | |
171 | rtx pat = PATTERN (insn); | |
172 | int diff_vec_p = GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC; | |
173 | int len = XVECLEN (pat, diff_vec_p); | |
174 | int i; | |
175 | ||
176 | for (i = 0; i < len; i++) | |
a124fcda RH |
177 | { |
178 | rtx label = XEXP (XVECEXP (pat, diff_vec_p, i), 0); | |
179 | ||
180 | /* When deleting code in bulk (e.g. removing many unreachable | |
181 | blocks) we can delete a label that's a target of the vector | |
182 | before deleting the vector itself. */ | |
183 | if (GET_CODE (label) != NOTE) | |
184 | LABEL_NUSES (label)--; | |
185 | } | |
ca6c03ca JH |
186 | } |
187 | ||
188 | return next; | |
189 | } | |
190 | ||
3dec4024 JH |
191 | /* Like delete_insn but also purge dead edges from BB. */ |
192 | rtx | |
d329e058 | 193 | delete_insn_and_edges (rtx insn) |
3dec4024 JH |
194 | { |
195 | rtx x; | |
196 | bool purge = false; | |
197 | ||
ba4f7968 | 198 | if (INSN_P (insn) |
3dec4024 | 199 | && BLOCK_FOR_INSN (insn) |
a813c111 | 200 | && BB_END (BLOCK_FOR_INSN (insn)) == insn) |
3dec4024 JH |
201 | purge = true; |
202 | x = delete_insn (insn); | |
203 | if (purge) | |
204 | purge_dead_edges (BLOCK_FOR_INSN (insn)); | |
205 | return x; | |
206 | } | |
207 | ||
ca6c03ca JH |
208 | /* Unlink a chain of insns between START and FINISH, leaving notes |
209 | that must be paired. */ | |
210 | ||
211 | void | |
d329e058 | 212 | delete_insn_chain (rtx start, rtx finish) |
ca6c03ca | 213 | { |
ca6c03ca JH |
214 | rtx next; |
215 | ||
5f0d2358 RK |
216 | /* Unchain the insns one by one. It would be quicker to delete all of these |
217 | with a single unchaining, rather than one at a time, but we need to keep | |
218 | the NOTE's. */ | |
ca6c03ca JH |
219 | while (1) |
220 | { | |
221 | next = NEXT_INSN (start); | |
222 | if (GET_CODE (start) == NOTE && !can_delete_note_p (start)) | |
223 | ; | |
224 | else | |
225 | next = delete_insn (start); | |
226 | ||
227 | if (start == finish) | |
228 | break; | |
229 | start = next; | |
230 | } | |
231 | } | |
3dec4024 JH |
232 | |
233 | /* Like delete_insn but also purge dead edges from BB. */ | |
234 | void | |
d329e058 | 235 | delete_insn_chain_and_edges (rtx first, rtx last) |
3dec4024 JH |
236 | { |
237 | bool purge = false; | |
238 | ||
ba4f7968 | 239 | if (INSN_P (last) |
3dec4024 | 240 | && BLOCK_FOR_INSN (last) |
a813c111 | 241 | && BB_END (BLOCK_FOR_INSN (last)) == last) |
3dec4024 JH |
242 | purge = true; |
243 | delete_insn_chain (first, last); | |
244 | if (purge) | |
245 | purge_dead_edges (BLOCK_FOR_INSN (last)); | |
246 | } | |
ca6c03ca | 247 | \f |
5f0d2358 RK |
248 | /* Create a new basic block consisting of the instructions between HEAD and END |
249 | inclusive. This function is designed to allow fast BB construction - reuses | |
250 | the note and basic block struct in BB_NOTE, if any and do not grow | |
251 | BASIC_BLOCK chain and should be used directly only by CFG construction code. | |
252 | END can be NULL in to create new empty basic block before HEAD. Both END | |
918ed612 ZD |
253 | and HEAD can be NULL to create basic block at the end of INSN chain. |
254 | AFTER is the basic block we should be put after. */ | |
ca6c03ca JH |
255 | |
256 | basic_block | |
d329e058 | 257 | create_basic_block_structure (rtx head, rtx end, rtx bb_note, basic_block after) |
ca6c03ca JH |
258 | { |
259 | basic_block bb; | |
260 | ||
261 | if (bb_note | |
262 | && ! RTX_INTEGRATED_P (bb_note) | |
263 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL | |
264 | && bb->aux == NULL) | |
265 | { | |
266 | /* If we found an existing note, thread it back onto the chain. */ | |
267 | ||
268 | rtx after; | |
269 | ||
270 | if (GET_CODE (head) == CODE_LABEL) | |
271 | after = head; | |
272 | else | |
273 | { | |
274 | after = PREV_INSN (head); | |
275 | head = bb_note; | |
276 | } | |
277 | ||
278 | if (after != bb_note && NEXT_INSN (after) != bb_note) | |
ba4f7968 | 279 | reorder_insns_nobb (bb_note, bb_note, after); |
ca6c03ca JH |
280 | } |
281 | else | |
282 | { | |
283 | /* Otherwise we must create a note and a basic block structure. */ | |
284 | ||
285 | bb = alloc_block (); | |
286 | ||
287 | if (!head && !end) | |
5f0d2358 RK |
288 | head = end = bb_note |
289 | = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); | |
ca6c03ca JH |
290 | else if (GET_CODE (head) == CODE_LABEL && end) |
291 | { | |
292 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); | |
293 | if (head == end) | |
294 | end = bb_note; | |
295 | } | |
296 | else | |
297 | { | |
298 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); | |
299 | head = bb_note; | |
300 | if (!end) | |
301 | end = head; | |
302 | } | |
5f0d2358 | 303 | |
ca6c03ca JH |
304 | NOTE_BASIC_BLOCK (bb_note) = bb; |
305 | } | |
306 | ||
307 | /* Always include the bb note in the block. */ | |
308 | if (NEXT_INSN (end) == bb_note) | |
309 | end = bb_note; | |
310 | ||
a813c111 SB |
311 | BB_HEAD (bb) = head; |
312 | BB_END (bb) = end; | |
852c6ec7 | 313 | bb->index = last_basic_block++; |
38c1593d | 314 | bb->flags = BB_NEW; |
918ed612 | 315 | link_block (bb, after); |
852c6ec7 | 316 | BASIC_BLOCK (bb->index) = bb; |
ba4f7968 | 317 | update_bb_for_insn (bb); |
750054a2 | 318 | bb->partition = UNPARTITIONED; |
ca6c03ca JH |
319 | |
320 | /* Tag the block so that we know it has been used when considering | |
321 | other basic block notes. */ | |
322 | bb->aux = bb; | |
323 | ||
324 | return bb; | |
325 | } | |
326 | ||
5f0d2358 | 327 | /* Create new basic block consisting of instructions in between HEAD and END |
918ed612 | 328 | and place it to the BB chain after block AFTER. END can be NULL in to |
5f0d2358 RK |
329 | create new empty basic block before HEAD. Both END and HEAD can be NULL to |
330 | create basic block at the end of INSN chain. */ | |
ca6c03ca | 331 | |
bc35512f JH |
332 | static basic_block |
333 | rtl_create_basic_block (void *headp, void *endp, basic_block after) | |
ca6c03ca | 334 | { |
bc35512f | 335 | rtx head = headp, end = endp; |
ca6c03ca | 336 | basic_block bb; |
0b17ab2f | 337 | |
7eca0767 JH |
338 | /* Grow the basic block array if needed. */ |
339 | if ((size_t) last_basic_block >= VARRAY_SIZE (basic_block_info)) | |
340 | { | |
341 | size_t new_size = last_basic_block + (last_basic_block + 3) / 4; | |
342 | VARRAY_GROW (basic_block_info, new_size); | |
343 | } | |
0b17ab2f | 344 | |
bf77398c | 345 | n_basic_blocks++; |
ca6c03ca | 346 | |
852c6ec7 | 347 | bb = create_basic_block_structure (head, end, NULL, after); |
ca6c03ca JH |
348 | bb->aux = NULL; |
349 | return bb; | |
350 | } | |
bc35512f JH |
351 | |
352 | static basic_block | |
353 | cfg_layout_create_basic_block (void *head, void *end, basic_block after) | |
354 | { | |
355 | basic_block newbb = rtl_create_basic_block (head, end, after); | |
356 | ||
357 | cfg_layout_initialize_rbi (newbb); | |
358 | return newbb; | |
359 | } | |
ca6c03ca JH |
360 | \f |
361 | /* Delete the insns in a (non-live) block. We physically delete every | |
362 | non-deleted-note insn, and update the flow graph appropriately. | |
363 | ||
364 | Return nonzero if we deleted an exception handler. */ | |
365 | ||
366 | /* ??? Preserving all such notes strikes me as wrong. It would be nice | |
367 | to post-process the stream to remove empty blocks, loops, ranges, etc. */ | |
368 | ||
f0fda11c | 369 | static void |
d329e058 | 370 | rtl_delete_block (basic_block b) |
ca6c03ca | 371 | { |
ca6c03ca JH |
372 | rtx insn, end, tmp; |
373 | ||
374 | /* If the head of this block is a CODE_LABEL, then it might be the | |
375 | label for an exception handler which can't be reached. | |
376 | ||
377 | We need to remove the label from the exception_handler_label list | |
378 | and remove the associated NOTE_INSN_EH_REGION_BEG and | |
379 | NOTE_INSN_EH_REGION_END notes. */ | |
380 | ||
07532fad RS |
381 | /* Get rid of all NOTE_INSN_PREDICTIONs and NOTE_INSN_LOOP_CONTs |
382 | hanging before the block. */ | |
f87c27b4 | 383 | |
a813c111 | 384 | for (insn = PREV_INSN (BB_HEAD (b)); insn; insn = PREV_INSN (insn)) |
969d70ca JH |
385 | { |
386 | if (GET_CODE (insn) != NOTE) | |
f87c27b4 | 387 | break; |
07532fad RS |
388 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_PREDICTION |
389 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_CONT) | |
f87c27b4 | 390 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; |
969d70ca JH |
391 | } |
392 | ||
a813c111 | 393 | insn = BB_HEAD (b); |
ca6c03ca | 394 | |
a813c111 | 395 | never_reached_warning (insn, BB_END (b)); |
ca6c03ca JH |
396 | |
397 | if (GET_CODE (insn) == CODE_LABEL) | |
398 | maybe_remove_eh_handler (insn); | |
399 | ||
400 | /* Include any jump table following the basic block. */ | |
a813c111 | 401 | end = BB_END (b); |
e1233a7d | 402 | if (tablejump_p (end, NULL, &tmp)) |
ca6c03ca JH |
403 | end = tmp; |
404 | ||
405 | /* Include any barrier that may follow the basic block. */ | |
406 | tmp = next_nonnote_insn (end); | |
407 | if (tmp && GET_CODE (tmp) == BARRIER) | |
408 | end = tmp; | |
409 | ||
410 | /* Selectively delete the entire chain. */ | |
a813c111 | 411 | BB_HEAD (b) = NULL; |
ca6c03ca | 412 | delete_insn_chain (insn, end); |
ca6c03ca JH |
413 | } |
414 | \f | |
852c6ec7 | 415 | /* Records the basic block struct in BLOCK_FOR_INSN for every insn. */ |
ca6c03ca JH |
416 | |
417 | void | |
d329e058 | 418 | compute_bb_for_insn (void) |
ca6c03ca | 419 | { |
e0082a72 | 420 | basic_block bb; |
ca6c03ca | 421 | |
e0082a72 | 422 | FOR_EACH_BB (bb) |
ca6c03ca | 423 | { |
a813c111 | 424 | rtx end = BB_END (bb); |
5f0d2358 | 425 | rtx insn; |
ca6c03ca | 426 | |
a813c111 | 427 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
ca6c03ca | 428 | { |
ba4f7968 | 429 | BLOCK_FOR_INSN (insn) = bb; |
ca6c03ca JH |
430 | if (insn == end) |
431 | break; | |
ca6c03ca JH |
432 | } |
433 | } | |
434 | } | |
435 | ||
436 | /* Release the basic_block_for_insn array. */ | |
437 | ||
438 | void | |
d329e058 | 439 | free_bb_for_insn (void) |
ca6c03ca | 440 | { |
ba4f7968 JH |
441 | rtx insn; |
442 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) | |
443 | if (GET_CODE (insn) != BARRIER) | |
444 | BLOCK_FOR_INSN (insn) = NULL; | |
ca6c03ca JH |
445 | } |
446 | ||
447 | /* Update insns block within BB. */ | |
448 | ||
449 | void | |
d329e058 | 450 | update_bb_for_insn (basic_block bb) |
ca6c03ca JH |
451 | { |
452 | rtx insn; | |
453 | ||
a813c111 | 454 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
ca6c03ca | 455 | { |
bcc53e2a JH |
456 | if (GET_CODE (insn) != BARRIER) |
457 | set_block_for_insn (insn, bb); | |
a813c111 | 458 | if (insn == BB_END (bb)) |
ca6c03ca JH |
459 | break; |
460 | } | |
461 | } | |
ca6c03ca | 462 | \f |
f470c378 ZD |
463 | /* Creates a new basic block just after basic block B by splitting |
464 | everything after specified instruction I. */ | |
ca6c03ca | 465 | |
f470c378 | 466 | static basic_block |
d329e058 | 467 | rtl_split_block (basic_block bb, void *insnp) |
ca6c03ca JH |
468 | { |
469 | basic_block new_bb; | |
9ee634e3 | 470 | rtx insn = insnp; |
f470c378 | 471 | edge e; |
ca6c03ca | 472 | |
f470c378 ZD |
473 | if (!insn) |
474 | { | |
475 | insn = first_insn_after_basic_block_note (bb); | |
476 | ||
477 | if (insn) | |
478 | insn = PREV_INSN (insn); | |
479 | else | |
480 | insn = get_last_insn (); | |
481 | } | |
482 | ||
483 | /* We probably should check type of the insn so that we do not create | |
484 | inconsistent cfg. It is checked in verify_flow_info anyway, so do not | |
485 | bother. */ | |
486 | if (insn == BB_END (bb)) | |
487 | emit_note_after (NOTE_INSN_DELETED, insn); | |
ca6c03ca JH |
488 | |
489 | /* Create the new basic block. */ | |
a813c111 | 490 | new_bb = create_basic_block (NEXT_INSN (insn), BB_END (bb), bb); |
a813c111 | 491 | BB_END (bb) = insn; |
ca6c03ca JH |
492 | |
493 | /* Redirect the outgoing edges. */ | |
494 | new_bb->succ = bb->succ; | |
495 | bb->succ = NULL; | |
496 | for (e = new_bb->succ; e; e = e->succ_next) | |
497 | e->src = new_bb; | |
498 | ||
ca6c03ca JH |
499 | if (bb->global_live_at_start) |
500 | { | |
501 | new_bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
502 | new_bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
503 | COPY_REG_SET (new_bb->global_live_at_end, bb->global_live_at_end); | |
504 | ||
505 | /* We now have to calculate which registers are live at the end | |
506 | of the split basic block and at the start of the new basic | |
507 | block. Start with those registers that are known to be live | |
508 | at the end of the original basic block and get | |
509 | propagate_block to determine which registers are live. */ | |
510 | COPY_REG_SET (new_bb->global_live_at_start, bb->global_live_at_end); | |
511 | propagate_block (new_bb, new_bb->global_live_at_start, NULL, NULL, 0); | |
512 | COPY_REG_SET (bb->global_live_at_end, | |
513 | new_bb->global_live_at_start); | |
0a2ed1f1 JH |
514 | #ifdef HAVE_conditional_execution |
515 | /* In the presence of conditional execution we are not able to update | |
516 | liveness precisely. */ | |
517 | if (reload_completed) | |
518 | { | |
519 | bb->flags |= BB_DIRTY; | |
520 | new_bb->flags |= BB_DIRTY; | |
521 | } | |
522 | #endif | |
ca6c03ca JH |
523 | } |
524 | ||
f470c378 | 525 | return new_bb; |
bc35512f JH |
526 | } |
527 | ||
ca6c03ca | 528 | /* Blocks A and B are to be merged into a single block A. The insns |
bc35512f | 529 | are already contiguous. */ |
ca6c03ca | 530 | |
bc35512f JH |
531 | static void |
532 | rtl_merge_blocks (basic_block a, basic_block b) | |
ca6c03ca | 533 | { |
a813c111 | 534 | rtx b_head = BB_HEAD (b), b_end = BB_END (b), a_end = BB_END (a); |
ca6c03ca JH |
535 | rtx del_first = NULL_RTX, del_last = NULL_RTX; |
536 | int b_empty = 0; | |
537 | ||
538 | /* If there was a CODE_LABEL beginning B, delete it. */ | |
ca6c03ca JH |
539 | if (GET_CODE (b_head) == CODE_LABEL) |
540 | { | |
541 | /* Detect basic blocks with nothing but a label. This can happen | |
542 | in particular at the end of a function. */ | |
543 | if (b_head == b_end) | |
544 | b_empty = 1; | |
5f0d2358 | 545 | |
ca6c03ca JH |
546 | del_first = del_last = b_head; |
547 | b_head = NEXT_INSN (b_head); | |
548 | } | |
549 | ||
5f0d2358 RK |
550 | /* Delete the basic block note and handle blocks containing just that |
551 | note. */ | |
ca6c03ca JH |
552 | if (NOTE_INSN_BASIC_BLOCK_P (b_head)) |
553 | { | |
554 | if (b_head == b_end) | |
555 | b_empty = 1; | |
556 | if (! del_last) | |
557 | del_first = b_head; | |
5f0d2358 | 558 | |
ca6c03ca JH |
559 | del_last = b_head; |
560 | b_head = NEXT_INSN (b_head); | |
561 | } | |
562 | ||
563 | /* If there was a jump out of A, delete it. */ | |
ca6c03ca JH |
564 | if (GET_CODE (a_end) == JUMP_INSN) |
565 | { | |
566 | rtx prev; | |
567 | ||
568 | for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev)) | |
569 | if (GET_CODE (prev) != NOTE | |
570 | || NOTE_LINE_NUMBER (prev) == NOTE_INSN_BASIC_BLOCK | |
a813c111 | 571 | || prev == BB_HEAD (a)) |
ca6c03ca JH |
572 | break; |
573 | ||
574 | del_first = a_end; | |
575 | ||
576 | #ifdef HAVE_cc0 | |
577 | /* If this was a conditional jump, we need to also delete | |
578 | the insn that set cc0. */ | |
579 | if (only_sets_cc0_p (prev)) | |
580 | { | |
581 | rtx tmp = prev; | |
5f0d2358 | 582 | |
ca6c03ca JH |
583 | prev = prev_nonnote_insn (prev); |
584 | if (!prev) | |
a813c111 | 585 | prev = BB_HEAD (a); |
ca6c03ca JH |
586 | del_first = tmp; |
587 | } | |
588 | #endif | |
589 | ||
590 | a_end = PREV_INSN (del_first); | |
591 | } | |
592 | else if (GET_CODE (NEXT_INSN (a_end)) == BARRIER) | |
593 | del_first = NEXT_INSN (a_end); | |
594 | ||
ca6c03ca JH |
595 | /* Delete everything marked above as well as crap that might be |
596 | hanging out between the two blocks. */ | |
f470c378 | 597 | BB_HEAD (b) = NULL; |
ca6c03ca JH |
598 | delete_insn_chain (del_first, del_last); |
599 | ||
600 | /* Reassociate the insns of B with A. */ | |
601 | if (!b_empty) | |
602 | { | |
ba4f7968 | 603 | rtx x; |
5f0d2358 | 604 | |
ba4f7968 JH |
605 | for (x = a_end; x != b_end; x = NEXT_INSN (x)) |
606 | set_block_for_insn (x, a); | |
5f0d2358 | 607 | |
ba4f7968 | 608 | set_block_for_insn (b_end, a); |
5f0d2358 | 609 | |
ca6c03ca JH |
610 | a_end = b_end; |
611 | } | |
5f0d2358 | 612 | |
a813c111 | 613 | BB_END (a) = a_end; |
ca6c03ca | 614 | } |
bc35512f JH |
615 | |
616 | /* Return true when block A and B can be merged. */ | |
617 | static bool | |
618 | rtl_can_merge_blocks (basic_block a,basic_block b) | |
619 | { | |
750054a2 CT |
620 | bool partitions_ok = true; |
621 | ||
622 | /* If we are partitioning hot/cold basic blocks, we don't want to | |
623 | mess up unconditional or indirect jumps that cross between hot | |
624 | and cold sections. */ | |
625 | ||
626 | if (flag_reorder_blocks_and_partition | |
627 | && (find_reg_note (BB_END (a), REG_CROSSING_JUMP, NULL_RTX) | |
628 | || find_reg_note (BB_END (b), REG_CROSSING_JUMP, NULL_RTX) | |
629 | || a->partition != b->partition)) | |
630 | partitions_ok = false; | |
631 | ||
bc35512f JH |
632 | /* There must be exactly one edge in between the blocks. */ |
633 | return (a->succ && !a->succ->succ_next && a->succ->dest == b | |
634 | && !b->pred->pred_next && a != b | |
635 | /* Must be simple edge. */ | |
636 | && !(a->succ->flags & EDGE_COMPLEX) | |
750054a2 | 637 | && partitions_ok |
bc35512f JH |
638 | && a->next_bb == b |
639 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR | |
640 | /* If the jump insn has side effects, | |
641 | we can't kill the edge. */ | |
a813c111 | 642 | && (GET_CODE (BB_END (a)) != JUMP_INSN |
e24e7211 | 643 | || (reload_completed |
a813c111 | 644 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f | 645 | } |
ca6c03ca | 646 | \f |
5f0d2358 RK |
647 | /* Return the label in the head of basic block BLOCK. Create one if it doesn't |
648 | exist. */ | |
ca6c03ca JH |
649 | |
650 | rtx | |
d329e058 | 651 | block_label (basic_block block) |
ca6c03ca JH |
652 | { |
653 | if (block == EXIT_BLOCK_PTR) | |
654 | return NULL_RTX; | |
5f0d2358 | 655 | |
a813c111 | 656 | if (GET_CODE (BB_HEAD (block)) != CODE_LABEL) |
ca6c03ca | 657 | { |
a813c111 | 658 | BB_HEAD (block) = emit_label_before (gen_label_rtx (), BB_HEAD (block)); |
ca6c03ca | 659 | } |
5f0d2358 | 660 | |
a813c111 | 661 | return BB_HEAD (block); |
ca6c03ca JH |
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 | 668 | |
3348b696 | 669 | bool |
bc35512f | 670 | try_redirect_by_replacing_jump (edge e, basic_block target, bool in_cfglayout) |
ca6c03ca JH |
671 | { |
672 | basic_block src = e->src; | |
a813c111 | 673 | rtx insn = BB_END (src), kill_from; |
ca6c03ca | 674 | edge tmp; |
e1233a7d | 675 | rtx set; |
ca6c03ca JH |
676 | int fallthru = 0; |
677 | ||
750054a2 CT |
678 | |
679 | /* If we are partitioning hot/cold basic blocks, we don't want to | |
680 | mess up unconditional or indirect jumps that cross between hot | |
681 | and cold sections. */ | |
682 | ||
683 | if (flag_reorder_blocks_and_partition | |
684 | && find_reg_note (insn, REG_CROSSING_JUMP, NULL_RTX)) | |
685 | return false; | |
686 | ||
ca6c03ca JH |
687 | /* Verify that all targets will be TARGET. */ |
688 | for (tmp = src->succ; tmp; tmp = tmp->succ_next) | |
689 | if (tmp->dest != target && tmp != e) | |
690 | break; | |
5f0d2358 | 691 | |
ca6c03ca JH |
692 | if (tmp || !onlyjump_p (insn)) |
693 | return false; | |
3348b696 | 694 | if ((!optimize || reload_completed) && tablejump_p (insn, NULL, NULL)) |
1b6763cf | 695 | return false; |
ca6c03ca JH |
696 | |
697 | /* Avoid removing branch with side effects. */ | |
698 | set = single_set (insn); | |
699 | if (!set || side_effects_p (set)) | |
700 | return false; | |
701 | ||
702 | /* In case we zap a conditional jump, we'll need to kill | |
703 | the cc0 setter too. */ | |
704 | kill_from = insn; | |
705 | #ifdef HAVE_cc0 | |
706 | if (reg_mentioned_p (cc0_rtx, PATTERN (insn))) | |
707 | kill_from = PREV_INSN (insn); | |
708 | #endif | |
709 | ||
710 | /* See if we can create the fallthru edge. */ | |
bc35512f | 711 | if (in_cfglayout || can_fallthru (src, target)) |
ca6c03ca | 712 | { |
c263766c RH |
713 | if (dump_file) |
714 | fprintf (dump_file, "Removing jump %i.\n", INSN_UID (insn)); | |
ca6c03ca JH |
715 | fallthru = 1; |
716 | ||
eaec9b3d | 717 | /* Selectively unlink whole insn chain. */ |
bc35512f JH |
718 | if (in_cfglayout) |
719 | { | |
720 | rtx insn = src->rbi->footer; | |
721 | ||
a813c111 | 722 | delete_insn_chain (kill_from, BB_END (src)); |
bc35512f JH |
723 | |
724 | /* Remove barriers but keep jumptables. */ | |
725 | while (insn) | |
726 | { | |
727 | if (GET_CODE (insn) == BARRIER) | |
728 | { | |
729 | if (PREV_INSN (insn)) | |
730 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
731 | else | |
732 | src->rbi->footer = NEXT_INSN (insn); | |
733 | if (NEXT_INSN (insn)) | |
734 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
735 | } | |
736 | if (GET_CODE (insn) == CODE_LABEL) | |
737 | break; | |
738 | insn = NEXT_INSN (insn); | |
739 | } | |
740 | } | |
741 | else | |
a813c111 | 742 | delete_insn_chain (kill_from, PREV_INSN (BB_HEAD (target))); |
ca6c03ca | 743 | } |
5f0d2358 | 744 | |
ca6c03ca JH |
745 | /* If this already is simplejump, redirect it. */ |
746 | else if (simplejump_p (insn)) | |
747 | { | |
748 | if (e->dest == target) | |
749 | return false; | |
c263766c RH |
750 | if (dump_file) |
751 | fprintf (dump_file, "Redirecting jump %i from %i to %i.\n", | |
0b17ab2f | 752 | INSN_UID (insn), e->dest->index, target->index); |
6ee3c8e4 JJ |
753 | if (!redirect_jump (insn, block_label (target), 0)) |
754 | { | |
755 | if (target == EXIT_BLOCK_PTR) | |
756 | return false; | |
757 | abort (); | |
758 | } | |
ca6c03ca | 759 | } |
5f0d2358 | 760 | |
6ee3c8e4 JJ |
761 | /* Cannot do anything for target exit block. */ |
762 | else if (target == EXIT_BLOCK_PTR) | |
763 | return false; | |
764 | ||
ca6c03ca JH |
765 | /* Or replace possibly complicated jump insn by simple jump insn. */ |
766 | else | |
767 | { | |
768 | rtx target_label = block_label (target); | |
eb5b8ad4 | 769 | rtx barrier, label, table; |
ca6c03ca | 770 | |
09eb1aab | 771 | emit_jump_insn_after (gen_jump (target_label), insn); |
a813c111 | 772 | JUMP_LABEL (BB_END (src)) = target_label; |
ca6c03ca | 773 | LABEL_NUSES (target_label)++; |
c263766c RH |
774 | if (dump_file) |
775 | fprintf (dump_file, "Replacing insn %i by jump %i\n", | |
a813c111 | 776 | INSN_UID (insn), INSN_UID (BB_END (src))); |
ca6c03ca | 777 | |
4da2eb6b | 778 | |
ca6c03ca JH |
779 | delete_insn_chain (kill_from, insn); |
780 | ||
4da2eb6b RH |
781 | /* Recognize a tablejump that we are converting to a |
782 | simple jump and remove its associated CODE_LABEL | |
783 | and ADDR_VEC or ADDR_DIFF_VEC. */ | |
3348b696 | 784 | if (tablejump_p (insn, &label, &table)) |
4da2eb6b | 785 | delete_insn_chain (label, table); |
eb5b8ad4 | 786 | |
a813c111 | 787 | barrier = next_nonnote_insn (BB_END (src)); |
ca6c03ca | 788 | if (!barrier || GET_CODE (barrier) != BARRIER) |
a813c111 | 789 | emit_barrier_after (BB_END (src)); |
5d693491 JZ |
790 | else |
791 | { | |
a813c111 | 792 | if (barrier != NEXT_INSN (BB_END (src))) |
5d693491 JZ |
793 | { |
794 | /* Move the jump before barrier so that the notes | |
795 | which originally were or were created before jump table are | |
796 | inside the basic block. */ | |
a813c111 | 797 | rtx new_insn = BB_END (src); |
5d693491 JZ |
798 | rtx tmp; |
799 | ||
a813c111 | 800 | for (tmp = NEXT_INSN (BB_END (src)); tmp != barrier; |
5d693491 JZ |
801 | tmp = NEXT_INSN (tmp)) |
802 | set_block_for_insn (tmp, src); | |
803 | ||
804 | NEXT_INSN (PREV_INSN (new_insn)) = NEXT_INSN (new_insn); | |
805 | PREV_INSN (NEXT_INSN (new_insn)) = PREV_INSN (new_insn); | |
806 | ||
807 | NEXT_INSN (new_insn) = barrier; | |
808 | NEXT_INSN (PREV_INSN (barrier)) = new_insn; | |
809 | ||
810 | PREV_INSN (new_insn) = PREV_INSN (barrier); | |
811 | PREV_INSN (barrier) = new_insn; | |
812 | } | |
813 | } | |
ca6c03ca JH |
814 | } |
815 | ||
816 | /* Keep only one edge out and set proper flags. */ | |
817 | while (src->succ->succ_next) | |
818 | remove_edge (src->succ); | |
819 | e = src->succ; | |
820 | if (fallthru) | |
821 | e->flags = EDGE_FALLTHRU; | |
822 | else | |
823 | e->flags = 0; | |
5f0d2358 | 824 | |
ca6c03ca JH |
825 | e->probability = REG_BR_PROB_BASE; |
826 | e->count = src->count; | |
827 | ||
828 | /* We don't want a block to end on a line-number note since that has | |
829 | the potential of changing the code between -g and not -g. */ | |
a813c111 SB |
830 | while (GET_CODE (BB_END (e->src)) == NOTE |
831 | && NOTE_LINE_NUMBER (BB_END (e->src)) >= 0) | |
832 | delete_insn (BB_END (e->src)); | |
ca6c03ca JH |
833 | |
834 | if (e->dest != target) | |
835 | redirect_edge_succ (e, target); | |
5f0d2358 | 836 | |
ca6c03ca JH |
837 | return true; |
838 | } | |
839 | ||
840 | /* Return last loop_beg note appearing after INSN, before start of next | |
841 | basic block. Return INSN if there are no such notes. | |
842 | ||
09da1532 | 843 | When emitting jump to redirect a fallthru edge, it should always appear |
5f0d2358 RK |
844 | after the LOOP_BEG notes, as loop optimizer expect loop to either start by |
845 | fallthru edge or jump following the LOOP_BEG note jumping to the loop exit | |
846 | test. */ | |
ca6c03ca JH |
847 | |
848 | static rtx | |
d329e058 | 849 | last_loop_beg_note (rtx insn) |
ca6c03ca JH |
850 | { |
851 | rtx last = insn; | |
5f0d2358 RK |
852 | |
853 | for (insn = NEXT_INSN (insn); insn && GET_CODE (insn) == NOTE | |
854 | && NOTE_LINE_NUMBER (insn) != NOTE_INSN_BASIC_BLOCK; | |
855 | insn = NEXT_INSN (insn)) | |
856 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
857 | last = insn; | |
858 | ||
ca6c03ca JH |
859 | return last; |
860 | } | |
861 | ||
bc35512f | 862 | /* Redirect edge representing branch of (un)conditional jump or tablejump. */ |
9ee634e3 | 863 | static bool |
bc35512f | 864 | redirect_branch_edge (edge e, basic_block target) |
ca6c03ca JH |
865 | { |
866 | rtx tmp; | |
a813c111 | 867 | rtx old_label = BB_HEAD (e->dest); |
ca6c03ca | 868 | basic_block src = e->src; |
a813c111 | 869 | rtx insn = BB_END (src); |
ca6c03ca | 870 | |
ca6c03ca JH |
871 | /* We can only redirect non-fallthru edges of jump insn. */ |
872 | if (e->flags & EDGE_FALLTHRU) | |
873 | return false; | |
5f0d2358 | 874 | else if (GET_CODE (insn) != JUMP_INSN) |
ca6c03ca JH |
875 | return false; |
876 | ||
877 | /* Recognize a tablejump and adjust all matching cases. */ | |
e1233a7d | 878 | if (tablejump_p (insn, NULL, &tmp)) |
ca6c03ca JH |
879 | { |
880 | rtvec vec; | |
881 | int j; | |
882 | rtx new_label = block_label (target); | |
883 | ||
6ee3c8e4 JJ |
884 | if (target == EXIT_BLOCK_PTR) |
885 | return false; | |
ca6c03ca JH |
886 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) |
887 | vec = XVEC (PATTERN (tmp), 0); | |
888 | else | |
889 | vec = XVEC (PATTERN (tmp), 1); | |
890 | ||
891 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
892 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
893 | { | |
894 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (Pmode, new_label); | |
895 | --LABEL_NUSES (old_label); | |
896 | ++LABEL_NUSES (new_label); | |
897 | } | |
898 | ||
f9da5064 | 899 | /* Handle casesi dispatch insns. */ |
ca6c03ca JH |
900 | if ((tmp = single_set (insn)) != NULL |
901 | && SET_DEST (tmp) == pc_rtx | |
902 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
903 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF | |
904 | && XEXP (XEXP (SET_SRC (tmp), 2), 0) == old_label) | |
905 | { | |
906 | XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (VOIDmode, | |
907 | new_label); | |
908 | --LABEL_NUSES (old_label); | |
909 | ++LABEL_NUSES (new_label); | |
910 | } | |
911 | } | |
912 | else | |
913 | { | |
914 | /* ?? We may play the games with moving the named labels from | |
915 | one basic block to the other in case only one computed_jump is | |
916 | available. */ | |
5f0d2358 RK |
917 | if (computed_jump_p (insn) |
918 | /* A return instruction can't be redirected. */ | |
919 | || returnjump_p (insn)) | |
ca6c03ca JH |
920 | return false; |
921 | ||
922 | /* If the insn doesn't go where we think, we're confused. */ | |
6ee3c8e4 | 923 | if (JUMP_LABEL (insn) != old_label) |
a3623c48 | 924 | abort (); |
6ee3c8e4 JJ |
925 | |
926 | /* If the substitution doesn't succeed, die. This can happen | |
927 | if the back end emitted unrecognizable instructions or if | |
928 | target is exit block on some arches. */ | |
929 | if (!redirect_jump (insn, block_label (target), 0)) | |
930 | { | |
931 | if (target == EXIT_BLOCK_PTR) | |
932 | return false; | |
933 | abort (); | |
934 | } | |
ca6c03ca JH |
935 | } |
936 | ||
c263766c RH |
937 | if (dump_file) |
938 | fprintf (dump_file, "Edge %i->%i redirected to %i\n", | |
0b17ab2f | 939 | e->src->index, e->dest->index, target->index); |
5f0d2358 | 940 | |
ca6c03ca JH |
941 | if (e->dest != target) |
942 | redirect_edge_succ_nodup (e, target); | |
bc35512f JH |
943 | return true; |
944 | } | |
945 | ||
946 | /* Attempt to change code to redirect edge E to TARGET. Don't do that on | |
947 | expense of adding new instructions or reordering basic blocks. | |
948 | ||
949 | Function can be also called with edge destination equivalent to the TARGET. | |
950 | Then it should try the simplifications and do nothing if none is possible. | |
951 | ||
952 | Return true if transformation succeeded. We still return false in case E | |
953 | already destinated TARGET and we didn't managed to simplify instruction | |
954 | stream. */ | |
955 | ||
956 | static bool | |
5671bf27 | 957 | rtl_redirect_edge_and_branch (edge e, basic_block target) |
bc35512f | 958 | { |
f345f21a JH |
959 | basic_block src = e->src; |
960 | ||
bc35512f JH |
961 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
962 | return false; | |
963 | ||
3348b696 JH |
964 | if (e->dest == target) |
965 | return true; | |
966 | ||
bc35512f | 967 | if (try_redirect_by_replacing_jump (e, target, false)) |
f345f21a JH |
968 | { |
969 | src->flags |= BB_DIRTY; | |
970 | return true; | |
971 | } | |
bc35512f | 972 | |
3348b696 | 973 | if (!redirect_branch_edge (e, target)) |
bc35512f | 974 | return false; |
5f0d2358 | 975 | |
f345f21a | 976 | src->flags |= BB_DIRTY; |
ca6c03ca JH |
977 | return true; |
978 | } | |
979 | ||
4fe9b91c | 980 | /* Like force_nonfallthru below, but additionally performs redirection |
ca6c03ca JH |
981 | Used by redirect_edge_and_branch_force. */ |
982 | ||
cb9a1d9b | 983 | basic_block |
d329e058 | 984 | force_nonfallthru_and_redirect (edge e, basic_block target) |
ca6c03ca | 985 | { |
a3716585 | 986 | basic_block jump_block, new_bb = NULL, src = e->src; |
ca6c03ca JH |
987 | rtx note; |
988 | edge new_edge; | |
a3716585 | 989 | int abnormal_edge_flags = 0; |
ca6c03ca | 990 | |
cb9a1d9b JH |
991 | /* In the case the last instruction is conditional jump to the next |
992 | instruction, first redirect the jump itself and then continue | |
b20b352b | 993 | by creating a basic block afterwards to redirect fallthru edge. */ |
cb9a1d9b | 994 | if (e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR |
a813c111 | 995 | && any_condjump_p (BB_END (e->src)) |
cde1d5bf | 996 | /* When called from cfglayout, fallthru edges do not |
e0bb17a8 | 997 | necessarily go to the next block. */ |
cde1d5bf | 998 | && e->src->next_bb == e->dest |
a813c111 | 999 | && JUMP_LABEL (BB_END (e->src)) == BB_HEAD (e->dest)) |
cb9a1d9b JH |
1000 | { |
1001 | rtx note; | |
58e6ae30 | 1002 | edge b = unchecked_make_edge (e->src, target, 0); |
cb9a1d9b | 1003 | |
a813c111 | 1004 | if (!redirect_jump (BB_END (e->src), block_label (target), 0)) |
cb9a1d9b | 1005 | abort (); |
a813c111 | 1006 | note = find_reg_note (BB_END (e->src), REG_BR_PROB, NULL_RTX); |
cb9a1d9b JH |
1007 | if (note) |
1008 | { | |
1009 | int prob = INTVAL (XEXP (note, 0)); | |
1010 | ||
1011 | b->probability = prob; | |
1012 | b->count = e->count * prob / REG_BR_PROB_BASE; | |
1013 | e->probability -= e->probability; | |
1014 | e->count -= b->count; | |
1015 | if (e->probability < 0) | |
1016 | e->probability = 0; | |
1017 | if (e->count < 0) | |
1018 | e->count = 0; | |
1019 | } | |
1020 | } | |
1021 | ||
ca6c03ca | 1022 | if (e->flags & EDGE_ABNORMAL) |
a3716585 JH |
1023 | { |
1024 | /* Irritating special case - fallthru edge to the same block as abnormal | |
1025 | edge. | |
1026 | We can't redirect abnormal edge, but we still can split the fallthru | |
d329e058 | 1027 | one and create separate abnormal edge to original destination. |
a3716585 JH |
1028 | This allows bb-reorder to make such edge non-fallthru. */ |
1029 | if (e->dest != target) | |
1030 | abort (); | |
1031 | abnormal_edge_flags = e->flags & ~(EDGE_FALLTHRU | EDGE_CAN_FALLTHRU); | |
1032 | e->flags &= EDGE_FALLTHRU | EDGE_CAN_FALLTHRU; | |
1033 | } | |
5f0d2358 | 1034 | else if (!(e->flags & EDGE_FALLTHRU)) |
ca6c03ca | 1035 | abort (); |
24c545ff BS |
1036 | else if (e->src == ENTRY_BLOCK_PTR) |
1037 | { | |
1038 | /* We can't redirect the entry block. Create an empty block at the | |
1039 | start of the function which we use to add the new jump. */ | |
1040 | edge *pe1; | |
a813c111 | 1041 | basic_block bb = create_basic_block (BB_HEAD (e->dest), NULL, ENTRY_BLOCK_PTR); |
24c545ff BS |
1042 | |
1043 | /* Change the existing edge's source to be the new block, and add | |
1044 | a new edge from the entry block to the new block. */ | |
1045 | e->src = bb; | |
1046 | for (pe1 = &ENTRY_BLOCK_PTR->succ; *pe1; pe1 = &(*pe1)->succ_next) | |
1047 | if (*pe1 == e) | |
1048 | { | |
1049 | *pe1 = e->succ_next; | |
1050 | break; | |
1051 | } | |
1052 | e->succ_next = 0; | |
1053 | bb->succ = e; | |
1054 | make_single_succ_edge (ENTRY_BLOCK_PTR, bb, EDGE_FALLTHRU); | |
1055 | } | |
1056 | ||
a3716585 | 1057 | if (e->src->succ->succ_next || abnormal_edge_flags) |
ca6c03ca JH |
1058 | { |
1059 | /* Create the new structures. */ | |
31a78298 | 1060 | |
79019985 RH |
1061 | /* If the old block ended with a tablejump, skip its table |
1062 | by searching forward from there. Otherwise start searching | |
1063 | forward from the last instruction of the old block. */ | |
a813c111 SB |
1064 | if (!tablejump_p (BB_END (e->src), NULL, ¬e)) |
1065 | note = BB_END (e->src); | |
79019985 | 1066 | |
31a78298 | 1067 | /* Position the new block correctly relative to loop notes. */ |
79019985 | 1068 | note = last_loop_beg_note (note); |
31a78298 RH |
1069 | note = NEXT_INSN (note); |
1070 | ||
31a78298 | 1071 | jump_block = create_basic_block (note, NULL, e->src); |
ca6c03ca JH |
1072 | jump_block->count = e->count; |
1073 | jump_block->frequency = EDGE_FREQUENCY (e); | |
1074 | jump_block->loop_depth = target->loop_depth; | |
1075 | ||
1076 | if (target->global_live_at_start) | |
1077 | { | |
5f0d2358 RK |
1078 | jump_block->global_live_at_start |
1079 | = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
1080 | jump_block->global_live_at_end | |
1081 | = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
ca6c03ca JH |
1082 | COPY_REG_SET (jump_block->global_live_at_start, |
1083 | target->global_live_at_start); | |
1084 | COPY_REG_SET (jump_block->global_live_at_end, | |
1085 | target->global_live_at_start); | |
1086 | } | |
1087 | ||
750054a2 CT |
1088 | /* Make sure new block ends up in correct hot/cold section. */ |
1089 | ||
1090 | jump_block->partition = e->src->partition; | |
1091 | if (flag_reorder_blocks_and_partition) | |
1092 | { | |
1093 | if (e->src->partition == COLD_PARTITION) | |
1094 | { | |
1095 | rtx bb_note, new_note; | |
1096 | for (bb_note = BB_HEAD (jump_block); | |
1097 | bb_note && bb_note != NEXT_INSN (BB_END (jump_block)); | |
1098 | bb_note = NEXT_INSN (bb_note)) | |
1099 | if (GET_CODE (bb_note) == NOTE | |
1100 | && NOTE_LINE_NUMBER (bb_note) == NOTE_INSN_BASIC_BLOCK) | |
1101 | break; | |
1102 | new_note = emit_note_after (NOTE_INSN_UNLIKELY_EXECUTED_CODE, | |
1103 | bb_note); | |
1104 | NOTE_BASIC_BLOCK (new_note) = jump_block; | |
1105 | jump_block->partition = COLD_PARTITION; | |
1106 | } | |
1107 | if (GET_CODE (BB_END (jump_block)) == JUMP_INSN | |
1108 | && !any_condjump_p (BB_END (jump_block)) | |
1109 | && jump_block->succ->crossing_edge ) | |
1110 | REG_NOTES (BB_END (jump_block)) = gen_rtx_EXPR_LIST | |
1111 | (REG_CROSSING_JUMP, NULL_RTX, | |
1112 | REG_NOTES (BB_END (jump_block))); | |
1113 | } | |
1114 | ||
ca6c03ca JH |
1115 | /* Wire edge in. */ |
1116 | new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU); | |
1117 | new_edge->probability = e->probability; | |
1118 | new_edge->count = e->count; | |
1119 | ||
1120 | /* Redirect old edge. */ | |
1121 | redirect_edge_pred (e, jump_block); | |
1122 | e->probability = REG_BR_PROB_BASE; | |
1123 | ||
1124 | new_bb = jump_block; | |
1125 | } | |
1126 | else | |
1127 | jump_block = e->src; | |
5f0d2358 | 1128 | |
ca6c03ca JH |
1129 | e->flags &= ~EDGE_FALLTHRU; |
1130 | if (target == EXIT_BLOCK_PTR) | |
1131 | { | |
cf22ce3c | 1132 | #ifdef HAVE_return |
a813c111 | 1133 | emit_jump_insn_after (gen_return (), BB_END (jump_block)); |
cf22ce3c | 1134 | #else |
ca6c03ca | 1135 | abort (); |
cf22ce3c | 1136 | #endif |
ca6c03ca JH |
1137 | } |
1138 | else | |
1139 | { | |
1140 | rtx label = block_label (target); | |
a813c111 SB |
1141 | emit_jump_insn_after (gen_jump (label), BB_END (jump_block)); |
1142 | JUMP_LABEL (BB_END (jump_block)) = label; | |
ca6c03ca JH |
1143 | LABEL_NUSES (label)++; |
1144 | } | |
5f0d2358 | 1145 | |
a813c111 | 1146 | emit_barrier_after (BB_END (jump_block)); |
ca6c03ca JH |
1147 | redirect_edge_succ_nodup (e, target); |
1148 | ||
a3716585 JH |
1149 | if (abnormal_edge_flags) |
1150 | make_edge (src, target, abnormal_edge_flags); | |
1151 | ||
ca6c03ca JH |
1152 | return new_bb; |
1153 | } | |
1154 | ||
1155 | /* Edge E is assumed to be fallthru edge. Emit needed jump instruction | |
1156 | (and possibly create new basic block) to make edge non-fallthru. | |
1157 | Return newly created BB or NULL if none. */ | |
5f0d2358 | 1158 | |
ca6c03ca | 1159 | basic_block |
d329e058 | 1160 | force_nonfallthru (edge e) |
ca6c03ca JH |
1161 | { |
1162 | return force_nonfallthru_and_redirect (e, e->dest); | |
1163 | } | |
1164 | ||
1165 | /* Redirect edge even at the expense of creating new jump insn or | |
1166 | basic block. Return new basic block if created, NULL otherwise. | |
eaec9b3d | 1167 | Abort if conversion is impossible. */ |
ca6c03ca | 1168 | |
9ee634e3 | 1169 | static basic_block |
d329e058 | 1170 | rtl_redirect_edge_and_branch_force (edge e, basic_block target) |
ca6c03ca | 1171 | { |
5f0d2358 RK |
1172 | if (redirect_edge_and_branch (e, target) |
1173 | || e->dest == target) | |
ca6c03ca JH |
1174 | return NULL; |
1175 | ||
1176 | /* In case the edge redirection failed, try to force it to be non-fallthru | |
1177 | and redirect newly created simplejump. */ | |
5f0d2358 | 1178 | return force_nonfallthru_and_redirect (e, target); |
ca6c03ca JH |
1179 | } |
1180 | ||
1181 | /* The given edge should potentially be a fallthru edge. If that is in | |
1182 | fact true, delete the jump and barriers that are in the way. */ | |
1183 | ||
f470c378 ZD |
1184 | static void |
1185 | rtl_tidy_fallthru_edge (edge e) | |
ca6c03ca JH |
1186 | { |
1187 | rtx q; | |
f470c378 ZD |
1188 | basic_block b = e->src, c = b->next_bb; |
1189 | ||
ca6c03ca JH |
1190 | /* ??? In a late-running flow pass, other folks may have deleted basic |
1191 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
1192 | and the target label. They ought to be chastized and fixed. | |
1193 | ||
1194 | We can also wind up with a sequence of undeletable labels between | |
1195 | one block and the next. | |
1196 | ||
1197 | So search through a sequence of barriers, labels, and notes for | |
1198 | the head of block C and assert that we really do fall through. */ | |
1199 | ||
a813c111 | 1200 | for (q = NEXT_INSN (BB_END (b)); q != BB_HEAD (c); q = NEXT_INSN (q)) |
9c0a0632 RH |
1201 | if (INSN_P (q)) |
1202 | return; | |
ca6c03ca JH |
1203 | |
1204 | /* Remove what will soon cease being the jump insn from the source block. | |
1205 | If block B consisted only of this single jump, turn it into a deleted | |
1206 | note. */ | |
a813c111 | 1207 | q = BB_END (b); |
ca6c03ca JH |
1208 | if (GET_CODE (q) == JUMP_INSN |
1209 | && onlyjump_p (q) | |
1210 | && (any_uncondjump_p (q) | |
1211 | || (b->succ == e && e->succ_next == NULL))) | |
1212 | { | |
1213 | #ifdef HAVE_cc0 | |
1214 | /* If this was a conditional jump, we need to also delete | |
1215 | the insn that set cc0. */ | |
1216 | if (any_condjump_p (q) && only_sets_cc0_p (PREV_INSN (q))) | |
1217 | q = PREV_INSN (q); | |
1218 | #endif | |
1219 | ||
1220 | q = PREV_INSN (q); | |
1221 | ||
1222 | /* We don't want a block to end on a line-number note since that has | |
1223 | the potential of changing the code between -g and not -g. */ | |
1224 | while (GET_CODE (q) == NOTE && NOTE_LINE_NUMBER (q) >= 0) | |
1225 | q = PREV_INSN (q); | |
1226 | } | |
1227 | ||
1228 | /* Selectively unlink the sequence. */ | |
a813c111 SB |
1229 | if (q != PREV_INSN (BB_HEAD (c))) |
1230 | delete_insn_chain (NEXT_INSN (q), PREV_INSN (BB_HEAD (c))); | |
ca6c03ca JH |
1231 | |
1232 | e->flags |= EDGE_FALLTHRU; | |
1233 | } | |
ca6c03ca JH |
1234 | \f |
1235 | /* Helper function for split_edge. Return true in case edge BB2 to BB1 | |
1236 | is back edge of syntactic loop. */ | |
1237 | ||
1238 | static bool | |
d329e058 | 1239 | back_edge_of_syntactic_loop_p (basic_block bb1, basic_block bb2) |
ca6c03ca JH |
1240 | { |
1241 | rtx insn; | |
1242 | int count = 0; | |
bf77398c | 1243 | basic_block bb; |
ca6c03ca | 1244 | |
bf77398c | 1245 | if (bb1 == bb2) |
0b17ab2f | 1246 | return true; |
355e4ec4 | 1247 | |
bf77398c ZD |
1248 | /* ??? Could we guarantee that bb indices are monotone, so that we could |
1249 | just compare them? */ | |
1250 | for (bb = bb1; bb && bb != bb2; bb = bb->next_bb) | |
1251 | continue; | |
1252 | ||
1253 | if (!bb) | |
1254 | return false; | |
1255 | ||
a813c111 | 1256 | for (insn = BB_END (bb1); insn != BB_HEAD (bb2) && count >= 0; |
ca6c03ca JH |
1257 | insn = NEXT_INSN (insn)) |
1258 | if (GET_CODE (insn) == NOTE) | |
1259 | { | |
1260 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
1261 | count++; | |
5f0d2358 | 1262 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) |
ca6c03ca JH |
1263 | count--; |
1264 | } | |
1265 | ||
1266 | return count >= 0; | |
1267 | } | |
1268 | ||
f470c378 ZD |
1269 | /* Should move basic block BB after basic block AFTER. NIY. */ |
1270 | ||
1271 | static bool | |
1272 | rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED, | |
1273 | basic_block after ATTRIBUTE_UNUSED) | |
1274 | { | |
1275 | return false; | |
1276 | } | |
1277 | ||
ca6c03ca JH |
1278 | /* Split a (typically critical) edge. Return the new block. |
1279 | Abort on abnormal edges. | |
1280 | ||
1281 | ??? The code generally expects to be called on critical edges. | |
1282 | The case of a block ending in an unconditional jump to a | |
1283 | block with multiple predecessors is not handled optimally. */ | |
1284 | ||
8ce33230 | 1285 | static basic_block |
d329e058 | 1286 | rtl_split_edge (edge edge_in) |
ca6c03ca JH |
1287 | { |
1288 | basic_block bb; | |
ca6c03ca JH |
1289 | rtx before; |
1290 | ||
1291 | /* Abnormal edges cannot be split. */ | |
1292 | if ((edge_in->flags & EDGE_ABNORMAL) != 0) | |
1293 | abort (); | |
1294 | ||
1295 | /* We are going to place the new block in front of edge destination. | |
eaec9b3d | 1296 | Avoid existence of fallthru predecessors. */ |
ca6c03ca JH |
1297 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) |
1298 | { | |
1299 | edge e; | |
5f0d2358 | 1300 | |
ca6c03ca JH |
1301 | for (e = edge_in->dest->pred; e; e = e->pred_next) |
1302 | if (e->flags & EDGE_FALLTHRU) | |
1303 | break; | |
1304 | ||
1305 | if (e) | |
1306 | force_nonfallthru (e); | |
1307 | } | |
1308 | ||
1309 | /* Create the basic block note. | |
1310 | ||
f63d1bf7 | 1311 | Where we place the note can have a noticeable impact on the generated |
ca6c03ca JH |
1312 | code. Consider this cfg: |
1313 | ||
1314 | E | |
1315 | | | |
1316 | 0 | |
1317 | / \ | |
1318 | +->1-->2--->E | |
1319 | | | | |
1320 | +--+ | |
1321 | ||
1322 | If we need to insert an insn on the edge from block 0 to block 1, | |
1323 | we want to ensure the instructions we insert are outside of any | |
1324 | loop notes that physically sit between block 0 and block 1. Otherwise | |
1325 | we confuse the loop optimizer into thinking the loop is a phony. */ | |
1326 | ||
1327 | if (edge_in->dest != EXIT_BLOCK_PTR | |
a813c111 SB |
1328 | && PREV_INSN (BB_HEAD (edge_in->dest)) |
1329 | && GET_CODE (PREV_INSN (BB_HEAD (edge_in->dest))) == NOTE | |
1330 | && (NOTE_LINE_NUMBER (PREV_INSN (BB_HEAD (edge_in->dest))) | |
5f0d2358 | 1331 | == NOTE_INSN_LOOP_BEG) |
ca6c03ca | 1332 | && !back_edge_of_syntactic_loop_p (edge_in->dest, edge_in->src)) |
a813c111 | 1333 | before = PREV_INSN (BB_HEAD (edge_in->dest)); |
ca6c03ca | 1334 | else if (edge_in->dest != EXIT_BLOCK_PTR) |
a813c111 | 1335 | before = BB_HEAD (edge_in->dest); |
ca6c03ca JH |
1336 | else |
1337 | before = NULL_RTX; | |
1338 | ||
918ed612 | 1339 | bb = create_basic_block (before, NULL, edge_in->dest->prev_bb); |
ca6c03ca JH |
1340 | |
1341 | /* ??? This info is likely going to be out of date very soon. */ | |
1342 | if (edge_in->dest->global_live_at_start) | |
1343 | { | |
1344 | bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
1345 | bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
5f0d2358 RK |
1346 | COPY_REG_SET (bb->global_live_at_start, |
1347 | edge_in->dest->global_live_at_start); | |
1348 | COPY_REG_SET (bb->global_live_at_end, | |
1349 | edge_in->dest->global_live_at_start); | |
ca6c03ca JH |
1350 | } |
1351 | ||
4977bab6 | 1352 | make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU); |
ca6c03ca | 1353 | |
4d6922ee | 1354 | /* For non-fallthru edges, we must adjust the predecessor's |
ca6c03ca JH |
1355 | jump instruction to target our new block. */ |
1356 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1357 | { | |
1358 | if (!redirect_edge_and_branch (edge_in, bb)) | |
1359 | abort (); | |
1360 | } | |
1361 | else | |
1362 | redirect_edge_succ (edge_in, bb); | |
1363 | ||
1364 | return bb; | |
1365 | } | |
1366 | ||
1367 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1368 | The new instructions and basic blocks (if any) will not appear in the | |
1369 | CFG until commit_edge_insertions is called. */ | |
1370 | ||
1371 | void | |
d329e058 | 1372 | insert_insn_on_edge (rtx pattern, edge e) |
ca6c03ca JH |
1373 | { |
1374 | /* We cannot insert instructions on an abnormal critical edge. | |
1375 | It will be easier to find the culprit if we die now. */ | |
1376 | if ((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e)) | |
1377 | abort (); | |
1378 | ||
1379 | if (e->insns == NULL_RTX) | |
1380 | start_sequence (); | |
1381 | else | |
1382 | push_to_sequence (e->insns); | |
1383 | ||
1384 | emit_insn (pattern); | |
1385 | ||
1386 | e->insns = get_insns (); | |
1387 | end_sequence (); | |
1388 | } | |
1389 | ||
ff25ef99 ZD |
1390 | /* Called from safe_insert_insn_on_edge through note_stores, marks live |
1391 | registers that are killed by the store. */ | |
1392 | static void | |
1393 | mark_killed_regs (rtx reg, rtx set ATTRIBUTE_UNUSED, void *data) | |
1394 | { | |
1395 | regset killed = data; | |
1396 | int regno, i; | |
1397 | ||
1398 | if (GET_CODE (reg) == SUBREG) | |
1399 | reg = SUBREG_REG (reg); | |
1400 | if (!REG_P (reg)) | |
1401 | return; | |
1402 | regno = REGNO (reg); | |
1403 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1404 | SET_REGNO_REG_SET (killed, regno); | |
1405 | else | |
1406 | { | |
66fd46b6 | 1407 | for (i = 0; i < (int) hard_regno_nregs[regno][GET_MODE (reg)]; i++) |
ff25ef99 ZD |
1408 | SET_REGNO_REG_SET (killed, regno + i); |
1409 | } | |
1410 | } | |
1411 | ||
1412 | /* Similar to insert_insn_on_edge, tries to put INSN to edge E. Additionally | |
1413 | it checks whether this will not clobber the registers that are live on the | |
e0bb17a8 | 1414 | edge (i.e. it requires liveness information to be up-to-date) and if there |
ff25ef99 | 1415 | are some, then it tries to save and restore them. Returns true if |
e0bb17a8 | 1416 | successful. */ |
ff25ef99 ZD |
1417 | bool |
1418 | safe_insert_insn_on_edge (rtx insn, edge e) | |
1419 | { | |
1420 | rtx x; | |
1421 | regset_head killed_head; | |
1422 | regset killed = INITIALIZE_REG_SET (killed_head); | |
1423 | rtx save_regs = NULL_RTX; | |
1424 | int regno, noccmode; | |
1425 | enum machine_mode mode; | |
1426 | ||
1427 | #ifdef AVOID_CCMODE_COPIES | |
1428 | noccmode = true; | |
1429 | #else | |
1430 | noccmode = false; | |
1431 | #endif | |
1432 | ||
1433 | for (x = insn; x; x = NEXT_INSN (x)) | |
1434 | if (INSN_P (x)) | |
1435 | note_stores (PATTERN (x), mark_killed_regs, killed); | |
1436 | bitmap_operation (killed, killed, e->dest->global_live_at_start, | |
1437 | BITMAP_AND); | |
1438 | ||
1439 | EXECUTE_IF_SET_IN_REG_SET (killed, 0, regno, | |
1440 | { | |
1441 | mode = regno < FIRST_PSEUDO_REGISTER | |
1442 | ? reg_raw_mode[regno] | |
1443 | : GET_MODE (regno_reg_rtx[regno]); | |
1444 | if (mode == VOIDmode) | |
1445 | return false; | |
1446 | ||
1447 | if (noccmode && mode == CCmode) | |
1448 | return false; | |
1449 | ||
1450 | save_regs = alloc_EXPR_LIST (0, | |
1451 | alloc_EXPR_LIST (0, | |
1452 | gen_reg_rtx (mode), | |
1453 | gen_raw_REG (mode, regno)), | |
1454 | save_regs); | |
1455 | }); | |
1456 | ||
1457 | if (save_regs) | |
1458 | { | |
1459 | rtx from, to; | |
1460 | ||
1461 | start_sequence (); | |
1462 | for (x = save_regs; x; x = XEXP (x, 1)) | |
1463 | { | |
1464 | from = XEXP (XEXP (x, 0), 1); | |
1465 | to = XEXP (XEXP (x, 0), 0); | |
1466 | emit_move_insn (to, from); | |
1467 | } | |
1468 | emit_insn (insn); | |
1469 | for (x = save_regs; x; x = XEXP (x, 1)) | |
1470 | { | |
1471 | from = XEXP (XEXP (x, 0), 0); | |
1472 | to = XEXP (XEXP (x, 0), 1); | |
1473 | emit_move_insn (to, from); | |
1474 | } | |
1475 | insn = get_insns (); | |
1476 | end_sequence (); | |
1477 | free_EXPR_LIST_list (&save_regs); | |
1478 | } | |
1479 | insert_insn_on_edge (insn, e); | |
1480 | ||
1481 | FREE_REG_SET (killed); | |
1482 | return true; | |
1483 | } | |
1484 | ||
ca6c03ca JH |
1485 | /* Update the CFG for the instructions queued on edge E. */ |
1486 | ||
1487 | static void | |
d329e058 | 1488 | commit_one_edge_insertion (edge e, int watch_calls) |
ca6c03ca JH |
1489 | { |
1490 | rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last; | |
eae4bc56 | 1491 | basic_block bb = NULL; |
ca6c03ca JH |
1492 | |
1493 | /* Pull the insns off the edge now since the edge might go away. */ | |
1494 | insns = e->insns; | |
1495 | e->insns = NULL_RTX; | |
1496 | ||
3dec4024 JH |
1497 | /* Special case -- avoid inserting code between call and storing |
1498 | its return value. */ | |
1499 | if (watch_calls && (e->flags & EDGE_FALLTHRU) && !e->dest->pred->pred_next | |
1500 | && e->src != ENTRY_BLOCK_PTR | |
a813c111 | 1501 | && GET_CODE (BB_END (e->src)) == CALL_INSN) |
ca6c03ca | 1502 | { |
a813c111 | 1503 | rtx next = next_nonnote_insn (BB_END (e->src)); |
ca6c03ca | 1504 | |
a813c111 | 1505 | after = BB_HEAD (e->dest); |
3dec4024 JH |
1506 | /* The first insn after the call may be a stack pop, skip it. */ |
1507 | while (next | |
1508 | && keep_with_call_p (next)) | |
f87c27b4 KH |
1509 | { |
1510 | after = next; | |
3dec4024 JH |
1511 | next = next_nonnote_insn (next); |
1512 | } | |
1513 | bb = e->dest; | |
ca6c03ca | 1514 | } |
3dec4024 | 1515 | if (!before && !after) |
ca6c03ca | 1516 | { |
3dec4024 JH |
1517 | /* Figure out where to put these things. If the destination has |
1518 | one predecessor, insert there. Except for the exit block. */ | |
1519 | if (e->dest->pred->pred_next == NULL && e->dest != EXIT_BLOCK_PTR) | |
ca6c03ca | 1520 | { |
3dec4024 JH |
1521 | bb = e->dest; |
1522 | ||
1523 | /* Get the location correct wrt a code label, and "nice" wrt | |
1524 | a basic block note, and before everything else. */ | |
a813c111 | 1525 | tmp = BB_HEAD (bb); |
3dec4024 JH |
1526 | if (GET_CODE (tmp) == CODE_LABEL) |
1527 | tmp = NEXT_INSN (tmp); | |
1528 | if (NOTE_INSN_BASIC_BLOCK_P (tmp)) | |
1529 | tmp = NEXT_INSN (tmp); | |
750054a2 CT |
1530 | if (tmp |
1531 | && GET_CODE (tmp) == NOTE | |
1532 | && NOTE_LINE_NUMBER (tmp) == NOTE_INSN_UNLIKELY_EXECUTED_CODE) | |
1533 | tmp = NEXT_INSN (tmp); | |
a813c111 | 1534 | if (tmp == BB_HEAD (bb)) |
3dec4024 JH |
1535 | before = tmp; |
1536 | else if (tmp) | |
1537 | after = PREV_INSN (tmp); | |
1538 | else | |
1539 | after = get_last_insn (); | |
1540 | } | |
1541 | ||
1542 | /* If the source has one successor and the edge is not abnormal, | |
1543 | insert there. Except for the entry block. */ | |
1544 | else if ((e->flags & EDGE_ABNORMAL) == 0 | |
1545 | && e->src->succ->succ_next == NULL | |
1546 | && e->src != ENTRY_BLOCK_PTR) | |
1547 | { | |
1548 | bb = e->src; | |
1549 | ||
1550 | /* It is possible to have a non-simple jump here. Consider a target | |
1551 | where some forms of unconditional jumps clobber a register. This | |
1552 | happens on the fr30 for example. | |
1553 | ||
1554 | We know this block has a single successor, so we can just emit | |
1555 | the queued insns before the jump. */ | |
a813c111 SB |
1556 | if (GET_CODE (BB_END (bb)) == JUMP_INSN) |
1557 | for (before = BB_END (bb); | |
3dec4024 JH |
1558 | GET_CODE (PREV_INSN (before)) == NOTE |
1559 | && NOTE_LINE_NUMBER (PREV_INSN (before)) == | |
1560 | NOTE_INSN_LOOP_BEG; before = PREV_INSN (before)) | |
1561 | ; | |
1562 | else | |
1563 | { | |
1564 | /* We'd better be fallthru, or we've lost track of what's what. */ | |
1565 | if ((e->flags & EDGE_FALLTHRU) == 0) | |
1566 | abort (); | |
ca6c03ca | 1567 | |
a813c111 | 1568 | after = BB_END (bb); |
3dec4024 JH |
1569 | } |
1570 | } | |
1571 | /* Otherwise we must split the edge. */ | |
1572 | else | |
1573 | { | |
1574 | bb = split_edge (e); | |
a813c111 | 1575 | after = BB_END (bb); |
750054a2 CT |
1576 | |
1577 | /* If we are partitioning hot/cold basic blocks, we must make sure | |
1578 | that the new basic block ends up in the correct section. */ | |
1579 | ||
1580 | bb->partition = e->src->partition; | |
1581 | if (flag_reorder_blocks_and_partition | |
1582 | && e->src != ENTRY_BLOCK_PTR | |
1583 | && e->src->partition == COLD_PARTITION) | |
1584 | { | |
1585 | rtx bb_note, new_note, cur_insn; | |
1586 | ||
1587 | bb_note = NULL_RTX; | |
1588 | for (cur_insn = BB_HEAD (bb); cur_insn != NEXT_INSN (BB_END (bb)); | |
1589 | cur_insn = NEXT_INSN (cur_insn)) | |
1590 | if (GET_CODE (cur_insn) == NOTE | |
1591 | && NOTE_LINE_NUMBER (cur_insn) == NOTE_INSN_BASIC_BLOCK) | |
1592 | { | |
1593 | bb_note = cur_insn; | |
1594 | break; | |
1595 | } | |
1596 | ||
1597 | new_note = emit_note_after (NOTE_INSN_UNLIKELY_EXECUTED_CODE, | |
1598 | bb_note); | |
1599 | NOTE_BASIC_BLOCK (new_note) = bb; | |
1600 | if (GET_CODE (BB_END (bb)) == JUMP_INSN | |
1601 | && !any_condjump_p (BB_END (bb)) | |
1602 | && bb->succ->crossing_edge ) | |
1603 | REG_NOTES (BB_END (bb)) = gen_rtx_EXPR_LIST | |
1604 | (REG_CROSSING_JUMP, NULL_RTX, REG_NOTES (BB_END (bb))); | |
1605 | if (after == bb_note) | |
1606 | after = new_note; | |
1607 | } | |
ca6c03ca JH |
1608 | } |
1609 | } | |
1610 | ||
ca6c03ca JH |
1611 | /* Now that we've found the spot, do the insertion. */ |
1612 | ||
1613 | if (before) | |
1614 | { | |
2f937369 | 1615 | emit_insn_before (insns, before); |
ca6c03ca JH |
1616 | last = prev_nonnote_insn (before); |
1617 | } | |
1618 | else | |
2f937369 | 1619 | last = emit_insn_after (insns, after); |
ca6c03ca JH |
1620 | |
1621 | if (returnjump_p (last)) | |
1622 | { | |
1623 | /* ??? Remove all outgoing edges from BB and add one for EXIT. | |
1624 | This is not currently a problem because this only happens | |
3dec4024 JH |
1625 | for the (single) epilogue, which already has a fallthru edge |
1626 | to EXIT. */ | |
ca6c03ca JH |
1627 | |
1628 | e = bb->succ; | |
1629 | if (e->dest != EXIT_BLOCK_PTR | |
3dec4024 | 1630 | || e->succ_next != NULL || (e->flags & EDGE_FALLTHRU) == 0) |
ca6c03ca | 1631 | abort (); |
ca6c03ca | 1632 | |
5f0d2358 | 1633 | e->flags &= ~EDGE_FALLTHRU; |
ca6c03ca | 1634 | emit_barrier_after (last); |
0b17ab2f | 1635 | |
ca6c03ca JH |
1636 | if (before) |
1637 | delete_insn (before); | |
1638 | } | |
1639 | else if (GET_CODE (last) == JUMP_INSN) | |
1640 | abort (); | |
5f0d2358 | 1641 | |
9dca2ad5 JH |
1642 | /* Mark the basic block for find_sub_basic_blocks. */ |
1643 | bb->aux = &bb->aux; | |
ca6c03ca JH |
1644 | } |
1645 | ||
1646 | /* Update the CFG for all queued instructions. */ | |
1647 | ||
1648 | void | |
d329e058 | 1649 | commit_edge_insertions (void) |
ca6c03ca | 1650 | { |
ca6c03ca | 1651 | basic_block bb; |
9dca2ad5 | 1652 | sbitmap blocks; |
9809a362 | 1653 | bool changed = false; |
ca6c03ca JH |
1654 | |
1655 | #ifdef ENABLE_CHECKING | |
1656 | verify_flow_info (); | |
1657 | #endif | |
1658 | ||
e0082a72 | 1659 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
ca6c03ca JH |
1660 | { |
1661 | edge e, next; | |
1662 | ||
1663 | for (e = bb->succ; e; e = next) | |
1664 | { | |
1665 | next = e->succ_next; | |
1666 | if (e->insns) | |
9809a362 JH |
1667 | { |
1668 | changed = true; | |
1669 | commit_one_edge_insertion (e, false); | |
1670 | } | |
3dec4024 | 1671 | } |
3dec4024 | 1672 | } |
9dca2ad5 | 1673 | |
9809a362 JH |
1674 | if (!changed) |
1675 | return; | |
1676 | ||
9dca2ad5 JH |
1677 | blocks = sbitmap_alloc (last_basic_block); |
1678 | sbitmap_zero (blocks); | |
1679 | FOR_EACH_BB (bb) | |
1680 | if (bb->aux) | |
1681 | { | |
1682 | SET_BIT (blocks, bb->index); | |
1683 | /* Check for forgotten bb->aux values before commit_edge_insertions | |
1684 | call. */ | |
1685 | if (bb->aux != &bb->aux) | |
1686 | abort (); | |
1687 | bb->aux = NULL; | |
1688 | } | |
1689 | find_many_sub_basic_blocks (blocks); | |
1690 | sbitmap_free (blocks); | |
3dec4024 JH |
1691 | } |
1692 | \f | |
1693 | /* Update the CFG for all queued instructions, taking special care of inserting | |
1694 | code on edges between call and storing its return value. */ | |
1695 | ||
1696 | void | |
d329e058 | 1697 | commit_edge_insertions_watch_calls (void) |
3dec4024 | 1698 | { |
3dec4024 | 1699 | basic_block bb; |
9809a362 JH |
1700 | sbitmap blocks; |
1701 | bool changed = false; | |
3dec4024 JH |
1702 | |
1703 | #ifdef ENABLE_CHECKING | |
1704 | verify_flow_info (); | |
1705 | #endif | |
1706 | ||
e0082a72 | 1707 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
3dec4024 JH |
1708 | { |
1709 | edge e, next; | |
1710 | ||
1711 | for (e = bb->succ; e; e = next) | |
1712 | { | |
1713 | next = e->succ_next; | |
1714 | if (e->insns) | |
9809a362 JH |
1715 | { |
1716 | changed = true; | |
1717 | commit_one_edge_insertion (e, true); | |
1718 | } | |
ca6c03ca | 1719 | } |
ca6c03ca | 1720 | } |
9809a362 JH |
1721 | |
1722 | if (!changed) | |
1723 | return; | |
1724 | ||
1725 | blocks = sbitmap_alloc (last_basic_block); | |
1726 | sbitmap_zero (blocks); | |
1727 | FOR_EACH_BB (bb) | |
1728 | if (bb->aux) | |
1729 | { | |
1730 | SET_BIT (blocks, bb->index); | |
1731 | /* Check for forgotten bb->aux values before commit_edge_insertions | |
1732 | call. */ | |
1733 | if (bb->aux != &bb->aux) | |
1734 | abort (); | |
1735 | bb->aux = NULL; | |
1736 | } | |
1737 | find_many_sub_basic_blocks (blocks); | |
1738 | sbitmap_free (blocks); | |
ca6c03ca JH |
1739 | } |
1740 | \f | |
f470c378 ZD |
1741 | /* Print out RTL-specific basic block information (live information |
1742 | at start and end). */ | |
ca6c03ca | 1743 | |
10e9fecc | 1744 | static void |
f470c378 | 1745 | rtl_dump_bb (basic_block bb, FILE *outf, int indent) |
ca6c03ca JH |
1746 | { |
1747 | rtx insn; | |
1748 | rtx last; | |
f470c378 | 1749 | char *s_indent; |
ca6c03ca | 1750 | |
400e39e3 KH |
1751 | s_indent = alloca ((size_t) indent + 1); |
1752 | memset (s_indent, ' ', (size_t) indent); | |
f470c378 ZD |
1753 | s_indent[indent] = '\0'; |
1754 | ||
1755 | fprintf (outf, ";;%s Registers live at start: ", s_indent); | |
ca6c03ca JH |
1756 | dump_regset (bb->global_live_at_start, outf); |
1757 | putc ('\n', outf); | |
1758 | ||
a813c111 | 1759 | for (insn = BB_HEAD (bb), last = NEXT_INSN (BB_END (bb)); insn != last; |
ca6c03ca JH |
1760 | insn = NEXT_INSN (insn)) |
1761 | print_rtl_single (outf, insn); | |
1762 | ||
f470c378 | 1763 | fprintf (outf, ";;%s Registers live at end: ", s_indent); |
ca6c03ca JH |
1764 | dump_regset (bb->global_live_at_end, outf); |
1765 | putc ('\n', outf); | |
ca6c03ca JH |
1766 | } |
1767 | \f | |
1768 | /* Like print_rtl, but also print out live information for the start of each | |
1769 | basic block. */ | |
1770 | ||
1771 | void | |
d329e058 | 1772 | print_rtl_with_bb (FILE *outf, rtx rtx_first) |
ca6c03ca | 1773 | { |
b3694847 | 1774 | rtx tmp_rtx; |
ca6c03ca JH |
1775 | |
1776 | if (rtx_first == 0) | |
1777 | fprintf (outf, "(nil)\n"); | |
1778 | else | |
1779 | { | |
ca6c03ca JH |
1780 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
1781 | int max_uid = get_max_uid (); | |
703ad42b KG |
1782 | basic_block *start = xcalloc (max_uid, sizeof (basic_block)); |
1783 | basic_block *end = xcalloc (max_uid, sizeof (basic_block)); | |
1784 | enum bb_state *in_bb_p = xcalloc (max_uid, sizeof (enum bb_state)); | |
ca6c03ca | 1785 | |
e0082a72 ZD |
1786 | basic_block bb; |
1787 | ||
1788 | FOR_EACH_BB_REVERSE (bb) | |
ca6c03ca | 1789 | { |
ca6c03ca JH |
1790 | rtx x; |
1791 | ||
a813c111 SB |
1792 | start[INSN_UID (BB_HEAD (bb))] = bb; |
1793 | end[INSN_UID (BB_END (bb))] = bb; | |
1794 | for (x = BB_HEAD (bb); x != NULL_RTX; x = NEXT_INSN (x)) | |
ca6c03ca JH |
1795 | { |
1796 | enum bb_state state = IN_MULTIPLE_BB; | |
5f0d2358 | 1797 | |
ca6c03ca JH |
1798 | if (in_bb_p[INSN_UID (x)] == NOT_IN_BB) |
1799 | state = IN_ONE_BB; | |
1800 | in_bb_p[INSN_UID (x)] = state; | |
1801 | ||
a813c111 | 1802 | if (x == BB_END (bb)) |
ca6c03ca JH |
1803 | break; |
1804 | } | |
1805 | } | |
1806 | ||
1807 | for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) | |
1808 | { | |
1809 | int did_output; | |
ca6c03ca JH |
1810 | |
1811 | if ((bb = start[INSN_UID (tmp_rtx)]) != NULL) | |
1812 | { | |
1813 | fprintf (outf, ";; Start of basic block %d, registers live:", | |
0b17ab2f | 1814 | bb->index); |
ca6c03ca JH |
1815 | dump_regset (bb->global_live_at_start, outf); |
1816 | putc ('\n', outf); | |
1817 | } | |
1818 | ||
1819 | if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB | |
1820 | && GET_CODE (tmp_rtx) != NOTE | |
1821 | && GET_CODE (tmp_rtx) != BARRIER) | |
1822 | fprintf (outf, ";; Insn is not within a basic block\n"); | |
1823 | else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB) | |
1824 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); | |
1825 | ||
1826 | did_output = print_rtl_single (outf, tmp_rtx); | |
1827 | ||
1828 | if ((bb = end[INSN_UID (tmp_rtx)]) != NULL) | |
1829 | { | |
1830 | fprintf (outf, ";; End of basic block %d, registers live:\n", | |
0b17ab2f | 1831 | bb->index); |
ca6c03ca JH |
1832 | dump_regset (bb->global_live_at_end, outf); |
1833 | putc ('\n', outf); | |
1834 | } | |
1835 | ||
1836 | if (did_output) | |
1837 | putc ('\n', outf); | |
1838 | } | |
1839 | ||
1840 | free (start); | |
1841 | free (end); | |
1842 | free (in_bb_p); | |
1843 | } | |
1844 | ||
1845 | if (current_function_epilogue_delay_list != 0) | |
1846 | { | |
1847 | fprintf (outf, "\n;; Insns in epilogue delay list:\n\n"); | |
1848 | for (tmp_rtx = current_function_epilogue_delay_list; tmp_rtx != 0; | |
1849 | tmp_rtx = XEXP (tmp_rtx, 1)) | |
1850 | print_rtl_single (outf, XEXP (tmp_rtx, 0)); | |
1851 | } | |
1852 | } | |
1853 | \f | |
b446e5a2 | 1854 | void |
d329e058 | 1855 | update_br_prob_note (basic_block bb) |
b446e5a2 JH |
1856 | { |
1857 | rtx note; | |
a813c111 | 1858 | if (GET_CODE (BB_END (bb)) != JUMP_INSN) |
b446e5a2 | 1859 | return; |
a813c111 | 1860 | note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX); |
b446e5a2 JH |
1861 | if (!note || INTVAL (XEXP (note, 0)) == BRANCH_EDGE (bb)->probability) |
1862 | return; | |
1863 | XEXP (note, 0) = GEN_INT (BRANCH_EDGE (bb)->probability); | |
1864 | } | |
1865 | \f | |
10e9fecc JH |
1866 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
1867 | cfglayout RTL. | |
ca6c03ca JH |
1868 | |
1869 | Currently it does following checks: | |
1870 | ||
1871 | - test head/end pointers | |
1872 | - overlapping of basic blocks | |
ca6c03ca | 1873 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) |
f63d1bf7 | 1874 | - tails of basic blocks (ensure that boundary is necessary) |
ca6c03ca JH |
1875 | - scans body of the basic block for JUMP_INSN, CODE_LABEL |
1876 | and NOTE_INSN_BASIC_BLOCK | |
750054a2 | 1877 | - verify that no fall_thru edge crosses hot/cold partition boundaries |
ca6c03ca JH |
1878 | |
1879 | In future it can be extended check a lot of other stuff as well | |
1880 | (reachability of basic blocks, life information, etc. etc.). */ | |
f470c378 | 1881 | |
10e9fecc | 1882 | static int |
d329e058 | 1883 | rtl_verify_flow_info_1 (void) |
ca6c03ca JH |
1884 | { |
1885 | const int max_uid = get_max_uid (); | |
ca6c03ca | 1886 | rtx last_head = get_last_insn (); |
10e9fecc | 1887 | basic_block *bb_info; |
ca6c03ca | 1888 | rtx x; |
10e9fecc | 1889 | int err = 0; |
918ed612 | 1890 | basic_block bb, last_bb_seen; |
ca6c03ca | 1891 | |
703ad42b | 1892 | bb_info = xcalloc (max_uid, sizeof (basic_block)); |
ca6c03ca | 1893 | |
918ed612 ZD |
1894 | /* Check bb chain & numbers. */ |
1895 | last_bb_seen = ENTRY_BLOCK_PTR; | |
918ed612 | 1896 | |
e0082a72 | 1897 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1898 | { |
a813c111 SB |
1899 | rtx head = BB_HEAD (bb); |
1900 | rtx end = BB_END (bb); | |
ca6c03ca JH |
1901 | |
1902 | /* Verify the end of the basic block is in the INSN chain. */ | |
1903 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) | |
1904 | if (x == end) | |
1905 | break; | |
5f0d2358 | 1906 | |
ca6c03ca JH |
1907 | if (!x) |
1908 | { | |
1f978f5f | 1909 | error ("end insn %d for block %d not found in the insn stream", |
0b17ab2f | 1910 | INSN_UID (end), bb->index); |
ca6c03ca JH |
1911 | err = 1; |
1912 | } | |
1913 | ||
1914 | /* Work backwards from the end to the head of the basic block | |
1915 | to verify the head is in the RTL chain. */ | |
1916 | for (; x != NULL_RTX; x = PREV_INSN (x)) | |
1917 | { | |
1918 | /* While walking over the insn chain, verify insns appear | |
1919 | in only one basic block and initialize the BB_INFO array | |
1920 | used by other passes. */ | |
1921 | if (bb_info[INSN_UID (x)] != NULL) | |
1922 | { | |
1f978f5f | 1923 | error ("insn %d is in multiple basic blocks (%d and %d)", |
0b17ab2f | 1924 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); |
ca6c03ca JH |
1925 | err = 1; |
1926 | } | |
5f0d2358 | 1927 | |
ca6c03ca JH |
1928 | bb_info[INSN_UID (x)] = bb; |
1929 | ||
1930 | if (x == head) | |
1931 | break; | |
1932 | } | |
1933 | if (!x) | |
1934 | { | |
1f978f5f | 1935 | error ("head insn %d for block %d not found in the insn stream", |
0b17ab2f | 1936 | INSN_UID (head), bb->index); |
ca6c03ca JH |
1937 | err = 1; |
1938 | } | |
1939 | ||
1940 | last_head = x; | |
1941 | } | |
1942 | ||
1943 | /* Now check the basic blocks (boundaries etc.) */ | |
e0082a72 | 1944 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1945 | { |
3dec4024 | 1946 | int n_fallthru = 0, n_eh = 0, n_call = 0, n_abnormal = 0, n_branch = 0; |
3cf54412 | 1947 | edge e, fallthru = NULL; |
5a1a3e5e | 1948 | rtx note; |
ca6c03ca | 1949 | |
a813c111 SB |
1950 | if (INSN_P (BB_END (bb)) |
1951 | && (note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX)) | |
3e638a90 | 1952 | && bb->succ && bb->succ->succ_next |
a813c111 | 1953 | && any_condjump_p (BB_END (bb))) |
5a1a3e5e | 1954 | { |
5a1a3e5e JH |
1955 | if (INTVAL (XEXP (note, 0)) != BRANCH_EDGE (bb)->probability) |
1956 | { | |
0108ae51 | 1957 | error ("verify_flow_info: REG_BR_PROB does not match cfg %wi %i", |
5a1a3e5e JH |
1958 | INTVAL (XEXP (note, 0)), BRANCH_EDGE (bb)->probability); |
1959 | err = 1; | |
1960 | } | |
1961 | } | |
5f0d2358 | 1962 | for (e = bb->succ; e; e = e->succ_next) |
ca6c03ca | 1963 | { |
ca6c03ca | 1964 | if (e->flags & EDGE_FALLTHRU) |
750054a2 CT |
1965 | { |
1966 | n_fallthru++, fallthru = e; | |
1967 | if (e->crossing_edge) | |
1968 | { | |
1969 | error ("Fallthru edge crosses section boundary (bb %i)", | |
1970 | e->src->index); | |
1971 | err = 1; | |
1972 | } | |
1973 | } | |
3dec4024 | 1974 | |
65f43cdf ZD |
1975 | if ((e->flags & ~(EDGE_DFS_BACK |
1976 | | EDGE_CAN_FALLTHRU | |
1977 | | EDGE_IRREDUCIBLE_LOOP | |
1978 | | EDGE_LOOP_EXIT)) == 0) | |
3dec4024 JH |
1979 | n_branch++; |
1980 | ||
1981 | if (e->flags & EDGE_ABNORMAL_CALL) | |
1982 | n_call++; | |
1983 | ||
1984 | if (e->flags & EDGE_EH) | |
1985 | n_eh++; | |
1986 | else if (e->flags & EDGE_ABNORMAL) | |
1987 | n_abnormal++; | |
ca6c03ca | 1988 | } |
5f0d2358 | 1989 | |
a813c111 SB |
1990 | if (n_eh && GET_CODE (PATTERN (BB_END (bb))) != RESX |
1991 | && !find_reg_note (BB_END (bb), REG_EH_REGION, NULL_RTX)) | |
3dec4024 | 1992 | { |
0b17ab2f | 1993 | error ("Missing REG_EH_REGION note in the end of bb %i", bb->index); |
3dec4024 JH |
1994 | err = 1; |
1995 | } | |
1996 | if (n_branch | |
a813c111 SB |
1997 | && (GET_CODE (BB_END (bb)) != JUMP_INSN |
1998 | || (n_branch > 1 && (any_uncondjump_p (BB_END (bb)) | |
1999 | || any_condjump_p (BB_END (bb)))))) | |
3dec4024 | 2000 | { |
0b17ab2f | 2001 | error ("Too many outgoing branch edges from bb %i", bb->index); |
3dec4024 JH |
2002 | err = 1; |
2003 | } | |
a813c111 | 2004 | if (n_fallthru && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 2005 | { |
0b17ab2f | 2006 | error ("Fallthru edge after unconditional jump %i", bb->index); |
3dec4024 JH |
2007 | err = 1; |
2008 | } | |
a813c111 | 2009 | if (n_branch != 1 && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 2010 | { |
0b17ab2f | 2011 | error ("Wrong amount of branch edges after unconditional jump %i", bb->index); |
3dec4024 JH |
2012 | err = 1; |
2013 | } | |
a813c111 SB |
2014 | if (n_branch != 1 && any_condjump_p (BB_END (bb)) |
2015 | && JUMP_LABEL (BB_END (bb)) != BB_HEAD (fallthru->dest)) | |
3dec4024 | 2016 | { |
0b17ab2f | 2017 | error ("Wrong amount of branch edges after conditional jump %i", bb->index); |
3dec4024 JH |
2018 | err = 1; |
2019 | } | |
a813c111 | 2020 | if (n_call && GET_CODE (BB_END (bb)) != CALL_INSN) |
3dec4024 | 2021 | { |
0b17ab2f | 2022 | error ("Call edges for non-call insn in bb %i", bb->index); |
3dec4024 JH |
2023 | err = 1; |
2024 | } | |
2025 | if (n_abnormal | |
a813c111 SB |
2026 | && (GET_CODE (BB_END (bb)) != CALL_INSN && n_call != n_abnormal) |
2027 | && (GET_CODE (BB_END (bb)) != JUMP_INSN | |
2028 | || any_condjump_p (BB_END (bb)) | |
2029 | || any_uncondjump_p (BB_END (bb)))) | |
3dec4024 | 2030 | { |
0b17ab2f | 2031 | error ("Abnormal edges for no purpose in bb %i", bb->index); |
3dec4024 JH |
2032 | err = 1; |
2033 | } | |
f87c27b4 | 2034 | |
a813c111 | 2035 | for (x = BB_HEAD (bb); x != NEXT_INSN (BB_END (bb)); x = NEXT_INSN (x)) |
ba4f7968 | 2036 | if (BLOCK_FOR_INSN (x) != bb) |
5f0d2358 RK |
2037 | { |
2038 | debug_rtx (x); | |
2039 | if (! BLOCK_FOR_INSN (x)) | |
2040 | error | |
2041 | ("insn %d inside basic block %d but block_for_insn is NULL", | |
0b17ab2f | 2042 | INSN_UID (x), bb->index); |
5f0d2358 RK |
2043 | else |
2044 | error | |
2045 | ("insn %d inside basic block %d but block_for_insn is %i", | |
0b17ab2f | 2046 | INSN_UID (x), bb->index, BLOCK_FOR_INSN (x)->index); |
5f0d2358 RK |
2047 | |
2048 | err = 1; | |
2049 | } | |
ca6c03ca JH |
2050 | |
2051 | /* OK pointers are correct. Now check the header of basic | |
2052 | block. It ought to contain optional CODE_LABEL followed | |
2053 | by NOTE_BASIC_BLOCK. */ | |
a813c111 | 2054 | x = BB_HEAD (bb); |
ca6c03ca JH |
2055 | if (GET_CODE (x) == CODE_LABEL) |
2056 | { | |
a813c111 | 2057 | if (BB_END (bb) == x) |
ca6c03ca JH |
2058 | { |
2059 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 2060 | bb->index); |
ca6c03ca JH |
2061 | err = 1; |
2062 | } | |
5f0d2358 | 2063 | |
ca6c03ca JH |
2064 | x = NEXT_INSN (x); |
2065 | } | |
5f0d2358 | 2066 | |
ca6c03ca JH |
2067 | if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb) |
2068 | { | |
2069 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 2070 | bb->index); |
ca6c03ca JH |
2071 | err = 1; |
2072 | } | |
2073 | ||
a813c111 | 2074 | if (BB_END (bb) == x) |
5f0d2358 RK |
2075 | /* Do checks for empty blocks her. e */ |
2076 | ; | |
ca6c03ca | 2077 | else |
5f0d2358 RK |
2078 | for (x = NEXT_INSN (x); x; x = NEXT_INSN (x)) |
2079 | { | |
2080 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2081 | { | |
2082 | error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d", | |
0b17ab2f | 2083 | INSN_UID (x), bb->index); |
5f0d2358 RK |
2084 | err = 1; |
2085 | } | |
2086 | ||
a813c111 | 2087 | if (x == BB_END (bb)) |
5f0d2358 | 2088 | break; |
ca6c03ca | 2089 | |
83fd323c | 2090 | if (control_flow_insn_p (x)) |
5f0d2358 | 2091 | { |
0b17ab2f | 2092 | error ("in basic block %d:", bb->index); |
5f0d2358 RK |
2093 | fatal_insn ("flow control insn inside a basic block", x); |
2094 | } | |
2095 | } | |
ca6c03ca JH |
2096 | } |
2097 | ||
10e9fecc JH |
2098 | /* Clean up. */ |
2099 | free (bb_info); | |
2100 | return err; | |
2101 | } | |
5f0d2358 | 2102 | |
10e9fecc JH |
2103 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
2104 | cfglayout RTL. | |
5f0d2358 | 2105 | |
10e9fecc JH |
2106 | Currently it does following checks: |
2107 | - all checks of rtl_verify_flow_info_1 | |
2108 | - check that all insns are in the basic blocks | |
2109 | (except the switch handling code, barriers and notes) | |
2110 | - check that all returns are followed by barriers | |
2111 | - check that all fallthru edge points to the adjacent blocks. */ | |
2112 | static int | |
d329e058 | 2113 | rtl_verify_flow_info (void) |
10e9fecc JH |
2114 | { |
2115 | basic_block bb; | |
2116 | int err = rtl_verify_flow_info_1 (); | |
2117 | rtx x; | |
2118 | int num_bb_notes; | |
2119 | const rtx rtx_first = get_insns (); | |
2120 | basic_block last_bb_seen = ENTRY_BLOCK_PTR, curr_bb = NULL; | |
ca6c03ca | 2121 | |
10e9fecc JH |
2122 | FOR_EACH_BB_REVERSE (bb) |
2123 | { | |
2124 | edge e; | |
2125 | for (e = bb->succ; e; e = e->succ_next) | |
2126 | if (e->flags & EDGE_FALLTHRU) | |
2127 | break; | |
2128 | if (!e) | |
2129 | { | |
2130 | rtx insn; | |
2131 | ||
2132 | /* Ensure existence of barrier in BB with no fallthru edges. */ | |
a813c111 | 2133 | for (insn = BB_END (bb); !insn || GET_CODE (insn) != BARRIER; |
10e9fecc JH |
2134 | insn = NEXT_INSN (insn)) |
2135 | if (!insn | |
2136 | || (GET_CODE (insn) == NOTE | |
2137 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_BASIC_BLOCK)) | |
2138 | { | |
2139 | error ("missing barrier after block %i", bb->index); | |
2140 | err = 1; | |
2141 | break; | |
2142 | } | |
2143 | } | |
2144 | else if (e->src != ENTRY_BLOCK_PTR | |
2145 | && e->dest != EXIT_BLOCK_PTR) | |
2146 | { | |
2147 | rtx insn; | |
2148 | ||
2149 | if (e->src->next_bb != e->dest) | |
2150 | { | |
2151 | error | |
2152 | ("verify_flow_info: Incorrect blocks for fallthru %i->%i", | |
2153 | e->src->index, e->dest->index); | |
2154 | err = 1; | |
2155 | } | |
2156 | else | |
a813c111 | 2157 | for (insn = NEXT_INSN (BB_END (e->src)); insn != BB_HEAD (e->dest); |
10e9fecc JH |
2158 | insn = NEXT_INSN (insn)) |
2159 | if (GET_CODE (insn) == BARRIER | |
2160 | #ifndef CASE_DROPS_THROUGH | |
2161 | || INSN_P (insn) | |
2162 | #else | |
2163 | || (INSN_P (insn) && ! JUMP_TABLE_DATA_P (insn)) | |
2164 | #endif | |
2165 | ) | |
2166 | { | |
2167 | error ("verify_flow_info: Incorrect fallthru %i->%i", | |
2168 | e->src->index, e->dest->index); | |
2169 | fatal_insn ("wrong insn in the fallthru edge", insn); | |
2170 | err = 1; | |
2171 | } | |
2172 | } | |
2173 | } | |
ca6c03ca | 2174 | |
ca6c03ca | 2175 | num_bb_notes = 0; |
e0082a72 ZD |
2176 | last_bb_seen = ENTRY_BLOCK_PTR; |
2177 | ||
5f0d2358 | 2178 | for (x = rtx_first; x; x = NEXT_INSN (x)) |
ca6c03ca JH |
2179 | { |
2180 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2181 | { | |
bf77398c | 2182 | bb = NOTE_BASIC_BLOCK (x); |
5f0d2358 | 2183 | |
ca6c03ca | 2184 | num_bb_notes++; |
e0082a72 | 2185 | if (bb != last_bb_seen->next_bb) |
10e9fecc | 2186 | internal_error ("basic blocks not laid down consecutively"); |
ca6c03ca | 2187 | |
10e9fecc | 2188 | curr_bb = last_bb_seen = bb; |
ca6c03ca JH |
2189 | } |
2190 | ||
10e9fecc | 2191 | if (!curr_bb) |
ca6c03ca JH |
2192 | { |
2193 | switch (GET_CODE (x)) | |
2194 | { | |
2195 | case BARRIER: | |
2196 | case NOTE: | |
2197 | break; | |
2198 | ||
2199 | case CODE_LABEL: | |
666c27b9 | 2200 | /* An addr_vec is placed outside any basic block. */ |
ca6c03ca JH |
2201 | if (NEXT_INSN (x) |
2202 | && GET_CODE (NEXT_INSN (x)) == JUMP_INSN | |
2203 | && (GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_DIFF_VEC | |
2204 | || GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_VEC)) | |
5f0d2358 | 2205 | x = NEXT_INSN (x); |
ca6c03ca JH |
2206 | |
2207 | /* But in any case, non-deletable labels can appear anywhere. */ | |
2208 | break; | |
2209 | ||
2210 | default: | |
1f978f5f | 2211 | fatal_insn ("insn outside basic block", x); |
ca6c03ca JH |
2212 | } |
2213 | } | |
2214 | ||
2215 | if (INSN_P (x) | |
2216 | && GET_CODE (x) == JUMP_INSN | |
2217 | && returnjump_p (x) && ! condjump_p (x) | |
2218 | && ! (NEXT_INSN (x) && GET_CODE (NEXT_INSN (x)) == BARRIER)) | |
1f978f5f | 2219 | fatal_insn ("return not followed by barrier", x); |
a813c111 | 2220 | if (curr_bb && x == BB_END (curr_bb)) |
10e9fecc | 2221 | curr_bb = NULL; |
ca6c03ca JH |
2222 | } |
2223 | ||
0b17ab2f | 2224 | if (num_bb_notes != n_basic_blocks) |
ca6c03ca | 2225 | internal_error |
0b17ab2f RH |
2226 | ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)", |
2227 | num_bb_notes, n_basic_blocks); | |
ca6c03ca | 2228 | |
10e9fecc | 2229 | return err; |
ca6c03ca JH |
2230 | } |
2231 | \f | |
eaec9b3d | 2232 | /* Assume that the preceding pass has possibly eliminated jump instructions |
ca6c03ca JH |
2233 | or converted the unconditional jumps. Eliminate the edges from CFG. |
2234 | Return true if any edges are eliminated. */ | |
2235 | ||
2236 | bool | |
d329e058 | 2237 | purge_dead_edges (basic_block bb) |
ca6c03ca JH |
2238 | { |
2239 | edge e, next; | |
a813c111 | 2240 | rtx insn = BB_END (bb), note; |
ca6c03ca JH |
2241 | bool purged = false; |
2242 | ||
70da1d03 JH |
2243 | /* If this instruction cannot trap, remove REG_EH_REGION notes. */ |
2244 | if (GET_CODE (insn) == INSN | |
2245 | && (note = find_reg_note (insn, REG_EH_REGION, NULL))) | |
2246 | { | |
2247 | rtx eqnote; | |
2248 | ||
2249 | if (! may_trap_p (PATTERN (insn)) | |
2250 | || ((eqnote = find_reg_equal_equiv_note (insn)) | |
2251 | && ! may_trap_p (XEXP (eqnote, 0)))) | |
2252 | remove_note (insn, note); | |
2253 | } | |
2254 | ||
546c093e RH |
2255 | /* Cleanup abnormal edges caused by exceptions or non-local gotos. */ |
2256 | for (e = bb->succ; e; e = next) | |
2257 | { | |
2258 | next = e->succ_next; | |
2259 | if (e->flags & EDGE_EH) | |
2260 | { | |
a813c111 | 2261 | if (can_throw_internal (BB_END (bb))) |
546c093e RH |
2262 | continue; |
2263 | } | |
2264 | else if (e->flags & EDGE_ABNORMAL_CALL) | |
2265 | { | |
a813c111 | 2266 | if (GET_CODE (BB_END (bb)) == CALL_INSN |
546c093e RH |
2267 | && (! (note = find_reg_note (insn, REG_EH_REGION, NULL)) |
2268 | || INTVAL (XEXP (note, 0)) >= 0)) | |
2269 | continue; | |
2270 | } | |
2271 | else | |
2272 | continue; | |
2273 | ||
2274 | remove_edge (e); | |
2275 | bb->flags |= BB_DIRTY; | |
2276 | purged = true; | |
2277 | } | |
5f0d2358 | 2278 | |
ca6c03ca JH |
2279 | if (GET_CODE (insn) == JUMP_INSN) |
2280 | { | |
2281 | rtx note; | |
2282 | edge b,f; | |
5f0d2358 | 2283 | |
ca6c03ca JH |
2284 | /* We do care only about conditional jumps and simplejumps. */ |
2285 | if (!any_condjump_p (insn) | |
2286 | && !returnjump_p (insn) | |
2287 | && !simplejump_p (insn)) | |
c51d95ec | 2288 | return purged; |
5f0d2358 | 2289 | |
5a1a3e5e JH |
2290 | /* Branch probability/prediction notes are defined only for |
2291 | condjumps. We've possibly turned condjump into simplejump. */ | |
2292 | if (simplejump_p (insn)) | |
2293 | { | |
2294 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2295 | if (note) | |
2296 | remove_note (insn, note); | |
2297 | while ((note = find_reg_note (insn, REG_BR_PRED, NULL))) | |
2298 | remove_note (insn, note); | |
2299 | } | |
2300 | ||
ca6c03ca JH |
2301 | for (e = bb->succ; e; e = next) |
2302 | { | |
2303 | next = e->succ_next; | |
2304 | ||
7fcd7218 JH |
2305 | /* Avoid abnormal flags to leak from computed jumps turned |
2306 | into simplejumps. */ | |
f87c27b4 | 2307 | |
0e1638d4 | 2308 | e->flags &= ~EDGE_ABNORMAL; |
7fcd7218 | 2309 | |
5a566bed MM |
2310 | /* See if this edge is one we should keep. */ |
2311 | if ((e->flags & EDGE_FALLTHRU) && any_condjump_p (insn)) | |
2312 | /* A conditional jump can fall through into the next | |
2313 | block, so we should keep the edge. */ | |
ca6c03ca | 2314 | continue; |
5f0d2358 | 2315 | else if (e->dest != EXIT_BLOCK_PTR |
a813c111 | 2316 | && BB_HEAD (e->dest) == JUMP_LABEL (insn)) |
5a566bed MM |
2317 | /* If the destination block is the target of the jump, |
2318 | keep the edge. */ | |
2319 | continue; | |
2320 | else if (e->dest == EXIT_BLOCK_PTR && returnjump_p (insn)) | |
2321 | /* If the destination block is the exit block, and this | |
2322 | instruction is a return, then keep the edge. */ | |
ca6c03ca | 2323 | continue; |
5a566bed MM |
2324 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) |
2325 | /* Keep the edges that correspond to exceptions thrown by | |
0b75beaa EB |
2326 | this instruction and rematerialize the EDGE_ABNORMAL |
2327 | flag we just cleared above. */ | |
2328 | { | |
2329 | e->flags |= EDGE_ABNORMAL; | |
2330 | continue; | |
2331 | } | |
5f0d2358 | 2332 | |
5a566bed | 2333 | /* We do not need this edge. */ |
c51d95ec | 2334 | bb->flags |= BB_DIRTY; |
ca6c03ca JH |
2335 | purged = true; |
2336 | remove_edge (e); | |
2337 | } | |
5f0d2358 | 2338 | |
ca6c03ca | 2339 | if (!bb->succ || !purged) |
c51d95ec | 2340 | return purged; |
5f0d2358 | 2341 | |
c263766c RH |
2342 | if (dump_file) |
2343 | fprintf (dump_file, "Purged edges from bb %i\n", bb->index); | |
5f0d2358 | 2344 | |
ca6c03ca JH |
2345 | if (!optimize) |
2346 | return purged; | |
2347 | ||
2348 | /* Redistribute probabilities. */ | |
2349 | if (!bb->succ->succ_next) | |
2350 | { | |
2351 | bb->succ->probability = REG_BR_PROB_BASE; | |
2352 | bb->succ->count = bb->count; | |
f87c27b4 | 2353 | } |
ca6c03ca JH |
2354 | else |
2355 | { | |
2356 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2357 | if (!note) | |
2358 | return purged; | |
5f0d2358 | 2359 | |
ca6c03ca JH |
2360 | b = BRANCH_EDGE (bb); |
2361 | f = FALLTHRU_EDGE (bb); | |
2362 | b->probability = INTVAL (XEXP (note, 0)); | |
2363 | f->probability = REG_BR_PROB_BASE - b->probability; | |
2364 | b->count = bb->count * b->probability / REG_BR_PROB_BASE; | |
2365 | f->count = bb->count * f->probability / REG_BR_PROB_BASE; | |
2366 | } | |
5f0d2358 | 2367 | |
ca6c03ca JH |
2368 | return purged; |
2369 | } | |
1722c2c8 RH |
2370 | else if (GET_CODE (insn) == CALL_INSN && SIBLING_CALL_P (insn)) |
2371 | { | |
2372 | /* First, there should not be any EH or ABCALL edges resulting | |
2373 | from non-local gotos and the like. If there were, we shouldn't | |
2374 | have created the sibcall in the first place. Second, there | |
2375 | should of course never have been a fallthru edge. */ | |
2376 | if (!bb->succ || bb->succ->succ_next) | |
2377 | abort (); | |
792bb204 | 2378 | if (bb->succ->flags != (EDGE_SIBCALL | EDGE_ABNORMAL)) |
1722c2c8 RH |
2379 | abort (); |
2380 | ||
2381 | return 0; | |
2382 | } | |
ca6c03ca | 2383 | |
ca6c03ca JH |
2384 | /* If we don't see a jump insn, we don't know exactly why the block would |
2385 | have been broken at this point. Look for a simple, non-fallthru edge, | |
2386 | as these are only created by conditional branches. If we find such an | |
2387 | edge we know that there used to be a jump here and can then safely | |
2388 | remove all non-fallthru edges. */ | |
2389 | for (e = bb->succ; e && (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU)); | |
5f0d2358 RK |
2390 | e = e->succ_next) |
2391 | ; | |
2392 | ||
ca6c03ca JH |
2393 | if (!e) |
2394 | return purged; | |
5f0d2358 | 2395 | |
ca6c03ca JH |
2396 | for (e = bb->succ; e; e = next) |
2397 | { | |
2398 | next = e->succ_next; | |
2399 | if (!(e->flags & EDGE_FALLTHRU)) | |
c51d95ec JH |
2400 | { |
2401 | bb->flags |= BB_DIRTY; | |
2402 | remove_edge (e); | |
2403 | purged = true; | |
2404 | } | |
ca6c03ca | 2405 | } |
5f0d2358 | 2406 | |
ca6c03ca JH |
2407 | if (!bb->succ || bb->succ->succ_next) |
2408 | abort (); | |
5f0d2358 | 2409 | |
ca6c03ca JH |
2410 | bb->succ->probability = REG_BR_PROB_BASE; |
2411 | bb->succ->count = bb->count; | |
2412 | ||
c263766c RH |
2413 | if (dump_file) |
2414 | fprintf (dump_file, "Purged non-fallthru edges from bb %i\n", | |
0b17ab2f | 2415 | bb->index); |
ca6c03ca JH |
2416 | return purged; |
2417 | } | |
2418 | ||
5f0d2358 RK |
2419 | /* Search all basic blocks for potentially dead edges and purge them. Return |
2420 | true if some edge has been eliminated. */ | |
ca6c03ca JH |
2421 | |
2422 | bool | |
d329e058 | 2423 | purge_all_dead_edges (int update_life_p) |
ca6c03ca | 2424 | { |
e0082a72 | 2425 | int purged = false; |
710af899 | 2426 | sbitmap blocks = 0; |
e0082a72 | 2427 | basic_block bb; |
473fb060 JH |
2428 | |
2429 | if (update_life_p) | |
2430 | { | |
d55bc081 | 2431 | blocks = sbitmap_alloc (last_basic_block); |
473fb060 JH |
2432 | sbitmap_zero (blocks); |
2433 | } | |
5f0d2358 | 2434 | |
e0082a72 | 2435 | FOR_EACH_BB (bb) |
473fb060 | 2436 | { |
e0082a72 | 2437 | bool purged_here = purge_dead_edges (bb); |
5f0d2358 | 2438 | |
473fb060 JH |
2439 | purged |= purged_here; |
2440 | if (purged_here && update_life_p) | |
e0082a72 | 2441 | SET_BIT (blocks, bb->index); |
473fb060 | 2442 | } |
5f0d2358 | 2443 | |
473fb060 JH |
2444 | if (update_life_p && purged) |
2445 | update_life_info (blocks, UPDATE_LIFE_GLOBAL, | |
2446 | PROP_DEATH_NOTES | PROP_SCAN_DEAD_CODE | |
2447 | | PROP_KILL_DEAD_CODE); | |
5f0d2358 | 2448 | |
473fb060 JH |
2449 | if (update_life_p) |
2450 | sbitmap_free (blocks); | |
ca6c03ca JH |
2451 | return purged; |
2452 | } | |
9ee634e3 JH |
2453 | |
2454 | /* Same as split_block but update cfg_layout structures. */ | |
f470c378 ZD |
2455 | |
2456 | static basic_block | |
d329e058 | 2457 | cfg_layout_split_block (basic_block bb, void *insnp) |
9ee634e3 JH |
2458 | { |
2459 | rtx insn = insnp; | |
f470c378 | 2460 | basic_block new_bb = rtl_split_block (bb, insn); |
9ee634e3 | 2461 | |
f470c378 ZD |
2462 | new_bb->rbi->footer = bb->rbi->footer; |
2463 | bb->rbi->footer = NULL; | |
9ee634e3 | 2464 | |
f470c378 | 2465 | return new_bb; |
9ee634e3 JH |
2466 | } |
2467 | ||
2468 | ||
2469 | /* Redirect Edge to DEST. */ | |
2470 | static bool | |
d329e058 | 2471 | cfg_layout_redirect_edge_and_branch (edge e, basic_block dest) |
9ee634e3 JH |
2472 | { |
2473 | basic_block src = e->src; | |
9ee634e3 JH |
2474 | bool ret; |
2475 | ||
bc35512f JH |
2476 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
2477 | return false; | |
2478 | ||
3348b696 | 2479 | if (e->dest == dest) |
bc35512f JH |
2480 | return true; |
2481 | ||
3348b696 JH |
2482 | if (e->src != ENTRY_BLOCK_PTR |
2483 | && try_redirect_by_replacing_jump (e, dest, true)) | |
f345f21a JH |
2484 | { |
2485 | src->flags |= BB_DIRTY; | |
2486 | return true; | |
2487 | } | |
bc35512f JH |
2488 | |
2489 | if (e->src == ENTRY_BLOCK_PTR | |
2490 | && (e->flags & EDGE_FALLTHRU) && !(e->flags & EDGE_COMPLEX)) | |
2491 | { | |
c263766c RH |
2492 | if (dump_file) |
2493 | fprintf (dump_file, "Redirecting entry edge from bb %i to %i\n", | |
bc35512f JH |
2494 | e->src->index, dest->index); |
2495 | ||
f345f21a | 2496 | e->src->flags |= BB_DIRTY; |
bc35512f JH |
2497 | redirect_edge_succ (e, dest); |
2498 | return true; | |
2499 | } | |
2500 | ||
9ee634e3 JH |
2501 | /* Redirect_edge_and_branch may decide to turn branch into fallthru edge |
2502 | in the case the basic block appears to be in sequence. Avoid this | |
2503 | transformation. */ | |
2504 | ||
9ee634e3 JH |
2505 | if (e->flags & EDGE_FALLTHRU) |
2506 | { | |
2507 | /* Redirect any branch edges unified with the fallthru one. */ | |
a813c111 | 2508 | if (GET_CODE (BB_END (src)) == JUMP_INSN |
432f982f JH |
2509 | && label_is_jump_target_p (BB_HEAD (e->dest), |
2510 | BB_END (src))) | |
9ee634e3 | 2511 | { |
c263766c RH |
2512 | if (dump_file) |
2513 | fprintf (dump_file, "Fallthru edge unified with branch " | |
432f982f JH |
2514 | "%i->%i redirected to %i\n", |
2515 | e->src->index, e->dest->index, dest->index); | |
2516 | e->flags &= ~EDGE_FALLTHRU; | |
2517 | if (!redirect_branch_edge (e, dest)) | |
9ee634e3 | 2518 | abort (); |
432f982f | 2519 | e->flags |= EDGE_FALLTHRU; |
f345f21a | 2520 | e->src->flags |= BB_DIRTY; |
432f982f | 2521 | return true; |
9ee634e3 JH |
2522 | } |
2523 | /* In case we are redirecting fallthru edge to the branch edge | |
2524 | of conditional jump, remove it. */ | |
2525 | if (src->succ->succ_next | |
2526 | && !src->succ->succ_next->succ_next) | |
2527 | { | |
2528 | edge s = e->succ_next ? e->succ_next : src->succ; | |
2529 | if (s->dest == dest | |
a813c111 SB |
2530 | && any_condjump_p (BB_END (src)) |
2531 | && onlyjump_p (BB_END (src))) | |
2532 | delete_insn (BB_END (src)); | |
9ee634e3 | 2533 | } |
eabd7d31 | 2534 | |
c263766c RH |
2535 | if (dump_file) |
2536 | fprintf (dump_file, "Fallthru edge %i->%i redirected to %i\n", | |
bc35512f | 2537 | e->src->index, e->dest->index, dest->index); |
eabd7d31 | 2538 | redirect_edge_succ_nodup (e, dest); |
9ee634e3 JH |
2539 | |
2540 | ret = true; | |
2541 | } | |
2542 | else | |
bc35512f | 2543 | ret = redirect_branch_edge (e, dest); |
9ee634e3 JH |
2544 | |
2545 | /* We don't want simplejumps in the insn stream during cfglayout. */ | |
a813c111 | 2546 | if (simplejump_p (BB_END (src))) |
bc35512f | 2547 | abort (); |
9ee634e3 | 2548 | |
f345f21a | 2549 | src->flags |= BB_DIRTY; |
9ee634e3 JH |
2550 | return ret; |
2551 | } | |
2552 | ||
2553 | /* Simple wrapper as we always can redirect fallthru edges. */ | |
2554 | static basic_block | |
d329e058 | 2555 | cfg_layout_redirect_edge_and_branch_force (edge e, basic_block dest) |
9ee634e3 JH |
2556 | { |
2557 | if (!cfg_layout_redirect_edge_and_branch (e, dest)) | |
2558 | abort (); | |
2559 | return NULL; | |
2560 | } | |
2561 | ||
f470c378 ZD |
2562 | /* Same as delete_basic_block but update cfg_layout structures. */ |
2563 | ||
9ee634e3 | 2564 | static void |
d329e058 | 2565 | cfg_layout_delete_block (basic_block bb) |
9ee634e3 | 2566 | { |
a813c111 | 2567 | rtx insn, next, prev = PREV_INSN (BB_HEAD (bb)), *to, remaints; |
9ee634e3 | 2568 | |
bc35512f | 2569 | if (bb->rbi->header) |
9ee634e3 | 2570 | { |
a813c111 | 2571 | next = BB_HEAD (bb); |
9ee634e3 | 2572 | if (prev) |
bc35512f | 2573 | NEXT_INSN (prev) = bb->rbi->header; |
9ee634e3 | 2574 | else |
bc35512f JH |
2575 | set_first_insn (bb->rbi->header); |
2576 | PREV_INSN (bb->rbi->header) = prev; | |
2577 | insn = bb->rbi->header; | |
9ee634e3 JH |
2578 | while (NEXT_INSN (insn)) |
2579 | insn = NEXT_INSN (insn); | |
2580 | NEXT_INSN (insn) = next; | |
2581 | PREV_INSN (next) = insn; | |
2582 | } | |
a813c111 | 2583 | next = NEXT_INSN (BB_END (bb)); |
bc35512f | 2584 | if (bb->rbi->footer) |
9ee634e3 | 2585 | { |
bc35512f JH |
2586 | insn = bb->rbi->footer; |
2587 | while (insn) | |
2588 | { | |
2589 | if (GET_CODE (insn) == BARRIER) | |
2590 | { | |
2591 | if (PREV_INSN (insn)) | |
2592 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
2593 | else | |
2594 | bb->rbi->footer = NEXT_INSN (insn); | |
2595 | if (NEXT_INSN (insn)) | |
2596 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
2597 | } | |
2598 | if (GET_CODE (insn) == CODE_LABEL) | |
2599 | break; | |
2600 | insn = NEXT_INSN (insn); | |
2601 | } | |
2602 | if (bb->rbi->footer) | |
2603 | { | |
a813c111 | 2604 | insn = BB_END (bb); |
bc35512f JH |
2605 | NEXT_INSN (insn) = bb->rbi->footer; |
2606 | PREV_INSN (bb->rbi->footer) = insn; | |
2607 | while (NEXT_INSN (insn)) | |
2608 | insn = NEXT_INSN (insn); | |
2609 | NEXT_INSN (insn) = next; | |
2610 | if (next) | |
2611 | PREV_INSN (next) = insn; | |
2612 | else | |
2613 | set_last_insn (insn); | |
2614 | } | |
9ee634e3 JH |
2615 | } |
2616 | if (bb->next_bb != EXIT_BLOCK_PTR) | |
bc35512f | 2617 | to = &bb->next_bb->rbi->header; |
9ee634e3 JH |
2618 | else |
2619 | to = &cfg_layout_function_footer; | |
2620 | rtl_delete_block (bb); | |
2621 | ||
2622 | if (prev) | |
2623 | prev = NEXT_INSN (prev); | |
d329e058 | 2624 | else |
9ee634e3 JH |
2625 | prev = get_insns (); |
2626 | if (next) | |
2627 | next = PREV_INSN (next); | |
d329e058 | 2628 | else |
9ee634e3 JH |
2629 | next = get_last_insn (); |
2630 | ||
2631 | if (next && NEXT_INSN (next) != prev) | |
2632 | { | |
2633 | remaints = unlink_insn_chain (prev, next); | |
2634 | insn = remaints; | |
2635 | while (NEXT_INSN (insn)) | |
2636 | insn = NEXT_INSN (insn); | |
2637 | NEXT_INSN (insn) = *to; | |
2638 | if (*to) | |
2639 | PREV_INSN (*to) = insn; | |
2640 | *to = remaints; | |
2641 | } | |
2642 | } | |
2643 | ||
beb235f8 | 2644 | /* Return true when blocks A and B can be safely merged. */ |
bc35512f JH |
2645 | static bool |
2646 | cfg_layout_can_merge_blocks_p (basic_block a, basic_block b) | |
2647 | { | |
750054a2 CT |
2648 | bool partitions_ok = true; |
2649 | ||
2650 | /* If we are partitioning hot/cold basic blocks, we don't want to | |
2651 | mess up unconditional or indirect jumps that cross between hot | |
2652 | and cold sections. */ | |
2653 | ||
2654 | if (flag_reorder_blocks_and_partition | |
2655 | && (find_reg_note (BB_END (a), REG_CROSSING_JUMP, NULL_RTX) | |
2656 | || find_reg_note (BB_END (b), REG_CROSSING_JUMP, NULL_RTX) | |
2657 | || a->partition != b->partition)) | |
2658 | partitions_ok = false; | |
2659 | ||
bc35512f JH |
2660 | /* There must be exactly one edge in between the blocks. */ |
2661 | return (a->succ && !a->succ->succ_next && a->succ->dest == b | |
2662 | && !b->pred->pred_next && a != b | |
2663 | /* Must be simple edge. */ | |
2664 | && !(a->succ->flags & EDGE_COMPLEX) | |
750054a2 | 2665 | && partitions_ok |
bc35512f JH |
2666 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR |
2667 | /* If the jump insn has side effects, | |
2668 | we can't kill the edge. */ | |
a813c111 | 2669 | && (GET_CODE (BB_END (a)) != JUMP_INSN |
e24e7211 | 2670 | || (reload_completed |
a813c111 | 2671 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f JH |
2672 | } |
2673 | ||
2674 | /* Merge block A and B, abort when it is not possible. */ | |
2675 | static void | |
2676 | cfg_layout_merge_blocks (basic_block a, basic_block b) | |
2677 | { | |
2678 | #ifdef ENABLE_CHECKING | |
2679 | if (!cfg_layout_can_merge_blocks_p (a, b)) | |
2680 | abort (); | |
2681 | #endif | |
2682 | ||
2683 | /* If there was a CODE_LABEL beginning B, delete it. */ | |
a813c111 SB |
2684 | if (GET_CODE (BB_HEAD (b)) == CODE_LABEL) |
2685 | delete_insn (BB_HEAD (b)); | |
bc35512f JH |
2686 | |
2687 | /* We should have fallthru edge in a, or we can do dummy redirection to get | |
2688 | it cleaned up. */ | |
a813c111 | 2689 | if (GET_CODE (BB_END (a)) == JUMP_INSN) |
3348b696 | 2690 | try_redirect_by_replacing_jump (a->succ, b, true); |
a813c111 | 2691 | if (GET_CODE (BB_END (a)) == JUMP_INSN) |
bc35512f JH |
2692 | abort (); |
2693 | ||
2694 | /* Possible line number notes should appear in between. */ | |
2695 | if (b->rbi->header) | |
2696 | { | |
a813c111 | 2697 | rtx first = BB_END (a), last; |
bc35512f | 2698 | |
a813c111 | 2699 | last = emit_insn_after (b->rbi->header, BB_END (a)); |
bc35512f JH |
2700 | delete_insn_chain (NEXT_INSN (first), last); |
2701 | b->rbi->header = NULL; | |
2702 | } | |
2703 | ||
2704 | /* In the case basic blocks are not adjacent, move them around. */ | |
a813c111 | 2705 | if (NEXT_INSN (BB_END (a)) != BB_HEAD (b)) |
bc35512f | 2706 | { |
a813c111 | 2707 | rtx first = unlink_insn_chain (BB_HEAD (b), BB_END (b)); |
bc35512f | 2708 | |
a813c111 | 2709 | emit_insn_after (first, BB_END (a)); |
bc35512f JH |
2710 | /* Skip possible DELETED_LABEL insn. */ |
2711 | if (!NOTE_INSN_BASIC_BLOCK_P (first)) | |
2712 | first = NEXT_INSN (first); | |
2713 | if (!NOTE_INSN_BASIC_BLOCK_P (first)) | |
2714 | abort (); | |
a813c111 | 2715 | BB_HEAD (b) = NULL; |
bc35512f JH |
2716 | delete_insn (first); |
2717 | } | |
2718 | /* Otherwise just re-associate the instructions. */ | |
2719 | else | |
2720 | { | |
2721 | rtx insn; | |
2722 | ||
a813c111 SB |
2723 | for (insn = BB_HEAD (b); |
2724 | insn != NEXT_INSN (BB_END (b)); | |
2725 | insn = NEXT_INSN (insn)) | |
bc35512f | 2726 | set_block_for_insn (insn, a); |
a813c111 | 2727 | insn = BB_HEAD (b); |
bc35512f JH |
2728 | /* Skip possible DELETED_LABEL insn. */ |
2729 | if (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
2730 | insn = NEXT_INSN (insn); | |
2731 | if (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
2732 | abort (); | |
a813c111 SB |
2733 | BB_HEAD (b) = NULL; |
2734 | BB_END (a) = BB_END (b); | |
bc35512f JH |
2735 | delete_insn (insn); |
2736 | } | |
2737 | ||
2738 | /* Possible tablejumps and barriers should appear after the block. */ | |
2739 | if (b->rbi->footer) | |
2740 | { | |
2741 | if (!a->rbi->footer) | |
2742 | a->rbi->footer = b->rbi->footer; | |
2743 | else | |
2744 | { | |
2745 | rtx last = a->rbi->footer; | |
2746 | ||
2747 | while (NEXT_INSN (last)) | |
2748 | last = NEXT_INSN (last); | |
2749 | NEXT_INSN (last) = b->rbi->footer; | |
2750 | PREV_INSN (b->rbi->footer) = last; | |
2751 | } | |
2752 | b->rbi->footer = NULL; | |
2753 | } | |
2754 | ||
c263766c RH |
2755 | if (dump_file) |
2756 | fprintf (dump_file, "Merged blocks %d and %d.\n", | |
bc35512f | 2757 | a->index, b->index); |
bc35512f JH |
2758 | } |
2759 | ||
2760 | /* Split edge E. */ | |
f470c378 | 2761 | |
bc35512f JH |
2762 | static basic_block |
2763 | cfg_layout_split_edge (edge e) | |
2764 | { | |
2765 | edge new_e; | |
2766 | basic_block new_bb = | |
2767 | create_basic_block (e->src != ENTRY_BLOCK_PTR | |
a813c111 | 2768 | ? NEXT_INSN (BB_END (e->src)) : get_insns (), |
bc35512f JH |
2769 | NULL_RTX, e->src); |
2770 | ||
bc35512f | 2771 | new_e = make_edge (new_bb, e->dest, EDGE_FALLTHRU); |
bc35512f JH |
2772 | redirect_edge_and_branch_force (e, new_bb); |
2773 | ||
2774 | return new_bb; | |
2775 | } | |
2776 | ||
f470c378 ZD |
2777 | /* Do postprocessing after making a forwarder block joined by edge FALLTHRU. */ |
2778 | ||
2779 | static void | |
2780 | rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED) | |
2781 | { | |
2782 | } | |
2783 | ||
9ee634e3 JH |
2784 | /* Implementation of CFG manipulation for linearized RTL. */ |
2785 | struct cfg_hooks rtl_cfg_hooks = { | |
f470c378 | 2786 | "rtl", |
9ee634e3 | 2787 | rtl_verify_flow_info, |
10e9fecc | 2788 | rtl_dump_bb, |
bc35512f | 2789 | rtl_create_basic_block, |
9ee634e3 JH |
2790 | rtl_redirect_edge_and_branch, |
2791 | rtl_redirect_edge_and_branch_force, | |
2792 | rtl_delete_block, | |
2793 | rtl_split_block, | |
f470c378 | 2794 | rtl_move_block_after, |
bc35512f JH |
2795 | rtl_can_merge_blocks, /* can_merge_blocks_p */ |
2796 | rtl_merge_blocks, | |
f470c378 ZD |
2797 | rtl_split_edge, |
2798 | rtl_make_forwarder_block, | |
2799 | rtl_tidy_fallthru_edge | |
9ee634e3 JH |
2800 | }; |
2801 | ||
2802 | /* Implementation of CFG manipulation for cfg layout RTL, where | |
2803 | basic block connected via fallthru edges does not have to be adjacent. | |
2804 | This representation will hopefully become the default one in future | |
2805 | version of the compiler. */ | |
2806 | struct cfg_hooks cfg_layout_rtl_cfg_hooks = { | |
f470c378 | 2807 | "cfglayout mode", |
bc35512f | 2808 | rtl_verify_flow_info_1, |
10e9fecc | 2809 | rtl_dump_bb, |
bc35512f | 2810 | cfg_layout_create_basic_block, |
9ee634e3 JH |
2811 | cfg_layout_redirect_edge_and_branch, |
2812 | cfg_layout_redirect_edge_and_branch_force, | |
2813 | cfg_layout_delete_block, | |
2814 | cfg_layout_split_block, | |
f470c378 | 2815 | rtl_move_block_after, |
bc35512f JH |
2816 | cfg_layout_can_merge_blocks_p, |
2817 | cfg_layout_merge_blocks, | |
f470c378 ZD |
2818 | cfg_layout_split_edge, |
2819 | rtl_make_forwarder_block, | |
2820 | NULL | |
9ee634e3 | 2821 | }; |