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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 | |
5f0d2358 | 60 | /* Stubs in case we don't have a return insn. */ |
ca6c03ca JH |
61 | #ifndef HAVE_return |
62 | #define HAVE_return 0 | |
63 | #define gen_return() NULL_RTX | |
64 | #endif | |
65 | ||
ca6c03ca JH |
66 | /* The labels mentioned in non-jump rtl. Valid during find_basic_blocks. */ |
67 | /* ??? Should probably be using LABEL_NUSES instead. It would take a | |
68 | bit of surgery to be able to use or co-opt the routines in jump. */ | |
ca6c03ca JH |
69 | rtx label_value_list; |
70 | rtx tail_recursion_label_list; | |
71 | ||
d329e058 AJ |
72 | static int can_delete_note_p (rtx); |
73 | static int can_delete_label_p (rtx); | |
74 | static void commit_one_edge_insertion (edge, int); | |
d329e058 AJ |
75 | static rtx last_loop_beg_note (rtx); |
76 | static bool back_edge_of_syntactic_loop_p (basic_block, basic_block); | |
77 | basic_block force_nonfallthru_and_redirect (edge, basic_block); | |
78 | static basic_block rtl_split_edge (edge); | |
79 | static int rtl_verify_flow_info (void); | |
80 | static edge cfg_layout_split_block (basic_block, void *); | |
81 | static bool cfg_layout_redirect_edge_and_branch (edge, basic_block); | |
82 | static basic_block cfg_layout_redirect_edge_and_branch_force (edge, basic_block); | |
83 | static void cfg_layout_delete_block (basic_block); | |
84 | static void rtl_delete_block (basic_block); | |
85 | static basic_block rtl_redirect_edge_and_branch_force (edge, basic_block); | |
86 | static bool rtl_redirect_edge_and_branch (edge, basic_block); | |
87 | static edge rtl_split_block (basic_block, void *); | |
88 | static void rtl_dump_bb (basic_block, FILE *); | |
89 | static int rtl_verify_flow_info_1 (void); | |
ff25ef99 | 90 | static void mark_killed_regs (rtx, rtx, void *); |
ca6c03ca JH |
91 | \f |
92 | /* Return true if NOTE is not one of the ones that must be kept paired, | |
5f0d2358 | 93 | so that we may simply delete it. */ |
ca6c03ca JH |
94 | |
95 | static int | |
d329e058 | 96 | can_delete_note_p (rtx note) |
ca6c03ca JH |
97 | { |
98 | return (NOTE_LINE_NUMBER (note) == NOTE_INSN_DELETED | |
969d70ca | 99 | || NOTE_LINE_NUMBER (note) == NOTE_INSN_BASIC_BLOCK |
f87c27b4 | 100 | || NOTE_LINE_NUMBER (note) == NOTE_INSN_PREDICTION); |
ca6c03ca JH |
101 | } |
102 | ||
103 | /* True if a given label can be deleted. */ | |
104 | ||
105 | static int | |
d329e058 | 106 | can_delete_label_p (rtx label) |
ca6c03ca | 107 | { |
5f0d2358 RK |
108 | return (!LABEL_PRESERVE_P (label) |
109 | /* User declared labels must be preserved. */ | |
110 | && LABEL_NAME (label) == 0 | |
111 | && !in_expr_list_p (forced_labels, label) | |
6a58eee9 | 112 | && !in_expr_list_p (label_value_list, label)); |
ca6c03ca JH |
113 | } |
114 | ||
115 | /* Delete INSN by patching it out. Return the next insn. */ | |
116 | ||
117 | rtx | |
d329e058 | 118 | delete_insn (rtx insn) |
ca6c03ca JH |
119 | { |
120 | rtx next = NEXT_INSN (insn); | |
121 | rtx note; | |
122 | bool really_delete = true; | |
123 | ||
124 | if (GET_CODE (insn) == CODE_LABEL) | |
125 | { | |
126 | /* Some labels can't be directly removed from the INSN chain, as they | |
f87c27b4 | 127 | might be references via variables, constant pool etc. |
ca6c03ca JH |
128 | Convert them to the special NOTE_INSN_DELETED_LABEL note. */ |
129 | if (! can_delete_label_p (insn)) | |
130 | { | |
131 | const char *name = LABEL_NAME (insn); | |
132 | ||
133 | really_delete = false; | |
134 | PUT_CODE (insn, NOTE); | |
135 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED_LABEL; | |
136 | NOTE_SOURCE_FILE (insn) = name; | |
137 | } | |
5f0d2358 | 138 | |
ca6c03ca JH |
139 | remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels); |
140 | } | |
141 | ||
142 | if (really_delete) | |
143 | { | |
cda94cbb RH |
144 | /* If this insn has already been deleted, something is very wrong. */ |
145 | if (INSN_DELETED_P (insn)) | |
146 | abort (); | |
ca6c03ca JH |
147 | remove_insn (insn); |
148 | INSN_DELETED_P (insn) = 1; | |
149 | } | |
150 | ||
151 | /* If deleting a jump, decrement the use count of the label. Deleting | |
152 | the label itself should happen in the normal course of block merging. */ | |
153 | if (GET_CODE (insn) == JUMP_INSN | |
154 | && JUMP_LABEL (insn) | |
155 | && GET_CODE (JUMP_LABEL (insn)) == CODE_LABEL) | |
156 | LABEL_NUSES (JUMP_LABEL (insn))--; | |
157 | ||
158 | /* Also if deleting an insn that references a label. */ | |
9295a326 JZ |
159 | else |
160 | { | |
161 | while ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)) != NULL_RTX | |
162 | && GET_CODE (XEXP (note, 0)) == CODE_LABEL) | |
163 | { | |
164 | LABEL_NUSES (XEXP (note, 0))--; | |
165 | remove_note (insn, note); | |
166 | } | |
167 | } | |
ca6c03ca JH |
168 | |
169 | if (GET_CODE (insn) == JUMP_INSN | |
170 | && (GET_CODE (PATTERN (insn)) == ADDR_VEC | |
171 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)) | |
172 | { | |
173 | rtx pat = PATTERN (insn); | |
174 | int diff_vec_p = GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC; | |
175 | int len = XVECLEN (pat, diff_vec_p); | |
176 | int i; | |
177 | ||
178 | for (i = 0; i < len; i++) | |
a124fcda RH |
179 | { |
180 | rtx label = XEXP (XVECEXP (pat, diff_vec_p, i), 0); | |
181 | ||
182 | /* When deleting code in bulk (e.g. removing many unreachable | |
183 | blocks) we can delete a label that's a target of the vector | |
184 | before deleting the vector itself. */ | |
185 | if (GET_CODE (label) != NOTE) | |
186 | LABEL_NUSES (label)--; | |
187 | } | |
ca6c03ca JH |
188 | } |
189 | ||
190 | return next; | |
191 | } | |
192 | ||
3dec4024 JH |
193 | /* Like delete_insn but also purge dead edges from BB. */ |
194 | rtx | |
d329e058 | 195 | delete_insn_and_edges (rtx insn) |
3dec4024 JH |
196 | { |
197 | rtx x; | |
198 | bool purge = false; | |
199 | ||
ba4f7968 | 200 | if (INSN_P (insn) |
3dec4024 | 201 | && BLOCK_FOR_INSN (insn) |
a813c111 | 202 | && BB_END (BLOCK_FOR_INSN (insn)) == insn) |
3dec4024 JH |
203 | purge = true; |
204 | x = delete_insn (insn); | |
205 | if (purge) | |
206 | purge_dead_edges (BLOCK_FOR_INSN (insn)); | |
207 | return x; | |
208 | } | |
209 | ||
ca6c03ca JH |
210 | /* Unlink a chain of insns between START and FINISH, leaving notes |
211 | that must be paired. */ | |
212 | ||
213 | void | |
d329e058 | 214 | delete_insn_chain (rtx start, rtx finish) |
ca6c03ca | 215 | { |
ca6c03ca JH |
216 | rtx next; |
217 | ||
5f0d2358 RK |
218 | /* Unchain the insns one by one. It would be quicker to delete all of these |
219 | with a single unchaining, rather than one at a time, but we need to keep | |
220 | the NOTE's. */ | |
ca6c03ca JH |
221 | while (1) |
222 | { | |
223 | next = NEXT_INSN (start); | |
224 | if (GET_CODE (start) == NOTE && !can_delete_note_p (start)) | |
225 | ; | |
226 | else | |
227 | next = delete_insn (start); | |
228 | ||
229 | if (start == finish) | |
230 | break; | |
231 | start = next; | |
232 | } | |
233 | } | |
3dec4024 JH |
234 | |
235 | /* Like delete_insn but also purge dead edges from BB. */ | |
236 | void | |
d329e058 | 237 | delete_insn_chain_and_edges (rtx first, rtx last) |
3dec4024 JH |
238 | { |
239 | bool purge = false; | |
240 | ||
ba4f7968 | 241 | if (INSN_P (last) |
3dec4024 | 242 | && BLOCK_FOR_INSN (last) |
a813c111 | 243 | && BB_END (BLOCK_FOR_INSN (last)) == last) |
3dec4024 JH |
244 | purge = true; |
245 | delete_insn_chain (first, last); | |
246 | if (purge) | |
247 | purge_dead_edges (BLOCK_FOR_INSN (last)); | |
248 | } | |
ca6c03ca | 249 | \f |
5f0d2358 RK |
250 | /* Create a new basic block consisting of the instructions between HEAD and END |
251 | inclusive. This function is designed to allow fast BB construction - reuses | |
252 | the note and basic block struct in BB_NOTE, if any and do not grow | |
253 | BASIC_BLOCK chain and should be used directly only by CFG construction code. | |
254 | END can be NULL in to create new empty basic block before HEAD. Both END | |
918ed612 ZD |
255 | and HEAD can be NULL to create basic block at the end of INSN chain. |
256 | AFTER is the basic block we should be put after. */ | |
ca6c03ca JH |
257 | |
258 | basic_block | |
d329e058 | 259 | create_basic_block_structure (rtx head, rtx end, rtx bb_note, basic_block after) |
ca6c03ca JH |
260 | { |
261 | basic_block bb; | |
262 | ||
263 | if (bb_note | |
264 | && ! RTX_INTEGRATED_P (bb_note) | |
265 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL | |
266 | && bb->aux == NULL) | |
267 | { | |
268 | /* If we found an existing note, thread it back onto the chain. */ | |
269 | ||
270 | rtx after; | |
271 | ||
272 | if (GET_CODE (head) == CODE_LABEL) | |
273 | after = head; | |
274 | else | |
275 | { | |
276 | after = PREV_INSN (head); | |
277 | head = bb_note; | |
278 | } | |
279 | ||
280 | if (after != bb_note && NEXT_INSN (after) != bb_note) | |
ba4f7968 | 281 | reorder_insns_nobb (bb_note, bb_note, after); |
ca6c03ca JH |
282 | } |
283 | else | |
284 | { | |
285 | /* Otherwise we must create a note and a basic block structure. */ | |
286 | ||
287 | bb = alloc_block (); | |
288 | ||
289 | if (!head && !end) | |
5f0d2358 RK |
290 | head = end = bb_note |
291 | = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); | |
ca6c03ca JH |
292 | else if (GET_CODE (head) == CODE_LABEL && end) |
293 | { | |
294 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); | |
295 | if (head == end) | |
296 | end = bb_note; | |
297 | } | |
298 | else | |
299 | { | |
300 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); | |
301 | head = bb_note; | |
302 | if (!end) | |
303 | end = head; | |
304 | } | |
5f0d2358 | 305 | |
ca6c03ca JH |
306 | NOTE_BASIC_BLOCK (bb_note) = bb; |
307 | } | |
308 | ||
309 | /* Always include the bb note in the block. */ | |
310 | if (NEXT_INSN (end) == bb_note) | |
311 | end = bb_note; | |
312 | ||
a813c111 SB |
313 | BB_HEAD (bb) = head; |
314 | BB_END (bb) = end; | |
852c6ec7 | 315 | bb->index = last_basic_block++; |
38c1593d | 316 | bb->flags = BB_NEW; |
918ed612 | 317 | link_block (bb, after); |
852c6ec7 | 318 | BASIC_BLOCK (bb->index) = bb; |
ba4f7968 | 319 | update_bb_for_insn (bb); |
ca6c03ca JH |
320 | |
321 | /* Tag the block so that we know it has been used when considering | |
322 | other basic block notes. */ | |
323 | bb->aux = bb; | |
324 | ||
325 | return bb; | |
326 | } | |
327 | ||
5f0d2358 | 328 | /* Create new basic block consisting of instructions in between HEAD and END |
918ed612 | 329 | and place it to the BB chain after block AFTER. END can be NULL in to |
5f0d2358 RK |
330 | create new empty basic block before HEAD. Both END and HEAD can be NULL to |
331 | create basic block at the end of INSN chain. */ | |
ca6c03ca | 332 | |
bc35512f JH |
333 | static basic_block |
334 | rtl_create_basic_block (void *headp, void *endp, basic_block after) | |
ca6c03ca | 335 | { |
bc35512f | 336 | rtx head = headp, end = endp; |
ca6c03ca | 337 | basic_block bb; |
0b17ab2f | 338 | |
bf77398c | 339 | /* Place the new block just after the end. */ |
852c6ec7 | 340 | VARRAY_GROW (basic_block_info, last_basic_block+1); |
0b17ab2f | 341 | |
bf77398c | 342 | n_basic_blocks++; |
ca6c03ca | 343 | |
852c6ec7 | 344 | bb = create_basic_block_structure (head, end, NULL, after); |
ca6c03ca JH |
345 | bb->aux = NULL; |
346 | return bb; | |
347 | } | |
bc35512f JH |
348 | |
349 | static basic_block | |
350 | cfg_layout_create_basic_block (void *head, void *end, basic_block after) | |
351 | { | |
352 | basic_block newbb = rtl_create_basic_block (head, end, after); | |
353 | ||
354 | cfg_layout_initialize_rbi (newbb); | |
355 | return newbb; | |
356 | } | |
ca6c03ca JH |
357 | \f |
358 | /* Delete the insns in a (non-live) block. We physically delete every | |
359 | non-deleted-note insn, and update the flow graph appropriately. | |
360 | ||
361 | Return nonzero if we deleted an exception handler. */ | |
362 | ||
363 | /* ??? Preserving all such notes strikes me as wrong. It would be nice | |
364 | to post-process the stream to remove empty blocks, loops, ranges, etc. */ | |
365 | ||
f0fda11c | 366 | static void |
d329e058 | 367 | rtl_delete_block (basic_block b) |
ca6c03ca | 368 | { |
ca6c03ca JH |
369 | rtx insn, end, tmp; |
370 | ||
371 | /* If the head of this block is a CODE_LABEL, then it might be the | |
372 | label for an exception handler which can't be reached. | |
373 | ||
374 | We need to remove the label from the exception_handler_label list | |
375 | and remove the associated NOTE_INSN_EH_REGION_BEG and | |
376 | NOTE_INSN_EH_REGION_END notes. */ | |
377 | ||
07532fad RS |
378 | /* Get rid of all NOTE_INSN_PREDICTIONs and NOTE_INSN_LOOP_CONTs |
379 | hanging before the block. */ | |
f87c27b4 | 380 | |
a813c111 | 381 | for (insn = PREV_INSN (BB_HEAD (b)); insn; insn = PREV_INSN (insn)) |
969d70ca JH |
382 | { |
383 | if (GET_CODE (insn) != NOTE) | |
f87c27b4 | 384 | break; |
07532fad RS |
385 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_PREDICTION |
386 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_CONT) | |
f87c27b4 | 387 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; |
969d70ca JH |
388 | } |
389 | ||
a813c111 | 390 | insn = BB_HEAD (b); |
ca6c03ca | 391 | |
a813c111 | 392 | never_reached_warning (insn, BB_END (b)); |
ca6c03ca JH |
393 | |
394 | if (GET_CODE (insn) == CODE_LABEL) | |
395 | maybe_remove_eh_handler (insn); | |
396 | ||
397 | /* Include any jump table following the basic block. */ | |
a813c111 | 398 | end = BB_END (b); |
e1233a7d | 399 | if (tablejump_p (end, NULL, &tmp)) |
ca6c03ca JH |
400 | end = tmp; |
401 | ||
402 | /* Include any barrier that may follow the basic block. */ | |
403 | tmp = next_nonnote_insn (end); | |
404 | if (tmp && GET_CODE (tmp) == BARRIER) | |
405 | end = tmp; | |
406 | ||
407 | /* Selectively delete the entire chain. */ | |
a813c111 | 408 | BB_HEAD (b) = NULL; |
ca6c03ca JH |
409 | delete_insn_chain (insn, end); |
410 | ||
411 | /* Remove the edges into and out of this block. Note that there may | |
412 | indeed be edges in, if we are removing an unreachable loop. */ | |
413 | while (b->pred != NULL) | |
414 | remove_edge (b->pred); | |
415 | while (b->succ != NULL) | |
416 | remove_edge (b->succ); | |
417 | ||
418 | b->pred = NULL; | |
419 | b->succ = NULL; | |
f87c27b4 | 420 | |
bf77398c | 421 | /* Remove the basic block from the array. */ |
ca6c03ca | 422 | expunge_block (b); |
ca6c03ca JH |
423 | } |
424 | \f | |
852c6ec7 | 425 | /* Records the basic block struct in BLOCK_FOR_INSN for every insn. */ |
ca6c03ca JH |
426 | |
427 | void | |
d329e058 | 428 | compute_bb_for_insn (void) |
ca6c03ca | 429 | { |
e0082a72 | 430 | basic_block bb; |
ca6c03ca | 431 | |
e0082a72 | 432 | FOR_EACH_BB (bb) |
ca6c03ca | 433 | { |
a813c111 | 434 | rtx end = BB_END (bb); |
5f0d2358 | 435 | rtx insn; |
ca6c03ca | 436 | |
a813c111 | 437 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
ca6c03ca | 438 | { |
ba4f7968 | 439 | BLOCK_FOR_INSN (insn) = bb; |
ca6c03ca JH |
440 | if (insn == end) |
441 | break; | |
ca6c03ca JH |
442 | } |
443 | } | |
444 | } | |
445 | ||
446 | /* Release the basic_block_for_insn array. */ | |
447 | ||
448 | void | |
d329e058 | 449 | free_bb_for_insn (void) |
ca6c03ca | 450 | { |
ba4f7968 JH |
451 | rtx insn; |
452 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) | |
453 | if (GET_CODE (insn) != BARRIER) | |
454 | BLOCK_FOR_INSN (insn) = NULL; | |
ca6c03ca JH |
455 | } |
456 | ||
457 | /* Update insns block within BB. */ | |
458 | ||
459 | void | |
d329e058 | 460 | update_bb_for_insn (basic_block bb) |
ca6c03ca JH |
461 | { |
462 | rtx insn; | |
463 | ||
a813c111 | 464 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
ca6c03ca | 465 | { |
bcc53e2a JH |
466 | if (GET_CODE (insn) != BARRIER) |
467 | set_block_for_insn (insn, bb); | |
a813c111 | 468 | if (insn == BB_END (bb)) |
ca6c03ca JH |
469 | break; |
470 | } | |
471 | } | |
ca6c03ca JH |
472 | \f |
473 | /* Split a block BB after insn INSN creating a new fallthru edge. | |
474 | Return the new edge. Note that to keep other parts of the compiler happy, | |
475 | this function renumbers all the basic blocks so that the new | |
476 | one has a number one greater than the block split. */ | |
477 | ||
9ee634e3 | 478 | static edge |
d329e058 | 479 | rtl_split_block (basic_block bb, void *insnp) |
ca6c03ca JH |
480 | { |
481 | basic_block new_bb; | |
482 | edge new_edge; | |
483 | edge e; | |
9ee634e3 | 484 | rtx insn = insnp; |
ca6c03ca JH |
485 | |
486 | /* There is no point splitting the block after its end. */ | |
a813c111 | 487 | if (BB_END (bb) == insn) |
ca6c03ca JH |
488 | return 0; |
489 | ||
490 | /* Create the new basic block. */ | |
a813c111 | 491 | new_bb = create_basic_block (NEXT_INSN (insn), BB_END (bb), bb); |
ca6c03ca JH |
492 | new_bb->count = bb->count; |
493 | new_bb->frequency = bb->frequency; | |
494 | new_bb->loop_depth = bb->loop_depth; | |
a813c111 | 495 | BB_END (bb) = insn; |
ca6c03ca JH |
496 | |
497 | /* Redirect the outgoing edges. */ | |
498 | new_bb->succ = bb->succ; | |
499 | bb->succ = NULL; | |
500 | for (e = new_bb->succ; e; e = e->succ_next) | |
501 | e->src = new_bb; | |
502 | ||
503 | new_edge = make_single_succ_edge (bb, new_bb, EDGE_FALLTHRU); | |
504 | ||
505 | if (bb->global_live_at_start) | |
506 | { | |
507 | new_bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
508 | new_bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
509 | COPY_REG_SET (new_bb->global_live_at_end, bb->global_live_at_end); | |
510 | ||
511 | /* We now have to calculate which registers are live at the end | |
512 | of the split basic block and at the start of the new basic | |
513 | block. Start with those registers that are known to be live | |
514 | at the end of the original basic block and get | |
515 | propagate_block to determine which registers are live. */ | |
516 | COPY_REG_SET (new_bb->global_live_at_start, bb->global_live_at_end); | |
517 | propagate_block (new_bb, new_bb->global_live_at_start, NULL, NULL, 0); | |
518 | COPY_REG_SET (bb->global_live_at_end, | |
519 | new_bb->global_live_at_start); | |
0a2ed1f1 JH |
520 | #ifdef HAVE_conditional_execution |
521 | /* In the presence of conditional execution we are not able to update | |
522 | liveness precisely. */ | |
523 | if (reload_completed) | |
524 | { | |
525 | bb->flags |= BB_DIRTY; | |
526 | new_bb->flags |= BB_DIRTY; | |
527 | } | |
528 | #endif | |
ca6c03ca JH |
529 | } |
530 | ||
531 | return new_edge; | |
532 | } | |
533 | ||
bc35512f JH |
534 | /* Assume that the code of basic block B has been merged into A. |
535 | Do corresponding CFG updates: redirect edges accordingly etc. */ | |
536 | static void | |
537 | update_cfg_after_block_merging (basic_block a, basic_block b) | |
538 | { | |
539 | edge e; | |
540 | ||
541 | /* Normally there should only be one successor of A and that is B, but | |
542 | partway though the merge of blocks for conditional_execution we'll | |
543 | be merging a TEST block with THEN and ELSE successors. Free the | |
544 | whole lot of them and hope the caller knows what they're doing. */ | |
545 | while (a->succ) | |
546 | remove_edge (a->succ); | |
547 | ||
548 | /* Adjust the edges out of B for the new owner. */ | |
549 | for (e = b->succ; e; e = e->succ_next) | |
550 | e->src = a; | |
551 | a->succ = b->succ; | |
552 | a->flags |= b->flags; | |
553 | ||
554 | /* B hasn't quite yet ceased to exist. Attempt to prevent mishap. */ | |
555 | b->pred = b->succ = NULL; | |
556 | a->global_live_at_end = b->global_live_at_end; | |
557 | ||
558 | expunge_block (b); | |
559 | } | |
560 | ||
ca6c03ca | 561 | /* Blocks A and B are to be merged into a single block A. The insns |
bc35512f | 562 | are already contiguous. */ |
ca6c03ca | 563 | |
bc35512f JH |
564 | static void |
565 | rtl_merge_blocks (basic_block a, basic_block b) | |
ca6c03ca | 566 | { |
a813c111 | 567 | rtx b_head = BB_HEAD (b), b_end = BB_END (b), a_end = BB_END (a); |
ca6c03ca JH |
568 | rtx del_first = NULL_RTX, del_last = NULL_RTX; |
569 | int b_empty = 0; | |
570 | ||
571 | /* If there was a CODE_LABEL beginning B, delete it. */ | |
ca6c03ca JH |
572 | if (GET_CODE (b_head) == CODE_LABEL) |
573 | { | |
574 | /* Detect basic blocks with nothing but a label. This can happen | |
575 | in particular at the end of a function. */ | |
576 | if (b_head == b_end) | |
577 | b_empty = 1; | |
5f0d2358 | 578 | |
ca6c03ca JH |
579 | del_first = del_last = b_head; |
580 | b_head = NEXT_INSN (b_head); | |
581 | } | |
582 | ||
5f0d2358 RK |
583 | /* Delete the basic block note and handle blocks containing just that |
584 | note. */ | |
ca6c03ca JH |
585 | if (NOTE_INSN_BASIC_BLOCK_P (b_head)) |
586 | { | |
587 | if (b_head == b_end) | |
588 | b_empty = 1; | |
589 | if (! del_last) | |
590 | del_first = b_head; | |
5f0d2358 | 591 | |
ca6c03ca JH |
592 | del_last = b_head; |
593 | b_head = NEXT_INSN (b_head); | |
594 | } | |
595 | ||
596 | /* If there was a jump out of A, delete it. */ | |
ca6c03ca JH |
597 | if (GET_CODE (a_end) == JUMP_INSN) |
598 | { | |
599 | rtx prev; | |
600 | ||
601 | for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev)) | |
602 | if (GET_CODE (prev) != NOTE | |
603 | || NOTE_LINE_NUMBER (prev) == NOTE_INSN_BASIC_BLOCK | |
a813c111 | 604 | || prev == BB_HEAD (a)) |
ca6c03ca JH |
605 | break; |
606 | ||
607 | del_first = a_end; | |
608 | ||
609 | #ifdef HAVE_cc0 | |
610 | /* If this was a conditional jump, we need to also delete | |
611 | the insn that set cc0. */ | |
612 | if (only_sets_cc0_p (prev)) | |
613 | { | |
614 | rtx tmp = prev; | |
5f0d2358 | 615 | |
ca6c03ca JH |
616 | prev = prev_nonnote_insn (prev); |
617 | if (!prev) | |
a813c111 | 618 | prev = BB_HEAD (a); |
ca6c03ca JH |
619 | del_first = tmp; |
620 | } | |
621 | #endif | |
622 | ||
623 | a_end = PREV_INSN (del_first); | |
624 | } | |
625 | else if (GET_CODE (NEXT_INSN (a_end)) == BARRIER) | |
626 | del_first = NEXT_INSN (a_end); | |
627 | ||
bc35512f | 628 | update_cfg_after_block_merging (a, b); |
ca6c03ca JH |
629 | |
630 | /* Delete everything marked above as well as crap that might be | |
631 | hanging out between the two blocks. */ | |
632 | delete_insn_chain (del_first, del_last); | |
633 | ||
634 | /* Reassociate the insns of B with A. */ | |
635 | if (!b_empty) | |
636 | { | |
ba4f7968 | 637 | rtx x; |
5f0d2358 | 638 | |
ba4f7968 JH |
639 | for (x = a_end; x != b_end; x = NEXT_INSN (x)) |
640 | set_block_for_insn (x, a); | |
5f0d2358 | 641 | |
ba4f7968 | 642 | set_block_for_insn (b_end, a); |
5f0d2358 | 643 | |
ca6c03ca JH |
644 | a_end = b_end; |
645 | } | |
5f0d2358 | 646 | |
a813c111 | 647 | BB_END (a) = a_end; |
ca6c03ca | 648 | } |
bc35512f JH |
649 | |
650 | /* Return true when block A and B can be merged. */ | |
651 | static bool | |
652 | rtl_can_merge_blocks (basic_block a,basic_block b) | |
653 | { | |
654 | /* There must be exactly one edge in between the blocks. */ | |
655 | return (a->succ && !a->succ->succ_next && a->succ->dest == b | |
656 | && !b->pred->pred_next && a != b | |
657 | /* Must be simple edge. */ | |
658 | && !(a->succ->flags & EDGE_COMPLEX) | |
659 | && a->next_bb == b | |
660 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR | |
661 | /* If the jump insn has side effects, | |
662 | we can't kill the edge. */ | |
a813c111 | 663 | && (GET_CODE (BB_END (a)) != JUMP_INSN |
e24e7211 | 664 | || (reload_completed |
a813c111 | 665 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f | 666 | } |
ca6c03ca | 667 | \f |
5f0d2358 RK |
668 | /* Return the label in the head of basic block BLOCK. Create one if it doesn't |
669 | exist. */ | |
ca6c03ca JH |
670 | |
671 | rtx | |
d329e058 | 672 | block_label (basic_block block) |
ca6c03ca JH |
673 | { |
674 | if (block == EXIT_BLOCK_PTR) | |
675 | return NULL_RTX; | |
5f0d2358 | 676 | |
a813c111 | 677 | if (GET_CODE (BB_HEAD (block)) != CODE_LABEL) |
ca6c03ca | 678 | { |
a813c111 | 679 | BB_HEAD (block) = emit_label_before (gen_label_rtx (), BB_HEAD (block)); |
ca6c03ca | 680 | } |
5f0d2358 | 681 | |
a813c111 | 682 | return BB_HEAD (block); |
ca6c03ca JH |
683 | } |
684 | ||
685 | /* Attempt to perform edge redirection by replacing possibly complex jump | |
5f0d2358 RK |
686 | instruction by unconditional jump or removing jump completely. This can |
687 | apply only if all edges now point to the same block. The parameters and | |
688 | return values are equivalent to redirect_edge_and_branch. */ | |
ca6c03ca | 689 | |
3348b696 | 690 | bool |
bc35512f | 691 | try_redirect_by_replacing_jump (edge e, basic_block target, bool in_cfglayout) |
ca6c03ca JH |
692 | { |
693 | basic_block src = e->src; | |
a813c111 | 694 | rtx insn = BB_END (src), kill_from; |
ca6c03ca | 695 | edge tmp; |
e1233a7d | 696 | rtx set; |
ca6c03ca JH |
697 | int fallthru = 0; |
698 | ||
699 | /* Verify that all targets will be TARGET. */ | |
700 | for (tmp = src->succ; tmp; tmp = tmp->succ_next) | |
701 | if (tmp->dest != target && tmp != e) | |
702 | break; | |
5f0d2358 | 703 | |
ca6c03ca JH |
704 | if (tmp || !onlyjump_p (insn)) |
705 | return false; | |
3348b696 | 706 | if ((!optimize || reload_completed) && tablejump_p (insn, NULL, NULL)) |
1b6763cf | 707 | return false; |
ca6c03ca JH |
708 | |
709 | /* Avoid removing branch with side effects. */ | |
710 | set = single_set (insn); | |
711 | if (!set || side_effects_p (set)) | |
712 | return false; | |
713 | ||
714 | /* In case we zap a conditional jump, we'll need to kill | |
715 | the cc0 setter too. */ | |
716 | kill_from = insn; | |
717 | #ifdef HAVE_cc0 | |
718 | if (reg_mentioned_p (cc0_rtx, PATTERN (insn))) | |
719 | kill_from = PREV_INSN (insn); | |
720 | #endif | |
721 | ||
722 | /* See if we can create the fallthru edge. */ | |
bc35512f | 723 | if (in_cfglayout || can_fallthru (src, target)) |
ca6c03ca JH |
724 | { |
725 | if (rtl_dump_file) | |
726 | fprintf (rtl_dump_file, "Removing jump %i.\n", INSN_UID (insn)); | |
727 | fallthru = 1; | |
728 | ||
eaec9b3d | 729 | /* Selectively unlink whole insn chain. */ |
bc35512f JH |
730 | if (in_cfglayout) |
731 | { | |
732 | rtx insn = src->rbi->footer; | |
733 | ||
a813c111 | 734 | delete_insn_chain (kill_from, BB_END (src)); |
bc35512f JH |
735 | |
736 | /* Remove barriers but keep jumptables. */ | |
737 | while (insn) | |
738 | { | |
739 | if (GET_CODE (insn) == BARRIER) | |
740 | { | |
741 | if (PREV_INSN (insn)) | |
742 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
743 | else | |
744 | src->rbi->footer = NEXT_INSN (insn); | |
745 | if (NEXT_INSN (insn)) | |
746 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
747 | } | |
748 | if (GET_CODE (insn) == CODE_LABEL) | |
749 | break; | |
750 | insn = NEXT_INSN (insn); | |
751 | } | |
752 | } | |
753 | else | |
a813c111 | 754 | delete_insn_chain (kill_from, PREV_INSN (BB_HEAD (target))); |
ca6c03ca | 755 | } |
5f0d2358 | 756 | |
ca6c03ca JH |
757 | /* If this already is simplejump, redirect it. */ |
758 | else if (simplejump_p (insn)) | |
759 | { | |
760 | if (e->dest == target) | |
761 | return false; | |
762 | if (rtl_dump_file) | |
763 | fprintf (rtl_dump_file, "Redirecting jump %i from %i to %i.\n", | |
0b17ab2f | 764 | INSN_UID (insn), e->dest->index, target->index); |
6ee3c8e4 JJ |
765 | if (!redirect_jump (insn, block_label (target), 0)) |
766 | { | |
767 | if (target == EXIT_BLOCK_PTR) | |
768 | return false; | |
769 | abort (); | |
770 | } | |
ca6c03ca | 771 | } |
5f0d2358 | 772 | |
6ee3c8e4 JJ |
773 | /* Cannot do anything for target exit block. */ |
774 | else if (target == EXIT_BLOCK_PTR) | |
775 | return false; | |
776 | ||
ca6c03ca JH |
777 | /* Or replace possibly complicated jump insn by simple jump insn. */ |
778 | else | |
779 | { | |
780 | rtx target_label = block_label (target); | |
eb5b8ad4 | 781 | rtx barrier, label, table; |
ca6c03ca | 782 | |
09eb1aab | 783 | emit_jump_insn_after (gen_jump (target_label), insn); |
a813c111 | 784 | JUMP_LABEL (BB_END (src)) = target_label; |
ca6c03ca JH |
785 | LABEL_NUSES (target_label)++; |
786 | if (rtl_dump_file) | |
787 | fprintf (rtl_dump_file, "Replacing insn %i by jump %i\n", | |
a813c111 | 788 | INSN_UID (insn), INSN_UID (BB_END (src))); |
ca6c03ca | 789 | |
4da2eb6b | 790 | |
ca6c03ca JH |
791 | delete_insn_chain (kill_from, insn); |
792 | ||
4da2eb6b RH |
793 | /* Recognize a tablejump that we are converting to a |
794 | simple jump and remove its associated CODE_LABEL | |
795 | and ADDR_VEC or ADDR_DIFF_VEC. */ | |
3348b696 | 796 | if (tablejump_p (insn, &label, &table)) |
4da2eb6b | 797 | delete_insn_chain (label, table); |
eb5b8ad4 | 798 | |
a813c111 | 799 | barrier = next_nonnote_insn (BB_END (src)); |
ca6c03ca | 800 | if (!barrier || GET_CODE (barrier) != BARRIER) |
a813c111 | 801 | emit_barrier_after (BB_END (src)); |
5d693491 JZ |
802 | else |
803 | { | |
a813c111 | 804 | if (barrier != NEXT_INSN (BB_END (src))) |
5d693491 JZ |
805 | { |
806 | /* Move the jump before barrier so that the notes | |
807 | which originally were or were created before jump table are | |
808 | inside the basic block. */ | |
a813c111 | 809 | rtx new_insn = BB_END (src); |
5d693491 JZ |
810 | rtx tmp; |
811 | ||
a813c111 | 812 | for (tmp = NEXT_INSN (BB_END (src)); tmp != barrier; |
5d693491 JZ |
813 | tmp = NEXT_INSN (tmp)) |
814 | set_block_for_insn (tmp, src); | |
815 | ||
816 | NEXT_INSN (PREV_INSN (new_insn)) = NEXT_INSN (new_insn); | |
817 | PREV_INSN (NEXT_INSN (new_insn)) = PREV_INSN (new_insn); | |
818 | ||
819 | NEXT_INSN (new_insn) = barrier; | |
820 | NEXT_INSN (PREV_INSN (barrier)) = new_insn; | |
821 | ||
822 | PREV_INSN (new_insn) = PREV_INSN (barrier); | |
823 | PREV_INSN (barrier) = new_insn; | |
824 | } | |
825 | } | |
ca6c03ca JH |
826 | } |
827 | ||
828 | /* Keep only one edge out and set proper flags. */ | |
829 | while (src->succ->succ_next) | |
830 | remove_edge (src->succ); | |
831 | e = src->succ; | |
832 | if (fallthru) | |
833 | e->flags = EDGE_FALLTHRU; | |
834 | else | |
835 | e->flags = 0; | |
5f0d2358 | 836 | |
ca6c03ca JH |
837 | e->probability = REG_BR_PROB_BASE; |
838 | e->count = src->count; | |
839 | ||
840 | /* We don't want a block to end on a line-number note since that has | |
841 | the potential of changing the code between -g and not -g. */ | |
a813c111 SB |
842 | while (GET_CODE (BB_END (e->src)) == NOTE |
843 | && NOTE_LINE_NUMBER (BB_END (e->src)) >= 0) | |
844 | delete_insn (BB_END (e->src)); | |
ca6c03ca JH |
845 | |
846 | if (e->dest != target) | |
847 | redirect_edge_succ (e, target); | |
5f0d2358 | 848 | |
ca6c03ca JH |
849 | return true; |
850 | } | |
851 | ||
852 | /* Return last loop_beg note appearing after INSN, before start of next | |
853 | basic block. Return INSN if there are no such notes. | |
854 | ||
09da1532 | 855 | When emitting jump to redirect a fallthru edge, it should always appear |
5f0d2358 RK |
856 | after the LOOP_BEG notes, as loop optimizer expect loop to either start by |
857 | fallthru edge or jump following the LOOP_BEG note jumping to the loop exit | |
858 | test. */ | |
ca6c03ca JH |
859 | |
860 | static rtx | |
d329e058 | 861 | last_loop_beg_note (rtx insn) |
ca6c03ca JH |
862 | { |
863 | rtx last = insn; | |
5f0d2358 RK |
864 | |
865 | for (insn = NEXT_INSN (insn); insn && GET_CODE (insn) == NOTE | |
866 | && NOTE_LINE_NUMBER (insn) != NOTE_INSN_BASIC_BLOCK; | |
867 | insn = NEXT_INSN (insn)) | |
868 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
869 | last = insn; | |
870 | ||
ca6c03ca JH |
871 | return last; |
872 | } | |
873 | ||
bc35512f | 874 | /* Redirect edge representing branch of (un)conditional jump or tablejump. */ |
9ee634e3 | 875 | static bool |
bc35512f | 876 | redirect_branch_edge (edge e, basic_block target) |
ca6c03ca JH |
877 | { |
878 | rtx tmp; | |
a813c111 | 879 | rtx old_label = BB_HEAD (e->dest); |
ca6c03ca | 880 | basic_block src = e->src; |
a813c111 | 881 | rtx insn = BB_END (src); |
ca6c03ca | 882 | |
ca6c03ca JH |
883 | /* We can only redirect non-fallthru edges of jump insn. */ |
884 | if (e->flags & EDGE_FALLTHRU) | |
885 | return false; | |
5f0d2358 | 886 | else if (GET_CODE (insn) != JUMP_INSN) |
ca6c03ca JH |
887 | return false; |
888 | ||
889 | /* Recognize a tablejump and adjust all matching cases. */ | |
e1233a7d | 890 | if (tablejump_p (insn, NULL, &tmp)) |
ca6c03ca JH |
891 | { |
892 | rtvec vec; | |
893 | int j; | |
894 | rtx new_label = block_label (target); | |
895 | ||
6ee3c8e4 JJ |
896 | if (target == EXIT_BLOCK_PTR) |
897 | return false; | |
ca6c03ca JH |
898 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) |
899 | vec = XVEC (PATTERN (tmp), 0); | |
900 | else | |
901 | vec = XVEC (PATTERN (tmp), 1); | |
902 | ||
903 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
904 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
905 | { | |
906 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (Pmode, new_label); | |
907 | --LABEL_NUSES (old_label); | |
908 | ++LABEL_NUSES (new_label); | |
909 | } | |
910 | ||
f9da5064 | 911 | /* Handle casesi dispatch insns. */ |
ca6c03ca JH |
912 | if ((tmp = single_set (insn)) != NULL |
913 | && SET_DEST (tmp) == pc_rtx | |
914 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
915 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF | |
916 | && XEXP (XEXP (SET_SRC (tmp), 2), 0) == old_label) | |
917 | { | |
918 | XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (VOIDmode, | |
919 | new_label); | |
920 | --LABEL_NUSES (old_label); | |
921 | ++LABEL_NUSES (new_label); | |
922 | } | |
923 | } | |
924 | else | |
925 | { | |
926 | /* ?? We may play the games with moving the named labels from | |
927 | one basic block to the other in case only one computed_jump is | |
928 | available. */ | |
5f0d2358 RK |
929 | if (computed_jump_p (insn) |
930 | /* A return instruction can't be redirected. */ | |
931 | || returnjump_p (insn)) | |
ca6c03ca JH |
932 | return false; |
933 | ||
934 | /* If the insn doesn't go where we think, we're confused. */ | |
6ee3c8e4 | 935 | if (JUMP_LABEL (insn) != old_label) |
a3623c48 | 936 | abort (); |
6ee3c8e4 JJ |
937 | |
938 | /* If the substitution doesn't succeed, die. This can happen | |
939 | if the back end emitted unrecognizable instructions or if | |
940 | target is exit block on some arches. */ | |
941 | if (!redirect_jump (insn, block_label (target), 0)) | |
942 | { | |
943 | if (target == EXIT_BLOCK_PTR) | |
944 | return false; | |
945 | abort (); | |
946 | } | |
ca6c03ca JH |
947 | } |
948 | ||
949 | if (rtl_dump_file) | |
950 | fprintf (rtl_dump_file, "Edge %i->%i redirected to %i\n", | |
0b17ab2f | 951 | e->src->index, e->dest->index, target->index); |
5f0d2358 | 952 | |
ca6c03ca JH |
953 | if (e->dest != target) |
954 | redirect_edge_succ_nodup (e, target); | |
bc35512f JH |
955 | return true; |
956 | } | |
957 | ||
958 | /* Attempt to change code to redirect edge E to TARGET. Don't do that on | |
959 | expense of adding new instructions or reordering basic blocks. | |
960 | ||
961 | Function can be also called with edge destination equivalent to the TARGET. | |
962 | Then it should try the simplifications and do nothing if none is possible. | |
963 | ||
964 | Return true if transformation succeeded. We still return false in case E | |
965 | already destinated TARGET and we didn't managed to simplify instruction | |
966 | stream. */ | |
967 | ||
968 | static bool | |
5671bf27 | 969 | rtl_redirect_edge_and_branch (edge e, basic_block target) |
bc35512f JH |
970 | { |
971 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) | |
972 | return false; | |
973 | ||
3348b696 JH |
974 | if (e->dest == target) |
975 | return true; | |
976 | ||
bc35512f JH |
977 | if (try_redirect_by_replacing_jump (e, target, false)) |
978 | return true; | |
979 | ||
3348b696 | 980 | if (!redirect_branch_edge (e, target)) |
bc35512f | 981 | return false; |
5f0d2358 | 982 | |
ca6c03ca JH |
983 | return true; |
984 | } | |
985 | ||
4fe9b91c | 986 | /* Like force_nonfallthru below, but additionally performs redirection |
ca6c03ca JH |
987 | Used by redirect_edge_and_branch_force. */ |
988 | ||
cb9a1d9b | 989 | basic_block |
d329e058 | 990 | force_nonfallthru_and_redirect (edge e, basic_block target) |
ca6c03ca | 991 | { |
a3716585 | 992 | basic_block jump_block, new_bb = NULL, src = e->src; |
ca6c03ca JH |
993 | rtx note; |
994 | edge new_edge; | |
a3716585 | 995 | int abnormal_edge_flags = 0; |
ca6c03ca | 996 | |
cb9a1d9b JH |
997 | /* In the case the last instruction is conditional jump to the next |
998 | instruction, first redirect the jump itself and then continue | |
b20b352b | 999 | by creating a basic block afterwards to redirect fallthru edge. */ |
cb9a1d9b | 1000 | if (e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR |
a813c111 | 1001 | && any_condjump_p (BB_END (e->src)) |
cde1d5bf | 1002 | /* When called from cfglayout, fallthru edges do not |
e0bb17a8 | 1003 | necessarily go to the next block. */ |
cde1d5bf | 1004 | && e->src->next_bb == e->dest |
a813c111 | 1005 | && JUMP_LABEL (BB_END (e->src)) == BB_HEAD (e->dest)) |
cb9a1d9b JH |
1006 | { |
1007 | rtx note; | |
58e6ae30 | 1008 | edge b = unchecked_make_edge (e->src, target, 0); |
cb9a1d9b | 1009 | |
a813c111 | 1010 | if (!redirect_jump (BB_END (e->src), block_label (target), 0)) |
cb9a1d9b | 1011 | abort (); |
a813c111 | 1012 | note = find_reg_note (BB_END (e->src), REG_BR_PROB, NULL_RTX); |
cb9a1d9b JH |
1013 | if (note) |
1014 | { | |
1015 | int prob = INTVAL (XEXP (note, 0)); | |
1016 | ||
1017 | b->probability = prob; | |
1018 | b->count = e->count * prob / REG_BR_PROB_BASE; | |
1019 | e->probability -= e->probability; | |
1020 | e->count -= b->count; | |
1021 | if (e->probability < 0) | |
1022 | e->probability = 0; | |
1023 | if (e->count < 0) | |
1024 | e->count = 0; | |
1025 | } | |
1026 | } | |
1027 | ||
ca6c03ca | 1028 | if (e->flags & EDGE_ABNORMAL) |
a3716585 JH |
1029 | { |
1030 | /* Irritating special case - fallthru edge to the same block as abnormal | |
1031 | edge. | |
1032 | We can't redirect abnormal edge, but we still can split the fallthru | |
d329e058 | 1033 | one and create separate abnormal edge to original destination. |
a3716585 JH |
1034 | This allows bb-reorder to make such edge non-fallthru. */ |
1035 | if (e->dest != target) | |
1036 | abort (); | |
1037 | abnormal_edge_flags = e->flags & ~(EDGE_FALLTHRU | EDGE_CAN_FALLTHRU); | |
1038 | e->flags &= EDGE_FALLTHRU | EDGE_CAN_FALLTHRU; | |
1039 | } | |
5f0d2358 | 1040 | else if (!(e->flags & EDGE_FALLTHRU)) |
ca6c03ca | 1041 | abort (); |
24c545ff BS |
1042 | else if (e->src == ENTRY_BLOCK_PTR) |
1043 | { | |
1044 | /* We can't redirect the entry block. Create an empty block at the | |
1045 | start of the function which we use to add the new jump. */ | |
1046 | edge *pe1; | |
a813c111 | 1047 | basic_block bb = create_basic_block (BB_HEAD (e->dest), NULL, ENTRY_BLOCK_PTR); |
24c545ff BS |
1048 | |
1049 | /* Change the existing edge's source to be the new block, and add | |
1050 | a new edge from the entry block to the new block. */ | |
1051 | e->src = bb; | |
1052 | for (pe1 = &ENTRY_BLOCK_PTR->succ; *pe1; pe1 = &(*pe1)->succ_next) | |
1053 | if (*pe1 == e) | |
1054 | { | |
1055 | *pe1 = e->succ_next; | |
1056 | break; | |
1057 | } | |
1058 | e->succ_next = 0; | |
1059 | bb->succ = e; | |
1060 | make_single_succ_edge (ENTRY_BLOCK_PTR, bb, EDGE_FALLTHRU); | |
1061 | } | |
1062 | ||
a3716585 | 1063 | if (e->src->succ->succ_next || abnormal_edge_flags) |
ca6c03ca JH |
1064 | { |
1065 | /* Create the new structures. */ | |
31a78298 | 1066 | |
79019985 RH |
1067 | /* If the old block ended with a tablejump, skip its table |
1068 | by searching forward from there. Otherwise start searching | |
1069 | forward from the last instruction of the old block. */ | |
a813c111 SB |
1070 | if (!tablejump_p (BB_END (e->src), NULL, ¬e)) |
1071 | note = BB_END (e->src); | |
79019985 | 1072 | |
31a78298 | 1073 | /* Position the new block correctly relative to loop notes. */ |
79019985 | 1074 | note = last_loop_beg_note (note); |
31a78298 RH |
1075 | note = NEXT_INSN (note); |
1076 | ||
31a78298 | 1077 | jump_block = create_basic_block (note, NULL, e->src); |
ca6c03ca JH |
1078 | jump_block->count = e->count; |
1079 | jump_block->frequency = EDGE_FREQUENCY (e); | |
1080 | jump_block->loop_depth = target->loop_depth; | |
1081 | ||
1082 | if (target->global_live_at_start) | |
1083 | { | |
5f0d2358 RK |
1084 | jump_block->global_live_at_start |
1085 | = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
1086 | jump_block->global_live_at_end | |
1087 | = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
ca6c03ca JH |
1088 | COPY_REG_SET (jump_block->global_live_at_start, |
1089 | target->global_live_at_start); | |
1090 | COPY_REG_SET (jump_block->global_live_at_end, | |
1091 | target->global_live_at_start); | |
1092 | } | |
1093 | ||
1094 | /* Wire edge in. */ | |
1095 | new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU); | |
1096 | new_edge->probability = e->probability; | |
1097 | new_edge->count = e->count; | |
1098 | ||
1099 | /* Redirect old edge. */ | |
1100 | redirect_edge_pred (e, jump_block); | |
1101 | e->probability = REG_BR_PROB_BASE; | |
1102 | ||
1103 | new_bb = jump_block; | |
1104 | } | |
1105 | else | |
1106 | jump_block = e->src; | |
5f0d2358 | 1107 | |
ca6c03ca JH |
1108 | e->flags &= ~EDGE_FALLTHRU; |
1109 | if (target == EXIT_BLOCK_PTR) | |
1110 | { | |
1111 | if (HAVE_return) | |
a813c111 | 1112 | emit_jump_insn_after (gen_return (), BB_END (jump_block)); |
ca6c03ca JH |
1113 | else |
1114 | abort (); | |
1115 | } | |
1116 | else | |
1117 | { | |
1118 | rtx label = block_label (target); | |
a813c111 SB |
1119 | emit_jump_insn_after (gen_jump (label), BB_END (jump_block)); |
1120 | JUMP_LABEL (BB_END (jump_block)) = label; | |
ca6c03ca JH |
1121 | LABEL_NUSES (label)++; |
1122 | } | |
5f0d2358 | 1123 | |
a813c111 | 1124 | emit_barrier_after (BB_END (jump_block)); |
ca6c03ca JH |
1125 | redirect_edge_succ_nodup (e, target); |
1126 | ||
a3716585 JH |
1127 | if (abnormal_edge_flags) |
1128 | make_edge (src, target, abnormal_edge_flags); | |
1129 | ||
ca6c03ca JH |
1130 | return new_bb; |
1131 | } | |
1132 | ||
1133 | /* Edge E is assumed to be fallthru edge. Emit needed jump instruction | |
1134 | (and possibly create new basic block) to make edge non-fallthru. | |
1135 | Return newly created BB or NULL if none. */ | |
5f0d2358 | 1136 | |
ca6c03ca | 1137 | basic_block |
d329e058 | 1138 | force_nonfallthru (edge e) |
ca6c03ca JH |
1139 | { |
1140 | return force_nonfallthru_and_redirect (e, e->dest); | |
1141 | } | |
1142 | ||
1143 | /* Redirect edge even at the expense of creating new jump insn or | |
1144 | basic block. Return new basic block if created, NULL otherwise. | |
eaec9b3d | 1145 | Abort if conversion is impossible. */ |
ca6c03ca | 1146 | |
9ee634e3 | 1147 | static basic_block |
d329e058 | 1148 | rtl_redirect_edge_and_branch_force (edge e, basic_block target) |
ca6c03ca | 1149 | { |
5f0d2358 RK |
1150 | if (redirect_edge_and_branch (e, target) |
1151 | || e->dest == target) | |
ca6c03ca JH |
1152 | return NULL; |
1153 | ||
1154 | /* In case the edge redirection failed, try to force it to be non-fallthru | |
1155 | and redirect newly created simplejump. */ | |
5f0d2358 | 1156 | return force_nonfallthru_and_redirect (e, target); |
ca6c03ca JH |
1157 | } |
1158 | ||
1159 | /* The given edge should potentially be a fallthru edge. If that is in | |
1160 | fact true, delete the jump and barriers that are in the way. */ | |
1161 | ||
1162 | void | |
d329e058 | 1163 | tidy_fallthru_edge (edge e, basic_block b, basic_block c) |
ca6c03ca JH |
1164 | { |
1165 | rtx q; | |
1166 | ||
1167 | /* ??? In a late-running flow pass, other folks may have deleted basic | |
1168 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
1169 | and the target label. They ought to be chastized and fixed. | |
1170 | ||
1171 | We can also wind up with a sequence of undeletable labels between | |
1172 | one block and the next. | |
1173 | ||
1174 | So search through a sequence of barriers, labels, and notes for | |
1175 | the head of block C and assert that we really do fall through. */ | |
1176 | ||
a813c111 | 1177 | for (q = NEXT_INSN (BB_END (b)); q != BB_HEAD (c); q = NEXT_INSN (q)) |
9c0a0632 RH |
1178 | if (INSN_P (q)) |
1179 | return; | |
ca6c03ca JH |
1180 | |
1181 | /* Remove what will soon cease being the jump insn from the source block. | |
1182 | If block B consisted only of this single jump, turn it into a deleted | |
1183 | note. */ | |
a813c111 | 1184 | q = BB_END (b); |
ca6c03ca JH |
1185 | if (GET_CODE (q) == JUMP_INSN |
1186 | && onlyjump_p (q) | |
1187 | && (any_uncondjump_p (q) | |
1188 | || (b->succ == e && e->succ_next == NULL))) | |
1189 | { | |
1190 | #ifdef HAVE_cc0 | |
1191 | /* If this was a conditional jump, we need to also delete | |
1192 | the insn that set cc0. */ | |
1193 | if (any_condjump_p (q) && only_sets_cc0_p (PREV_INSN (q))) | |
1194 | q = PREV_INSN (q); | |
1195 | #endif | |
1196 | ||
1197 | q = PREV_INSN (q); | |
1198 | ||
1199 | /* We don't want a block to end on a line-number note since that has | |
1200 | the potential of changing the code between -g and not -g. */ | |
1201 | while (GET_CODE (q) == NOTE && NOTE_LINE_NUMBER (q) >= 0) | |
1202 | q = PREV_INSN (q); | |
1203 | } | |
1204 | ||
1205 | /* Selectively unlink the sequence. */ | |
a813c111 SB |
1206 | if (q != PREV_INSN (BB_HEAD (c))) |
1207 | delete_insn_chain (NEXT_INSN (q), PREV_INSN (BB_HEAD (c))); | |
ca6c03ca JH |
1208 | |
1209 | e->flags |= EDGE_FALLTHRU; | |
1210 | } | |
1211 | ||
1212 | /* Fix up edges that now fall through, or rather should now fall through | |
1213 | but previously required a jump around now deleted blocks. Simplify | |
1214 | the search by only examining blocks numerically adjacent, since this | |
1215 | is how find_basic_blocks created them. */ | |
1216 | ||
1217 | void | |
d329e058 | 1218 | tidy_fallthru_edges (void) |
ca6c03ca | 1219 | { |
e0082a72 ZD |
1220 | basic_block b, c; |
1221 | ||
1222 | if (ENTRY_BLOCK_PTR->next_bb == EXIT_BLOCK_PTR) | |
1223 | return; | |
ca6c03ca | 1224 | |
e0082a72 | 1225 | FOR_BB_BETWEEN (b, ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR->prev_bb, next_bb) |
ca6c03ca | 1226 | { |
ca6c03ca JH |
1227 | edge s; |
1228 | ||
e0082a72 ZD |
1229 | c = b->next_bb; |
1230 | ||
ca6c03ca JH |
1231 | /* We care about simple conditional or unconditional jumps with |
1232 | a single successor. | |
1233 | ||
1234 | If we had a conditional branch to the next instruction when | |
1235 | find_basic_blocks was called, then there will only be one | |
1236 | out edge for the block which ended with the conditional | |
1237 | branch (since we do not create duplicate edges). | |
1238 | ||
1239 | Furthermore, the edge will be marked as a fallthru because we | |
1240 | merge the flags for the duplicate edges. So we do not want to | |
1241 | check that the edge is not a FALLTHRU edge. */ | |
5f0d2358 | 1242 | |
ca6c03ca JH |
1243 | if ((s = b->succ) != NULL |
1244 | && ! (s->flags & EDGE_COMPLEX) | |
1245 | && s->succ_next == NULL | |
1246 | && s->dest == c | |
1247 | /* If the jump insn has side effects, we can't tidy the edge. */ | |
a813c111 SB |
1248 | && (GET_CODE (BB_END (b)) != JUMP_INSN |
1249 | || onlyjump_p (BB_END (b)))) | |
ca6c03ca JH |
1250 | tidy_fallthru_edge (s, b, c); |
1251 | } | |
1252 | } | |
1253 | \f | |
1254 | /* Helper function for split_edge. Return true in case edge BB2 to BB1 | |
1255 | is back edge of syntactic loop. */ | |
1256 | ||
1257 | static bool | |
d329e058 | 1258 | back_edge_of_syntactic_loop_p (basic_block bb1, basic_block bb2) |
ca6c03ca JH |
1259 | { |
1260 | rtx insn; | |
1261 | int count = 0; | |
bf77398c | 1262 | basic_block bb; |
ca6c03ca | 1263 | |
bf77398c | 1264 | if (bb1 == bb2) |
0b17ab2f | 1265 | return true; |
355e4ec4 | 1266 | |
bf77398c ZD |
1267 | /* ??? Could we guarantee that bb indices are monotone, so that we could |
1268 | just compare them? */ | |
1269 | for (bb = bb1; bb && bb != bb2; bb = bb->next_bb) | |
1270 | continue; | |
1271 | ||
1272 | if (!bb) | |
1273 | return false; | |
1274 | ||
a813c111 | 1275 | for (insn = BB_END (bb1); insn != BB_HEAD (bb2) && count >= 0; |
ca6c03ca JH |
1276 | insn = NEXT_INSN (insn)) |
1277 | if (GET_CODE (insn) == NOTE) | |
1278 | { | |
1279 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
1280 | count++; | |
5f0d2358 | 1281 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) |
ca6c03ca JH |
1282 | count--; |
1283 | } | |
1284 | ||
1285 | return count >= 0; | |
1286 | } | |
1287 | ||
1288 | /* Split a (typically critical) edge. Return the new block. | |
1289 | Abort on abnormal edges. | |
1290 | ||
1291 | ??? The code generally expects to be called on critical edges. | |
1292 | The case of a block ending in an unconditional jump to a | |
1293 | block with multiple predecessors is not handled optimally. */ | |
1294 | ||
8ce33230 | 1295 | static basic_block |
d329e058 | 1296 | rtl_split_edge (edge edge_in) |
ca6c03ca JH |
1297 | { |
1298 | basic_block bb; | |
ca6c03ca JH |
1299 | rtx before; |
1300 | ||
1301 | /* Abnormal edges cannot be split. */ | |
1302 | if ((edge_in->flags & EDGE_ABNORMAL) != 0) | |
1303 | abort (); | |
1304 | ||
1305 | /* We are going to place the new block in front of edge destination. | |
eaec9b3d | 1306 | Avoid existence of fallthru predecessors. */ |
ca6c03ca JH |
1307 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) |
1308 | { | |
1309 | edge e; | |
5f0d2358 | 1310 | |
ca6c03ca JH |
1311 | for (e = edge_in->dest->pred; e; e = e->pred_next) |
1312 | if (e->flags & EDGE_FALLTHRU) | |
1313 | break; | |
1314 | ||
1315 | if (e) | |
1316 | force_nonfallthru (e); | |
1317 | } | |
1318 | ||
1319 | /* Create the basic block note. | |
1320 | ||
f63d1bf7 | 1321 | Where we place the note can have a noticeable impact on the generated |
ca6c03ca JH |
1322 | code. Consider this cfg: |
1323 | ||
1324 | E | |
1325 | | | |
1326 | 0 | |
1327 | / \ | |
1328 | +->1-->2--->E | |
1329 | | | | |
1330 | +--+ | |
1331 | ||
1332 | If we need to insert an insn on the edge from block 0 to block 1, | |
1333 | we want to ensure the instructions we insert are outside of any | |
1334 | loop notes that physically sit between block 0 and block 1. Otherwise | |
1335 | we confuse the loop optimizer into thinking the loop is a phony. */ | |
1336 | ||
1337 | if (edge_in->dest != EXIT_BLOCK_PTR | |
a813c111 SB |
1338 | && PREV_INSN (BB_HEAD (edge_in->dest)) |
1339 | && GET_CODE (PREV_INSN (BB_HEAD (edge_in->dest))) == NOTE | |
1340 | && (NOTE_LINE_NUMBER (PREV_INSN (BB_HEAD (edge_in->dest))) | |
5f0d2358 | 1341 | == NOTE_INSN_LOOP_BEG) |
ca6c03ca | 1342 | && !back_edge_of_syntactic_loop_p (edge_in->dest, edge_in->src)) |
a813c111 | 1343 | before = PREV_INSN (BB_HEAD (edge_in->dest)); |
ca6c03ca | 1344 | else if (edge_in->dest != EXIT_BLOCK_PTR) |
a813c111 | 1345 | before = BB_HEAD (edge_in->dest); |
ca6c03ca JH |
1346 | else |
1347 | before = NULL_RTX; | |
1348 | ||
918ed612 | 1349 | bb = create_basic_block (before, NULL, edge_in->dest->prev_bb); |
ca6c03ca JH |
1350 | bb->count = edge_in->count; |
1351 | bb->frequency = EDGE_FREQUENCY (edge_in); | |
1352 | ||
1353 | /* ??? This info is likely going to be out of date very soon. */ | |
1354 | if (edge_in->dest->global_live_at_start) | |
1355 | { | |
1356 | bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
1357 | bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
5f0d2358 RK |
1358 | COPY_REG_SET (bb->global_live_at_start, |
1359 | edge_in->dest->global_live_at_start); | |
1360 | COPY_REG_SET (bb->global_live_at_end, | |
1361 | edge_in->dest->global_live_at_start); | |
ca6c03ca JH |
1362 | } |
1363 | ||
4977bab6 | 1364 | make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU); |
ca6c03ca | 1365 | |
4d6922ee | 1366 | /* For non-fallthru edges, we must adjust the predecessor's |
ca6c03ca JH |
1367 | jump instruction to target our new block. */ |
1368 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1369 | { | |
1370 | if (!redirect_edge_and_branch (edge_in, bb)) | |
1371 | abort (); | |
1372 | } | |
1373 | else | |
1374 | redirect_edge_succ (edge_in, bb); | |
1375 | ||
1376 | return bb; | |
1377 | } | |
1378 | ||
1379 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1380 | The new instructions and basic blocks (if any) will not appear in the | |
1381 | CFG until commit_edge_insertions is called. */ | |
1382 | ||
1383 | void | |
d329e058 | 1384 | insert_insn_on_edge (rtx pattern, edge e) |
ca6c03ca JH |
1385 | { |
1386 | /* We cannot insert instructions on an abnormal critical edge. | |
1387 | It will be easier to find the culprit if we die now. */ | |
1388 | if ((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e)) | |
1389 | abort (); | |
1390 | ||
1391 | if (e->insns == NULL_RTX) | |
1392 | start_sequence (); | |
1393 | else | |
1394 | push_to_sequence (e->insns); | |
1395 | ||
1396 | emit_insn (pattern); | |
1397 | ||
1398 | e->insns = get_insns (); | |
1399 | end_sequence (); | |
1400 | } | |
1401 | ||
ff25ef99 ZD |
1402 | /* Called from safe_insert_insn_on_edge through note_stores, marks live |
1403 | registers that are killed by the store. */ | |
1404 | static void | |
1405 | mark_killed_regs (rtx reg, rtx set ATTRIBUTE_UNUSED, void *data) | |
1406 | { | |
1407 | regset killed = data; | |
1408 | int regno, i; | |
1409 | ||
1410 | if (GET_CODE (reg) == SUBREG) | |
1411 | reg = SUBREG_REG (reg); | |
1412 | if (!REG_P (reg)) | |
1413 | return; | |
1414 | regno = REGNO (reg); | |
1415 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1416 | SET_REGNO_REG_SET (killed, regno); | |
1417 | else | |
1418 | { | |
73383a81 | 1419 | for (i = 0; i < (int) HARD_REGNO_NREGS (regno, GET_MODE (reg)); i++) |
ff25ef99 ZD |
1420 | SET_REGNO_REG_SET (killed, regno + i); |
1421 | } | |
1422 | } | |
1423 | ||
1424 | /* Similar to insert_insn_on_edge, tries to put INSN to edge E. Additionally | |
1425 | it checks whether this will not clobber the registers that are live on the | |
e0bb17a8 | 1426 | edge (i.e. it requires liveness information to be up-to-date) and if there |
ff25ef99 | 1427 | are some, then it tries to save and restore them. Returns true if |
e0bb17a8 | 1428 | successful. */ |
ff25ef99 ZD |
1429 | bool |
1430 | safe_insert_insn_on_edge (rtx insn, edge e) | |
1431 | { | |
1432 | rtx x; | |
1433 | regset_head killed_head; | |
1434 | regset killed = INITIALIZE_REG_SET (killed_head); | |
1435 | rtx save_regs = NULL_RTX; | |
1436 | int regno, noccmode; | |
1437 | enum machine_mode mode; | |
1438 | ||
1439 | #ifdef AVOID_CCMODE_COPIES | |
1440 | noccmode = true; | |
1441 | #else | |
1442 | noccmode = false; | |
1443 | #endif | |
1444 | ||
1445 | for (x = insn; x; x = NEXT_INSN (x)) | |
1446 | if (INSN_P (x)) | |
1447 | note_stores (PATTERN (x), mark_killed_regs, killed); | |
1448 | bitmap_operation (killed, killed, e->dest->global_live_at_start, | |
1449 | BITMAP_AND); | |
1450 | ||
1451 | EXECUTE_IF_SET_IN_REG_SET (killed, 0, regno, | |
1452 | { | |
1453 | mode = regno < FIRST_PSEUDO_REGISTER | |
1454 | ? reg_raw_mode[regno] | |
1455 | : GET_MODE (regno_reg_rtx[regno]); | |
1456 | if (mode == VOIDmode) | |
1457 | return false; | |
1458 | ||
1459 | if (noccmode && mode == CCmode) | |
1460 | return false; | |
1461 | ||
1462 | save_regs = alloc_EXPR_LIST (0, | |
1463 | alloc_EXPR_LIST (0, | |
1464 | gen_reg_rtx (mode), | |
1465 | gen_raw_REG (mode, regno)), | |
1466 | save_regs); | |
1467 | }); | |
1468 | ||
1469 | if (save_regs) | |
1470 | { | |
1471 | rtx from, to; | |
1472 | ||
1473 | start_sequence (); | |
1474 | for (x = save_regs; x; x = XEXP (x, 1)) | |
1475 | { | |
1476 | from = XEXP (XEXP (x, 0), 1); | |
1477 | to = XEXP (XEXP (x, 0), 0); | |
1478 | emit_move_insn (to, from); | |
1479 | } | |
1480 | emit_insn (insn); | |
1481 | for (x = save_regs; x; x = XEXP (x, 1)) | |
1482 | { | |
1483 | from = XEXP (XEXP (x, 0), 0); | |
1484 | to = XEXP (XEXP (x, 0), 1); | |
1485 | emit_move_insn (to, from); | |
1486 | } | |
1487 | insn = get_insns (); | |
1488 | end_sequence (); | |
1489 | free_EXPR_LIST_list (&save_regs); | |
1490 | } | |
1491 | insert_insn_on_edge (insn, e); | |
1492 | ||
1493 | FREE_REG_SET (killed); | |
1494 | return true; | |
1495 | } | |
1496 | ||
ca6c03ca JH |
1497 | /* Update the CFG for the instructions queued on edge E. */ |
1498 | ||
1499 | static void | |
d329e058 | 1500 | commit_one_edge_insertion (edge e, int watch_calls) |
ca6c03ca JH |
1501 | { |
1502 | rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last; | |
eae4bc56 | 1503 | basic_block bb = NULL; |
ca6c03ca JH |
1504 | |
1505 | /* Pull the insns off the edge now since the edge might go away. */ | |
1506 | insns = e->insns; | |
1507 | e->insns = NULL_RTX; | |
1508 | ||
3dec4024 JH |
1509 | /* Special case -- avoid inserting code between call and storing |
1510 | its return value. */ | |
1511 | if (watch_calls && (e->flags & EDGE_FALLTHRU) && !e->dest->pred->pred_next | |
1512 | && e->src != ENTRY_BLOCK_PTR | |
a813c111 | 1513 | && GET_CODE (BB_END (e->src)) == CALL_INSN) |
ca6c03ca | 1514 | { |
a813c111 | 1515 | rtx next = next_nonnote_insn (BB_END (e->src)); |
ca6c03ca | 1516 | |
a813c111 | 1517 | after = BB_HEAD (e->dest); |
3dec4024 JH |
1518 | /* The first insn after the call may be a stack pop, skip it. */ |
1519 | while (next | |
1520 | && keep_with_call_p (next)) | |
f87c27b4 KH |
1521 | { |
1522 | after = next; | |
3dec4024 JH |
1523 | next = next_nonnote_insn (next); |
1524 | } | |
1525 | bb = e->dest; | |
ca6c03ca | 1526 | } |
3dec4024 | 1527 | if (!before && !after) |
ca6c03ca | 1528 | { |
3dec4024 JH |
1529 | /* Figure out where to put these things. If the destination has |
1530 | one predecessor, insert there. Except for the exit block. */ | |
1531 | if (e->dest->pred->pred_next == NULL && e->dest != EXIT_BLOCK_PTR) | |
ca6c03ca | 1532 | { |
3dec4024 JH |
1533 | bb = e->dest; |
1534 | ||
1535 | /* Get the location correct wrt a code label, and "nice" wrt | |
1536 | a basic block note, and before everything else. */ | |
a813c111 | 1537 | tmp = BB_HEAD (bb); |
3dec4024 JH |
1538 | if (GET_CODE (tmp) == CODE_LABEL) |
1539 | tmp = NEXT_INSN (tmp); | |
1540 | if (NOTE_INSN_BASIC_BLOCK_P (tmp)) | |
1541 | tmp = NEXT_INSN (tmp); | |
a813c111 | 1542 | if (tmp == BB_HEAD (bb)) |
3dec4024 JH |
1543 | before = tmp; |
1544 | else if (tmp) | |
1545 | after = PREV_INSN (tmp); | |
1546 | else | |
1547 | after = get_last_insn (); | |
1548 | } | |
1549 | ||
1550 | /* If the source has one successor and the edge is not abnormal, | |
1551 | insert there. Except for the entry block. */ | |
1552 | else if ((e->flags & EDGE_ABNORMAL) == 0 | |
1553 | && e->src->succ->succ_next == NULL | |
1554 | && e->src != ENTRY_BLOCK_PTR) | |
1555 | { | |
1556 | bb = e->src; | |
1557 | ||
1558 | /* It is possible to have a non-simple jump here. Consider a target | |
1559 | where some forms of unconditional jumps clobber a register. This | |
1560 | happens on the fr30 for example. | |
1561 | ||
1562 | We know this block has a single successor, so we can just emit | |
1563 | the queued insns before the jump. */ | |
a813c111 SB |
1564 | if (GET_CODE (BB_END (bb)) == JUMP_INSN) |
1565 | for (before = BB_END (bb); | |
3dec4024 JH |
1566 | GET_CODE (PREV_INSN (before)) == NOTE |
1567 | && NOTE_LINE_NUMBER (PREV_INSN (before)) == | |
1568 | NOTE_INSN_LOOP_BEG; before = PREV_INSN (before)) | |
1569 | ; | |
1570 | else | |
1571 | { | |
1572 | /* We'd better be fallthru, or we've lost track of what's what. */ | |
1573 | if ((e->flags & EDGE_FALLTHRU) == 0) | |
1574 | abort (); | |
ca6c03ca | 1575 | |
a813c111 | 1576 | after = BB_END (bb); |
3dec4024 JH |
1577 | } |
1578 | } | |
1579 | /* Otherwise we must split the edge. */ | |
1580 | else | |
1581 | { | |
1582 | bb = split_edge (e); | |
a813c111 | 1583 | after = BB_END (bb); |
ca6c03ca JH |
1584 | } |
1585 | } | |
1586 | ||
ca6c03ca JH |
1587 | /* Now that we've found the spot, do the insertion. */ |
1588 | ||
1589 | if (before) | |
1590 | { | |
2f937369 | 1591 | emit_insn_before (insns, before); |
ca6c03ca JH |
1592 | last = prev_nonnote_insn (before); |
1593 | } | |
1594 | else | |
2f937369 | 1595 | last = emit_insn_after (insns, after); |
ca6c03ca JH |
1596 | |
1597 | if (returnjump_p (last)) | |
1598 | { | |
1599 | /* ??? Remove all outgoing edges from BB and add one for EXIT. | |
1600 | This is not currently a problem because this only happens | |
3dec4024 JH |
1601 | for the (single) epilogue, which already has a fallthru edge |
1602 | to EXIT. */ | |
ca6c03ca JH |
1603 | |
1604 | e = bb->succ; | |
1605 | if (e->dest != EXIT_BLOCK_PTR | |
3dec4024 | 1606 | || e->succ_next != NULL || (e->flags & EDGE_FALLTHRU) == 0) |
ca6c03ca | 1607 | abort (); |
ca6c03ca | 1608 | |
5f0d2358 | 1609 | e->flags &= ~EDGE_FALLTHRU; |
ca6c03ca | 1610 | emit_barrier_after (last); |
0b17ab2f | 1611 | |
ca6c03ca JH |
1612 | if (before) |
1613 | delete_insn (before); | |
1614 | } | |
1615 | else if (GET_CODE (last) == JUMP_INSN) | |
1616 | abort (); | |
5f0d2358 | 1617 | |
9dca2ad5 JH |
1618 | /* Mark the basic block for find_sub_basic_blocks. */ |
1619 | bb->aux = &bb->aux; | |
ca6c03ca JH |
1620 | } |
1621 | ||
1622 | /* Update the CFG for all queued instructions. */ | |
1623 | ||
1624 | void | |
d329e058 | 1625 | commit_edge_insertions (void) |
ca6c03ca | 1626 | { |
ca6c03ca | 1627 | basic_block bb; |
9dca2ad5 | 1628 | sbitmap blocks; |
9809a362 | 1629 | bool changed = false; |
ca6c03ca JH |
1630 | |
1631 | #ifdef ENABLE_CHECKING | |
1632 | verify_flow_info (); | |
1633 | #endif | |
1634 | ||
e0082a72 | 1635 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
ca6c03ca JH |
1636 | { |
1637 | edge e, next; | |
1638 | ||
1639 | for (e = bb->succ; e; e = next) | |
1640 | { | |
1641 | next = e->succ_next; | |
1642 | if (e->insns) | |
9809a362 JH |
1643 | { |
1644 | changed = true; | |
1645 | commit_one_edge_insertion (e, false); | |
1646 | } | |
3dec4024 | 1647 | } |
3dec4024 | 1648 | } |
9dca2ad5 | 1649 | |
9809a362 JH |
1650 | if (!changed) |
1651 | return; | |
1652 | ||
9dca2ad5 JH |
1653 | blocks = sbitmap_alloc (last_basic_block); |
1654 | sbitmap_zero (blocks); | |
1655 | FOR_EACH_BB (bb) | |
1656 | if (bb->aux) | |
1657 | { | |
1658 | SET_BIT (blocks, bb->index); | |
1659 | /* Check for forgotten bb->aux values before commit_edge_insertions | |
1660 | call. */ | |
1661 | if (bb->aux != &bb->aux) | |
1662 | abort (); | |
1663 | bb->aux = NULL; | |
1664 | } | |
1665 | find_many_sub_basic_blocks (blocks); | |
1666 | sbitmap_free (blocks); | |
3dec4024 JH |
1667 | } |
1668 | \f | |
1669 | /* Update the CFG for all queued instructions, taking special care of inserting | |
1670 | code on edges between call and storing its return value. */ | |
1671 | ||
1672 | void | |
d329e058 | 1673 | commit_edge_insertions_watch_calls (void) |
3dec4024 | 1674 | { |
3dec4024 | 1675 | basic_block bb; |
9809a362 JH |
1676 | sbitmap blocks; |
1677 | bool changed = false; | |
3dec4024 JH |
1678 | |
1679 | #ifdef ENABLE_CHECKING | |
1680 | verify_flow_info (); | |
1681 | #endif | |
1682 | ||
e0082a72 | 1683 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
3dec4024 JH |
1684 | { |
1685 | edge e, next; | |
1686 | ||
1687 | for (e = bb->succ; e; e = next) | |
1688 | { | |
1689 | next = e->succ_next; | |
1690 | if (e->insns) | |
9809a362 JH |
1691 | { |
1692 | changed = true; | |
1693 | commit_one_edge_insertion (e, true); | |
1694 | } | |
ca6c03ca | 1695 | } |
ca6c03ca | 1696 | } |
9809a362 JH |
1697 | |
1698 | if (!changed) | |
1699 | return; | |
1700 | ||
1701 | blocks = sbitmap_alloc (last_basic_block); | |
1702 | sbitmap_zero (blocks); | |
1703 | FOR_EACH_BB (bb) | |
1704 | if (bb->aux) | |
1705 | { | |
1706 | SET_BIT (blocks, bb->index); | |
1707 | /* Check for forgotten bb->aux values before commit_edge_insertions | |
1708 | call. */ | |
1709 | if (bb->aux != &bb->aux) | |
1710 | abort (); | |
1711 | bb->aux = NULL; | |
1712 | } | |
1713 | find_many_sub_basic_blocks (blocks); | |
1714 | sbitmap_free (blocks); | |
ca6c03ca JH |
1715 | } |
1716 | \f | |
1717 | /* Print out one basic block with live information at start and end. */ | |
1718 | ||
10e9fecc | 1719 | static void |
d329e058 | 1720 | rtl_dump_bb (basic_block bb, FILE *outf) |
ca6c03ca JH |
1721 | { |
1722 | rtx insn; | |
1723 | rtx last; | |
ca6c03ca JH |
1724 | |
1725 | fputs (";; Registers live at start:", outf); | |
1726 | dump_regset (bb->global_live_at_start, outf); | |
1727 | putc ('\n', outf); | |
1728 | ||
a813c111 | 1729 | for (insn = BB_HEAD (bb), last = NEXT_INSN (BB_END (bb)); insn != last; |
ca6c03ca JH |
1730 | insn = NEXT_INSN (insn)) |
1731 | print_rtl_single (outf, insn); | |
1732 | ||
1733 | fputs (";; Registers live at end:", outf); | |
1734 | dump_regset (bb->global_live_at_end, outf); | |
1735 | putc ('\n', outf); | |
ca6c03ca JH |
1736 | } |
1737 | \f | |
1738 | /* Like print_rtl, but also print out live information for the start of each | |
1739 | basic block. */ | |
1740 | ||
1741 | void | |
d329e058 | 1742 | print_rtl_with_bb (FILE *outf, rtx rtx_first) |
ca6c03ca | 1743 | { |
b3694847 | 1744 | rtx tmp_rtx; |
ca6c03ca JH |
1745 | |
1746 | if (rtx_first == 0) | |
1747 | fprintf (outf, "(nil)\n"); | |
1748 | else | |
1749 | { | |
ca6c03ca JH |
1750 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
1751 | int max_uid = get_max_uid (); | |
703ad42b KG |
1752 | basic_block *start = xcalloc (max_uid, sizeof (basic_block)); |
1753 | basic_block *end = xcalloc (max_uid, sizeof (basic_block)); | |
1754 | enum bb_state *in_bb_p = xcalloc (max_uid, sizeof (enum bb_state)); | |
ca6c03ca | 1755 | |
e0082a72 ZD |
1756 | basic_block bb; |
1757 | ||
1758 | FOR_EACH_BB_REVERSE (bb) | |
ca6c03ca | 1759 | { |
ca6c03ca JH |
1760 | rtx x; |
1761 | ||
a813c111 SB |
1762 | start[INSN_UID (BB_HEAD (bb))] = bb; |
1763 | end[INSN_UID (BB_END (bb))] = bb; | |
1764 | for (x = BB_HEAD (bb); x != NULL_RTX; x = NEXT_INSN (x)) | |
ca6c03ca JH |
1765 | { |
1766 | enum bb_state state = IN_MULTIPLE_BB; | |
5f0d2358 | 1767 | |
ca6c03ca JH |
1768 | if (in_bb_p[INSN_UID (x)] == NOT_IN_BB) |
1769 | state = IN_ONE_BB; | |
1770 | in_bb_p[INSN_UID (x)] = state; | |
1771 | ||
a813c111 | 1772 | if (x == BB_END (bb)) |
ca6c03ca JH |
1773 | break; |
1774 | } | |
1775 | } | |
1776 | ||
1777 | for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) | |
1778 | { | |
1779 | int did_output; | |
ca6c03ca JH |
1780 | |
1781 | if ((bb = start[INSN_UID (tmp_rtx)]) != NULL) | |
1782 | { | |
1783 | fprintf (outf, ";; Start of basic block %d, registers live:", | |
0b17ab2f | 1784 | bb->index); |
ca6c03ca JH |
1785 | dump_regset (bb->global_live_at_start, outf); |
1786 | putc ('\n', outf); | |
1787 | } | |
1788 | ||
1789 | if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB | |
1790 | && GET_CODE (tmp_rtx) != NOTE | |
1791 | && GET_CODE (tmp_rtx) != BARRIER) | |
1792 | fprintf (outf, ";; Insn is not within a basic block\n"); | |
1793 | else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB) | |
1794 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); | |
1795 | ||
1796 | did_output = print_rtl_single (outf, tmp_rtx); | |
1797 | ||
1798 | if ((bb = end[INSN_UID (tmp_rtx)]) != NULL) | |
1799 | { | |
1800 | fprintf (outf, ";; End of basic block %d, registers live:\n", | |
0b17ab2f | 1801 | bb->index); |
ca6c03ca JH |
1802 | dump_regset (bb->global_live_at_end, outf); |
1803 | putc ('\n', outf); | |
1804 | } | |
1805 | ||
1806 | if (did_output) | |
1807 | putc ('\n', outf); | |
1808 | } | |
1809 | ||
1810 | free (start); | |
1811 | free (end); | |
1812 | free (in_bb_p); | |
1813 | } | |
1814 | ||
1815 | if (current_function_epilogue_delay_list != 0) | |
1816 | { | |
1817 | fprintf (outf, "\n;; Insns in epilogue delay list:\n\n"); | |
1818 | for (tmp_rtx = current_function_epilogue_delay_list; tmp_rtx != 0; | |
1819 | tmp_rtx = XEXP (tmp_rtx, 1)) | |
1820 | print_rtl_single (outf, XEXP (tmp_rtx, 0)); | |
1821 | } | |
1822 | } | |
1823 | \f | |
b446e5a2 | 1824 | void |
d329e058 | 1825 | update_br_prob_note (basic_block bb) |
b446e5a2 JH |
1826 | { |
1827 | rtx note; | |
a813c111 | 1828 | if (GET_CODE (BB_END (bb)) != JUMP_INSN) |
b446e5a2 | 1829 | return; |
a813c111 | 1830 | note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX); |
b446e5a2 JH |
1831 | if (!note || INTVAL (XEXP (note, 0)) == BRANCH_EDGE (bb)->probability) |
1832 | return; | |
1833 | XEXP (note, 0) = GEN_INT (BRANCH_EDGE (bb)->probability); | |
1834 | } | |
1835 | \f | |
10e9fecc JH |
1836 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
1837 | cfglayout RTL. | |
ca6c03ca JH |
1838 | |
1839 | Currently it does following checks: | |
1840 | ||
1841 | - test head/end pointers | |
1842 | - overlapping of basic blocks | |
ca6c03ca | 1843 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) |
f63d1bf7 | 1844 | - tails of basic blocks (ensure that boundary is necessary) |
ca6c03ca JH |
1845 | - scans body of the basic block for JUMP_INSN, CODE_LABEL |
1846 | and NOTE_INSN_BASIC_BLOCK | |
ca6c03ca JH |
1847 | |
1848 | In future it can be extended check a lot of other stuff as well | |
1849 | (reachability of basic blocks, life information, etc. etc.). */ | |
10e9fecc | 1850 | static int |
d329e058 | 1851 | rtl_verify_flow_info_1 (void) |
ca6c03ca JH |
1852 | { |
1853 | const int max_uid = get_max_uid (); | |
ca6c03ca | 1854 | rtx last_head = get_last_insn (); |
10e9fecc | 1855 | basic_block *bb_info; |
ca6c03ca | 1856 | rtx x; |
10e9fecc | 1857 | int err = 0; |
918ed612 | 1858 | basic_block bb, last_bb_seen; |
ca6c03ca | 1859 | |
703ad42b | 1860 | bb_info = xcalloc (max_uid, sizeof (basic_block)); |
ca6c03ca | 1861 | |
918ed612 ZD |
1862 | /* Check bb chain & numbers. */ |
1863 | last_bb_seen = ENTRY_BLOCK_PTR; | |
918ed612 | 1864 | |
e0082a72 | 1865 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1866 | { |
a813c111 SB |
1867 | rtx head = BB_HEAD (bb); |
1868 | rtx end = BB_END (bb); | |
ca6c03ca JH |
1869 | |
1870 | /* Verify the end of the basic block is in the INSN chain. */ | |
1871 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) | |
1872 | if (x == end) | |
1873 | break; | |
5f0d2358 | 1874 | |
ca6c03ca JH |
1875 | if (!x) |
1876 | { | |
1f978f5f | 1877 | error ("end insn %d for block %d not found in the insn stream", |
0b17ab2f | 1878 | INSN_UID (end), bb->index); |
ca6c03ca JH |
1879 | err = 1; |
1880 | } | |
1881 | ||
1882 | /* Work backwards from the end to the head of the basic block | |
1883 | to verify the head is in the RTL chain. */ | |
1884 | for (; x != NULL_RTX; x = PREV_INSN (x)) | |
1885 | { | |
1886 | /* While walking over the insn chain, verify insns appear | |
1887 | in only one basic block and initialize the BB_INFO array | |
1888 | used by other passes. */ | |
1889 | if (bb_info[INSN_UID (x)] != NULL) | |
1890 | { | |
1f978f5f | 1891 | error ("insn %d is in multiple basic blocks (%d and %d)", |
0b17ab2f | 1892 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); |
ca6c03ca JH |
1893 | err = 1; |
1894 | } | |
5f0d2358 | 1895 | |
ca6c03ca JH |
1896 | bb_info[INSN_UID (x)] = bb; |
1897 | ||
1898 | if (x == head) | |
1899 | break; | |
1900 | } | |
1901 | if (!x) | |
1902 | { | |
1f978f5f | 1903 | error ("head insn %d for block %d not found in the insn stream", |
0b17ab2f | 1904 | INSN_UID (head), bb->index); |
ca6c03ca JH |
1905 | err = 1; |
1906 | } | |
1907 | ||
1908 | last_head = x; | |
1909 | } | |
1910 | ||
1911 | /* Now check the basic blocks (boundaries etc.) */ | |
e0082a72 | 1912 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1913 | { |
3dec4024 | 1914 | int n_fallthru = 0, n_eh = 0, n_call = 0, n_abnormal = 0, n_branch = 0; |
3cf54412 | 1915 | edge e, fallthru = NULL; |
5a1a3e5e | 1916 | rtx note; |
ca6c03ca | 1917 | |
a813c111 SB |
1918 | if (INSN_P (BB_END (bb)) |
1919 | && (note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX)) | |
3e638a90 | 1920 | && bb->succ && bb->succ->succ_next |
a813c111 | 1921 | && any_condjump_p (BB_END (bb))) |
5a1a3e5e | 1922 | { |
5a1a3e5e JH |
1923 | if (INTVAL (XEXP (note, 0)) != BRANCH_EDGE (bb)->probability) |
1924 | { | |
0108ae51 | 1925 | error ("verify_flow_info: REG_BR_PROB does not match cfg %wi %i", |
5a1a3e5e JH |
1926 | INTVAL (XEXP (note, 0)), BRANCH_EDGE (bb)->probability); |
1927 | err = 1; | |
1928 | } | |
1929 | } | |
5f0d2358 | 1930 | for (e = bb->succ; e; e = e->succ_next) |
ca6c03ca | 1931 | { |
ca6c03ca | 1932 | if (e->flags & EDGE_FALLTHRU) |
3cf54412 | 1933 | n_fallthru++, fallthru = e; |
3dec4024 | 1934 | |
65f43cdf ZD |
1935 | if ((e->flags & ~(EDGE_DFS_BACK |
1936 | | EDGE_CAN_FALLTHRU | |
1937 | | EDGE_IRREDUCIBLE_LOOP | |
1938 | | EDGE_LOOP_EXIT)) == 0) | |
3dec4024 JH |
1939 | n_branch++; |
1940 | ||
1941 | if (e->flags & EDGE_ABNORMAL_CALL) | |
1942 | n_call++; | |
1943 | ||
1944 | if (e->flags & EDGE_EH) | |
1945 | n_eh++; | |
1946 | else if (e->flags & EDGE_ABNORMAL) | |
1947 | n_abnormal++; | |
ca6c03ca | 1948 | } |
5f0d2358 | 1949 | |
a813c111 SB |
1950 | if (n_eh && GET_CODE (PATTERN (BB_END (bb))) != RESX |
1951 | && !find_reg_note (BB_END (bb), REG_EH_REGION, NULL_RTX)) | |
3dec4024 | 1952 | { |
0b17ab2f | 1953 | error ("Missing REG_EH_REGION note in the end of bb %i", bb->index); |
3dec4024 JH |
1954 | err = 1; |
1955 | } | |
1956 | if (n_branch | |
a813c111 SB |
1957 | && (GET_CODE (BB_END (bb)) != JUMP_INSN |
1958 | || (n_branch > 1 && (any_uncondjump_p (BB_END (bb)) | |
1959 | || any_condjump_p (BB_END (bb)))))) | |
3dec4024 | 1960 | { |
0b17ab2f | 1961 | error ("Too many outgoing branch edges from bb %i", bb->index); |
3dec4024 JH |
1962 | err = 1; |
1963 | } | |
a813c111 | 1964 | if (n_fallthru && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 1965 | { |
0b17ab2f | 1966 | error ("Fallthru edge after unconditional jump %i", bb->index); |
3dec4024 JH |
1967 | err = 1; |
1968 | } | |
a813c111 | 1969 | if (n_branch != 1 && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 1970 | { |
0b17ab2f | 1971 | error ("Wrong amount of branch edges after unconditional jump %i", bb->index); |
3dec4024 JH |
1972 | err = 1; |
1973 | } | |
a813c111 SB |
1974 | if (n_branch != 1 && any_condjump_p (BB_END (bb)) |
1975 | && JUMP_LABEL (BB_END (bb)) != BB_HEAD (fallthru->dest)) | |
3dec4024 | 1976 | { |
0b17ab2f | 1977 | error ("Wrong amount of branch edges after conditional jump %i", bb->index); |
3dec4024 JH |
1978 | err = 1; |
1979 | } | |
a813c111 | 1980 | if (n_call && GET_CODE (BB_END (bb)) != CALL_INSN) |
3dec4024 | 1981 | { |
0b17ab2f | 1982 | error ("Call edges for non-call insn in bb %i", bb->index); |
3dec4024 JH |
1983 | err = 1; |
1984 | } | |
1985 | if (n_abnormal | |
a813c111 SB |
1986 | && (GET_CODE (BB_END (bb)) != CALL_INSN && n_call != n_abnormal) |
1987 | && (GET_CODE (BB_END (bb)) != JUMP_INSN | |
1988 | || any_condjump_p (BB_END (bb)) | |
1989 | || any_uncondjump_p (BB_END (bb)))) | |
3dec4024 | 1990 | { |
0b17ab2f | 1991 | error ("Abnormal edges for no purpose in bb %i", bb->index); |
3dec4024 JH |
1992 | err = 1; |
1993 | } | |
f87c27b4 | 1994 | |
a813c111 | 1995 | for (x = BB_HEAD (bb); x != NEXT_INSN (BB_END (bb)); x = NEXT_INSN (x)) |
ba4f7968 | 1996 | if (BLOCK_FOR_INSN (x) != bb) |
5f0d2358 RK |
1997 | { |
1998 | debug_rtx (x); | |
1999 | if (! BLOCK_FOR_INSN (x)) | |
2000 | error | |
2001 | ("insn %d inside basic block %d but block_for_insn is NULL", | |
0b17ab2f | 2002 | INSN_UID (x), bb->index); |
5f0d2358 RK |
2003 | else |
2004 | error | |
2005 | ("insn %d inside basic block %d but block_for_insn is %i", | |
0b17ab2f | 2006 | INSN_UID (x), bb->index, BLOCK_FOR_INSN (x)->index); |
5f0d2358 RK |
2007 | |
2008 | err = 1; | |
2009 | } | |
ca6c03ca JH |
2010 | |
2011 | /* OK pointers are correct. Now check the header of basic | |
2012 | block. It ought to contain optional CODE_LABEL followed | |
2013 | by NOTE_BASIC_BLOCK. */ | |
a813c111 | 2014 | x = BB_HEAD (bb); |
ca6c03ca JH |
2015 | if (GET_CODE (x) == CODE_LABEL) |
2016 | { | |
a813c111 | 2017 | if (BB_END (bb) == x) |
ca6c03ca JH |
2018 | { |
2019 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 2020 | bb->index); |
ca6c03ca JH |
2021 | err = 1; |
2022 | } | |
5f0d2358 | 2023 | |
ca6c03ca JH |
2024 | x = NEXT_INSN (x); |
2025 | } | |
5f0d2358 | 2026 | |
ca6c03ca JH |
2027 | if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb) |
2028 | { | |
2029 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 2030 | bb->index); |
ca6c03ca JH |
2031 | err = 1; |
2032 | } | |
2033 | ||
a813c111 | 2034 | if (BB_END (bb) == x) |
5f0d2358 RK |
2035 | /* Do checks for empty blocks her. e */ |
2036 | ; | |
ca6c03ca | 2037 | else |
5f0d2358 RK |
2038 | for (x = NEXT_INSN (x); x; x = NEXT_INSN (x)) |
2039 | { | |
2040 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2041 | { | |
2042 | error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d", | |
0b17ab2f | 2043 | INSN_UID (x), bb->index); |
5f0d2358 RK |
2044 | err = 1; |
2045 | } | |
2046 | ||
a813c111 | 2047 | if (x == BB_END (bb)) |
5f0d2358 | 2048 | break; |
ca6c03ca | 2049 | |
83fd323c | 2050 | if (control_flow_insn_p (x)) |
5f0d2358 | 2051 | { |
0b17ab2f | 2052 | error ("in basic block %d:", bb->index); |
5f0d2358 RK |
2053 | fatal_insn ("flow control insn inside a basic block", x); |
2054 | } | |
2055 | } | |
ca6c03ca JH |
2056 | } |
2057 | ||
10e9fecc JH |
2058 | /* Clean up. */ |
2059 | free (bb_info); | |
2060 | return err; | |
2061 | } | |
5f0d2358 | 2062 | |
10e9fecc JH |
2063 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
2064 | cfglayout RTL. | |
5f0d2358 | 2065 | |
10e9fecc JH |
2066 | Currently it does following checks: |
2067 | - all checks of rtl_verify_flow_info_1 | |
2068 | - check that all insns are in the basic blocks | |
2069 | (except the switch handling code, barriers and notes) | |
2070 | - check that all returns are followed by barriers | |
2071 | - check that all fallthru edge points to the adjacent blocks. */ | |
2072 | static int | |
d329e058 | 2073 | rtl_verify_flow_info (void) |
10e9fecc JH |
2074 | { |
2075 | basic_block bb; | |
2076 | int err = rtl_verify_flow_info_1 (); | |
2077 | rtx x; | |
2078 | int num_bb_notes; | |
2079 | const rtx rtx_first = get_insns (); | |
2080 | basic_block last_bb_seen = ENTRY_BLOCK_PTR, curr_bb = NULL; | |
ca6c03ca | 2081 | |
10e9fecc JH |
2082 | FOR_EACH_BB_REVERSE (bb) |
2083 | { | |
2084 | edge e; | |
2085 | for (e = bb->succ; e; e = e->succ_next) | |
2086 | if (e->flags & EDGE_FALLTHRU) | |
2087 | break; | |
2088 | if (!e) | |
2089 | { | |
2090 | rtx insn; | |
2091 | ||
2092 | /* Ensure existence of barrier in BB with no fallthru edges. */ | |
a813c111 | 2093 | for (insn = BB_END (bb); !insn || GET_CODE (insn) != BARRIER; |
10e9fecc JH |
2094 | insn = NEXT_INSN (insn)) |
2095 | if (!insn | |
2096 | || (GET_CODE (insn) == NOTE | |
2097 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_BASIC_BLOCK)) | |
2098 | { | |
2099 | error ("missing barrier after block %i", bb->index); | |
2100 | err = 1; | |
2101 | break; | |
2102 | } | |
2103 | } | |
2104 | else if (e->src != ENTRY_BLOCK_PTR | |
2105 | && e->dest != EXIT_BLOCK_PTR) | |
2106 | { | |
2107 | rtx insn; | |
2108 | ||
2109 | if (e->src->next_bb != e->dest) | |
2110 | { | |
2111 | error | |
2112 | ("verify_flow_info: Incorrect blocks for fallthru %i->%i", | |
2113 | e->src->index, e->dest->index); | |
2114 | err = 1; | |
2115 | } | |
2116 | else | |
a813c111 | 2117 | for (insn = NEXT_INSN (BB_END (e->src)); insn != BB_HEAD (e->dest); |
10e9fecc JH |
2118 | insn = NEXT_INSN (insn)) |
2119 | if (GET_CODE (insn) == BARRIER | |
2120 | #ifndef CASE_DROPS_THROUGH | |
2121 | || INSN_P (insn) | |
2122 | #else | |
2123 | || (INSN_P (insn) && ! JUMP_TABLE_DATA_P (insn)) | |
2124 | #endif | |
2125 | ) | |
2126 | { | |
2127 | error ("verify_flow_info: Incorrect fallthru %i->%i", | |
2128 | e->src->index, e->dest->index); | |
2129 | fatal_insn ("wrong insn in the fallthru edge", insn); | |
2130 | err = 1; | |
2131 | } | |
2132 | } | |
2133 | } | |
ca6c03ca | 2134 | |
ca6c03ca | 2135 | num_bb_notes = 0; |
e0082a72 ZD |
2136 | last_bb_seen = ENTRY_BLOCK_PTR; |
2137 | ||
5f0d2358 | 2138 | for (x = rtx_first; x; x = NEXT_INSN (x)) |
ca6c03ca JH |
2139 | { |
2140 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2141 | { | |
bf77398c | 2142 | bb = NOTE_BASIC_BLOCK (x); |
5f0d2358 | 2143 | |
ca6c03ca | 2144 | num_bb_notes++; |
e0082a72 | 2145 | if (bb != last_bb_seen->next_bb) |
10e9fecc | 2146 | internal_error ("basic blocks not laid down consecutively"); |
ca6c03ca | 2147 | |
10e9fecc | 2148 | curr_bb = last_bb_seen = bb; |
ca6c03ca JH |
2149 | } |
2150 | ||
10e9fecc | 2151 | if (!curr_bb) |
ca6c03ca JH |
2152 | { |
2153 | switch (GET_CODE (x)) | |
2154 | { | |
2155 | case BARRIER: | |
2156 | case NOTE: | |
2157 | break; | |
2158 | ||
2159 | case CODE_LABEL: | |
2160 | /* An addr_vec is placed outside any block block. */ | |
2161 | if (NEXT_INSN (x) | |
2162 | && GET_CODE (NEXT_INSN (x)) == JUMP_INSN | |
2163 | && (GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_DIFF_VEC | |
2164 | || GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_VEC)) | |
5f0d2358 | 2165 | x = NEXT_INSN (x); |
ca6c03ca JH |
2166 | |
2167 | /* But in any case, non-deletable labels can appear anywhere. */ | |
2168 | break; | |
2169 | ||
2170 | default: | |
1f978f5f | 2171 | fatal_insn ("insn outside basic block", x); |
ca6c03ca JH |
2172 | } |
2173 | } | |
2174 | ||
2175 | if (INSN_P (x) | |
2176 | && GET_CODE (x) == JUMP_INSN | |
2177 | && returnjump_p (x) && ! condjump_p (x) | |
2178 | && ! (NEXT_INSN (x) && GET_CODE (NEXT_INSN (x)) == BARRIER)) | |
1f978f5f | 2179 | fatal_insn ("return not followed by barrier", x); |
a813c111 | 2180 | if (curr_bb && x == BB_END (curr_bb)) |
10e9fecc | 2181 | curr_bb = NULL; |
ca6c03ca JH |
2182 | } |
2183 | ||
0b17ab2f | 2184 | if (num_bb_notes != n_basic_blocks) |
ca6c03ca | 2185 | internal_error |
0b17ab2f RH |
2186 | ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)", |
2187 | num_bb_notes, n_basic_blocks); | |
ca6c03ca | 2188 | |
10e9fecc | 2189 | return err; |
ca6c03ca JH |
2190 | } |
2191 | \f | |
eaec9b3d | 2192 | /* Assume that the preceding pass has possibly eliminated jump instructions |
ca6c03ca JH |
2193 | or converted the unconditional jumps. Eliminate the edges from CFG. |
2194 | Return true if any edges are eliminated. */ | |
2195 | ||
2196 | bool | |
d329e058 | 2197 | purge_dead_edges (basic_block bb) |
ca6c03ca JH |
2198 | { |
2199 | edge e, next; | |
a813c111 | 2200 | rtx insn = BB_END (bb), note; |
ca6c03ca JH |
2201 | bool purged = false; |
2202 | ||
70da1d03 JH |
2203 | /* If this instruction cannot trap, remove REG_EH_REGION notes. */ |
2204 | if (GET_CODE (insn) == INSN | |
2205 | && (note = find_reg_note (insn, REG_EH_REGION, NULL))) | |
2206 | { | |
2207 | rtx eqnote; | |
2208 | ||
2209 | if (! may_trap_p (PATTERN (insn)) | |
2210 | || ((eqnote = find_reg_equal_equiv_note (insn)) | |
2211 | && ! may_trap_p (XEXP (eqnote, 0)))) | |
2212 | remove_note (insn, note); | |
2213 | } | |
2214 | ||
546c093e RH |
2215 | /* Cleanup abnormal edges caused by exceptions or non-local gotos. */ |
2216 | for (e = bb->succ; e; e = next) | |
2217 | { | |
2218 | next = e->succ_next; | |
2219 | if (e->flags & EDGE_EH) | |
2220 | { | |
a813c111 | 2221 | if (can_throw_internal (BB_END (bb))) |
546c093e RH |
2222 | continue; |
2223 | } | |
2224 | else if (e->flags & EDGE_ABNORMAL_CALL) | |
2225 | { | |
a813c111 | 2226 | if (GET_CODE (BB_END (bb)) == CALL_INSN |
546c093e RH |
2227 | && (! (note = find_reg_note (insn, REG_EH_REGION, NULL)) |
2228 | || INTVAL (XEXP (note, 0)) >= 0)) | |
2229 | continue; | |
2230 | } | |
2231 | else | |
2232 | continue; | |
2233 | ||
2234 | remove_edge (e); | |
2235 | bb->flags |= BB_DIRTY; | |
2236 | purged = true; | |
2237 | } | |
5f0d2358 | 2238 | |
ca6c03ca JH |
2239 | if (GET_CODE (insn) == JUMP_INSN) |
2240 | { | |
2241 | rtx note; | |
2242 | edge b,f; | |
5f0d2358 | 2243 | |
ca6c03ca JH |
2244 | /* We do care only about conditional jumps and simplejumps. */ |
2245 | if (!any_condjump_p (insn) | |
2246 | && !returnjump_p (insn) | |
2247 | && !simplejump_p (insn)) | |
c51d95ec | 2248 | return purged; |
5f0d2358 | 2249 | |
5a1a3e5e JH |
2250 | /* Branch probability/prediction notes are defined only for |
2251 | condjumps. We've possibly turned condjump into simplejump. */ | |
2252 | if (simplejump_p (insn)) | |
2253 | { | |
2254 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2255 | if (note) | |
2256 | remove_note (insn, note); | |
2257 | while ((note = find_reg_note (insn, REG_BR_PRED, NULL))) | |
2258 | remove_note (insn, note); | |
2259 | } | |
2260 | ||
ca6c03ca JH |
2261 | for (e = bb->succ; e; e = next) |
2262 | { | |
2263 | next = e->succ_next; | |
2264 | ||
7fcd7218 JH |
2265 | /* Avoid abnormal flags to leak from computed jumps turned |
2266 | into simplejumps. */ | |
f87c27b4 | 2267 | |
0e1638d4 | 2268 | e->flags &= ~EDGE_ABNORMAL; |
7fcd7218 | 2269 | |
5a566bed MM |
2270 | /* See if this edge is one we should keep. */ |
2271 | if ((e->flags & EDGE_FALLTHRU) && any_condjump_p (insn)) | |
2272 | /* A conditional jump can fall through into the next | |
2273 | block, so we should keep the edge. */ | |
ca6c03ca | 2274 | continue; |
5f0d2358 | 2275 | else if (e->dest != EXIT_BLOCK_PTR |
a813c111 | 2276 | && BB_HEAD (e->dest) == JUMP_LABEL (insn)) |
5a566bed MM |
2277 | /* If the destination block is the target of the jump, |
2278 | keep the edge. */ | |
2279 | continue; | |
2280 | else if (e->dest == EXIT_BLOCK_PTR && returnjump_p (insn)) | |
2281 | /* If the destination block is the exit block, and this | |
2282 | instruction is a return, then keep the edge. */ | |
ca6c03ca | 2283 | continue; |
5a566bed MM |
2284 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) |
2285 | /* Keep the edges that correspond to exceptions thrown by | |
0b75beaa EB |
2286 | this instruction and rematerialize the EDGE_ABNORMAL |
2287 | flag we just cleared above. */ | |
2288 | { | |
2289 | e->flags |= EDGE_ABNORMAL; | |
2290 | continue; | |
2291 | } | |
5f0d2358 | 2292 | |
5a566bed | 2293 | /* We do not need this edge. */ |
c51d95ec | 2294 | bb->flags |= BB_DIRTY; |
ca6c03ca JH |
2295 | purged = true; |
2296 | remove_edge (e); | |
2297 | } | |
5f0d2358 | 2298 | |
ca6c03ca | 2299 | if (!bb->succ || !purged) |
c51d95ec | 2300 | return purged; |
5f0d2358 | 2301 | |
ca6c03ca | 2302 | if (rtl_dump_file) |
0b17ab2f | 2303 | fprintf (rtl_dump_file, "Purged edges from bb %i\n", bb->index); |
5f0d2358 | 2304 | |
ca6c03ca JH |
2305 | if (!optimize) |
2306 | return purged; | |
2307 | ||
2308 | /* Redistribute probabilities. */ | |
2309 | if (!bb->succ->succ_next) | |
2310 | { | |
2311 | bb->succ->probability = REG_BR_PROB_BASE; | |
2312 | bb->succ->count = bb->count; | |
f87c27b4 | 2313 | } |
ca6c03ca JH |
2314 | else |
2315 | { | |
2316 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2317 | if (!note) | |
2318 | return purged; | |
5f0d2358 | 2319 | |
ca6c03ca JH |
2320 | b = BRANCH_EDGE (bb); |
2321 | f = FALLTHRU_EDGE (bb); | |
2322 | b->probability = INTVAL (XEXP (note, 0)); | |
2323 | f->probability = REG_BR_PROB_BASE - b->probability; | |
2324 | b->count = bb->count * b->probability / REG_BR_PROB_BASE; | |
2325 | f->count = bb->count * f->probability / REG_BR_PROB_BASE; | |
2326 | } | |
5f0d2358 | 2327 | |
ca6c03ca JH |
2328 | return purged; |
2329 | } | |
1722c2c8 RH |
2330 | else if (GET_CODE (insn) == CALL_INSN && SIBLING_CALL_P (insn)) |
2331 | { | |
2332 | /* First, there should not be any EH or ABCALL edges resulting | |
2333 | from non-local gotos and the like. If there were, we shouldn't | |
2334 | have created the sibcall in the first place. Second, there | |
2335 | should of course never have been a fallthru edge. */ | |
2336 | if (!bb->succ || bb->succ->succ_next) | |
2337 | abort (); | |
792bb204 | 2338 | if (bb->succ->flags != (EDGE_SIBCALL | EDGE_ABNORMAL)) |
1722c2c8 RH |
2339 | abort (); |
2340 | ||
2341 | return 0; | |
2342 | } | |
ca6c03ca | 2343 | |
ca6c03ca JH |
2344 | /* If we don't see a jump insn, we don't know exactly why the block would |
2345 | have been broken at this point. Look for a simple, non-fallthru edge, | |
2346 | as these are only created by conditional branches. If we find such an | |
2347 | edge we know that there used to be a jump here and can then safely | |
2348 | remove all non-fallthru edges. */ | |
2349 | for (e = bb->succ; e && (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU)); | |
5f0d2358 RK |
2350 | e = e->succ_next) |
2351 | ; | |
2352 | ||
ca6c03ca JH |
2353 | if (!e) |
2354 | return purged; | |
5f0d2358 | 2355 | |
ca6c03ca JH |
2356 | for (e = bb->succ; e; e = next) |
2357 | { | |
2358 | next = e->succ_next; | |
2359 | if (!(e->flags & EDGE_FALLTHRU)) | |
c51d95ec JH |
2360 | { |
2361 | bb->flags |= BB_DIRTY; | |
2362 | remove_edge (e); | |
2363 | purged = true; | |
2364 | } | |
ca6c03ca | 2365 | } |
5f0d2358 | 2366 | |
ca6c03ca JH |
2367 | if (!bb->succ || bb->succ->succ_next) |
2368 | abort (); | |
5f0d2358 | 2369 | |
ca6c03ca JH |
2370 | bb->succ->probability = REG_BR_PROB_BASE; |
2371 | bb->succ->count = bb->count; | |
2372 | ||
2373 | if (rtl_dump_file) | |
2374 | fprintf (rtl_dump_file, "Purged non-fallthru edges from bb %i\n", | |
0b17ab2f | 2375 | bb->index); |
ca6c03ca JH |
2376 | return purged; |
2377 | } | |
2378 | ||
5f0d2358 RK |
2379 | /* Search all basic blocks for potentially dead edges and purge them. Return |
2380 | true if some edge has been eliminated. */ | |
ca6c03ca JH |
2381 | |
2382 | bool | |
d329e058 | 2383 | purge_all_dead_edges (int update_life_p) |
ca6c03ca | 2384 | { |
e0082a72 | 2385 | int purged = false; |
710af899 | 2386 | sbitmap blocks = 0; |
e0082a72 | 2387 | basic_block bb; |
473fb060 JH |
2388 | |
2389 | if (update_life_p) | |
2390 | { | |
d55bc081 | 2391 | blocks = sbitmap_alloc (last_basic_block); |
473fb060 JH |
2392 | sbitmap_zero (blocks); |
2393 | } | |
5f0d2358 | 2394 | |
e0082a72 | 2395 | FOR_EACH_BB (bb) |
473fb060 | 2396 | { |
e0082a72 | 2397 | bool purged_here = purge_dead_edges (bb); |
5f0d2358 | 2398 | |
473fb060 JH |
2399 | purged |= purged_here; |
2400 | if (purged_here && update_life_p) | |
e0082a72 | 2401 | SET_BIT (blocks, bb->index); |
473fb060 | 2402 | } |
5f0d2358 | 2403 | |
473fb060 JH |
2404 | if (update_life_p && purged) |
2405 | update_life_info (blocks, UPDATE_LIFE_GLOBAL, | |
2406 | PROP_DEATH_NOTES | PROP_SCAN_DEAD_CODE | |
2407 | | PROP_KILL_DEAD_CODE); | |
5f0d2358 | 2408 | |
473fb060 JH |
2409 | if (update_life_p) |
2410 | sbitmap_free (blocks); | |
ca6c03ca JH |
2411 | return purged; |
2412 | } | |
9ee634e3 JH |
2413 | |
2414 | /* Same as split_block but update cfg_layout structures. */ | |
2415 | static edge | |
d329e058 | 2416 | cfg_layout_split_block (basic_block bb, void *insnp) |
9ee634e3 JH |
2417 | { |
2418 | rtx insn = insnp; | |
2419 | ||
2420 | edge fallthru = rtl_split_block (bb, insn); | |
2421 | ||
bc35512f JH |
2422 | fallthru->dest->rbi->footer = fallthru->src->rbi->footer; |
2423 | fallthru->src->rbi->footer = NULL; | |
9ee634e3 JH |
2424 | return fallthru; |
2425 | } | |
2426 | ||
2427 | ||
2428 | /* Redirect Edge to DEST. */ | |
2429 | static bool | |
d329e058 | 2430 | cfg_layout_redirect_edge_and_branch (edge e, basic_block dest) |
9ee634e3 JH |
2431 | { |
2432 | basic_block src = e->src; | |
9ee634e3 JH |
2433 | bool ret; |
2434 | ||
bc35512f JH |
2435 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
2436 | return false; | |
2437 | ||
3348b696 | 2438 | if (e->dest == dest) |
bc35512f JH |
2439 | return true; |
2440 | ||
3348b696 JH |
2441 | if (e->src != ENTRY_BLOCK_PTR |
2442 | && try_redirect_by_replacing_jump (e, dest, true)) | |
bc35512f JH |
2443 | return true; |
2444 | ||
2445 | if (e->src == ENTRY_BLOCK_PTR | |
2446 | && (e->flags & EDGE_FALLTHRU) && !(e->flags & EDGE_COMPLEX)) | |
2447 | { | |
2448 | if (rtl_dump_file) | |
2449 | fprintf (rtl_dump_file, "Redirecting entry edge from bb %i to %i\n", | |
2450 | e->src->index, dest->index); | |
2451 | ||
2452 | redirect_edge_succ (e, dest); | |
2453 | return true; | |
2454 | } | |
2455 | ||
9ee634e3 JH |
2456 | /* Redirect_edge_and_branch may decide to turn branch into fallthru edge |
2457 | in the case the basic block appears to be in sequence. Avoid this | |
2458 | transformation. */ | |
2459 | ||
9ee634e3 JH |
2460 | if (e->flags & EDGE_FALLTHRU) |
2461 | { | |
2462 | /* Redirect any branch edges unified with the fallthru one. */ | |
a813c111 | 2463 | if (GET_CODE (BB_END (src)) == JUMP_INSN |
432f982f JH |
2464 | && label_is_jump_target_p (BB_HEAD (e->dest), |
2465 | BB_END (src))) | |
9ee634e3 | 2466 | { |
432f982f JH |
2467 | if (rtl_dump_file) |
2468 | fprintf (rtl_dump_file, "Fallthru edge unified with branch " | |
2469 | "%i->%i redirected to %i\n", | |
2470 | e->src->index, e->dest->index, dest->index); | |
2471 | e->flags &= ~EDGE_FALLTHRU; | |
2472 | if (!redirect_branch_edge (e, dest)) | |
9ee634e3 | 2473 | abort (); |
432f982f JH |
2474 | e->flags |= EDGE_FALLTHRU; |
2475 | return true; | |
9ee634e3 JH |
2476 | } |
2477 | /* In case we are redirecting fallthru edge to the branch edge | |
2478 | of conditional jump, remove it. */ | |
2479 | if (src->succ->succ_next | |
2480 | && !src->succ->succ_next->succ_next) | |
2481 | { | |
2482 | edge s = e->succ_next ? e->succ_next : src->succ; | |
2483 | if (s->dest == dest | |
a813c111 SB |
2484 | && any_condjump_p (BB_END (src)) |
2485 | && onlyjump_p (BB_END (src))) | |
2486 | delete_insn (BB_END (src)); | |
9ee634e3 JH |
2487 | } |
2488 | redirect_edge_succ_nodup (e, dest); | |
bc35512f JH |
2489 | if (rtl_dump_file) |
2490 | fprintf (rtl_dump_file, "Fallthru edge %i->%i redirected to %i\n", | |
2491 | e->src->index, e->dest->index, dest->index); | |
9ee634e3 JH |
2492 | |
2493 | ret = true; | |
2494 | } | |
2495 | else | |
bc35512f | 2496 | ret = redirect_branch_edge (e, dest); |
9ee634e3 JH |
2497 | |
2498 | /* We don't want simplejumps in the insn stream during cfglayout. */ | |
a813c111 | 2499 | if (simplejump_p (BB_END (src))) |
bc35512f | 2500 | abort (); |
9ee634e3 JH |
2501 | |
2502 | return ret; | |
2503 | } | |
2504 | ||
2505 | /* Simple wrapper as we always can redirect fallthru edges. */ | |
2506 | static basic_block | |
d329e058 | 2507 | cfg_layout_redirect_edge_and_branch_force (edge e, basic_block dest) |
9ee634e3 JH |
2508 | { |
2509 | if (!cfg_layout_redirect_edge_and_branch (e, dest)) | |
2510 | abort (); | |
2511 | return NULL; | |
2512 | } | |
2513 | ||
2514 | /* Same as flow_delete_block but update cfg_layout structures. */ | |
2515 | static void | |
d329e058 | 2516 | cfg_layout_delete_block (basic_block bb) |
9ee634e3 | 2517 | { |
a813c111 | 2518 | rtx insn, next, prev = PREV_INSN (BB_HEAD (bb)), *to, remaints; |
9ee634e3 | 2519 | |
bc35512f | 2520 | if (bb->rbi->header) |
9ee634e3 | 2521 | { |
a813c111 | 2522 | next = BB_HEAD (bb); |
9ee634e3 | 2523 | if (prev) |
bc35512f | 2524 | NEXT_INSN (prev) = bb->rbi->header; |
9ee634e3 | 2525 | else |
bc35512f JH |
2526 | set_first_insn (bb->rbi->header); |
2527 | PREV_INSN (bb->rbi->header) = prev; | |
2528 | insn = bb->rbi->header; | |
9ee634e3 JH |
2529 | while (NEXT_INSN (insn)) |
2530 | insn = NEXT_INSN (insn); | |
2531 | NEXT_INSN (insn) = next; | |
2532 | PREV_INSN (next) = insn; | |
2533 | } | |
a813c111 | 2534 | next = NEXT_INSN (BB_END (bb)); |
bc35512f | 2535 | if (bb->rbi->footer) |
9ee634e3 | 2536 | { |
bc35512f JH |
2537 | insn = bb->rbi->footer; |
2538 | while (insn) | |
2539 | { | |
2540 | if (GET_CODE (insn) == BARRIER) | |
2541 | { | |
2542 | if (PREV_INSN (insn)) | |
2543 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
2544 | else | |
2545 | bb->rbi->footer = NEXT_INSN (insn); | |
2546 | if (NEXT_INSN (insn)) | |
2547 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
2548 | } | |
2549 | if (GET_CODE (insn) == CODE_LABEL) | |
2550 | break; | |
2551 | insn = NEXT_INSN (insn); | |
2552 | } | |
2553 | if (bb->rbi->footer) | |
2554 | { | |
a813c111 | 2555 | insn = BB_END (bb); |
bc35512f JH |
2556 | NEXT_INSN (insn) = bb->rbi->footer; |
2557 | PREV_INSN (bb->rbi->footer) = insn; | |
2558 | while (NEXT_INSN (insn)) | |
2559 | insn = NEXT_INSN (insn); | |
2560 | NEXT_INSN (insn) = next; | |
2561 | if (next) | |
2562 | PREV_INSN (next) = insn; | |
2563 | else | |
2564 | set_last_insn (insn); | |
2565 | } | |
9ee634e3 JH |
2566 | } |
2567 | if (bb->next_bb != EXIT_BLOCK_PTR) | |
bc35512f | 2568 | to = &bb->next_bb->rbi->header; |
9ee634e3 JH |
2569 | else |
2570 | to = &cfg_layout_function_footer; | |
2571 | rtl_delete_block (bb); | |
2572 | ||
2573 | if (prev) | |
2574 | prev = NEXT_INSN (prev); | |
d329e058 | 2575 | else |
9ee634e3 JH |
2576 | prev = get_insns (); |
2577 | if (next) | |
2578 | next = PREV_INSN (next); | |
d329e058 | 2579 | else |
9ee634e3 JH |
2580 | next = get_last_insn (); |
2581 | ||
2582 | if (next && NEXT_INSN (next) != prev) | |
2583 | { | |
2584 | remaints = unlink_insn_chain (prev, next); | |
2585 | insn = remaints; | |
2586 | while (NEXT_INSN (insn)) | |
2587 | insn = NEXT_INSN (insn); | |
2588 | NEXT_INSN (insn) = *to; | |
2589 | if (*to) | |
2590 | PREV_INSN (*to) = insn; | |
2591 | *to = remaints; | |
2592 | } | |
2593 | } | |
2594 | ||
beb235f8 | 2595 | /* Return true when blocks A and B can be safely merged. */ |
bc35512f JH |
2596 | static bool |
2597 | cfg_layout_can_merge_blocks_p (basic_block a, basic_block b) | |
2598 | { | |
2599 | /* There must be exactly one edge in between the blocks. */ | |
2600 | return (a->succ && !a->succ->succ_next && a->succ->dest == b | |
2601 | && !b->pred->pred_next && a != b | |
2602 | /* Must be simple edge. */ | |
2603 | && !(a->succ->flags & EDGE_COMPLEX) | |
2604 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR | |
2605 | /* If the jump insn has side effects, | |
2606 | we can't kill the edge. */ | |
a813c111 | 2607 | && (GET_CODE (BB_END (a)) != JUMP_INSN |
e24e7211 | 2608 | || (reload_completed |
a813c111 | 2609 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f JH |
2610 | } |
2611 | ||
2612 | /* Merge block A and B, abort when it is not possible. */ | |
2613 | static void | |
2614 | cfg_layout_merge_blocks (basic_block a, basic_block b) | |
2615 | { | |
2616 | #ifdef ENABLE_CHECKING | |
2617 | if (!cfg_layout_can_merge_blocks_p (a, b)) | |
2618 | abort (); | |
2619 | #endif | |
2620 | ||
2621 | /* If there was a CODE_LABEL beginning B, delete it. */ | |
a813c111 SB |
2622 | if (GET_CODE (BB_HEAD (b)) == CODE_LABEL) |
2623 | delete_insn (BB_HEAD (b)); | |
bc35512f JH |
2624 | |
2625 | /* We should have fallthru edge in a, or we can do dummy redirection to get | |
2626 | it cleaned up. */ | |
a813c111 | 2627 | if (GET_CODE (BB_END (a)) == JUMP_INSN) |
3348b696 | 2628 | try_redirect_by_replacing_jump (a->succ, b, true); |
a813c111 | 2629 | if (GET_CODE (BB_END (a)) == JUMP_INSN) |
bc35512f JH |
2630 | abort (); |
2631 | ||
2632 | /* Possible line number notes should appear in between. */ | |
2633 | if (b->rbi->header) | |
2634 | { | |
a813c111 | 2635 | rtx first = BB_END (a), last; |
bc35512f | 2636 | |
a813c111 | 2637 | last = emit_insn_after (b->rbi->header, BB_END (a)); |
bc35512f JH |
2638 | delete_insn_chain (NEXT_INSN (first), last); |
2639 | b->rbi->header = NULL; | |
2640 | } | |
2641 | ||
2642 | /* In the case basic blocks are not adjacent, move them around. */ | |
a813c111 | 2643 | if (NEXT_INSN (BB_END (a)) != BB_HEAD (b)) |
bc35512f | 2644 | { |
a813c111 | 2645 | rtx first = unlink_insn_chain (BB_HEAD (b), BB_END (b)); |
bc35512f | 2646 | |
a813c111 | 2647 | emit_insn_after (first, BB_END (a)); |
bc35512f JH |
2648 | /* Skip possible DELETED_LABEL insn. */ |
2649 | if (!NOTE_INSN_BASIC_BLOCK_P (first)) | |
2650 | first = NEXT_INSN (first); | |
2651 | if (!NOTE_INSN_BASIC_BLOCK_P (first)) | |
2652 | abort (); | |
a813c111 | 2653 | BB_HEAD (b) = NULL; |
bc35512f JH |
2654 | delete_insn (first); |
2655 | } | |
2656 | /* Otherwise just re-associate the instructions. */ | |
2657 | else | |
2658 | { | |
2659 | rtx insn; | |
2660 | ||
a813c111 SB |
2661 | for (insn = BB_HEAD (b); |
2662 | insn != NEXT_INSN (BB_END (b)); | |
2663 | insn = NEXT_INSN (insn)) | |
bc35512f | 2664 | set_block_for_insn (insn, a); |
a813c111 | 2665 | insn = BB_HEAD (b); |
bc35512f JH |
2666 | /* Skip possible DELETED_LABEL insn. */ |
2667 | if (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
2668 | insn = NEXT_INSN (insn); | |
2669 | if (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
2670 | abort (); | |
a813c111 SB |
2671 | BB_HEAD (b) = NULL; |
2672 | BB_END (a) = BB_END (b); | |
bc35512f JH |
2673 | delete_insn (insn); |
2674 | } | |
2675 | ||
2676 | /* Possible tablejumps and barriers should appear after the block. */ | |
2677 | if (b->rbi->footer) | |
2678 | { | |
2679 | if (!a->rbi->footer) | |
2680 | a->rbi->footer = b->rbi->footer; | |
2681 | else | |
2682 | { | |
2683 | rtx last = a->rbi->footer; | |
2684 | ||
2685 | while (NEXT_INSN (last)) | |
2686 | last = NEXT_INSN (last); | |
2687 | NEXT_INSN (last) = b->rbi->footer; | |
2688 | PREV_INSN (b->rbi->footer) = last; | |
2689 | } | |
2690 | b->rbi->footer = NULL; | |
2691 | } | |
2692 | ||
2693 | if (rtl_dump_file) | |
2694 | fprintf (rtl_dump_file, "Merged blocks %d and %d.\n", | |
2695 | a->index, b->index); | |
2696 | ||
2697 | update_cfg_after_block_merging (a, b); | |
2698 | } | |
2699 | ||
2700 | /* Split edge E. */ | |
2701 | static basic_block | |
2702 | cfg_layout_split_edge (edge e) | |
2703 | { | |
2704 | edge new_e; | |
2705 | basic_block new_bb = | |
2706 | create_basic_block (e->src != ENTRY_BLOCK_PTR | |
a813c111 | 2707 | ? NEXT_INSN (BB_END (e->src)) : get_insns (), |
bc35512f JH |
2708 | NULL_RTX, e->src); |
2709 | ||
2710 | new_bb->count = e->count; | |
2711 | new_bb->frequency = EDGE_FREQUENCY (e); | |
2712 | ||
2713 | new_e = make_edge (new_bb, e->dest, EDGE_FALLTHRU); | |
2714 | new_e->probability = REG_BR_PROB_BASE; | |
2715 | new_e->count = e->count; | |
2716 | redirect_edge_and_branch_force (e, new_bb); | |
2717 | ||
2718 | return new_bb; | |
2719 | } | |
2720 | ||
9ee634e3 JH |
2721 | /* Implementation of CFG manipulation for linearized RTL. */ |
2722 | struct cfg_hooks rtl_cfg_hooks = { | |
2723 | rtl_verify_flow_info, | |
10e9fecc | 2724 | rtl_dump_bb, |
bc35512f | 2725 | rtl_create_basic_block, |
9ee634e3 JH |
2726 | rtl_redirect_edge_and_branch, |
2727 | rtl_redirect_edge_and_branch_force, | |
2728 | rtl_delete_block, | |
2729 | rtl_split_block, | |
bc35512f JH |
2730 | rtl_can_merge_blocks, /* can_merge_blocks_p */ |
2731 | rtl_merge_blocks, | |
9ee634e3 JH |
2732 | rtl_split_edge |
2733 | }; | |
2734 | ||
2735 | /* Implementation of CFG manipulation for cfg layout RTL, where | |
2736 | basic block connected via fallthru edges does not have to be adjacent. | |
2737 | This representation will hopefully become the default one in future | |
2738 | version of the compiler. */ | |
2739 | struct cfg_hooks cfg_layout_rtl_cfg_hooks = { | |
bc35512f | 2740 | rtl_verify_flow_info_1, |
10e9fecc | 2741 | rtl_dump_bb, |
bc35512f | 2742 | cfg_layout_create_basic_block, |
9ee634e3 JH |
2743 | cfg_layout_redirect_edge_and_branch, |
2744 | cfg_layout_redirect_edge_and_branch_force, | |
2745 | cfg_layout_delete_block, | |
2746 | cfg_layout_split_block, | |
bc35512f JH |
2747 | cfg_layout_can_merge_blocks_p, |
2748 | cfg_layout_merge_blocks, | |
2749 | cfg_layout_split_edge | |
9ee634e3 | 2750 | }; |