]>
Commit | Line | Data |
---|---|---|
ca6c03ca JH |
1 | /* Control flow graph manipulation code for GNU compiler. |
2 | Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, | |
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); | |
f470c378 | 79 | static bool rtl_move_block_after (basic_block, basic_block); |
d329e058 | 80 | static int rtl_verify_flow_info (void); |
f470c378 | 81 | static basic_block cfg_layout_split_block (basic_block, void *); |
d329e058 AJ |
82 | static bool cfg_layout_redirect_edge_and_branch (edge, basic_block); |
83 | static basic_block cfg_layout_redirect_edge_and_branch_force (edge, basic_block); | |
84 | static void cfg_layout_delete_block (basic_block); | |
85 | static void rtl_delete_block (basic_block); | |
86 | static basic_block rtl_redirect_edge_and_branch_force (edge, basic_block); | |
87 | static bool rtl_redirect_edge_and_branch (edge, basic_block); | |
f470c378 ZD |
88 | static basic_block rtl_split_block (basic_block, void *); |
89 | static void rtl_dump_bb (basic_block, FILE *, int); | |
d329e058 | 90 | static int rtl_verify_flow_info_1 (void); |
ff25ef99 | 91 | static void mark_killed_regs (rtx, rtx, void *); |
f470c378 | 92 | static void rtl_make_forwarder_block (edge); |
ca6c03ca JH |
93 | \f |
94 | /* Return true if NOTE is not one of the ones that must be kept paired, | |
5f0d2358 | 95 | so that we may simply delete it. */ |
ca6c03ca JH |
96 | |
97 | static int | |
d329e058 | 98 | can_delete_note_p (rtx note) |
ca6c03ca JH |
99 | { |
100 | return (NOTE_LINE_NUMBER (note) == NOTE_INSN_DELETED | |
969d70ca | 101 | || NOTE_LINE_NUMBER (note) == NOTE_INSN_BASIC_BLOCK |
f87c27b4 | 102 | || NOTE_LINE_NUMBER (note) == NOTE_INSN_PREDICTION); |
ca6c03ca JH |
103 | } |
104 | ||
105 | /* True if a given label can be deleted. */ | |
106 | ||
107 | static int | |
d329e058 | 108 | can_delete_label_p (rtx label) |
ca6c03ca | 109 | { |
5f0d2358 RK |
110 | return (!LABEL_PRESERVE_P (label) |
111 | /* User declared labels must be preserved. */ | |
112 | && LABEL_NAME (label) == 0 | |
113 | && !in_expr_list_p (forced_labels, label) | |
6a58eee9 | 114 | && !in_expr_list_p (label_value_list, label)); |
ca6c03ca JH |
115 | } |
116 | ||
117 | /* Delete INSN by patching it out. Return the next insn. */ | |
118 | ||
119 | rtx | |
d329e058 | 120 | delete_insn (rtx insn) |
ca6c03ca JH |
121 | { |
122 | rtx next = NEXT_INSN (insn); | |
123 | rtx note; | |
124 | bool really_delete = true; | |
125 | ||
126 | if (GET_CODE (insn) == CODE_LABEL) | |
127 | { | |
128 | /* Some labels can't be directly removed from the INSN chain, as they | |
f87c27b4 | 129 | might be references via variables, constant pool etc. |
ca6c03ca JH |
130 | Convert them to the special NOTE_INSN_DELETED_LABEL note. */ |
131 | if (! can_delete_label_p (insn)) | |
132 | { | |
133 | const char *name = LABEL_NAME (insn); | |
134 | ||
135 | really_delete = false; | |
136 | PUT_CODE (insn, NOTE); | |
137 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED_LABEL; | |
138 | NOTE_SOURCE_FILE (insn) = name; | |
139 | } | |
5f0d2358 | 140 | |
ca6c03ca JH |
141 | remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels); |
142 | } | |
143 | ||
144 | if (really_delete) | |
145 | { | |
cda94cbb RH |
146 | /* If this insn has already been deleted, something is very wrong. */ |
147 | if (INSN_DELETED_P (insn)) | |
148 | abort (); | |
ca6c03ca JH |
149 | remove_insn (insn); |
150 | INSN_DELETED_P (insn) = 1; | |
151 | } | |
152 | ||
153 | /* If deleting a jump, decrement the use count of the label. Deleting | |
154 | the label itself should happen in the normal course of block merging. */ | |
155 | if (GET_CODE (insn) == JUMP_INSN | |
156 | && JUMP_LABEL (insn) | |
157 | && GET_CODE (JUMP_LABEL (insn)) == CODE_LABEL) | |
158 | LABEL_NUSES (JUMP_LABEL (insn))--; | |
159 | ||
160 | /* Also if deleting an insn that references a label. */ | |
9295a326 JZ |
161 | else |
162 | { | |
163 | while ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)) != NULL_RTX | |
164 | && GET_CODE (XEXP (note, 0)) == CODE_LABEL) | |
165 | { | |
166 | LABEL_NUSES (XEXP (note, 0))--; | |
167 | remove_note (insn, note); | |
168 | } | |
169 | } | |
ca6c03ca JH |
170 | |
171 | if (GET_CODE (insn) == JUMP_INSN | |
172 | && (GET_CODE (PATTERN (insn)) == ADDR_VEC | |
173 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)) | |
174 | { | |
175 | rtx pat = PATTERN (insn); | |
176 | int diff_vec_p = GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC; | |
177 | int len = XVECLEN (pat, diff_vec_p); | |
178 | int i; | |
179 | ||
180 | for (i = 0; i < len; i++) | |
a124fcda RH |
181 | { |
182 | rtx label = XEXP (XVECEXP (pat, diff_vec_p, i), 0); | |
183 | ||
184 | /* When deleting code in bulk (e.g. removing many unreachable | |
185 | blocks) we can delete a label that's a target of the vector | |
186 | before deleting the vector itself. */ | |
187 | if (GET_CODE (label) != NOTE) | |
188 | LABEL_NUSES (label)--; | |
189 | } | |
ca6c03ca JH |
190 | } |
191 | ||
192 | return next; | |
193 | } | |
194 | ||
3dec4024 JH |
195 | /* Like delete_insn but also purge dead edges from BB. */ |
196 | rtx | |
d329e058 | 197 | delete_insn_and_edges (rtx insn) |
3dec4024 JH |
198 | { |
199 | rtx x; | |
200 | bool purge = false; | |
201 | ||
ba4f7968 | 202 | if (INSN_P (insn) |
3dec4024 | 203 | && BLOCK_FOR_INSN (insn) |
a813c111 | 204 | && BB_END (BLOCK_FOR_INSN (insn)) == insn) |
3dec4024 JH |
205 | purge = true; |
206 | x = delete_insn (insn); | |
207 | if (purge) | |
208 | purge_dead_edges (BLOCK_FOR_INSN (insn)); | |
209 | return x; | |
210 | } | |
211 | ||
ca6c03ca JH |
212 | /* Unlink a chain of insns between START and FINISH, leaving notes |
213 | that must be paired. */ | |
214 | ||
215 | void | |
d329e058 | 216 | delete_insn_chain (rtx start, rtx finish) |
ca6c03ca | 217 | { |
ca6c03ca JH |
218 | rtx next; |
219 | ||
5f0d2358 RK |
220 | /* Unchain the insns one by one. It would be quicker to delete all of these |
221 | with a single unchaining, rather than one at a time, but we need to keep | |
222 | the NOTE's. */ | |
ca6c03ca JH |
223 | while (1) |
224 | { | |
225 | next = NEXT_INSN (start); | |
226 | if (GET_CODE (start) == NOTE && !can_delete_note_p (start)) | |
227 | ; | |
228 | else | |
229 | next = delete_insn (start); | |
230 | ||
231 | if (start == finish) | |
232 | break; | |
233 | start = next; | |
234 | } | |
235 | } | |
3dec4024 JH |
236 | |
237 | /* Like delete_insn but also purge dead edges from BB. */ | |
238 | void | |
d329e058 | 239 | delete_insn_chain_and_edges (rtx first, rtx last) |
3dec4024 JH |
240 | { |
241 | bool purge = false; | |
242 | ||
ba4f7968 | 243 | if (INSN_P (last) |
3dec4024 | 244 | && BLOCK_FOR_INSN (last) |
a813c111 | 245 | && BB_END (BLOCK_FOR_INSN (last)) == last) |
3dec4024 JH |
246 | purge = true; |
247 | delete_insn_chain (first, last); | |
248 | if (purge) | |
249 | purge_dead_edges (BLOCK_FOR_INSN (last)); | |
250 | } | |
ca6c03ca | 251 | \f |
5f0d2358 RK |
252 | /* Create a new basic block consisting of the instructions between HEAD and END |
253 | inclusive. This function is designed to allow fast BB construction - reuses | |
254 | the note and basic block struct in BB_NOTE, if any and do not grow | |
255 | BASIC_BLOCK chain and should be used directly only by CFG construction code. | |
256 | END can be NULL in to create new empty basic block before HEAD. Both END | |
918ed612 ZD |
257 | and HEAD can be NULL to create basic block at the end of INSN chain. |
258 | AFTER is the basic block we should be put after. */ | |
ca6c03ca JH |
259 | |
260 | basic_block | |
d329e058 | 261 | create_basic_block_structure (rtx head, rtx end, rtx bb_note, basic_block after) |
ca6c03ca JH |
262 | { |
263 | basic_block bb; | |
264 | ||
265 | if (bb_note | |
266 | && ! RTX_INTEGRATED_P (bb_note) | |
267 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL | |
268 | && bb->aux == NULL) | |
269 | { | |
270 | /* If we found an existing note, thread it back onto the chain. */ | |
271 | ||
272 | rtx after; | |
273 | ||
274 | if (GET_CODE (head) == CODE_LABEL) | |
275 | after = head; | |
276 | else | |
277 | { | |
278 | after = PREV_INSN (head); | |
279 | head = bb_note; | |
280 | } | |
281 | ||
282 | if (after != bb_note && NEXT_INSN (after) != bb_note) | |
ba4f7968 | 283 | reorder_insns_nobb (bb_note, bb_note, after); |
ca6c03ca JH |
284 | } |
285 | else | |
286 | { | |
287 | /* Otherwise we must create a note and a basic block structure. */ | |
288 | ||
289 | bb = alloc_block (); | |
290 | ||
291 | if (!head && !end) | |
5f0d2358 RK |
292 | head = end = bb_note |
293 | = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); | |
ca6c03ca JH |
294 | else if (GET_CODE (head) == CODE_LABEL && end) |
295 | { | |
296 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); | |
297 | if (head == end) | |
298 | end = bb_note; | |
299 | } | |
300 | else | |
301 | { | |
302 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); | |
303 | head = bb_note; | |
304 | if (!end) | |
305 | end = head; | |
306 | } | |
5f0d2358 | 307 | |
ca6c03ca JH |
308 | NOTE_BASIC_BLOCK (bb_note) = bb; |
309 | } | |
310 | ||
311 | /* Always include the bb note in the block. */ | |
312 | if (NEXT_INSN (end) == bb_note) | |
313 | end = bb_note; | |
314 | ||
a813c111 SB |
315 | BB_HEAD (bb) = head; |
316 | BB_END (bb) = end; | |
852c6ec7 | 317 | bb->index = last_basic_block++; |
38c1593d | 318 | bb->flags = BB_NEW; |
918ed612 | 319 | link_block (bb, after); |
852c6ec7 | 320 | BASIC_BLOCK (bb->index) = bb; |
ba4f7968 | 321 | update_bb_for_insn (bb); |
ca6c03ca JH |
322 | |
323 | /* Tag the block so that we know it has been used when considering | |
324 | other basic block notes. */ | |
325 | bb->aux = bb; | |
326 | ||
327 | return bb; | |
328 | } | |
329 | ||
5f0d2358 | 330 | /* Create new basic block consisting of instructions in between HEAD and END |
918ed612 | 331 | and place it to the BB chain after block AFTER. END can be NULL in to |
5f0d2358 RK |
332 | create new empty basic block before HEAD. Both END and HEAD can be NULL to |
333 | create basic block at the end of INSN chain. */ | |
ca6c03ca | 334 | |
bc35512f JH |
335 | static basic_block |
336 | rtl_create_basic_block (void *headp, void *endp, basic_block after) | |
ca6c03ca | 337 | { |
bc35512f | 338 | rtx head = headp, end = endp; |
ca6c03ca | 339 | basic_block bb; |
0b17ab2f | 340 | |
bf77398c | 341 | /* Place the new block just after the end. */ |
f470c378 | 342 | VARRAY_GROW (basic_block_info, last_basic_block + 1); |
0b17ab2f | 343 | |
bf77398c | 344 | n_basic_blocks++; |
ca6c03ca | 345 | |
852c6ec7 | 346 | bb = create_basic_block_structure (head, end, NULL, after); |
ca6c03ca JH |
347 | bb->aux = NULL; |
348 | return bb; | |
349 | } | |
bc35512f JH |
350 | |
351 | static basic_block | |
352 | cfg_layout_create_basic_block (void *head, void *end, basic_block after) | |
353 | { | |
354 | basic_block newbb = rtl_create_basic_block (head, end, after); | |
355 | ||
356 | cfg_layout_initialize_rbi (newbb); | |
357 | return newbb; | |
358 | } | |
ca6c03ca JH |
359 | \f |
360 | /* Delete the insns in a (non-live) block. We physically delete every | |
361 | non-deleted-note insn, and update the flow graph appropriately. | |
362 | ||
363 | Return nonzero if we deleted an exception handler. */ | |
364 | ||
365 | /* ??? Preserving all such notes strikes me as wrong. It would be nice | |
366 | to post-process the stream to remove empty blocks, loops, ranges, etc. */ | |
367 | ||
f0fda11c | 368 | static void |
d329e058 | 369 | rtl_delete_block (basic_block b) |
ca6c03ca | 370 | { |
ca6c03ca JH |
371 | rtx insn, end, tmp; |
372 | ||
373 | /* If the head of this block is a CODE_LABEL, then it might be the | |
374 | label for an exception handler which can't be reached. | |
375 | ||
376 | We need to remove the label from the exception_handler_label list | |
377 | and remove the associated NOTE_INSN_EH_REGION_BEG and | |
378 | NOTE_INSN_EH_REGION_END notes. */ | |
379 | ||
07532fad RS |
380 | /* Get rid of all NOTE_INSN_PREDICTIONs and NOTE_INSN_LOOP_CONTs |
381 | hanging before the block. */ | |
f87c27b4 | 382 | |
a813c111 | 383 | for (insn = PREV_INSN (BB_HEAD (b)); insn; insn = PREV_INSN (insn)) |
969d70ca JH |
384 | { |
385 | if (GET_CODE (insn) != NOTE) | |
f87c27b4 | 386 | break; |
07532fad RS |
387 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_PREDICTION |
388 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_CONT) | |
f87c27b4 | 389 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; |
969d70ca JH |
390 | } |
391 | ||
a813c111 | 392 | insn = BB_HEAD (b); |
ca6c03ca | 393 | |
a813c111 | 394 | never_reached_warning (insn, BB_END (b)); |
ca6c03ca JH |
395 | |
396 | if (GET_CODE (insn) == CODE_LABEL) | |
397 | maybe_remove_eh_handler (insn); | |
398 | ||
399 | /* Include any jump table following the basic block. */ | |
a813c111 | 400 | end = BB_END (b); |
e1233a7d | 401 | if (tablejump_p (end, NULL, &tmp)) |
ca6c03ca JH |
402 | end = tmp; |
403 | ||
404 | /* Include any barrier that may follow the basic block. */ | |
405 | tmp = next_nonnote_insn (end); | |
406 | if (tmp && GET_CODE (tmp) == BARRIER) | |
407 | end = tmp; | |
408 | ||
409 | /* Selectively delete the entire chain. */ | |
a813c111 | 410 | BB_HEAD (b) = NULL; |
ca6c03ca | 411 | delete_insn_chain (insn, end); |
ca6c03ca JH |
412 | } |
413 | \f | |
852c6ec7 | 414 | /* Records the basic block struct in BLOCK_FOR_INSN for every insn. */ |
ca6c03ca JH |
415 | |
416 | void | |
d329e058 | 417 | compute_bb_for_insn (void) |
ca6c03ca | 418 | { |
e0082a72 | 419 | basic_block bb; |
ca6c03ca | 420 | |
e0082a72 | 421 | FOR_EACH_BB (bb) |
ca6c03ca | 422 | { |
a813c111 | 423 | rtx end = BB_END (bb); |
5f0d2358 | 424 | rtx insn; |
ca6c03ca | 425 | |
a813c111 | 426 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
ca6c03ca | 427 | { |
ba4f7968 | 428 | BLOCK_FOR_INSN (insn) = bb; |
ca6c03ca JH |
429 | if (insn == end) |
430 | break; | |
ca6c03ca JH |
431 | } |
432 | } | |
433 | } | |
434 | ||
435 | /* Release the basic_block_for_insn array. */ | |
436 | ||
437 | void | |
d329e058 | 438 | free_bb_for_insn (void) |
ca6c03ca | 439 | { |
ba4f7968 JH |
440 | rtx insn; |
441 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) | |
442 | if (GET_CODE (insn) != BARRIER) | |
443 | BLOCK_FOR_INSN (insn) = NULL; | |
ca6c03ca JH |
444 | } |
445 | ||
446 | /* Update insns block within BB. */ | |
447 | ||
448 | void | |
d329e058 | 449 | update_bb_for_insn (basic_block bb) |
ca6c03ca JH |
450 | { |
451 | rtx insn; | |
452 | ||
a813c111 | 453 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
ca6c03ca | 454 | { |
bcc53e2a JH |
455 | if (GET_CODE (insn) != BARRIER) |
456 | set_block_for_insn (insn, bb); | |
a813c111 | 457 | if (insn == BB_END (bb)) |
ca6c03ca JH |
458 | break; |
459 | } | |
460 | } | |
ca6c03ca | 461 | \f |
f470c378 ZD |
462 | /* Creates a new basic block just after basic block B by splitting |
463 | everything after specified instruction I. */ | |
ca6c03ca | 464 | |
f470c378 | 465 | static basic_block |
d329e058 | 466 | rtl_split_block (basic_block bb, void *insnp) |
ca6c03ca JH |
467 | { |
468 | basic_block new_bb; | |
9ee634e3 | 469 | rtx insn = insnp; |
f470c378 | 470 | edge e; |
ca6c03ca | 471 | |
f470c378 ZD |
472 | if (!insn) |
473 | { | |
474 | insn = first_insn_after_basic_block_note (bb); | |
475 | ||
476 | if (insn) | |
477 | insn = PREV_INSN (insn); | |
478 | else | |
479 | insn = get_last_insn (); | |
480 | } | |
481 | ||
482 | /* We probably should check type of the insn so that we do not create | |
483 | inconsistent cfg. It is checked in verify_flow_info anyway, so do not | |
484 | bother. */ | |
485 | if (insn == BB_END (bb)) | |
486 | emit_note_after (NOTE_INSN_DELETED, insn); | |
ca6c03ca JH |
487 | |
488 | /* Create the new basic block. */ | |
a813c111 | 489 | new_bb = create_basic_block (NEXT_INSN (insn), BB_END (bb), bb); |
a813c111 | 490 | BB_END (bb) = insn; |
ca6c03ca JH |
491 | |
492 | /* Redirect the outgoing edges. */ | |
493 | new_bb->succ = bb->succ; | |
494 | bb->succ = NULL; | |
495 | for (e = new_bb->succ; e; e = e->succ_next) | |
496 | e->src = new_bb; | |
497 | ||
ca6c03ca JH |
498 | if (bb->global_live_at_start) |
499 | { | |
500 | new_bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
501 | new_bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
502 | COPY_REG_SET (new_bb->global_live_at_end, bb->global_live_at_end); | |
503 | ||
504 | /* We now have to calculate which registers are live at the end | |
505 | of the split basic block and at the start of the new basic | |
506 | block. Start with those registers that are known to be live | |
507 | at the end of the original basic block and get | |
508 | propagate_block to determine which registers are live. */ | |
509 | COPY_REG_SET (new_bb->global_live_at_start, bb->global_live_at_end); | |
510 | propagate_block (new_bb, new_bb->global_live_at_start, NULL, NULL, 0); | |
511 | COPY_REG_SET (bb->global_live_at_end, | |
512 | new_bb->global_live_at_start); | |
0a2ed1f1 JH |
513 | #ifdef HAVE_conditional_execution |
514 | /* In the presence of conditional execution we are not able to update | |
515 | liveness precisely. */ | |
516 | if (reload_completed) | |
517 | { | |
518 | bb->flags |= BB_DIRTY; | |
519 | new_bb->flags |= BB_DIRTY; | |
520 | } | |
521 | #endif | |
ca6c03ca JH |
522 | } |
523 | ||
f470c378 | 524 | return new_bb; |
bc35512f JH |
525 | } |
526 | ||
ca6c03ca | 527 | /* Blocks A and B are to be merged into a single block A. The insns |
bc35512f | 528 | are already contiguous. */ |
ca6c03ca | 529 | |
bc35512f JH |
530 | static void |
531 | rtl_merge_blocks (basic_block a, basic_block b) | |
ca6c03ca | 532 | { |
a813c111 | 533 | rtx b_head = BB_HEAD (b), b_end = BB_END (b), a_end = BB_END (a); |
ca6c03ca JH |
534 | rtx del_first = NULL_RTX, del_last = NULL_RTX; |
535 | int b_empty = 0; | |
536 | ||
537 | /* If there was a CODE_LABEL beginning B, delete it. */ | |
ca6c03ca JH |
538 | if (GET_CODE (b_head) == CODE_LABEL) |
539 | { | |
540 | /* Detect basic blocks with nothing but a label. This can happen | |
541 | in particular at the end of a function. */ | |
542 | if (b_head == b_end) | |
543 | b_empty = 1; | |
5f0d2358 | 544 | |
ca6c03ca JH |
545 | del_first = del_last = b_head; |
546 | b_head = NEXT_INSN (b_head); | |
547 | } | |
548 | ||
5f0d2358 RK |
549 | /* Delete the basic block note and handle blocks containing just that |
550 | note. */ | |
ca6c03ca JH |
551 | if (NOTE_INSN_BASIC_BLOCK_P (b_head)) |
552 | { | |
553 | if (b_head == b_end) | |
554 | b_empty = 1; | |
555 | if (! del_last) | |
556 | del_first = b_head; | |
5f0d2358 | 557 | |
ca6c03ca JH |
558 | del_last = b_head; |
559 | b_head = NEXT_INSN (b_head); | |
560 | } | |
561 | ||
562 | /* If there was a jump out of A, delete it. */ | |
ca6c03ca JH |
563 | if (GET_CODE (a_end) == JUMP_INSN) |
564 | { | |
565 | rtx prev; | |
566 | ||
567 | for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev)) | |
568 | if (GET_CODE (prev) != NOTE | |
569 | || NOTE_LINE_NUMBER (prev) == NOTE_INSN_BASIC_BLOCK | |
a813c111 | 570 | || prev == BB_HEAD (a)) |
ca6c03ca JH |
571 | break; |
572 | ||
573 | del_first = a_end; | |
574 | ||
575 | #ifdef HAVE_cc0 | |
576 | /* If this was a conditional jump, we need to also delete | |
577 | the insn that set cc0. */ | |
578 | if (only_sets_cc0_p (prev)) | |
579 | { | |
580 | rtx tmp = prev; | |
5f0d2358 | 581 | |
ca6c03ca JH |
582 | prev = prev_nonnote_insn (prev); |
583 | if (!prev) | |
a813c111 | 584 | prev = BB_HEAD (a); |
ca6c03ca JH |
585 | del_first = tmp; |
586 | } | |
587 | #endif | |
588 | ||
589 | a_end = PREV_INSN (del_first); | |
590 | } | |
591 | else if (GET_CODE (NEXT_INSN (a_end)) == BARRIER) | |
592 | del_first = NEXT_INSN (a_end); | |
593 | ||
ca6c03ca JH |
594 | /* Delete everything marked above as well as crap that might be |
595 | hanging out between the two blocks. */ | |
f470c378 | 596 | BB_HEAD (b) = NULL; |
ca6c03ca JH |
597 | delete_insn_chain (del_first, del_last); |
598 | ||
599 | /* Reassociate the insns of B with A. */ | |
600 | if (!b_empty) | |
601 | { | |
ba4f7968 | 602 | rtx x; |
5f0d2358 | 603 | |
ba4f7968 JH |
604 | for (x = a_end; x != b_end; x = NEXT_INSN (x)) |
605 | set_block_for_insn (x, a); | |
5f0d2358 | 606 | |
ba4f7968 | 607 | set_block_for_insn (b_end, a); |
5f0d2358 | 608 | |
ca6c03ca JH |
609 | a_end = b_end; |
610 | } | |
5f0d2358 | 611 | |
a813c111 | 612 | BB_END (a) = a_end; |
ca6c03ca | 613 | } |
bc35512f JH |
614 | |
615 | /* Return true when block A and B can be merged. */ | |
616 | static bool | |
617 | rtl_can_merge_blocks (basic_block a,basic_block b) | |
618 | { | |
619 | /* There must be exactly one edge in between the blocks. */ | |
620 | return (a->succ && !a->succ->succ_next && a->succ->dest == b | |
621 | && !b->pred->pred_next && a != b | |
622 | /* Must be simple edge. */ | |
623 | && !(a->succ->flags & EDGE_COMPLEX) | |
624 | && a->next_bb == b | |
625 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR | |
626 | /* If the jump insn has side effects, | |
627 | we can't kill the edge. */ | |
a813c111 | 628 | && (GET_CODE (BB_END (a)) != JUMP_INSN |
e24e7211 | 629 | || (reload_completed |
a813c111 | 630 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f | 631 | } |
ca6c03ca | 632 | \f |
5f0d2358 RK |
633 | /* Return the label in the head of basic block BLOCK. Create one if it doesn't |
634 | exist. */ | |
ca6c03ca JH |
635 | |
636 | rtx | |
d329e058 | 637 | block_label (basic_block block) |
ca6c03ca JH |
638 | { |
639 | if (block == EXIT_BLOCK_PTR) | |
640 | return NULL_RTX; | |
5f0d2358 | 641 | |
a813c111 | 642 | if (GET_CODE (BB_HEAD (block)) != CODE_LABEL) |
ca6c03ca | 643 | { |
a813c111 | 644 | BB_HEAD (block) = emit_label_before (gen_label_rtx (), BB_HEAD (block)); |
ca6c03ca | 645 | } |
5f0d2358 | 646 | |
a813c111 | 647 | return BB_HEAD (block); |
ca6c03ca JH |
648 | } |
649 | ||
650 | /* Attempt to perform edge redirection by replacing possibly complex jump | |
5f0d2358 RK |
651 | instruction by unconditional jump or removing jump completely. This can |
652 | apply only if all edges now point to the same block. The parameters and | |
653 | return values are equivalent to redirect_edge_and_branch. */ | |
ca6c03ca | 654 | |
3348b696 | 655 | bool |
bc35512f | 656 | try_redirect_by_replacing_jump (edge e, basic_block target, bool in_cfglayout) |
ca6c03ca JH |
657 | { |
658 | basic_block src = e->src; | |
a813c111 | 659 | rtx insn = BB_END (src), kill_from; |
ca6c03ca | 660 | edge tmp; |
e1233a7d | 661 | rtx set; |
ca6c03ca JH |
662 | int fallthru = 0; |
663 | ||
664 | /* Verify that all targets will be TARGET. */ | |
665 | for (tmp = src->succ; tmp; tmp = tmp->succ_next) | |
666 | if (tmp->dest != target && tmp != e) | |
667 | break; | |
5f0d2358 | 668 | |
ca6c03ca JH |
669 | if (tmp || !onlyjump_p (insn)) |
670 | return false; | |
3348b696 | 671 | if ((!optimize || reload_completed) && tablejump_p (insn, NULL, NULL)) |
1b6763cf | 672 | return false; |
ca6c03ca JH |
673 | |
674 | /* Avoid removing branch with side effects. */ | |
675 | set = single_set (insn); | |
676 | if (!set || side_effects_p (set)) | |
677 | return false; | |
678 | ||
679 | /* In case we zap a conditional jump, we'll need to kill | |
680 | the cc0 setter too. */ | |
681 | kill_from = insn; | |
682 | #ifdef HAVE_cc0 | |
683 | if (reg_mentioned_p (cc0_rtx, PATTERN (insn))) | |
684 | kill_from = PREV_INSN (insn); | |
685 | #endif | |
686 | ||
687 | /* See if we can create the fallthru edge. */ | |
bc35512f | 688 | if (in_cfglayout || can_fallthru (src, target)) |
ca6c03ca | 689 | { |
c263766c RH |
690 | if (dump_file) |
691 | fprintf (dump_file, "Removing jump %i.\n", INSN_UID (insn)); | |
ca6c03ca JH |
692 | fallthru = 1; |
693 | ||
eaec9b3d | 694 | /* Selectively unlink whole insn chain. */ |
bc35512f JH |
695 | if (in_cfglayout) |
696 | { | |
697 | rtx insn = src->rbi->footer; | |
698 | ||
a813c111 | 699 | delete_insn_chain (kill_from, BB_END (src)); |
bc35512f JH |
700 | |
701 | /* Remove barriers but keep jumptables. */ | |
702 | while (insn) | |
703 | { | |
704 | if (GET_CODE (insn) == BARRIER) | |
705 | { | |
706 | if (PREV_INSN (insn)) | |
707 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
708 | else | |
709 | src->rbi->footer = NEXT_INSN (insn); | |
710 | if (NEXT_INSN (insn)) | |
711 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
712 | } | |
713 | if (GET_CODE (insn) == CODE_LABEL) | |
714 | break; | |
715 | insn = NEXT_INSN (insn); | |
716 | } | |
717 | } | |
718 | else | |
a813c111 | 719 | delete_insn_chain (kill_from, PREV_INSN (BB_HEAD (target))); |
ca6c03ca | 720 | } |
5f0d2358 | 721 | |
ca6c03ca JH |
722 | /* If this already is simplejump, redirect it. */ |
723 | else if (simplejump_p (insn)) | |
724 | { | |
725 | if (e->dest == target) | |
726 | return false; | |
c263766c RH |
727 | if (dump_file) |
728 | fprintf (dump_file, "Redirecting jump %i from %i to %i.\n", | |
0b17ab2f | 729 | INSN_UID (insn), e->dest->index, target->index); |
6ee3c8e4 JJ |
730 | if (!redirect_jump (insn, block_label (target), 0)) |
731 | { | |
732 | if (target == EXIT_BLOCK_PTR) | |
733 | return false; | |
734 | abort (); | |
735 | } | |
ca6c03ca | 736 | } |
5f0d2358 | 737 | |
6ee3c8e4 JJ |
738 | /* Cannot do anything for target exit block. */ |
739 | else if (target == EXIT_BLOCK_PTR) | |
740 | return false; | |
741 | ||
ca6c03ca JH |
742 | /* Or replace possibly complicated jump insn by simple jump insn. */ |
743 | else | |
744 | { | |
745 | rtx target_label = block_label (target); | |
eb5b8ad4 | 746 | rtx barrier, label, table; |
ca6c03ca | 747 | |
09eb1aab | 748 | emit_jump_insn_after (gen_jump (target_label), insn); |
a813c111 | 749 | JUMP_LABEL (BB_END (src)) = target_label; |
ca6c03ca | 750 | LABEL_NUSES (target_label)++; |
c263766c RH |
751 | if (dump_file) |
752 | fprintf (dump_file, "Replacing insn %i by jump %i\n", | |
a813c111 | 753 | INSN_UID (insn), INSN_UID (BB_END (src))); |
ca6c03ca | 754 | |
4da2eb6b | 755 | |
ca6c03ca JH |
756 | delete_insn_chain (kill_from, insn); |
757 | ||
4da2eb6b RH |
758 | /* Recognize a tablejump that we are converting to a |
759 | simple jump and remove its associated CODE_LABEL | |
760 | and ADDR_VEC or ADDR_DIFF_VEC. */ | |
3348b696 | 761 | if (tablejump_p (insn, &label, &table)) |
4da2eb6b | 762 | delete_insn_chain (label, table); |
eb5b8ad4 | 763 | |
a813c111 | 764 | barrier = next_nonnote_insn (BB_END (src)); |
ca6c03ca | 765 | if (!barrier || GET_CODE (barrier) != BARRIER) |
a813c111 | 766 | emit_barrier_after (BB_END (src)); |
5d693491 JZ |
767 | else |
768 | { | |
a813c111 | 769 | if (barrier != NEXT_INSN (BB_END (src))) |
5d693491 JZ |
770 | { |
771 | /* Move the jump before barrier so that the notes | |
772 | which originally were or were created before jump table are | |
773 | inside the basic block. */ | |
a813c111 | 774 | rtx new_insn = BB_END (src); |
5d693491 JZ |
775 | rtx tmp; |
776 | ||
a813c111 | 777 | for (tmp = NEXT_INSN (BB_END (src)); tmp != barrier; |
5d693491 JZ |
778 | tmp = NEXT_INSN (tmp)) |
779 | set_block_for_insn (tmp, src); | |
780 | ||
781 | NEXT_INSN (PREV_INSN (new_insn)) = NEXT_INSN (new_insn); | |
782 | PREV_INSN (NEXT_INSN (new_insn)) = PREV_INSN (new_insn); | |
783 | ||
784 | NEXT_INSN (new_insn) = barrier; | |
785 | NEXT_INSN (PREV_INSN (barrier)) = new_insn; | |
786 | ||
787 | PREV_INSN (new_insn) = PREV_INSN (barrier); | |
788 | PREV_INSN (barrier) = new_insn; | |
789 | } | |
790 | } | |
ca6c03ca JH |
791 | } |
792 | ||
793 | /* Keep only one edge out and set proper flags. */ | |
794 | while (src->succ->succ_next) | |
795 | remove_edge (src->succ); | |
796 | e = src->succ; | |
797 | if (fallthru) | |
798 | e->flags = EDGE_FALLTHRU; | |
799 | else | |
800 | e->flags = 0; | |
5f0d2358 | 801 | |
ca6c03ca JH |
802 | e->probability = REG_BR_PROB_BASE; |
803 | e->count = src->count; | |
804 | ||
805 | /* We don't want a block to end on a line-number note since that has | |
806 | the potential of changing the code between -g and not -g. */ | |
a813c111 SB |
807 | while (GET_CODE (BB_END (e->src)) == NOTE |
808 | && NOTE_LINE_NUMBER (BB_END (e->src)) >= 0) | |
809 | delete_insn (BB_END (e->src)); | |
ca6c03ca JH |
810 | |
811 | if (e->dest != target) | |
812 | redirect_edge_succ (e, target); | |
5f0d2358 | 813 | |
ca6c03ca JH |
814 | return true; |
815 | } | |
816 | ||
817 | /* Return last loop_beg note appearing after INSN, before start of next | |
818 | basic block. Return INSN if there are no such notes. | |
819 | ||
09da1532 | 820 | When emitting jump to redirect a fallthru edge, it should always appear |
5f0d2358 RK |
821 | after the LOOP_BEG notes, as loop optimizer expect loop to either start by |
822 | fallthru edge or jump following the LOOP_BEG note jumping to the loop exit | |
823 | test. */ | |
ca6c03ca JH |
824 | |
825 | static rtx | |
d329e058 | 826 | last_loop_beg_note (rtx insn) |
ca6c03ca JH |
827 | { |
828 | rtx last = insn; | |
5f0d2358 RK |
829 | |
830 | for (insn = NEXT_INSN (insn); insn && GET_CODE (insn) == NOTE | |
831 | && NOTE_LINE_NUMBER (insn) != NOTE_INSN_BASIC_BLOCK; | |
832 | insn = NEXT_INSN (insn)) | |
833 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
834 | last = insn; | |
835 | ||
ca6c03ca JH |
836 | return last; |
837 | } | |
838 | ||
bc35512f | 839 | /* Redirect edge representing branch of (un)conditional jump or tablejump. */ |
9ee634e3 | 840 | static bool |
bc35512f | 841 | redirect_branch_edge (edge e, basic_block target) |
ca6c03ca JH |
842 | { |
843 | rtx tmp; | |
a813c111 | 844 | rtx old_label = BB_HEAD (e->dest); |
ca6c03ca | 845 | basic_block src = e->src; |
a813c111 | 846 | rtx insn = BB_END (src); |
ca6c03ca | 847 | |
ca6c03ca JH |
848 | /* We can only redirect non-fallthru edges of jump insn. */ |
849 | if (e->flags & EDGE_FALLTHRU) | |
850 | return false; | |
5f0d2358 | 851 | else if (GET_CODE (insn) != JUMP_INSN) |
ca6c03ca JH |
852 | return false; |
853 | ||
854 | /* Recognize a tablejump and adjust all matching cases. */ | |
e1233a7d | 855 | if (tablejump_p (insn, NULL, &tmp)) |
ca6c03ca JH |
856 | { |
857 | rtvec vec; | |
858 | int j; | |
859 | rtx new_label = block_label (target); | |
860 | ||
6ee3c8e4 JJ |
861 | if (target == EXIT_BLOCK_PTR) |
862 | return false; | |
ca6c03ca JH |
863 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) |
864 | vec = XVEC (PATTERN (tmp), 0); | |
865 | else | |
866 | vec = XVEC (PATTERN (tmp), 1); | |
867 | ||
868 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
869 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
870 | { | |
871 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (Pmode, new_label); | |
872 | --LABEL_NUSES (old_label); | |
873 | ++LABEL_NUSES (new_label); | |
874 | } | |
875 | ||
f9da5064 | 876 | /* Handle casesi dispatch insns. */ |
ca6c03ca JH |
877 | if ((tmp = single_set (insn)) != NULL |
878 | && SET_DEST (tmp) == pc_rtx | |
879 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
880 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF | |
881 | && XEXP (XEXP (SET_SRC (tmp), 2), 0) == old_label) | |
882 | { | |
883 | XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (VOIDmode, | |
884 | new_label); | |
885 | --LABEL_NUSES (old_label); | |
886 | ++LABEL_NUSES (new_label); | |
887 | } | |
888 | } | |
889 | else | |
890 | { | |
891 | /* ?? We may play the games with moving the named labels from | |
892 | one basic block to the other in case only one computed_jump is | |
893 | available. */ | |
5f0d2358 RK |
894 | if (computed_jump_p (insn) |
895 | /* A return instruction can't be redirected. */ | |
896 | || returnjump_p (insn)) | |
ca6c03ca JH |
897 | return false; |
898 | ||
899 | /* If the insn doesn't go where we think, we're confused. */ | |
6ee3c8e4 | 900 | if (JUMP_LABEL (insn) != old_label) |
a3623c48 | 901 | abort (); |
6ee3c8e4 JJ |
902 | |
903 | /* If the substitution doesn't succeed, die. This can happen | |
904 | if the back end emitted unrecognizable instructions or if | |
905 | target is exit block on some arches. */ | |
906 | if (!redirect_jump (insn, block_label (target), 0)) | |
907 | { | |
908 | if (target == EXIT_BLOCK_PTR) | |
909 | return false; | |
910 | abort (); | |
911 | } | |
ca6c03ca JH |
912 | } |
913 | ||
c263766c RH |
914 | if (dump_file) |
915 | fprintf (dump_file, "Edge %i->%i redirected to %i\n", | |
0b17ab2f | 916 | e->src->index, e->dest->index, target->index); |
5f0d2358 | 917 | |
ca6c03ca JH |
918 | if (e->dest != target) |
919 | redirect_edge_succ_nodup (e, target); | |
bc35512f JH |
920 | return true; |
921 | } | |
922 | ||
923 | /* Attempt to change code to redirect edge E to TARGET. Don't do that on | |
924 | expense of adding new instructions or reordering basic blocks. | |
925 | ||
926 | Function can be also called with edge destination equivalent to the TARGET. | |
927 | Then it should try the simplifications and do nothing if none is possible. | |
928 | ||
929 | Return true if transformation succeeded. We still return false in case E | |
930 | already destinated TARGET and we didn't managed to simplify instruction | |
931 | stream. */ | |
932 | ||
933 | static bool | |
5671bf27 | 934 | rtl_redirect_edge_and_branch (edge e, basic_block target) |
bc35512f JH |
935 | { |
936 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) | |
937 | return false; | |
938 | ||
3348b696 JH |
939 | if (e->dest == target) |
940 | return true; | |
941 | ||
bc35512f JH |
942 | if (try_redirect_by_replacing_jump (e, target, false)) |
943 | return true; | |
944 | ||
3348b696 | 945 | if (!redirect_branch_edge (e, target)) |
bc35512f | 946 | return false; |
5f0d2358 | 947 | |
ca6c03ca JH |
948 | return true; |
949 | } | |
950 | ||
4fe9b91c | 951 | /* Like force_nonfallthru below, but additionally performs redirection |
ca6c03ca JH |
952 | Used by redirect_edge_and_branch_force. */ |
953 | ||
cb9a1d9b | 954 | basic_block |
d329e058 | 955 | force_nonfallthru_and_redirect (edge e, basic_block target) |
ca6c03ca | 956 | { |
a3716585 | 957 | basic_block jump_block, new_bb = NULL, src = e->src; |
ca6c03ca JH |
958 | rtx note; |
959 | edge new_edge; | |
a3716585 | 960 | int abnormal_edge_flags = 0; |
ca6c03ca | 961 | |
cb9a1d9b JH |
962 | /* In the case the last instruction is conditional jump to the next |
963 | instruction, first redirect the jump itself and then continue | |
b20b352b | 964 | by creating a basic block afterwards to redirect fallthru edge. */ |
cb9a1d9b | 965 | if (e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR |
a813c111 | 966 | && any_condjump_p (BB_END (e->src)) |
cde1d5bf | 967 | /* When called from cfglayout, fallthru edges do not |
e0bb17a8 | 968 | necessarily go to the next block. */ |
cde1d5bf | 969 | && e->src->next_bb == e->dest |
a813c111 | 970 | && JUMP_LABEL (BB_END (e->src)) == BB_HEAD (e->dest)) |
cb9a1d9b JH |
971 | { |
972 | rtx note; | |
58e6ae30 | 973 | edge b = unchecked_make_edge (e->src, target, 0); |
cb9a1d9b | 974 | |
a813c111 | 975 | if (!redirect_jump (BB_END (e->src), block_label (target), 0)) |
cb9a1d9b | 976 | abort (); |
a813c111 | 977 | note = find_reg_note (BB_END (e->src), REG_BR_PROB, NULL_RTX); |
cb9a1d9b JH |
978 | if (note) |
979 | { | |
980 | int prob = INTVAL (XEXP (note, 0)); | |
981 | ||
982 | b->probability = prob; | |
983 | b->count = e->count * prob / REG_BR_PROB_BASE; | |
984 | e->probability -= e->probability; | |
985 | e->count -= b->count; | |
986 | if (e->probability < 0) | |
987 | e->probability = 0; | |
988 | if (e->count < 0) | |
989 | e->count = 0; | |
990 | } | |
991 | } | |
992 | ||
ca6c03ca | 993 | if (e->flags & EDGE_ABNORMAL) |
a3716585 JH |
994 | { |
995 | /* Irritating special case - fallthru edge to the same block as abnormal | |
996 | edge. | |
997 | We can't redirect abnormal edge, but we still can split the fallthru | |
d329e058 | 998 | one and create separate abnormal edge to original destination. |
a3716585 JH |
999 | This allows bb-reorder to make such edge non-fallthru. */ |
1000 | if (e->dest != target) | |
1001 | abort (); | |
1002 | abnormal_edge_flags = e->flags & ~(EDGE_FALLTHRU | EDGE_CAN_FALLTHRU); | |
1003 | e->flags &= EDGE_FALLTHRU | EDGE_CAN_FALLTHRU; | |
1004 | } | |
5f0d2358 | 1005 | else if (!(e->flags & EDGE_FALLTHRU)) |
ca6c03ca | 1006 | abort (); |
24c545ff BS |
1007 | else if (e->src == ENTRY_BLOCK_PTR) |
1008 | { | |
1009 | /* We can't redirect the entry block. Create an empty block at the | |
1010 | start of the function which we use to add the new jump. */ | |
1011 | edge *pe1; | |
a813c111 | 1012 | basic_block bb = create_basic_block (BB_HEAD (e->dest), NULL, ENTRY_BLOCK_PTR); |
24c545ff BS |
1013 | |
1014 | /* Change the existing edge's source to be the new block, and add | |
1015 | a new edge from the entry block to the new block. */ | |
1016 | e->src = bb; | |
1017 | for (pe1 = &ENTRY_BLOCK_PTR->succ; *pe1; pe1 = &(*pe1)->succ_next) | |
1018 | if (*pe1 == e) | |
1019 | { | |
1020 | *pe1 = e->succ_next; | |
1021 | break; | |
1022 | } | |
1023 | e->succ_next = 0; | |
1024 | bb->succ = e; | |
1025 | make_single_succ_edge (ENTRY_BLOCK_PTR, bb, EDGE_FALLTHRU); | |
1026 | } | |
1027 | ||
a3716585 | 1028 | if (e->src->succ->succ_next || abnormal_edge_flags) |
ca6c03ca JH |
1029 | { |
1030 | /* Create the new structures. */ | |
31a78298 | 1031 | |
79019985 RH |
1032 | /* If the old block ended with a tablejump, skip its table |
1033 | by searching forward from there. Otherwise start searching | |
1034 | forward from the last instruction of the old block. */ | |
a813c111 SB |
1035 | if (!tablejump_p (BB_END (e->src), NULL, ¬e)) |
1036 | note = BB_END (e->src); | |
79019985 | 1037 | |
31a78298 | 1038 | /* Position the new block correctly relative to loop notes. */ |
79019985 | 1039 | note = last_loop_beg_note (note); |
31a78298 RH |
1040 | note = NEXT_INSN (note); |
1041 | ||
31a78298 | 1042 | jump_block = create_basic_block (note, NULL, e->src); |
ca6c03ca JH |
1043 | jump_block->count = e->count; |
1044 | jump_block->frequency = EDGE_FREQUENCY (e); | |
1045 | jump_block->loop_depth = target->loop_depth; | |
1046 | ||
1047 | if (target->global_live_at_start) | |
1048 | { | |
5f0d2358 RK |
1049 | jump_block->global_live_at_start |
1050 | = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
1051 | jump_block->global_live_at_end | |
1052 | = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
ca6c03ca JH |
1053 | COPY_REG_SET (jump_block->global_live_at_start, |
1054 | target->global_live_at_start); | |
1055 | COPY_REG_SET (jump_block->global_live_at_end, | |
1056 | target->global_live_at_start); | |
1057 | } | |
1058 | ||
1059 | /* Wire edge in. */ | |
1060 | new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU); | |
1061 | new_edge->probability = e->probability; | |
1062 | new_edge->count = e->count; | |
1063 | ||
1064 | /* Redirect old edge. */ | |
1065 | redirect_edge_pred (e, jump_block); | |
1066 | e->probability = REG_BR_PROB_BASE; | |
1067 | ||
1068 | new_bb = jump_block; | |
1069 | } | |
1070 | else | |
1071 | jump_block = e->src; | |
5f0d2358 | 1072 | |
ca6c03ca JH |
1073 | e->flags &= ~EDGE_FALLTHRU; |
1074 | if (target == EXIT_BLOCK_PTR) | |
1075 | { | |
1076 | if (HAVE_return) | |
a813c111 | 1077 | emit_jump_insn_after (gen_return (), BB_END (jump_block)); |
ca6c03ca JH |
1078 | else |
1079 | abort (); | |
1080 | } | |
1081 | else | |
1082 | { | |
1083 | rtx label = block_label (target); | |
a813c111 SB |
1084 | emit_jump_insn_after (gen_jump (label), BB_END (jump_block)); |
1085 | JUMP_LABEL (BB_END (jump_block)) = label; | |
ca6c03ca JH |
1086 | LABEL_NUSES (label)++; |
1087 | } | |
5f0d2358 | 1088 | |
a813c111 | 1089 | emit_barrier_after (BB_END (jump_block)); |
ca6c03ca JH |
1090 | redirect_edge_succ_nodup (e, target); |
1091 | ||
a3716585 JH |
1092 | if (abnormal_edge_flags) |
1093 | make_edge (src, target, abnormal_edge_flags); | |
1094 | ||
ca6c03ca JH |
1095 | return new_bb; |
1096 | } | |
1097 | ||
1098 | /* Edge E is assumed to be fallthru edge. Emit needed jump instruction | |
1099 | (and possibly create new basic block) to make edge non-fallthru. | |
1100 | Return newly created BB or NULL if none. */ | |
5f0d2358 | 1101 | |
ca6c03ca | 1102 | basic_block |
d329e058 | 1103 | force_nonfallthru (edge e) |
ca6c03ca JH |
1104 | { |
1105 | return force_nonfallthru_and_redirect (e, e->dest); | |
1106 | } | |
1107 | ||
1108 | /* Redirect edge even at the expense of creating new jump insn or | |
1109 | basic block. Return new basic block if created, NULL otherwise. | |
eaec9b3d | 1110 | Abort if conversion is impossible. */ |
ca6c03ca | 1111 | |
9ee634e3 | 1112 | static basic_block |
d329e058 | 1113 | rtl_redirect_edge_and_branch_force (edge e, basic_block target) |
ca6c03ca | 1114 | { |
5f0d2358 RK |
1115 | if (redirect_edge_and_branch (e, target) |
1116 | || e->dest == target) | |
ca6c03ca JH |
1117 | return NULL; |
1118 | ||
1119 | /* In case the edge redirection failed, try to force it to be non-fallthru | |
1120 | and redirect newly created simplejump. */ | |
5f0d2358 | 1121 | return force_nonfallthru_and_redirect (e, target); |
ca6c03ca JH |
1122 | } |
1123 | ||
1124 | /* The given edge should potentially be a fallthru edge. If that is in | |
1125 | fact true, delete the jump and barriers that are in the way. */ | |
1126 | ||
f470c378 ZD |
1127 | static void |
1128 | rtl_tidy_fallthru_edge (edge e) | |
ca6c03ca JH |
1129 | { |
1130 | rtx q; | |
f470c378 ZD |
1131 | basic_block b = e->src, c = b->next_bb; |
1132 | ||
ca6c03ca JH |
1133 | /* ??? In a late-running flow pass, other folks may have deleted basic |
1134 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
1135 | and the target label. They ought to be chastized and fixed. | |
1136 | ||
1137 | We can also wind up with a sequence of undeletable labels between | |
1138 | one block and the next. | |
1139 | ||
1140 | So search through a sequence of barriers, labels, and notes for | |
1141 | the head of block C and assert that we really do fall through. */ | |
1142 | ||
a813c111 | 1143 | for (q = NEXT_INSN (BB_END (b)); q != BB_HEAD (c); q = NEXT_INSN (q)) |
9c0a0632 RH |
1144 | if (INSN_P (q)) |
1145 | return; | |
ca6c03ca JH |
1146 | |
1147 | /* Remove what will soon cease being the jump insn from the source block. | |
1148 | If block B consisted only of this single jump, turn it into a deleted | |
1149 | note. */ | |
a813c111 | 1150 | q = BB_END (b); |
ca6c03ca JH |
1151 | if (GET_CODE (q) == JUMP_INSN |
1152 | && onlyjump_p (q) | |
1153 | && (any_uncondjump_p (q) | |
1154 | || (b->succ == e && e->succ_next == NULL))) | |
1155 | { | |
1156 | #ifdef HAVE_cc0 | |
1157 | /* If this was a conditional jump, we need to also delete | |
1158 | the insn that set cc0. */ | |
1159 | if (any_condjump_p (q) && only_sets_cc0_p (PREV_INSN (q))) | |
1160 | q = PREV_INSN (q); | |
1161 | #endif | |
1162 | ||
1163 | q = PREV_INSN (q); | |
1164 | ||
1165 | /* We don't want a block to end on a line-number note since that has | |
1166 | the potential of changing the code between -g and not -g. */ | |
1167 | while (GET_CODE (q) == NOTE && NOTE_LINE_NUMBER (q) >= 0) | |
1168 | q = PREV_INSN (q); | |
1169 | } | |
1170 | ||
1171 | /* Selectively unlink the sequence. */ | |
a813c111 SB |
1172 | if (q != PREV_INSN (BB_HEAD (c))) |
1173 | delete_insn_chain (NEXT_INSN (q), PREV_INSN (BB_HEAD (c))); | |
ca6c03ca JH |
1174 | |
1175 | e->flags |= EDGE_FALLTHRU; | |
1176 | } | |
ca6c03ca JH |
1177 | \f |
1178 | /* Helper function for split_edge. Return true in case edge BB2 to BB1 | |
1179 | is back edge of syntactic loop. */ | |
1180 | ||
1181 | static bool | |
d329e058 | 1182 | back_edge_of_syntactic_loop_p (basic_block bb1, basic_block bb2) |
ca6c03ca JH |
1183 | { |
1184 | rtx insn; | |
1185 | int count = 0; | |
bf77398c | 1186 | basic_block bb; |
ca6c03ca | 1187 | |
bf77398c | 1188 | if (bb1 == bb2) |
0b17ab2f | 1189 | return true; |
355e4ec4 | 1190 | |
bf77398c ZD |
1191 | /* ??? Could we guarantee that bb indices are monotone, so that we could |
1192 | just compare them? */ | |
1193 | for (bb = bb1; bb && bb != bb2; bb = bb->next_bb) | |
1194 | continue; | |
1195 | ||
1196 | if (!bb) | |
1197 | return false; | |
1198 | ||
a813c111 | 1199 | for (insn = BB_END (bb1); insn != BB_HEAD (bb2) && count >= 0; |
ca6c03ca JH |
1200 | insn = NEXT_INSN (insn)) |
1201 | if (GET_CODE (insn) == NOTE) | |
1202 | { | |
1203 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
1204 | count++; | |
5f0d2358 | 1205 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) |
ca6c03ca JH |
1206 | count--; |
1207 | } | |
1208 | ||
1209 | return count >= 0; | |
1210 | } | |
1211 | ||
f470c378 ZD |
1212 | /* Should move basic block BB after basic block AFTER. NIY. */ |
1213 | ||
1214 | static bool | |
1215 | rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED, | |
1216 | basic_block after ATTRIBUTE_UNUSED) | |
1217 | { | |
1218 | return false; | |
1219 | } | |
1220 | ||
ca6c03ca JH |
1221 | /* Split a (typically critical) edge. Return the new block. |
1222 | Abort on abnormal edges. | |
1223 | ||
1224 | ??? The code generally expects to be called on critical edges. | |
1225 | The case of a block ending in an unconditional jump to a | |
1226 | block with multiple predecessors is not handled optimally. */ | |
1227 | ||
8ce33230 | 1228 | static basic_block |
d329e058 | 1229 | rtl_split_edge (edge edge_in) |
ca6c03ca JH |
1230 | { |
1231 | basic_block bb; | |
ca6c03ca JH |
1232 | rtx before; |
1233 | ||
1234 | /* Abnormal edges cannot be split. */ | |
1235 | if ((edge_in->flags & EDGE_ABNORMAL) != 0) | |
1236 | abort (); | |
1237 | ||
1238 | /* We are going to place the new block in front of edge destination. | |
eaec9b3d | 1239 | Avoid existence of fallthru predecessors. */ |
ca6c03ca JH |
1240 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) |
1241 | { | |
1242 | edge e; | |
5f0d2358 | 1243 | |
ca6c03ca JH |
1244 | for (e = edge_in->dest->pred; e; e = e->pred_next) |
1245 | if (e->flags & EDGE_FALLTHRU) | |
1246 | break; | |
1247 | ||
1248 | if (e) | |
1249 | force_nonfallthru (e); | |
1250 | } | |
1251 | ||
1252 | /* Create the basic block note. | |
1253 | ||
f63d1bf7 | 1254 | Where we place the note can have a noticeable impact on the generated |
ca6c03ca JH |
1255 | code. Consider this cfg: |
1256 | ||
1257 | E | |
1258 | | | |
1259 | 0 | |
1260 | / \ | |
1261 | +->1-->2--->E | |
1262 | | | | |
1263 | +--+ | |
1264 | ||
1265 | If we need to insert an insn on the edge from block 0 to block 1, | |
1266 | we want to ensure the instructions we insert are outside of any | |
1267 | loop notes that physically sit between block 0 and block 1. Otherwise | |
1268 | we confuse the loop optimizer into thinking the loop is a phony. */ | |
1269 | ||
1270 | if (edge_in->dest != EXIT_BLOCK_PTR | |
a813c111 SB |
1271 | && PREV_INSN (BB_HEAD (edge_in->dest)) |
1272 | && GET_CODE (PREV_INSN (BB_HEAD (edge_in->dest))) == NOTE | |
1273 | && (NOTE_LINE_NUMBER (PREV_INSN (BB_HEAD (edge_in->dest))) | |
5f0d2358 | 1274 | == NOTE_INSN_LOOP_BEG) |
ca6c03ca | 1275 | && !back_edge_of_syntactic_loop_p (edge_in->dest, edge_in->src)) |
a813c111 | 1276 | before = PREV_INSN (BB_HEAD (edge_in->dest)); |
ca6c03ca | 1277 | else if (edge_in->dest != EXIT_BLOCK_PTR) |
a813c111 | 1278 | before = BB_HEAD (edge_in->dest); |
ca6c03ca JH |
1279 | else |
1280 | before = NULL_RTX; | |
1281 | ||
918ed612 | 1282 | bb = create_basic_block (before, NULL, edge_in->dest->prev_bb); |
ca6c03ca JH |
1283 | |
1284 | /* ??? This info is likely going to be out of date very soon. */ | |
1285 | if (edge_in->dest->global_live_at_start) | |
1286 | { | |
1287 | bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
1288 | bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
5f0d2358 RK |
1289 | COPY_REG_SET (bb->global_live_at_start, |
1290 | edge_in->dest->global_live_at_start); | |
1291 | COPY_REG_SET (bb->global_live_at_end, | |
1292 | edge_in->dest->global_live_at_start); | |
ca6c03ca JH |
1293 | } |
1294 | ||
4977bab6 | 1295 | make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU); |
ca6c03ca | 1296 | |
4d6922ee | 1297 | /* For non-fallthru edges, we must adjust the predecessor's |
ca6c03ca JH |
1298 | jump instruction to target our new block. */ |
1299 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1300 | { | |
1301 | if (!redirect_edge_and_branch (edge_in, bb)) | |
1302 | abort (); | |
1303 | } | |
1304 | else | |
1305 | redirect_edge_succ (edge_in, bb); | |
1306 | ||
1307 | return bb; | |
1308 | } | |
1309 | ||
1310 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1311 | The new instructions and basic blocks (if any) will not appear in the | |
1312 | CFG until commit_edge_insertions is called. */ | |
1313 | ||
1314 | void | |
d329e058 | 1315 | insert_insn_on_edge (rtx pattern, edge e) |
ca6c03ca JH |
1316 | { |
1317 | /* We cannot insert instructions on an abnormal critical edge. | |
1318 | It will be easier to find the culprit if we die now. */ | |
1319 | if ((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e)) | |
1320 | abort (); | |
1321 | ||
1322 | if (e->insns == NULL_RTX) | |
1323 | start_sequence (); | |
1324 | else | |
1325 | push_to_sequence (e->insns); | |
1326 | ||
1327 | emit_insn (pattern); | |
1328 | ||
1329 | e->insns = get_insns (); | |
1330 | end_sequence (); | |
1331 | } | |
1332 | ||
ff25ef99 ZD |
1333 | /* Called from safe_insert_insn_on_edge through note_stores, marks live |
1334 | registers that are killed by the store. */ | |
1335 | static void | |
1336 | mark_killed_regs (rtx reg, rtx set ATTRIBUTE_UNUSED, void *data) | |
1337 | { | |
1338 | regset killed = data; | |
1339 | int regno, i; | |
1340 | ||
1341 | if (GET_CODE (reg) == SUBREG) | |
1342 | reg = SUBREG_REG (reg); | |
1343 | if (!REG_P (reg)) | |
1344 | return; | |
1345 | regno = REGNO (reg); | |
1346 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1347 | SET_REGNO_REG_SET (killed, regno); | |
1348 | else | |
1349 | { | |
66fd46b6 | 1350 | for (i = 0; i < (int) hard_regno_nregs[regno][GET_MODE (reg)]; i++) |
ff25ef99 ZD |
1351 | SET_REGNO_REG_SET (killed, regno + i); |
1352 | } | |
1353 | } | |
1354 | ||
1355 | /* Similar to insert_insn_on_edge, tries to put INSN to edge E. Additionally | |
1356 | it checks whether this will not clobber the registers that are live on the | |
e0bb17a8 | 1357 | edge (i.e. it requires liveness information to be up-to-date) and if there |
ff25ef99 | 1358 | are some, then it tries to save and restore them. Returns true if |
e0bb17a8 | 1359 | successful. */ |
ff25ef99 ZD |
1360 | bool |
1361 | safe_insert_insn_on_edge (rtx insn, edge e) | |
1362 | { | |
1363 | rtx x; | |
1364 | regset_head killed_head; | |
1365 | regset killed = INITIALIZE_REG_SET (killed_head); | |
1366 | rtx save_regs = NULL_RTX; | |
1367 | int regno, noccmode; | |
1368 | enum machine_mode mode; | |
1369 | ||
1370 | #ifdef AVOID_CCMODE_COPIES | |
1371 | noccmode = true; | |
1372 | #else | |
1373 | noccmode = false; | |
1374 | #endif | |
1375 | ||
1376 | for (x = insn; x; x = NEXT_INSN (x)) | |
1377 | if (INSN_P (x)) | |
1378 | note_stores (PATTERN (x), mark_killed_regs, killed); | |
1379 | bitmap_operation (killed, killed, e->dest->global_live_at_start, | |
1380 | BITMAP_AND); | |
1381 | ||
1382 | EXECUTE_IF_SET_IN_REG_SET (killed, 0, regno, | |
1383 | { | |
1384 | mode = regno < FIRST_PSEUDO_REGISTER | |
1385 | ? reg_raw_mode[regno] | |
1386 | : GET_MODE (regno_reg_rtx[regno]); | |
1387 | if (mode == VOIDmode) | |
1388 | return false; | |
1389 | ||
1390 | if (noccmode && mode == CCmode) | |
1391 | return false; | |
1392 | ||
1393 | save_regs = alloc_EXPR_LIST (0, | |
1394 | alloc_EXPR_LIST (0, | |
1395 | gen_reg_rtx (mode), | |
1396 | gen_raw_REG (mode, regno)), | |
1397 | save_regs); | |
1398 | }); | |
1399 | ||
1400 | if (save_regs) | |
1401 | { | |
1402 | rtx from, to; | |
1403 | ||
1404 | start_sequence (); | |
1405 | for (x = save_regs; x; x = XEXP (x, 1)) | |
1406 | { | |
1407 | from = XEXP (XEXP (x, 0), 1); | |
1408 | to = XEXP (XEXP (x, 0), 0); | |
1409 | emit_move_insn (to, from); | |
1410 | } | |
1411 | emit_insn (insn); | |
1412 | for (x = save_regs; x; x = XEXP (x, 1)) | |
1413 | { | |
1414 | from = XEXP (XEXP (x, 0), 0); | |
1415 | to = XEXP (XEXP (x, 0), 1); | |
1416 | emit_move_insn (to, from); | |
1417 | } | |
1418 | insn = get_insns (); | |
1419 | end_sequence (); | |
1420 | free_EXPR_LIST_list (&save_regs); | |
1421 | } | |
1422 | insert_insn_on_edge (insn, e); | |
1423 | ||
1424 | FREE_REG_SET (killed); | |
1425 | return true; | |
1426 | } | |
1427 | ||
ca6c03ca JH |
1428 | /* Update the CFG for the instructions queued on edge E. */ |
1429 | ||
1430 | static void | |
d329e058 | 1431 | commit_one_edge_insertion (edge e, int watch_calls) |
ca6c03ca JH |
1432 | { |
1433 | rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last; | |
eae4bc56 | 1434 | basic_block bb = NULL; |
ca6c03ca JH |
1435 | |
1436 | /* Pull the insns off the edge now since the edge might go away. */ | |
1437 | insns = e->insns; | |
1438 | e->insns = NULL_RTX; | |
1439 | ||
3dec4024 JH |
1440 | /* Special case -- avoid inserting code between call and storing |
1441 | its return value. */ | |
1442 | if (watch_calls && (e->flags & EDGE_FALLTHRU) && !e->dest->pred->pred_next | |
1443 | && e->src != ENTRY_BLOCK_PTR | |
a813c111 | 1444 | && GET_CODE (BB_END (e->src)) == CALL_INSN) |
ca6c03ca | 1445 | { |
a813c111 | 1446 | rtx next = next_nonnote_insn (BB_END (e->src)); |
ca6c03ca | 1447 | |
a813c111 | 1448 | after = BB_HEAD (e->dest); |
3dec4024 JH |
1449 | /* The first insn after the call may be a stack pop, skip it. */ |
1450 | while (next | |
1451 | && keep_with_call_p (next)) | |
f87c27b4 KH |
1452 | { |
1453 | after = next; | |
3dec4024 JH |
1454 | next = next_nonnote_insn (next); |
1455 | } | |
1456 | bb = e->dest; | |
ca6c03ca | 1457 | } |
3dec4024 | 1458 | if (!before && !after) |
ca6c03ca | 1459 | { |
3dec4024 JH |
1460 | /* Figure out where to put these things. If the destination has |
1461 | one predecessor, insert there. Except for the exit block. */ | |
1462 | if (e->dest->pred->pred_next == NULL && e->dest != EXIT_BLOCK_PTR) | |
ca6c03ca | 1463 | { |
3dec4024 JH |
1464 | bb = e->dest; |
1465 | ||
1466 | /* Get the location correct wrt a code label, and "nice" wrt | |
1467 | a basic block note, and before everything else. */ | |
a813c111 | 1468 | tmp = BB_HEAD (bb); |
3dec4024 JH |
1469 | if (GET_CODE (tmp) == CODE_LABEL) |
1470 | tmp = NEXT_INSN (tmp); | |
1471 | if (NOTE_INSN_BASIC_BLOCK_P (tmp)) | |
1472 | tmp = NEXT_INSN (tmp); | |
a813c111 | 1473 | if (tmp == BB_HEAD (bb)) |
3dec4024 JH |
1474 | before = tmp; |
1475 | else if (tmp) | |
1476 | after = PREV_INSN (tmp); | |
1477 | else | |
1478 | after = get_last_insn (); | |
1479 | } | |
1480 | ||
1481 | /* If the source has one successor and the edge is not abnormal, | |
1482 | insert there. Except for the entry block. */ | |
1483 | else if ((e->flags & EDGE_ABNORMAL) == 0 | |
1484 | && e->src->succ->succ_next == NULL | |
1485 | && e->src != ENTRY_BLOCK_PTR) | |
1486 | { | |
1487 | bb = e->src; | |
1488 | ||
1489 | /* It is possible to have a non-simple jump here. Consider a target | |
1490 | where some forms of unconditional jumps clobber a register. This | |
1491 | happens on the fr30 for example. | |
1492 | ||
1493 | We know this block has a single successor, so we can just emit | |
1494 | the queued insns before the jump. */ | |
a813c111 SB |
1495 | if (GET_CODE (BB_END (bb)) == JUMP_INSN) |
1496 | for (before = BB_END (bb); | |
3dec4024 JH |
1497 | GET_CODE (PREV_INSN (before)) == NOTE |
1498 | && NOTE_LINE_NUMBER (PREV_INSN (before)) == | |
1499 | NOTE_INSN_LOOP_BEG; before = PREV_INSN (before)) | |
1500 | ; | |
1501 | else | |
1502 | { | |
1503 | /* We'd better be fallthru, or we've lost track of what's what. */ | |
1504 | if ((e->flags & EDGE_FALLTHRU) == 0) | |
1505 | abort (); | |
ca6c03ca | 1506 | |
a813c111 | 1507 | after = BB_END (bb); |
3dec4024 JH |
1508 | } |
1509 | } | |
1510 | /* Otherwise we must split the edge. */ | |
1511 | else | |
1512 | { | |
1513 | bb = split_edge (e); | |
a813c111 | 1514 | after = BB_END (bb); |
ca6c03ca JH |
1515 | } |
1516 | } | |
1517 | ||
ca6c03ca JH |
1518 | /* Now that we've found the spot, do the insertion. */ |
1519 | ||
1520 | if (before) | |
1521 | { | |
2f937369 | 1522 | emit_insn_before (insns, before); |
ca6c03ca JH |
1523 | last = prev_nonnote_insn (before); |
1524 | } | |
1525 | else | |
2f937369 | 1526 | last = emit_insn_after (insns, after); |
ca6c03ca JH |
1527 | |
1528 | if (returnjump_p (last)) | |
1529 | { | |
1530 | /* ??? Remove all outgoing edges from BB and add one for EXIT. | |
1531 | This is not currently a problem because this only happens | |
3dec4024 JH |
1532 | for the (single) epilogue, which already has a fallthru edge |
1533 | to EXIT. */ | |
ca6c03ca JH |
1534 | |
1535 | e = bb->succ; | |
1536 | if (e->dest != EXIT_BLOCK_PTR | |
3dec4024 | 1537 | || e->succ_next != NULL || (e->flags & EDGE_FALLTHRU) == 0) |
ca6c03ca | 1538 | abort (); |
ca6c03ca | 1539 | |
5f0d2358 | 1540 | e->flags &= ~EDGE_FALLTHRU; |
ca6c03ca | 1541 | emit_barrier_after (last); |
0b17ab2f | 1542 | |
ca6c03ca JH |
1543 | if (before) |
1544 | delete_insn (before); | |
1545 | } | |
1546 | else if (GET_CODE (last) == JUMP_INSN) | |
1547 | abort (); | |
5f0d2358 | 1548 | |
9dca2ad5 JH |
1549 | /* Mark the basic block for find_sub_basic_blocks. */ |
1550 | bb->aux = &bb->aux; | |
ca6c03ca JH |
1551 | } |
1552 | ||
1553 | /* Update the CFG for all queued instructions. */ | |
1554 | ||
1555 | void | |
d329e058 | 1556 | commit_edge_insertions (void) |
ca6c03ca | 1557 | { |
ca6c03ca | 1558 | basic_block bb; |
9dca2ad5 | 1559 | sbitmap blocks; |
9809a362 | 1560 | bool changed = false; |
ca6c03ca JH |
1561 | |
1562 | #ifdef ENABLE_CHECKING | |
1563 | verify_flow_info (); | |
1564 | #endif | |
1565 | ||
e0082a72 | 1566 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
ca6c03ca JH |
1567 | { |
1568 | edge e, next; | |
1569 | ||
1570 | for (e = bb->succ; e; e = next) | |
1571 | { | |
1572 | next = e->succ_next; | |
1573 | if (e->insns) | |
9809a362 JH |
1574 | { |
1575 | changed = true; | |
1576 | commit_one_edge_insertion (e, false); | |
1577 | } | |
3dec4024 | 1578 | } |
3dec4024 | 1579 | } |
9dca2ad5 | 1580 | |
9809a362 JH |
1581 | if (!changed) |
1582 | return; | |
1583 | ||
9dca2ad5 JH |
1584 | blocks = sbitmap_alloc (last_basic_block); |
1585 | sbitmap_zero (blocks); | |
1586 | FOR_EACH_BB (bb) | |
1587 | if (bb->aux) | |
1588 | { | |
1589 | SET_BIT (blocks, bb->index); | |
1590 | /* Check for forgotten bb->aux values before commit_edge_insertions | |
1591 | call. */ | |
1592 | if (bb->aux != &bb->aux) | |
1593 | abort (); | |
1594 | bb->aux = NULL; | |
1595 | } | |
1596 | find_many_sub_basic_blocks (blocks); | |
1597 | sbitmap_free (blocks); | |
3dec4024 JH |
1598 | } |
1599 | \f | |
1600 | /* Update the CFG for all queued instructions, taking special care of inserting | |
1601 | code on edges between call and storing its return value. */ | |
1602 | ||
1603 | void | |
d329e058 | 1604 | commit_edge_insertions_watch_calls (void) |
3dec4024 | 1605 | { |
3dec4024 | 1606 | basic_block bb; |
9809a362 JH |
1607 | sbitmap blocks; |
1608 | bool changed = false; | |
3dec4024 JH |
1609 | |
1610 | #ifdef ENABLE_CHECKING | |
1611 | verify_flow_info (); | |
1612 | #endif | |
1613 | ||
e0082a72 | 1614 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
3dec4024 JH |
1615 | { |
1616 | edge e, next; | |
1617 | ||
1618 | for (e = bb->succ; e; e = next) | |
1619 | { | |
1620 | next = e->succ_next; | |
1621 | if (e->insns) | |
9809a362 JH |
1622 | { |
1623 | changed = true; | |
1624 | commit_one_edge_insertion (e, true); | |
1625 | } | |
ca6c03ca | 1626 | } |
ca6c03ca | 1627 | } |
9809a362 JH |
1628 | |
1629 | if (!changed) | |
1630 | return; | |
1631 | ||
1632 | blocks = sbitmap_alloc (last_basic_block); | |
1633 | sbitmap_zero (blocks); | |
1634 | FOR_EACH_BB (bb) | |
1635 | if (bb->aux) | |
1636 | { | |
1637 | SET_BIT (blocks, bb->index); | |
1638 | /* Check for forgotten bb->aux values before commit_edge_insertions | |
1639 | call. */ | |
1640 | if (bb->aux != &bb->aux) | |
1641 | abort (); | |
1642 | bb->aux = NULL; | |
1643 | } | |
1644 | find_many_sub_basic_blocks (blocks); | |
1645 | sbitmap_free (blocks); | |
ca6c03ca JH |
1646 | } |
1647 | \f | |
f470c378 ZD |
1648 | /* Print out RTL-specific basic block information (live information |
1649 | at start and end). */ | |
ca6c03ca | 1650 | |
10e9fecc | 1651 | static void |
f470c378 | 1652 | rtl_dump_bb (basic_block bb, FILE *outf, int indent) |
ca6c03ca JH |
1653 | { |
1654 | rtx insn; | |
1655 | rtx last; | |
f470c378 | 1656 | char *s_indent; |
ca6c03ca | 1657 | |
f470c378 ZD |
1658 | s_indent = (char *) alloca ((size_t) indent + 1); |
1659 | memset ((void *) s_indent, ' ', (size_t) indent); | |
1660 | s_indent[indent] = '\0'; | |
1661 | ||
1662 | fprintf (outf, ";;%s Registers live at start: ", s_indent); | |
ca6c03ca JH |
1663 | dump_regset (bb->global_live_at_start, outf); |
1664 | putc ('\n', outf); | |
1665 | ||
a813c111 | 1666 | for (insn = BB_HEAD (bb), last = NEXT_INSN (BB_END (bb)); insn != last; |
ca6c03ca JH |
1667 | insn = NEXT_INSN (insn)) |
1668 | print_rtl_single (outf, insn); | |
1669 | ||
f470c378 | 1670 | fprintf (outf, ";;%s Registers live at end: ", s_indent); |
ca6c03ca JH |
1671 | dump_regset (bb->global_live_at_end, outf); |
1672 | putc ('\n', outf); | |
ca6c03ca JH |
1673 | } |
1674 | \f | |
1675 | /* Like print_rtl, but also print out live information for the start of each | |
1676 | basic block. */ | |
1677 | ||
1678 | void | |
d329e058 | 1679 | print_rtl_with_bb (FILE *outf, rtx rtx_first) |
ca6c03ca | 1680 | { |
b3694847 | 1681 | rtx tmp_rtx; |
ca6c03ca JH |
1682 | |
1683 | if (rtx_first == 0) | |
1684 | fprintf (outf, "(nil)\n"); | |
1685 | else | |
1686 | { | |
ca6c03ca JH |
1687 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
1688 | int max_uid = get_max_uid (); | |
703ad42b KG |
1689 | basic_block *start = xcalloc (max_uid, sizeof (basic_block)); |
1690 | basic_block *end = xcalloc (max_uid, sizeof (basic_block)); | |
1691 | enum bb_state *in_bb_p = xcalloc (max_uid, sizeof (enum bb_state)); | |
ca6c03ca | 1692 | |
e0082a72 ZD |
1693 | basic_block bb; |
1694 | ||
1695 | FOR_EACH_BB_REVERSE (bb) | |
ca6c03ca | 1696 | { |
ca6c03ca JH |
1697 | rtx x; |
1698 | ||
a813c111 SB |
1699 | start[INSN_UID (BB_HEAD (bb))] = bb; |
1700 | end[INSN_UID (BB_END (bb))] = bb; | |
1701 | for (x = BB_HEAD (bb); x != NULL_RTX; x = NEXT_INSN (x)) | |
ca6c03ca JH |
1702 | { |
1703 | enum bb_state state = IN_MULTIPLE_BB; | |
5f0d2358 | 1704 | |
ca6c03ca JH |
1705 | if (in_bb_p[INSN_UID (x)] == NOT_IN_BB) |
1706 | state = IN_ONE_BB; | |
1707 | in_bb_p[INSN_UID (x)] = state; | |
1708 | ||
a813c111 | 1709 | if (x == BB_END (bb)) |
ca6c03ca JH |
1710 | break; |
1711 | } | |
1712 | } | |
1713 | ||
1714 | for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) | |
1715 | { | |
1716 | int did_output; | |
ca6c03ca JH |
1717 | |
1718 | if ((bb = start[INSN_UID (tmp_rtx)]) != NULL) | |
1719 | { | |
1720 | fprintf (outf, ";; Start of basic block %d, registers live:", | |
0b17ab2f | 1721 | bb->index); |
ca6c03ca JH |
1722 | dump_regset (bb->global_live_at_start, outf); |
1723 | putc ('\n', outf); | |
1724 | } | |
1725 | ||
1726 | if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB | |
1727 | && GET_CODE (tmp_rtx) != NOTE | |
1728 | && GET_CODE (tmp_rtx) != BARRIER) | |
1729 | fprintf (outf, ";; Insn is not within a basic block\n"); | |
1730 | else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB) | |
1731 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); | |
1732 | ||
1733 | did_output = print_rtl_single (outf, tmp_rtx); | |
1734 | ||
1735 | if ((bb = end[INSN_UID (tmp_rtx)]) != NULL) | |
1736 | { | |
1737 | fprintf (outf, ";; End of basic block %d, registers live:\n", | |
0b17ab2f | 1738 | bb->index); |
ca6c03ca JH |
1739 | dump_regset (bb->global_live_at_end, outf); |
1740 | putc ('\n', outf); | |
1741 | } | |
1742 | ||
1743 | if (did_output) | |
1744 | putc ('\n', outf); | |
1745 | } | |
1746 | ||
1747 | free (start); | |
1748 | free (end); | |
1749 | free (in_bb_p); | |
1750 | } | |
1751 | ||
1752 | if (current_function_epilogue_delay_list != 0) | |
1753 | { | |
1754 | fprintf (outf, "\n;; Insns in epilogue delay list:\n\n"); | |
1755 | for (tmp_rtx = current_function_epilogue_delay_list; tmp_rtx != 0; | |
1756 | tmp_rtx = XEXP (tmp_rtx, 1)) | |
1757 | print_rtl_single (outf, XEXP (tmp_rtx, 0)); | |
1758 | } | |
1759 | } | |
1760 | \f | |
b446e5a2 | 1761 | void |
d329e058 | 1762 | update_br_prob_note (basic_block bb) |
b446e5a2 JH |
1763 | { |
1764 | rtx note; | |
a813c111 | 1765 | if (GET_CODE (BB_END (bb)) != JUMP_INSN) |
b446e5a2 | 1766 | return; |
a813c111 | 1767 | note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX); |
b446e5a2 JH |
1768 | if (!note || INTVAL (XEXP (note, 0)) == BRANCH_EDGE (bb)->probability) |
1769 | return; | |
1770 | XEXP (note, 0) = GEN_INT (BRANCH_EDGE (bb)->probability); | |
1771 | } | |
1772 | \f | |
10e9fecc JH |
1773 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
1774 | cfglayout RTL. | |
ca6c03ca JH |
1775 | |
1776 | Currently it does following checks: | |
1777 | ||
1778 | - test head/end pointers | |
1779 | - overlapping of basic blocks | |
ca6c03ca | 1780 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) |
f63d1bf7 | 1781 | - tails of basic blocks (ensure that boundary is necessary) |
ca6c03ca JH |
1782 | - scans body of the basic block for JUMP_INSN, CODE_LABEL |
1783 | and NOTE_INSN_BASIC_BLOCK | |
ca6c03ca JH |
1784 | |
1785 | In future it can be extended check a lot of other stuff as well | |
1786 | (reachability of basic blocks, life information, etc. etc.). */ | |
f470c378 | 1787 | |
10e9fecc | 1788 | static int |
d329e058 | 1789 | rtl_verify_flow_info_1 (void) |
ca6c03ca JH |
1790 | { |
1791 | const int max_uid = get_max_uid (); | |
ca6c03ca | 1792 | rtx last_head = get_last_insn (); |
10e9fecc | 1793 | basic_block *bb_info; |
ca6c03ca | 1794 | rtx x; |
10e9fecc | 1795 | int err = 0; |
918ed612 | 1796 | basic_block bb, last_bb_seen; |
ca6c03ca | 1797 | |
703ad42b | 1798 | bb_info = xcalloc (max_uid, sizeof (basic_block)); |
ca6c03ca | 1799 | |
918ed612 ZD |
1800 | /* Check bb chain & numbers. */ |
1801 | last_bb_seen = ENTRY_BLOCK_PTR; | |
918ed612 | 1802 | |
e0082a72 | 1803 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1804 | { |
a813c111 SB |
1805 | rtx head = BB_HEAD (bb); |
1806 | rtx end = BB_END (bb); | |
ca6c03ca JH |
1807 | |
1808 | /* Verify the end of the basic block is in the INSN chain. */ | |
1809 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) | |
1810 | if (x == end) | |
1811 | break; | |
5f0d2358 | 1812 | |
ca6c03ca JH |
1813 | if (!x) |
1814 | { | |
1f978f5f | 1815 | error ("end insn %d for block %d not found in the insn stream", |
0b17ab2f | 1816 | INSN_UID (end), bb->index); |
ca6c03ca JH |
1817 | err = 1; |
1818 | } | |
1819 | ||
1820 | /* Work backwards from the end to the head of the basic block | |
1821 | to verify the head is in the RTL chain. */ | |
1822 | for (; x != NULL_RTX; x = PREV_INSN (x)) | |
1823 | { | |
1824 | /* While walking over the insn chain, verify insns appear | |
1825 | in only one basic block and initialize the BB_INFO array | |
1826 | used by other passes. */ | |
1827 | if (bb_info[INSN_UID (x)] != NULL) | |
1828 | { | |
1f978f5f | 1829 | error ("insn %d is in multiple basic blocks (%d and %d)", |
0b17ab2f | 1830 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); |
ca6c03ca JH |
1831 | err = 1; |
1832 | } | |
5f0d2358 | 1833 | |
ca6c03ca JH |
1834 | bb_info[INSN_UID (x)] = bb; |
1835 | ||
1836 | if (x == head) | |
1837 | break; | |
1838 | } | |
1839 | if (!x) | |
1840 | { | |
1f978f5f | 1841 | error ("head insn %d for block %d not found in the insn stream", |
0b17ab2f | 1842 | INSN_UID (head), bb->index); |
ca6c03ca JH |
1843 | err = 1; |
1844 | } | |
1845 | ||
1846 | last_head = x; | |
1847 | } | |
1848 | ||
1849 | /* Now check the basic blocks (boundaries etc.) */ | |
e0082a72 | 1850 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1851 | { |
3dec4024 | 1852 | int n_fallthru = 0, n_eh = 0, n_call = 0, n_abnormal = 0, n_branch = 0; |
3cf54412 | 1853 | edge e, fallthru = NULL; |
5a1a3e5e | 1854 | rtx note; |
ca6c03ca | 1855 | |
a813c111 SB |
1856 | if (INSN_P (BB_END (bb)) |
1857 | && (note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX)) | |
3e638a90 | 1858 | && bb->succ && bb->succ->succ_next |
a813c111 | 1859 | && any_condjump_p (BB_END (bb))) |
5a1a3e5e | 1860 | { |
5a1a3e5e JH |
1861 | if (INTVAL (XEXP (note, 0)) != BRANCH_EDGE (bb)->probability) |
1862 | { | |
0108ae51 | 1863 | error ("verify_flow_info: REG_BR_PROB does not match cfg %wi %i", |
5a1a3e5e JH |
1864 | INTVAL (XEXP (note, 0)), BRANCH_EDGE (bb)->probability); |
1865 | err = 1; | |
1866 | } | |
1867 | } | |
5f0d2358 | 1868 | for (e = bb->succ; e; e = e->succ_next) |
ca6c03ca | 1869 | { |
ca6c03ca | 1870 | if (e->flags & EDGE_FALLTHRU) |
3cf54412 | 1871 | n_fallthru++, fallthru = e; |
3dec4024 | 1872 | |
65f43cdf ZD |
1873 | if ((e->flags & ~(EDGE_DFS_BACK |
1874 | | EDGE_CAN_FALLTHRU | |
1875 | | EDGE_IRREDUCIBLE_LOOP | |
1876 | | EDGE_LOOP_EXIT)) == 0) | |
3dec4024 JH |
1877 | n_branch++; |
1878 | ||
1879 | if (e->flags & EDGE_ABNORMAL_CALL) | |
1880 | n_call++; | |
1881 | ||
1882 | if (e->flags & EDGE_EH) | |
1883 | n_eh++; | |
1884 | else if (e->flags & EDGE_ABNORMAL) | |
1885 | n_abnormal++; | |
ca6c03ca | 1886 | } |
5f0d2358 | 1887 | |
a813c111 SB |
1888 | if (n_eh && GET_CODE (PATTERN (BB_END (bb))) != RESX |
1889 | && !find_reg_note (BB_END (bb), REG_EH_REGION, NULL_RTX)) | |
3dec4024 | 1890 | { |
0b17ab2f | 1891 | error ("Missing REG_EH_REGION note in the end of bb %i", bb->index); |
3dec4024 JH |
1892 | err = 1; |
1893 | } | |
1894 | if (n_branch | |
a813c111 SB |
1895 | && (GET_CODE (BB_END (bb)) != JUMP_INSN |
1896 | || (n_branch > 1 && (any_uncondjump_p (BB_END (bb)) | |
1897 | || any_condjump_p (BB_END (bb)))))) | |
3dec4024 | 1898 | { |
0b17ab2f | 1899 | error ("Too many outgoing branch edges from bb %i", bb->index); |
3dec4024 JH |
1900 | err = 1; |
1901 | } | |
a813c111 | 1902 | if (n_fallthru && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 1903 | { |
0b17ab2f | 1904 | error ("Fallthru edge after unconditional jump %i", bb->index); |
3dec4024 JH |
1905 | err = 1; |
1906 | } | |
a813c111 | 1907 | if (n_branch != 1 && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 1908 | { |
0b17ab2f | 1909 | error ("Wrong amount of branch edges after unconditional jump %i", bb->index); |
3dec4024 JH |
1910 | err = 1; |
1911 | } | |
a813c111 SB |
1912 | if (n_branch != 1 && any_condjump_p (BB_END (bb)) |
1913 | && JUMP_LABEL (BB_END (bb)) != BB_HEAD (fallthru->dest)) | |
3dec4024 | 1914 | { |
0b17ab2f | 1915 | error ("Wrong amount of branch edges after conditional jump %i", bb->index); |
3dec4024 JH |
1916 | err = 1; |
1917 | } | |
a813c111 | 1918 | if (n_call && GET_CODE (BB_END (bb)) != CALL_INSN) |
3dec4024 | 1919 | { |
0b17ab2f | 1920 | error ("Call edges for non-call insn in bb %i", bb->index); |
3dec4024 JH |
1921 | err = 1; |
1922 | } | |
1923 | if (n_abnormal | |
a813c111 SB |
1924 | && (GET_CODE (BB_END (bb)) != CALL_INSN && n_call != n_abnormal) |
1925 | && (GET_CODE (BB_END (bb)) != JUMP_INSN | |
1926 | || any_condjump_p (BB_END (bb)) | |
1927 | || any_uncondjump_p (BB_END (bb)))) | |
3dec4024 | 1928 | { |
0b17ab2f | 1929 | error ("Abnormal edges for no purpose in bb %i", bb->index); |
3dec4024 JH |
1930 | err = 1; |
1931 | } | |
f87c27b4 | 1932 | |
a813c111 | 1933 | for (x = BB_HEAD (bb); x != NEXT_INSN (BB_END (bb)); x = NEXT_INSN (x)) |
ba4f7968 | 1934 | if (BLOCK_FOR_INSN (x) != bb) |
5f0d2358 RK |
1935 | { |
1936 | debug_rtx (x); | |
1937 | if (! BLOCK_FOR_INSN (x)) | |
1938 | error | |
1939 | ("insn %d inside basic block %d but block_for_insn is NULL", | |
0b17ab2f | 1940 | INSN_UID (x), bb->index); |
5f0d2358 RK |
1941 | else |
1942 | error | |
1943 | ("insn %d inside basic block %d but block_for_insn is %i", | |
0b17ab2f | 1944 | INSN_UID (x), bb->index, BLOCK_FOR_INSN (x)->index); |
5f0d2358 RK |
1945 | |
1946 | err = 1; | |
1947 | } | |
ca6c03ca JH |
1948 | |
1949 | /* OK pointers are correct. Now check the header of basic | |
1950 | block. It ought to contain optional CODE_LABEL followed | |
1951 | by NOTE_BASIC_BLOCK. */ | |
a813c111 | 1952 | x = BB_HEAD (bb); |
ca6c03ca JH |
1953 | if (GET_CODE (x) == CODE_LABEL) |
1954 | { | |
a813c111 | 1955 | if (BB_END (bb) == x) |
ca6c03ca JH |
1956 | { |
1957 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 1958 | bb->index); |
ca6c03ca JH |
1959 | err = 1; |
1960 | } | |
5f0d2358 | 1961 | |
ca6c03ca JH |
1962 | x = NEXT_INSN (x); |
1963 | } | |
5f0d2358 | 1964 | |
ca6c03ca JH |
1965 | if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb) |
1966 | { | |
1967 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 1968 | bb->index); |
ca6c03ca JH |
1969 | err = 1; |
1970 | } | |
1971 | ||
a813c111 | 1972 | if (BB_END (bb) == x) |
5f0d2358 RK |
1973 | /* Do checks for empty blocks her. e */ |
1974 | ; | |
ca6c03ca | 1975 | else |
5f0d2358 RK |
1976 | for (x = NEXT_INSN (x); x; x = NEXT_INSN (x)) |
1977 | { | |
1978 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
1979 | { | |
1980 | error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d", | |
0b17ab2f | 1981 | INSN_UID (x), bb->index); |
5f0d2358 RK |
1982 | err = 1; |
1983 | } | |
1984 | ||
a813c111 | 1985 | if (x == BB_END (bb)) |
5f0d2358 | 1986 | break; |
ca6c03ca | 1987 | |
83fd323c | 1988 | if (control_flow_insn_p (x)) |
5f0d2358 | 1989 | { |
0b17ab2f | 1990 | error ("in basic block %d:", bb->index); |
5f0d2358 RK |
1991 | fatal_insn ("flow control insn inside a basic block", x); |
1992 | } | |
1993 | } | |
ca6c03ca JH |
1994 | } |
1995 | ||
10e9fecc JH |
1996 | /* Clean up. */ |
1997 | free (bb_info); | |
1998 | return err; | |
1999 | } | |
5f0d2358 | 2000 | |
10e9fecc JH |
2001 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
2002 | cfglayout RTL. | |
5f0d2358 | 2003 | |
10e9fecc JH |
2004 | Currently it does following checks: |
2005 | - all checks of rtl_verify_flow_info_1 | |
2006 | - check that all insns are in the basic blocks | |
2007 | (except the switch handling code, barriers and notes) | |
2008 | - check that all returns are followed by barriers | |
2009 | - check that all fallthru edge points to the adjacent blocks. */ | |
2010 | static int | |
d329e058 | 2011 | rtl_verify_flow_info (void) |
10e9fecc JH |
2012 | { |
2013 | basic_block bb; | |
2014 | int err = rtl_verify_flow_info_1 (); | |
2015 | rtx x; | |
2016 | int num_bb_notes; | |
2017 | const rtx rtx_first = get_insns (); | |
2018 | basic_block last_bb_seen = ENTRY_BLOCK_PTR, curr_bb = NULL; | |
ca6c03ca | 2019 | |
10e9fecc JH |
2020 | FOR_EACH_BB_REVERSE (bb) |
2021 | { | |
2022 | edge e; | |
2023 | for (e = bb->succ; e; e = e->succ_next) | |
2024 | if (e->flags & EDGE_FALLTHRU) | |
2025 | break; | |
2026 | if (!e) | |
2027 | { | |
2028 | rtx insn; | |
2029 | ||
2030 | /* Ensure existence of barrier in BB with no fallthru edges. */ | |
a813c111 | 2031 | for (insn = BB_END (bb); !insn || GET_CODE (insn) != BARRIER; |
10e9fecc JH |
2032 | insn = NEXT_INSN (insn)) |
2033 | if (!insn | |
2034 | || (GET_CODE (insn) == NOTE | |
2035 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_BASIC_BLOCK)) | |
2036 | { | |
2037 | error ("missing barrier after block %i", bb->index); | |
2038 | err = 1; | |
2039 | break; | |
2040 | } | |
2041 | } | |
2042 | else if (e->src != ENTRY_BLOCK_PTR | |
2043 | && e->dest != EXIT_BLOCK_PTR) | |
2044 | { | |
2045 | rtx insn; | |
2046 | ||
2047 | if (e->src->next_bb != e->dest) | |
2048 | { | |
2049 | error | |
2050 | ("verify_flow_info: Incorrect blocks for fallthru %i->%i", | |
2051 | e->src->index, e->dest->index); | |
2052 | err = 1; | |
2053 | } | |
2054 | else | |
a813c111 | 2055 | for (insn = NEXT_INSN (BB_END (e->src)); insn != BB_HEAD (e->dest); |
10e9fecc JH |
2056 | insn = NEXT_INSN (insn)) |
2057 | if (GET_CODE (insn) == BARRIER | |
2058 | #ifndef CASE_DROPS_THROUGH | |
2059 | || INSN_P (insn) | |
2060 | #else | |
2061 | || (INSN_P (insn) && ! JUMP_TABLE_DATA_P (insn)) | |
2062 | #endif | |
2063 | ) | |
2064 | { | |
2065 | error ("verify_flow_info: Incorrect fallthru %i->%i", | |
2066 | e->src->index, e->dest->index); | |
2067 | fatal_insn ("wrong insn in the fallthru edge", insn); | |
2068 | err = 1; | |
2069 | } | |
2070 | } | |
2071 | } | |
ca6c03ca | 2072 | |
ca6c03ca | 2073 | num_bb_notes = 0; |
e0082a72 ZD |
2074 | last_bb_seen = ENTRY_BLOCK_PTR; |
2075 | ||
5f0d2358 | 2076 | for (x = rtx_first; x; x = NEXT_INSN (x)) |
ca6c03ca JH |
2077 | { |
2078 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2079 | { | |
bf77398c | 2080 | bb = NOTE_BASIC_BLOCK (x); |
5f0d2358 | 2081 | |
ca6c03ca | 2082 | num_bb_notes++; |
e0082a72 | 2083 | if (bb != last_bb_seen->next_bb) |
10e9fecc | 2084 | internal_error ("basic blocks not laid down consecutively"); |
ca6c03ca | 2085 | |
10e9fecc | 2086 | curr_bb = last_bb_seen = bb; |
ca6c03ca JH |
2087 | } |
2088 | ||
10e9fecc | 2089 | if (!curr_bb) |
ca6c03ca JH |
2090 | { |
2091 | switch (GET_CODE (x)) | |
2092 | { | |
2093 | case BARRIER: | |
2094 | case NOTE: | |
2095 | break; | |
2096 | ||
2097 | case CODE_LABEL: | |
2098 | /* An addr_vec is placed outside any block block. */ | |
2099 | if (NEXT_INSN (x) | |
2100 | && GET_CODE (NEXT_INSN (x)) == JUMP_INSN | |
2101 | && (GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_DIFF_VEC | |
2102 | || GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_VEC)) | |
5f0d2358 | 2103 | x = NEXT_INSN (x); |
ca6c03ca JH |
2104 | |
2105 | /* But in any case, non-deletable labels can appear anywhere. */ | |
2106 | break; | |
2107 | ||
2108 | default: | |
1f978f5f | 2109 | fatal_insn ("insn outside basic block", x); |
ca6c03ca JH |
2110 | } |
2111 | } | |
2112 | ||
2113 | if (INSN_P (x) | |
2114 | && GET_CODE (x) == JUMP_INSN | |
2115 | && returnjump_p (x) && ! condjump_p (x) | |
2116 | && ! (NEXT_INSN (x) && GET_CODE (NEXT_INSN (x)) == BARRIER)) | |
1f978f5f | 2117 | fatal_insn ("return not followed by barrier", x); |
a813c111 | 2118 | if (curr_bb && x == BB_END (curr_bb)) |
10e9fecc | 2119 | curr_bb = NULL; |
ca6c03ca JH |
2120 | } |
2121 | ||
0b17ab2f | 2122 | if (num_bb_notes != n_basic_blocks) |
ca6c03ca | 2123 | internal_error |
0b17ab2f RH |
2124 | ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)", |
2125 | num_bb_notes, n_basic_blocks); | |
ca6c03ca | 2126 | |
10e9fecc | 2127 | return err; |
ca6c03ca JH |
2128 | } |
2129 | \f | |
eaec9b3d | 2130 | /* Assume that the preceding pass has possibly eliminated jump instructions |
ca6c03ca JH |
2131 | or converted the unconditional jumps. Eliminate the edges from CFG. |
2132 | Return true if any edges are eliminated. */ | |
2133 | ||
2134 | bool | |
d329e058 | 2135 | purge_dead_edges (basic_block bb) |
ca6c03ca JH |
2136 | { |
2137 | edge e, next; | |
a813c111 | 2138 | rtx insn = BB_END (bb), note; |
ca6c03ca JH |
2139 | bool purged = false; |
2140 | ||
70da1d03 JH |
2141 | /* If this instruction cannot trap, remove REG_EH_REGION notes. */ |
2142 | if (GET_CODE (insn) == INSN | |
2143 | && (note = find_reg_note (insn, REG_EH_REGION, NULL))) | |
2144 | { | |
2145 | rtx eqnote; | |
2146 | ||
2147 | if (! may_trap_p (PATTERN (insn)) | |
2148 | || ((eqnote = find_reg_equal_equiv_note (insn)) | |
2149 | && ! may_trap_p (XEXP (eqnote, 0)))) | |
2150 | remove_note (insn, note); | |
2151 | } | |
2152 | ||
546c093e RH |
2153 | /* Cleanup abnormal edges caused by exceptions or non-local gotos. */ |
2154 | for (e = bb->succ; e; e = next) | |
2155 | { | |
2156 | next = e->succ_next; | |
2157 | if (e->flags & EDGE_EH) | |
2158 | { | |
a813c111 | 2159 | if (can_throw_internal (BB_END (bb))) |
546c093e RH |
2160 | continue; |
2161 | } | |
2162 | else if (e->flags & EDGE_ABNORMAL_CALL) | |
2163 | { | |
a813c111 | 2164 | if (GET_CODE (BB_END (bb)) == CALL_INSN |
546c093e RH |
2165 | && (! (note = find_reg_note (insn, REG_EH_REGION, NULL)) |
2166 | || INTVAL (XEXP (note, 0)) >= 0)) | |
2167 | continue; | |
2168 | } | |
2169 | else | |
2170 | continue; | |
2171 | ||
2172 | remove_edge (e); | |
2173 | bb->flags |= BB_DIRTY; | |
2174 | purged = true; | |
2175 | } | |
5f0d2358 | 2176 | |
ca6c03ca JH |
2177 | if (GET_CODE (insn) == JUMP_INSN) |
2178 | { | |
2179 | rtx note; | |
2180 | edge b,f; | |
5f0d2358 | 2181 | |
ca6c03ca JH |
2182 | /* We do care only about conditional jumps and simplejumps. */ |
2183 | if (!any_condjump_p (insn) | |
2184 | && !returnjump_p (insn) | |
2185 | && !simplejump_p (insn)) | |
c51d95ec | 2186 | return purged; |
5f0d2358 | 2187 | |
5a1a3e5e JH |
2188 | /* Branch probability/prediction notes are defined only for |
2189 | condjumps. We've possibly turned condjump into simplejump. */ | |
2190 | if (simplejump_p (insn)) | |
2191 | { | |
2192 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2193 | if (note) | |
2194 | remove_note (insn, note); | |
2195 | while ((note = find_reg_note (insn, REG_BR_PRED, NULL))) | |
2196 | remove_note (insn, note); | |
2197 | } | |
2198 | ||
ca6c03ca JH |
2199 | for (e = bb->succ; e; e = next) |
2200 | { | |
2201 | next = e->succ_next; | |
2202 | ||
7fcd7218 JH |
2203 | /* Avoid abnormal flags to leak from computed jumps turned |
2204 | into simplejumps. */ | |
f87c27b4 | 2205 | |
0e1638d4 | 2206 | e->flags &= ~EDGE_ABNORMAL; |
7fcd7218 | 2207 | |
5a566bed MM |
2208 | /* See if this edge is one we should keep. */ |
2209 | if ((e->flags & EDGE_FALLTHRU) && any_condjump_p (insn)) | |
2210 | /* A conditional jump can fall through into the next | |
2211 | block, so we should keep the edge. */ | |
ca6c03ca | 2212 | continue; |
5f0d2358 | 2213 | else if (e->dest != EXIT_BLOCK_PTR |
a813c111 | 2214 | && BB_HEAD (e->dest) == JUMP_LABEL (insn)) |
5a566bed MM |
2215 | /* If the destination block is the target of the jump, |
2216 | keep the edge. */ | |
2217 | continue; | |
2218 | else if (e->dest == EXIT_BLOCK_PTR && returnjump_p (insn)) | |
2219 | /* If the destination block is the exit block, and this | |
2220 | instruction is a return, then keep the edge. */ | |
ca6c03ca | 2221 | continue; |
5a566bed MM |
2222 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) |
2223 | /* Keep the edges that correspond to exceptions thrown by | |
0b75beaa EB |
2224 | this instruction and rematerialize the EDGE_ABNORMAL |
2225 | flag we just cleared above. */ | |
2226 | { | |
2227 | e->flags |= EDGE_ABNORMAL; | |
2228 | continue; | |
2229 | } | |
5f0d2358 | 2230 | |
5a566bed | 2231 | /* We do not need this edge. */ |
c51d95ec | 2232 | bb->flags |= BB_DIRTY; |
ca6c03ca JH |
2233 | purged = true; |
2234 | remove_edge (e); | |
2235 | } | |
5f0d2358 | 2236 | |
ca6c03ca | 2237 | if (!bb->succ || !purged) |
c51d95ec | 2238 | return purged; |
5f0d2358 | 2239 | |
c263766c RH |
2240 | if (dump_file) |
2241 | fprintf (dump_file, "Purged edges from bb %i\n", bb->index); | |
5f0d2358 | 2242 | |
ca6c03ca JH |
2243 | if (!optimize) |
2244 | return purged; | |
2245 | ||
2246 | /* Redistribute probabilities. */ | |
2247 | if (!bb->succ->succ_next) | |
2248 | { | |
2249 | bb->succ->probability = REG_BR_PROB_BASE; | |
2250 | bb->succ->count = bb->count; | |
f87c27b4 | 2251 | } |
ca6c03ca JH |
2252 | else |
2253 | { | |
2254 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2255 | if (!note) | |
2256 | return purged; | |
5f0d2358 | 2257 | |
ca6c03ca JH |
2258 | b = BRANCH_EDGE (bb); |
2259 | f = FALLTHRU_EDGE (bb); | |
2260 | b->probability = INTVAL (XEXP (note, 0)); | |
2261 | f->probability = REG_BR_PROB_BASE - b->probability; | |
2262 | b->count = bb->count * b->probability / REG_BR_PROB_BASE; | |
2263 | f->count = bb->count * f->probability / REG_BR_PROB_BASE; | |
2264 | } | |
5f0d2358 | 2265 | |
ca6c03ca JH |
2266 | return purged; |
2267 | } | |
1722c2c8 RH |
2268 | else if (GET_CODE (insn) == CALL_INSN && SIBLING_CALL_P (insn)) |
2269 | { | |
2270 | /* First, there should not be any EH or ABCALL edges resulting | |
2271 | from non-local gotos and the like. If there were, we shouldn't | |
2272 | have created the sibcall in the first place. Second, there | |
2273 | should of course never have been a fallthru edge. */ | |
2274 | if (!bb->succ || bb->succ->succ_next) | |
2275 | abort (); | |
792bb204 | 2276 | if (bb->succ->flags != (EDGE_SIBCALL | EDGE_ABNORMAL)) |
1722c2c8 RH |
2277 | abort (); |
2278 | ||
2279 | return 0; | |
2280 | } | |
ca6c03ca | 2281 | |
ca6c03ca JH |
2282 | /* If we don't see a jump insn, we don't know exactly why the block would |
2283 | have been broken at this point. Look for a simple, non-fallthru edge, | |
2284 | as these are only created by conditional branches. If we find such an | |
2285 | edge we know that there used to be a jump here and can then safely | |
2286 | remove all non-fallthru edges. */ | |
2287 | for (e = bb->succ; e && (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU)); | |
5f0d2358 RK |
2288 | e = e->succ_next) |
2289 | ; | |
2290 | ||
ca6c03ca JH |
2291 | if (!e) |
2292 | return purged; | |
5f0d2358 | 2293 | |
ca6c03ca JH |
2294 | for (e = bb->succ; e; e = next) |
2295 | { | |
2296 | next = e->succ_next; | |
2297 | if (!(e->flags & EDGE_FALLTHRU)) | |
c51d95ec JH |
2298 | { |
2299 | bb->flags |= BB_DIRTY; | |
2300 | remove_edge (e); | |
2301 | purged = true; | |
2302 | } | |
ca6c03ca | 2303 | } |
5f0d2358 | 2304 | |
ca6c03ca JH |
2305 | if (!bb->succ || bb->succ->succ_next) |
2306 | abort (); | |
5f0d2358 | 2307 | |
ca6c03ca JH |
2308 | bb->succ->probability = REG_BR_PROB_BASE; |
2309 | bb->succ->count = bb->count; | |
2310 | ||
c263766c RH |
2311 | if (dump_file) |
2312 | fprintf (dump_file, "Purged non-fallthru edges from bb %i\n", | |
0b17ab2f | 2313 | bb->index); |
ca6c03ca JH |
2314 | return purged; |
2315 | } | |
2316 | ||
5f0d2358 RK |
2317 | /* Search all basic blocks for potentially dead edges and purge them. Return |
2318 | true if some edge has been eliminated. */ | |
ca6c03ca JH |
2319 | |
2320 | bool | |
d329e058 | 2321 | purge_all_dead_edges (int update_life_p) |
ca6c03ca | 2322 | { |
e0082a72 | 2323 | int purged = false; |
710af899 | 2324 | sbitmap blocks = 0; |
e0082a72 | 2325 | basic_block bb; |
473fb060 JH |
2326 | |
2327 | if (update_life_p) | |
2328 | { | |
d55bc081 | 2329 | blocks = sbitmap_alloc (last_basic_block); |
473fb060 JH |
2330 | sbitmap_zero (blocks); |
2331 | } | |
5f0d2358 | 2332 | |
e0082a72 | 2333 | FOR_EACH_BB (bb) |
473fb060 | 2334 | { |
e0082a72 | 2335 | bool purged_here = purge_dead_edges (bb); |
5f0d2358 | 2336 | |
473fb060 JH |
2337 | purged |= purged_here; |
2338 | if (purged_here && update_life_p) | |
e0082a72 | 2339 | SET_BIT (blocks, bb->index); |
473fb060 | 2340 | } |
5f0d2358 | 2341 | |
473fb060 JH |
2342 | if (update_life_p && purged) |
2343 | update_life_info (blocks, UPDATE_LIFE_GLOBAL, | |
2344 | PROP_DEATH_NOTES | PROP_SCAN_DEAD_CODE | |
2345 | | PROP_KILL_DEAD_CODE); | |
5f0d2358 | 2346 | |
473fb060 JH |
2347 | if (update_life_p) |
2348 | sbitmap_free (blocks); | |
ca6c03ca JH |
2349 | return purged; |
2350 | } | |
9ee634e3 JH |
2351 | |
2352 | /* Same as split_block but update cfg_layout structures. */ | |
f470c378 ZD |
2353 | |
2354 | static basic_block | |
d329e058 | 2355 | cfg_layout_split_block (basic_block bb, void *insnp) |
9ee634e3 JH |
2356 | { |
2357 | rtx insn = insnp; | |
f470c378 | 2358 | basic_block new_bb = rtl_split_block (bb, insn); |
9ee634e3 | 2359 | |
f470c378 ZD |
2360 | new_bb->rbi->footer = bb->rbi->footer; |
2361 | bb->rbi->footer = NULL; | |
9ee634e3 | 2362 | |
f470c378 | 2363 | return new_bb; |
9ee634e3 JH |
2364 | } |
2365 | ||
2366 | ||
2367 | /* Redirect Edge to DEST. */ | |
2368 | static bool | |
d329e058 | 2369 | cfg_layout_redirect_edge_and_branch (edge e, basic_block dest) |
9ee634e3 JH |
2370 | { |
2371 | basic_block src = e->src; | |
9ee634e3 JH |
2372 | bool ret; |
2373 | ||
bc35512f JH |
2374 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
2375 | return false; | |
2376 | ||
3348b696 | 2377 | if (e->dest == dest) |
bc35512f JH |
2378 | return true; |
2379 | ||
3348b696 JH |
2380 | if (e->src != ENTRY_BLOCK_PTR |
2381 | && try_redirect_by_replacing_jump (e, dest, true)) | |
bc35512f JH |
2382 | return true; |
2383 | ||
2384 | if (e->src == ENTRY_BLOCK_PTR | |
2385 | && (e->flags & EDGE_FALLTHRU) && !(e->flags & EDGE_COMPLEX)) | |
2386 | { | |
c263766c RH |
2387 | if (dump_file) |
2388 | fprintf (dump_file, "Redirecting entry edge from bb %i to %i\n", | |
bc35512f JH |
2389 | e->src->index, dest->index); |
2390 | ||
2391 | redirect_edge_succ (e, dest); | |
2392 | return true; | |
2393 | } | |
2394 | ||
9ee634e3 JH |
2395 | /* Redirect_edge_and_branch may decide to turn branch into fallthru edge |
2396 | in the case the basic block appears to be in sequence. Avoid this | |
2397 | transformation. */ | |
2398 | ||
9ee634e3 JH |
2399 | if (e->flags & EDGE_FALLTHRU) |
2400 | { | |
2401 | /* Redirect any branch edges unified with the fallthru one. */ | |
a813c111 | 2402 | if (GET_CODE (BB_END (src)) == JUMP_INSN |
432f982f JH |
2403 | && label_is_jump_target_p (BB_HEAD (e->dest), |
2404 | BB_END (src))) | |
9ee634e3 | 2405 | { |
c263766c RH |
2406 | if (dump_file) |
2407 | fprintf (dump_file, "Fallthru edge unified with branch " | |
432f982f JH |
2408 | "%i->%i redirected to %i\n", |
2409 | e->src->index, e->dest->index, dest->index); | |
2410 | e->flags &= ~EDGE_FALLTHRU; | |
2411 | if (!redirect_branch_edge (e, dest)) | |
9ee634e3 | 2412 | abort (); |
432f982f JH |
2413 | e->flags |= EDGE_FALLTHRU; |
2414 | return true; | |
9ee634e3 JH |
2415 | } |
2416 | /* In case we are redirecting fallthru edge to the branch edge | |
2417 | of conditional jump, remove it. */ | |
2418 | if (src->succ->succ_next | |
2419 | && !src->succ->succ_next->succ_next) | |
2420 | { | |
2421 | edge s = e->succ_next ? e->succ_next : src->succ; | |
2422 | if (s->dest == dest | |
a813c111 SB |
2423 | && any_condjump_p (BB_END (src)) |
2424 | && onlyjump_p (BB_END (src))) | |
2425 | delete_insn (BB_END (src)); | |
9ee634e3 JH |
2426 | } |
2427 | redirect_edge_succ_nodup (e, dest); | |
c263766c RH |
2428 | if (dump_file) |
2429 | fprintf (dump_file, "Fallthru edge %i->%i redirected to %i\n", | |
bc35512f | 2430 | e->src->index, e->dest->index, dest->index); |
9ee634e3 JH |
2431 | |
2432 | ret = true; | |
2433 | } | |
2434 | else | |
bc35512f | 2435 | ret = redirect_branch_edge (e, dest); |
9ee634e3 JH |
2436 | |
2437 | /* We don't want simplejumps in the insn stream during cfglayout. */ | |
a813c111 | 2438 | if (simplejump_p (BB_END (src))) |
bc35512f | 2439 | abort (); |
9ee634e3 JH |
2440 | |
2441 | return ret; | |
2442 | } | |
2443 | ||
2444 | /* Simple wrapper as we always can redirect fallthru edges. */ | |
2445 | static basic_block | |
d329e058 | 2446 | cfg_layout_redirect_edge_and_branch_force (edge e, basic_block dest) |
9ee634e3 JH |
2447 | { |
2448 | if (!cfg_layout_redirect_edge_and_branch (e, dest)) | |
2449 | abort (); | |
2450 | return NULL; | |
2451 | } | |
2452 | ||
f470c378 ZD |
2453 | /* Same as delete_basic_block but update cfg_layout structures. */ |
2454 | ||
9ee634e3 | 2455 | static void |
d329e058 | 2456 | cfg_layout_delete_block (basic_block bb) |
9ee634e3 | 2457 | { |
a813c111 | 2458 | rtx insn, next, prev = PREV_INSN (BB_HEAD (bb)), *to, remaints; |
9ee634e3 | 2459 | |
bc35512f | 2460 | if (bb->rbi->header) |
9ee634e3 | 2461 | { |
a813c111 | 2462 | next = BB_HEAD (bb); |
9ee634e3 | 2463 | if (prev) |
bc35512f | 2464 | NEXT_INSN (prev) = bb->rbi->header; |
9ee634e3 | 2465 | else |
bc35512f JH |
2466 | set_first_insn (bb->rbi->header); |
2467 | PREV_INSN (bb->rbi->header) = prev; | |
2468 | insn = bb->rbi->header; | |
9ee634e3 JH |
2469 | while (NEXT_INSN (insn)) |
2470 | insn = NEXT_INSN (insn); | |
2471 | NEXT_INSN (insn) = next; | |
2472 | PREV_INSN (next) = insn; | |
2473 | } | |
a813c111 | 2474 | next = NEXT_INSN (BB_END (bb)); |
bc35512f | 2475 | if (bb->rbi->footer) |
9ee634e3 | 2476 | { |
bc35512f JH |
2477 | insn = bb->rbi->footer; |
2478 | while (insn) | |
2479 | { | |
2480 | if (GET_CODE (insn) == BARRIER) | |
2481 | { | |
2482 | if (PREV_INSN (insn)) | |
2483 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
2484 | else | |
2485 | bb->rbi->footer = NEXT_INSN (insn); | |
2486 | if (NEXT_INSN (insn)) | |
2487 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
2488 | } | |
2489 | if (GET_CODE (insn) == CODE_LABEL) | |
2490 | break; | |
2491 | insn = NEXT_INSN (insn); | |
2492 | } | |
2493 | if (bb->rbi->footer) | |
2494 | { | |
a813c111 | 2495 | insn = BB_END (bb); |
bc35512f JH |
2496 | NEXT_INSN (insn) = bb->rbi->footer; |
2497 | PREV_INSN (bb->rbi->footer) = insn; | |
2498 | while (NEXT_INSN (insn)) | |
2499 | insn = NEXT_INSN (insn); | |
2500 | NEXT_INSN (insn) = next; | |
2501 | if (next) | |
2502 | PREV_INSN (next) = insn; | |
2503 | else | |
2504 | set_last_insn (insn); | |
2505 | } | |
9ee634e3 JH |
2506 | } |
2507 | if (bb->next_bb != EXIT_BLOCK_PTR) | |
bc35512f | 2508 | to = &bb->next_bb->rbi->header; |
9ee634e3 JH |
2509 | else |
2510 | to = &cfg_layout_function_footer; | |
2511 | rtl_delete_block (bb); | |
2512 | ||
2513 | if (prev) | |
2514 | prev = NEXT_INSN (prev); | |
d329e058 | 2515 | else |
9ee634e3 JH |
2516 | prev = get_insns (); |
2517 | if (next) | |
2518 | next = PREV_INSN (next); | |
d329e058 | 2519 | else |
9ee634e3 JH |
2520 | next = get_last_insn (); |
2521 | ||
2522 | if (next && NEXT_INSN (next) != prev) | |
2523 | { | |
2524 | remaints = unlink_insn_chain (prev, next); | |
2525 | insn = remaints; | |
2526 | while (NEXT_INSN (insn)) | |
2527 | insn = NEXT_INSN (insn); | |
2528 | NEXT_INSN (insn) = *to; | |
2529 | if (*to) | |
2530 | PREV_INSN (*to) = insn; | |
2531 | *to = remaints; | |
2532 | } | |
2533 | } | |
2534 | ||
beb235f8 | 2535 | /* Return true when blocks A and B can be safely merged. */ |
bc35512f JH |
2536 | static bool |
2537 | cfg_layout_can_merge_blocks_p (basic_block a, basic_block b) | |
2538 | { | |
2539 | /* There must be exactly one edge in between the blocks. */ | |
2540 | return (a->succ && !a->succ->succ_next && a->succ->dest == b | |
2541 | && !b->pred->pred_next && a != b | |
2542 | /* Must be simple edge. */ | |
2543 | && !(a->succ->flags & EDGE_COMPLEX) | |
2544 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR | |
2545 | /* If the jump insn has side effects, | |
2546 | we can't kill the edge. */ | |
a813c111 | 2547 | && (GET_CODE (BB_END (a)) != JUMP_INSN |
e24e7211 | 2548 | || (reload_completed |
a813c111 | 2549 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f JH |
2550 | } |
2551 | ||
2552 | /* Merge block A and B, abort when it is not possible. */ | |
2553 | static void | |
2554 | cfg_layout_merge_blocks (basic_block a, basic_block b) | |
2555 | { | |
2556 | #ifdef ENABLE_CHECKING | |
2557 | if (!cfg_layout_can_merge_blocks_p (a, b)) | |
2558 | abort (); | |
2559 | #endif | |
2560 | ||
2561 | /* If there was a CODE_LABEL beginning B, delete it. */ | |
a813c111 SB |
2562 | if (GET_CODE (BB_HEAD (b)) == CODE_LABEL) |
2563 | delete_insn (BB_HEAD (b)); | |
bc35512f JH |
2564 | |
2565 | /* We should have fallthru edge in a, or we can do dummy redirection to get | |
2566 | it cleaned up. */ | |
a813c111 | 2567 | if (GET_CODE (BB_END (a)) == JUMP_INSN) |
3348b696 | 2568 | try_redirect_by_replacing_jump (a->succ, b, true); |
a813c111 | 2569 | if (GET_CODE (BB_END (a)) == JUMP_INSN) |
bc35512f JH |
2570 | abort (); |
2571 | ||
2572 | /* Possible line number notes should appear in between. */ | |
2573 | if (b->rbi->header) | |
2574 | { | |
a813c111 | 2575 | rtx first = BB_END (a), last; |
bc35512f | 2576 | |
a813c111 | 2577 | last = emit_insn_after (b->rbi->header, BB_END (a)); |
bc35512f JH |
2578 | delete_insn_chain (NEXT_INSN (first), last); |
2579 | b->rbi->header = NULL; | |
2580 | } | |
2581 | ||
2582 | /* In the case basic blocks are not adjacent, move them around. */ | |
a813c111 | 2583 | if (NEXT_INSN (BB_END (a)) != BB_HEAD (b)) |
bc35512f | 2584 | { |
a813c111 | 2585 | rtx first = unlink_insn_chain (BB_HEAD (b), BB_END (b)); |
bc35512f | 2586 | |
a813c111 | 2587 | emit_insn_after (first, BB_END (a)); |
bc35512f JH |
2588 | /* Skip possible DELETED_LABEL insn. */ |
2589 | if (!NOTE_INSN_BASIC_BLOCK_P (first)) | |
2590 | first = NEXT_INSN (first); | |
2591 | if (!NOTE_INSN_BASIC_BLOCK_P (first)) | |
2592 | abort (); | |
a813c111 | 2593 | BB_HEAD (b) = NULL; |
bc35512f JH |
2594 | delete_insn (first); |
2595 | } | |
2596 | /* Otherwise just re-associate the instructions. */ | |
2597 | else | |
2598 | { | |
2599 | rtx insn; | |
2600 | ||
a813c111 SB |
2601 | for (insn = BB_HEAD (b); |
2602 | insn != NEXT_INSN (BB_END (b)); | |
2603 | insn = NEXT_INSN (insn)) | |
bc35512f | 2604 | set_block_for_insn (insn, a); |
a813c111 | 2605 | insn = BB_HEAD (b); |
bc35512f JH |
2606 | /* Skip possible DELETED_LABEL insn. */ |
2607 | if (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
2608 | insn = NEXT_INSN (insn); | |
2609 | if (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
2610 | abort (); | |
a813c111 SB |
2611 | BB_HEAD (b) = NULL; |
2612 | BB_END (a) = BB_END (b); | |
bc35512f JH |
2613 | delete_insn (insn); |
2614 | } | |
2615 | ||
2616 | /* Possible tablejumps and barriers should appear after the block. */ | |
2617 | if (b->rbi->footer) | |
2618 | { | |
2619 | if (!a->rbi->footer) | |
2620 | a->rbi->footer = b->rbi->footer; | |
2621 | else | |
2622 | { | |
2623 | rtx last = a->rbi->footer; | |
2624 | ||
2625 | while (NEXT_INSN (last)) | |
2626 | last = NEXT_INSN (last); | |
2627 | NEXT_INSN (last) = b->rbi->footer; | |
2628 | PREV_INSN (b->rbi->footer) = last; | |
2629 | } | |
2630 | b->rbi->footer = NULL; | |
2631 | } | |
2632 | ||
c263766c RH |
2633 | if (dump_file) |
2634 | fprintf (dump_file, "Merged blocks %d and %d.\n", | |
bc35512f | 2635 | a->index, b->index); |
bc35512f JH |
2636 | } |
2637 | ||
2638 | /* Split edge E. */ | |
f470c378 | 2639 | |
bc35512f JH |
2640 | static basic_block |
2641 | cfg_layout_split_edge (edge e) | |
2642 | { | |
2643 | edge new_e; | |
2644 | basic_block new_bb = | |
2645 | create_basic_block (e->src != ENTRY_BLOCK_PTR | |
a813c111 | 2646 | ? NEXT_INSN (BB_END (e->src)) : get_insns (), |
bc35512f JH |
2647 | NULL_RTX, e->src); |
2648 | ||
bc35512f | 2649 | new_e = make_edge (new_bb, e->dest, EDGE_FALLTHRU); |
bc35512f JH |
2650 | redirect_edge_and_branch_force (e, new_bb); |
2651 | ||
2652 | return new_bb; | |
2653 | } | |
2654 | ||
f470c378 ZD |
2655 | /* Do postprocessing after making a forwarder block joined by edge FALLTHRU. */ |
2656 | ||
2657 | static void | |
2658 | rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED) | |
2659 | { | |
2660 | } | |
2661 | ||
9ee634e3 JH |
2662 | /* Implementation of CFG manipulation for linearized RTL. */ |
2663 | struct cfg_hooks rtl_cfg_hooks = { | |
f470c378 | 2664 | "rtl", |
9ee634e3 | 2665 | rtl_verify_flow_info, |
10e9fecc | 2666 | rtl_dump_bb, |
bc35512f | 2667 | rtl_create_basic_block, |
9ee634e3 JH |
2668 | rtl_redirect_edge_and_branch, |
2669 | rtl_redirect_edge_and_branch_force, | |
2670 | rtl_delete_block, | |
2671 | rtl_split_block, | |
f470c378 | 2672 | rtl_move_block_after, |
bc35512f JH |
2673 | rtl_can_merge_blocks, /* can_merge_blocks_p */ |
2674 | rtl_merge_blocks, | |
f470c378 ZD |
2675 | rtl_split_edge, |
2676 | rtl_make_forwarder_block, | |
2677 | rtl_tidy_fallthru_edge | |
9ee634e3 JH |
2678 | }; |
2679 | ||
2680 | /* Implementation of CFG manipulation for cfg layout RTL, where | |
2681 | basic block connected via fallthru edges does not have to be adjacent. | |
2682 | This representation will hopefully become the default one in future | |
2683 | version of the compiler. */ | |
2684 | struct cfg_hooks cfg_layout_rtl_cfg_hooks = { | |
f470c378 | 2685 | "cfglayout mode", |
bc35512f | 2686 | rtl_verify_flow_info_1, |
10e9fecc | 2687 | rtl_dump_bb, |
bc35512f | 2688 | cfg_layout_create_basic_block, |
9ee634e3 JH |
2689 | cfg_layout_redirect_edge_and_branch, |
2690 | cfg_layout_redirect_edge_and_branch_force, | |
2691 | cfg_layout_delete_block, | |
2692 | cfg_layout_split_block, | |
f470c378 | 2693 | rtl_move_block_after, |
bc35512f JH |
2694 | cfg_layout_can_merge_blocks_p, |
2695 | cfg_layout_merge_blocks, | |
f470c378 ZD |
2696 | cfg_layout_split_edge, |
2697 | rtl_make_forwarder_block, | |
2698 | NULL | |
9ee634e3 | 2699 | }; |