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Commit | Line | Data |
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ca6c03ca JH |
1 | /* Control flow graph manipulation code for GNU compiler. |
2 | Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, | |
d329e058 | 3 | 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc. |
ca6c03ca JH |
4 | |
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it under | |
8 | the terms of the GNU General Public License as published by the Free | |
9 | Software Foundation; either version 2, or (at your option) any later | |
10 | version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING. If not, write to the Free | |
19 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA | |
20 | 02111-1307, USA. */ | |
21 | ||
5f0d2358 RK |
22 | /* This file contains low level functions to manipulate the CFG and analyze it |
23 | that are aware of the RTL intermediate language. | |
ca6c03ca JH |
24 | |
25 | Available functionality: | |
bc35512f | 26 | - Basic CFG/RTL manipulation API documented in cfghooks.h |
5f0d2358 | 27 | - CFG-aware instruction chain manipulation |
ca6c03ca | 28 | delete_insn, delete_insn_chain |
bc35512f JH |
29 | - Edge splitting and committing to edges |
30 | insert_insn_on_edge, commit_edge_insertions | |
31 | - CFG updating after insn simplification | |
32 | purge_dead_edges, purge_all_dead_edges | |
33 | ||
34 | Functions not supposed for generic use: | |
5f0d2358 | 35 | - Infrastructure to determine quickly basic block for insn |
ca6c03ca | 36 | compute_bb_for_insn, update_bb_for_insn, set_block_for_insn, |
5f0d2358 | 37 | - Edge redirection with updating and optimizing of insn chain |
bc35512f | 38 | block_label, tidy_fallthru_edge, force_nonfallthru */ |
ca6c03ca JH |
39 | \f |
40 | #include "config.h" | |
41 | #include "system.h" | |
4977bab6 ZW |
42 | #include "coretypes.h" |
43 | #include "tm.h" | |
ca6c03ca JH |
44 | #include "tree.h" |
45 | #include "rtl.h" | |
46 | #include "hard-reg-set.h" | |
47 | #include "basic-block.h" | |
48 | #include "regs.h" | |
49 | #include "flags.h" | |
50 | #include "output.h" | |
51 | #include "function.h" | |
52 | #include "except.h" | |
53 | #include "toplev.h" | |
54 | #include "tm_p.h" | |
55 | #include "obstack.h" | |
0a2ed1f1 | 56 | #include "insn-config.h" |
9ee634e3 | 57 | #include "cfglayout.h" |
ff25ef99 | 58 | #include "expr.h" |
ca6c03ca | 59 | |
5f0d2358 | 60 | /* Stubs in case we don't have a return insn. */ |
ca6c03ca JH |
61 | #ifndef HAVE_return |
62 | #define HAVE_return 0 | |
63 | #define gen_return() NULL_RTX | |
64 | #endif | |
65 | ||
ca6c03ca JH |
66 | /* The labels mentioned in non-jump rtl. Valid during find_basic_blocks. */ |
67 | /* ??? Should probably be using LABEL_NUSES instead. It would take a | |
68 | bit of surgery to be able to use or co-opt the routines in jump. */ | |
ca6c03ca JH |
69 | rtx label_value_list; |
70 | rtx tail_recursion_label_list; | |
71 | ||
d329e058 AJ |
72 | static int can_delete_note_p (rtx); |
73 | static int can_delete_label_p (rtx); | |
74 | static void commit_one_edge_insertion (edge, int); | |
d329e058 AJ |
75 | static rtx last_loop_beg_note (rtx); |
76 | static bool back_edge_of_syntactic_loop_p (basic_block, basic_block); | |
77 | basic_block force_nonfallthru_and_redirect (edge, basic_block); | |
78 | static basic_block rtl_split_edge (edge); | |
79 | static int rtl_verify_flow_info (void); | |
80 | static edge cfg_layout_split_block (basic_block, void *); | |
81 | static bool cfg_layout_redirect_edge_and_branch (edge, basic_block); | |
82 | static basic_block cfg_layout_redirect_edge_and_branch_force (edge, basic_block); | |
83 | static void cfg_layout_delete_block (basic_block); | |
84 | static void rtl_delete_block (basic_block); | |
85 | static basic_block rtl_redirect_edge_and_branch_force (edge, basic_block); | |
86 | static bool rtl_redirect_edge_and_branch (edge, basic_block); | |
87 | static edge rtl_split_block (basic_block, void *); | |
88 | static void rtl_dump_bb (basic_block, FILE *); | |
89 | static int rtl_verify_flow_info_1 (void); | |
ff25ef99 | 90 | static void mark_killed_regs (rtx, rtx, void *); |
ca6c03ca JH |
91 | \f |
92 | /* Return true if NOTE is not one of the ones that must be kept paired, | |
5f0d2358 | 93 | so that we may simply delete it. */ |
ca6c03ca JH |
94 | |
95 | static int | |
d329e058 | 96 | can_delete_note_p (rtx note) |
ca6c03ca JH |
97 | { |
98 | return (NOTE_LINE_NUMBER (note) == NOTE_INSN_DELETED | |
969d70ca | 99 | || NOTE_LINE_NUMBER (note) == NOTE_INSN_BASIC_BLOCK |
f87c27b4 | 100 | || NOTE_LINE_NUMBER (note) == NOTE_INSN_PREDICTION); |
ca6c03ca JH |
101 | } |
102 | ||
103 | /* True if a given label can be deleted. */ | |
104 | ||
105 | static int | |
d329e058 | 106 | can_delete_label_p (rtx label) |
ca6c03ca | 107 | { |
5f0d2358 RK |
108 | return (!LABEL_PRESERVE_P (label) |
109 | /* User declared labels must be preserved. */ | |
110 | && LABEL_NAME (label) == 0 | |
111 | && !in_expr_list_p (forced_labels, label) | |
6a58eee9 | 112 | && !in_expr_list_p (label_value_list, label)); |
ca6c03ca JH |
113 | } |
114 | ||
115 | /* Delete INSN by patching it out. Return the next insn. */ | |
116 | ||
117 | rtx | |
d329e058 | 118 | delete_insn (rtx insn) |
ca6c03ca JH |
119 | { |
120 | rtx next = NEXT_INSN (insn); | |
121 | rtx note; | |
122 | bool really_delete = true; | |
123 | ||
124 | if (GET_CODE (insn) == CODE_LABEL) | |
125 | { | |
126 | /* Some labels can't be directly removed from the INSN chain, as they | |
f87c27b4 | 127 | might be references via variables, constant pool etc. |
ca6c03ca JH |
128 | Convert them to the special NOTE_INSN_DELETED_LABEL note. */ |
129 | if (! can_delete_label_p (insn)) | |
130 | { | |
131 | const char *name = LABEL_NAME (insn); | |
132 | ||
133 | really_delete = false; | |
134 | PUT_CODE (insn, NOTE); | |
135 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED_LABEL; | |
136 | NOTE_SOURCE_FILE (insn) = name; | |
137 | } | |
5f0d2358 | 138 | |
ca6c03ca JH |
139 | remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels); |
140 | } | |
141 | ||
142 | if (really_delete) | |
143 | { | |
cda94cbb RH |
144 | /* If this insn has already been deleted, something is very wrong. */ |
145 | if (INSN_DELETED_P (insn)) | |
146 | abort (); | |
ca6c03ca JH |
147 | remove_insn (insn); |
148 | INSN_DELETED_P (insn) = 1; | |
149 | } | |
150 | ||
151 | /* If deleting a jump, decrement the use count of the label. Deleting | |
152 | the label itself should happen in the normal course of block merging. */ | |
153 | if (GET_CODE (insn) == JUMP_INSN | |
154 | && JUMP_LABEL (insn) | |
155 | && GET_CODE (JUMP_LABEL (insn)) == CODE_LABEL) | |
156 | LABEL_NUSES (JUMP_LABEL (insn))--; | |
157 | ||
158 | /* Also if deleting an insn that references a label. */ | |
159 | else if ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)) != NULL_RTX | |
160 | && GET_CODE (XEXP (note, 0)) == CODE_LABEL) | |
161 | LABEL_NUSES (XEXP (note, 0))--; | |
162 | ||
163 | if (GET_CODE (insn) == JUMP_INSN | |
164 | && (GET_CODE (PATTERN (insn)) == ADDR_VEC | |
165 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)) | |
166 | { | |
167 | rtx pat = PATTERN (insn); | |
168 | int diff_vec_p = GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC; | |
169 | int len = XVECLEN (pat, diff_vec_p); | |
170 | int i; | |
171 | ||
172 | for (i = 0; i < len; i++) | |
a124fcda RH |
173 | { |
174 | rtx label = XEXP (XVECEXP (pat, diff_vec_p, i), 0); | |
175 | ||
176 | /* When deleting code in bulk (e.g. removing many unreachable | |
177 | blocks) we can delete a label that's a target of the vector | |
178 | before deleting the vector itself. */ | |
179 | if (GET_CODE (label) != NOTE) | |
180 | LABEL_NUSES (label)--; | |
181 | } | |
ca6c03ca JH |
182 | } |
183 | ||
184 | return next; | |
185 | } | |
186 | ||
3dec4024 JH |
187 | /* Like delete_insn but also purge dead edges from BB. */ |
188 | rtx | |
d329e058 | 189 | delete_insn_and_edges (rtx insn) |
3dec4024 JH |
190 | { |
191 | rtx x; | |
192 | bool purge = false; | |
193 | ||
ba4f7968 | 194 | if (INSN_P (insn) |
3dec4024 JH |
195 | && BLOCK_FOR_INSN (insn) |
196 | && BLOCK_FOR_INSN (insn)->end == insn) | |
197 | purge = true; | |
198 | x = delete_insn (insn); | |
199 | if (purge) | |
200 | purge_dead_edges (BLOCK_FOR_INSN (insn)); | |
201 | return x; | |
202 | } | |
203 | ||
ca6c03ca JH |
204 | /* Unlink a chain of insns between START and FINISH, leaving notes |
205 | that must be paired. */ | |
206 | ||
207 | void | |
d329e058 | 208 | delete_insn_chain (rtx start, rtx finish) |
ca6c03ca | 209 | { |
ca6c03ca JH |
210 | rtx next; |
211 | ||
5f0d2358 RK |
212 | /* Unchain the insns one by one. It would be quicker to delete all of these |
213 | with a single unchaining, rather than one at a time, but we need to keep | |
214 | the NOTE's. */ | |
ca6c03ca JH |
215 | while (1) |
216 | { | |
217 | next = NEXT_INSN (start); | |
218 | if (GET_CODE (start) == NOTE && !can_delete_note_p (start)) | |
219 | ; | |
220 | else | |
221 | next = delete_insn (start); | |
222 | ||
223 | if (start == finish) | |
224 | break; | |
225 | start = next; | |
226 | } | |
227 | } | |
3dec4024 JH |
228 | |
229 | /* Like delete_insn but also purge dead edges from BB. */ | |
230 | void | |
d329e058 | 231 | delete_insn_chain_and_edges (rtx first, rtx last) |
3dec4024 JH |
232 | { |
233 | bool purge = false; | |
234 | ||
ba4f7968 | 235 | if (INSN_P (last) |
3dec4024 JH |
236 | && BLOCK_FOR_INSN (last) |
237 | && BLOCK_FOR_INSN (last)->end == last) | |
238 | purge = true; | |
239 | delete_insn_chain (first, last); | |
240 | if (purge) | |
241 | purge_dead_edges (BLOCK_FOR_INSN (last)); | |
242 | } | |
ca6c03ca | 243 | \f |
5f0d2358 RK |
244 | /* Create a new basic block consisting of the instructions between HEAD and END |
245 | inclusive. This function is designed to allow fast BB construction - reuses | |
246 | the note and basic block struct in BB_NOTE, if any and do not grow | |
247 | BASIC_BLOCK chain and should be used directly only by CFG construction code. | |
248 | END can be NULL in to create new empty basic block before HEAD. Both END | |
918ed612 ZD |
249 | and HEAD can be NULL to create basic block at the end of INSN chain. |
250 | AFTER is the basic block we should be put after. */ | |
ca6c03ca JH |
251 | |
252 | basic_block | |
d329e058 | 253 | create_basic_block_structure (rtx head, rtx end, rtx bb_note, basic_block after) |
ca6c03ca JH |
254 | { |
255 | basic_block bb; | |
256 | ||
257 | if (bb_note | |
258 | && ! RTX_INTEGRATED_P (bb_note) | |
259 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL | |
260 | && bb->aux == NULL) | |
261 | { | |
262 | /* If we found an existing note, thread it back onto the chain. */ | |
263 | ||
264 | rtx after; | |
265 | ||
266 | if (GET_CODE (head) == CODE_LABEL) | |
267 | after = head; | |
268 | else | |
269 | { | |
270 | after = PREV_INSN (head); | |
271 | head = bb_note; | |
272 | } | |
273 | ||
274 | if (after != bb_note && NEXT_INSN (after) != bb_note) | |
ba4f7968 | 275 | reorder_insns_nobb (bb_note, bb_note, after); |
ca6c03ca JH |
276 | } |
277 | else | |
278 | { | |
279 | /* Otherwise we must create a note and a basic block structure. */ | |
280 | ||
281 | bb = alloc_block (); | |
282 | ||
283 | if (!head && !end) | |
5f0d2358 RK |
284 | head = end = bb_note |
285 | = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); | |
ca6c03ca JH |
286 | else if (GET_CODE (head) == CODE_LABEL && end) |
287 | { | |
288 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); | |
289 | if (head == end) | |
290 | end = bb_note; | |
291 | } | |
292 | else | |
293 | { | |
294 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); | |
295 | head = bb_note; | |
296 | if (!end) | |
297 | end = head; | |
298 | } | |
5f0d2358 | 299 | |
ca6c03ca JH |
300 | NOTE_BASIC_BLOCK (bb_note) = bb; |
301 | } | |
302 | ||
303 | /* Always include the bb note in the block. */ | |
304 | if (NEXT_INSN (end) == bb_note) | |
305 | end = bb_note; | |
306 | ||
307 | bb->head = head; | |
308 | bb->end = end; | |
852c6ec7 | 309 | bb->index = last_basic_block++; |
38c1593d | 310 | bb->flags = BB_NEW; |
918ed612 | 311 | link_block (bb, after); |
852c6ec7 | 312 | BASIC_BLOCK (bb->index) = bb; |
ba4f7968 | 313 | update_bb_for_insn (bb); |
ca6c03ca JH |
314 | |
315 | /* Tag the block so that we know it has been used when considering | |
316 | other basic block notes. */ | |
317 | bb->aux = bb; | |
318 | ||
319 | return bb; | |
320 | } | |
321 | ||
5f0d2358 | 322 | /* Create new basic block consisting of instructions in between HEAD and END |
918ed612 | 323 | and place it to the BB chain after block AFTER. END can be NULL in to |
5f0d2358 RK |
324 | create new empty basic block before HEAD. Both END and HEAD can be NULL to |
325 | create basic block at the end of INSN chain. */ | |
ca6c03ca | 326 | |
bc35512f JH |
327 | static basic_block |
328 | rtl_create_basic_block (void *headp, void *endp, basic_block after) | |
ca6c03ca | 329 | { |
bc35512f | 330 | rtx head = headp, end = endp; |
ca6c03ca | 331 | basic_block bb; |
0b17ab2f | 332 | |
bf77398c | 333 | /* Place the new block just after the end. */ |
852c6ec7 | 334 | VARRAY_GROW (basic_block_info, last_basic_block+1); |
0b17ab2f | 335 | |
bf77398c | 336 | n_basic_blocks++; |
ca6c03ca | 337 | |
852c6ec7 | 338 | bb = create_basic_block_structure (head, end, NULL, after); |
ca6c03ca JH |
339 | bb->aux = NULL; |
340 | return bb; | |
341 | } | |
bc35512f JH |
342 | |
343 | static basic_block | |
344 | cfg_layout_create_basic_block (void *head, void *end, basic_block after) | |
345 | { | |
346 | basic_block newbb = rtl_create_basic_block (head, end, after); | |
347 | ||
348 | cfg_layout_initialize_rbi (newbb); | |
349 | return newbb; | |
350 | } | |
ca6c03ca JH |
351 | \f |
352 | /* Delete the insns in a (non-live) block. We physically delete every | |
353 | non-deleted-note insn, and update the flow graph appropriately. | |
354 | ||
355 | Return nonzero if we deleted an exception handler. */ | |
356 | ||
357 | /* ??? Preserving all such notes strikes me as wrong. It would be nice | |
358 | to post-process the stream to remove empty blocks, loops, ranges, etc. */ | |
359 | ||
f0fda11c | 360 | static void |
d329e058 | 361 | rtl_delete_block (basic_block b) |
ca6c03ca | 362 | { |
ca6c03ca JH |
363 | rtx insn, end, tmp; |
364 | ||
365 | /* If the head of this block is a CODE_LABEL, then it might be the | |
366 | label for an exception handler which can't be reached. | |
367 | ||
368 | We need to remove the label from the exception_handler_label list | |
369 | and remove the associated NOTE_INSN_EH_REGION_BEG and | |
370 | NOTE_INSN_EH_REGION_END notes. */ | |
371 | ||
07532fad RS |
372 | /* Get rid of all NOTE_INSN_PREDICTIONs and NOTE_INSN_LOOP_CONTs |
373 | hanging before the block. */ | |
f87c27b4 | 374 | |
969d70ca JH |
375 | for (insn = PREV_INSN (b->head); insn; insn = PREV_INSN (insn)) |
376 | { | |
377 | if (GET_CODE (insn) != NOTE) | |
f87c27b4 | 378 | break; |
07532fad RS |
379 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_PREDICTION |
380 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_CONT) | |
f87c27b4 | 381 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; |
969d70ca JH |
382 | } |
383 | ||
ca6c03ca JH |
384 | insn = b->head; |
385 | ||
56d44285 | 386 | never_reached_warning (insn, b->end); |
ca6c03ca JH |
387 | |
388 | if (GET_CODE (insn) == CODE_LABEL) | |
389 | maybe_remove_eh_handler (insn); | |
390 | ||
391 | /* Include any jump table following the basic block. */ | |
392 | end = b->end; | |
e1233a7d | 393 | if (tablejump_p (end, NULL, &tmp)) |
ca6c03ca JH |
394 | end = tmp; |
395 | ||
396 | /* Include any barrier that may follow the basic block. */ | |
397 | tmp = next_nonnote_insn (end); | |
398 | if (tmp && GET_CODE (tmp) == BARRIER) | |
399 | end = tmp; | |
400 | ||
401 | /* Selectively delete the entire chain. */ | |
402 | b->head = NULL; | |
403 | delete_insn_chain (insn, end); | |
404 | ||
405 | /* Remove the edges into and out of this block. Note that there may | |
406 | indeed be edges in, if we are removing an unreachable loop. */ | |
407 | while (b->pred != NULL) | |
408 | remove_edge (b->pred); | |
409 | while (b->succ != NULL) | |
410 | remove_edge (b->succ); | |
411 | ||
412 | b->pred = NULL; | |
413 | b->succ = NULL; | |
f87c27b4 | 414 | |
bf77398c | 415 | /* Remove the basic block from the array. */ |
ca6c03ca | 416 | expunge_block (b); |
ca6c03ca JH |
417 | } |
418 | \f | |
852c6ec7 | 419 | /* Records the basic block struct in BLOCK_FOR_INSN for every insn. */ |
ca6c03ca JH |
420 | |
421 | void | |
d329e058 | 422 | compute_bb_for_insn (void) |
ca6c03ca | 423 | { |
e0082a72 | 424 | basic_block bb; |
ca6c03ca | 425 | |
e0082a72 | 426 | FOR_EACH_BB (bb) |
ca6c03ca | 427 | { |
5f0d2358 RK |
428 | rtx end = bb->end; |
429 | rtx insn; | |
ca6c03ca | 430 | |
5f0d2358 | 431 | for (insn = bb->head; ; insn = NEXT_INSN (insn)) |
ca6c03ca | 432 | { |
ba4f7968 | 433 | BLOCK_FOR_INSN (insn) = bb; |
ca6c03ca JH |
434 | if (insn == end) |
435 | break; | |
ca6c03ca JH |
436 | } |
437 | } | |
438 | } | |
439 | ||
440 | /* Release the basic_block_for_insn array. */ | |
441 | ||
442 | void | |
d329e058 | 443 | free_bb_for_insn (void) |
ca6c03ca | 444 | { |
ba4f7968 JH |
445 | rtx insn; |
446 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) | |
447 | if (GET_CODE (insn) != BARRIER) | |
448 | BLOCK_FOR_INSN (insn) = NULL; | |
ca6c03ca JH |
449 | } |
450 | ||
451 | /* Update insns block within BB. */ | |
452 | ||
453 | void | |
d329e058 | 454 | update_bb_for_insn (basic_block bb) |
ca6c03ca JH |
455 | { |
456 | rtx insn; | |
457 | ||
ca6c03ca JH |
458 | for (insn = bb->head; ; insn = NEXT_INSN (insn)) |
459 | { | |
bcc53e2a JH |
460 | if (GET_CODE (insn) != BARRIER) |
461 | set_block_for_insn (insn, bb); | |
ca6c03ca JH |
462 | if (insn == bb->end) |
463 | break; | |
464 | } | |
465 | } | |
ca6c03ca JH |
466 | \f |
467 | /* Split a block BB after insn INSN creating a new fallthru edge. | |
468 | Return the new edge. Note that to keep other parts of the compiler happy, | |
469 | this function renumbers all the basic blocks so that the new | |
470 | one has a number one greater than the block split. */ | |
471 | ||
9ee634e3 | 472 | static edge |
d329e058 | 473 | rtl_split_block (basic_block bb, void *insnp) |
ca6c03ca JH |
474 | { |
475 | basic_block new_bb; | |
476 | edge new_edge; | |
477 | edge e; | |
9ee634e3 | 478 | rtx insn = insnp; |
ca6c03ca JH |
479 | |
480 | /* There is no point splitting the block after its end. */ | |
481 | if (bb->end == insn) | |
482 | return 0; | |
483 | ||
484 | /* Create the new basic block. */ | |
918ed612 | 485 | new_bb = create_basic_block (NEXT_INSN (insn), bb->end, bb); |
ca6c03ca JH |
486 | new_bb->count = bb->count; |
487 | new_bb->frequency = bb->frequency; | |
488 | new_bb->loop_depth = bb->loop_depth; | |
489 | bb->end = insn; | |
490 | ||
491 | /* Redirect the outgoing edges. */ | |
492 | new_bb->succ = bb->succ; | |
493 | bb->succ = NULL; | |
494 | for (e = new_bb->succ; e; e = e->succ_next) | |
495 | e->src = new_bb; | |
496 | ||
497 | new_edge = make_single_succ_edge (bb, new_bb, EDGE_FALLTHRU); | |
498 | ||
499 | if (bb->global_live_at_start) | |
500 | { | |
501 | new_bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
502 | new_bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
503 | COPY_REG_SET (new_bb->global_live_at_end, bb->global_live_at_end); | |
504 | ||
505 | /* We now have to calculate which registers are live at the end | |
506 | of the split basic block and at the start of the new basic | |
507 | block. Start with those registers that are known to be live | |
508 | at the end of the original basic block and get | |
509 | propagate_block to determine which registers are live. */ | |
510 | COPY_REG_SET (new_bb->global_live_at_start, bb->global_live_at_end); | |
511 | propagate_block (new_bb, new_bb->global_live_at_start, NULL, NULL, 0); | |
512 | COPY_REG_SET (bb->global_live_at_end, | |
513 | new_bb->global_live_at_start); | |
0a2ed1f1 JH |
514 | #ifdef HAVE_conditional_execution |
515 | /* In the presence of conditional execution we are not able to update | |
516 | liveness precisely. */ | |
517 | if (reload_completed) | |
518 | { | |
519 | bb->flags |= BB_DIRTY; | |
520 | new_bb->flags |= BB_DIRTY; | |
521 | } | |
522 | #endif | |
ca6c03ca JH |
523 | } |
524 | ||
525 | return new_edge; | |
526 | } | |
527 | ||
bc35512f JH |
528 | /* Assume that the code of basic block B has been merged into A. |
529 | Do corresponding CFG updates: redirect edges accordingly etc. */ | |
530 | static void | |
531 | update_cfg_after_block_merging (basic_block a, basic_block b) | |
532 | { | |
533 | edge e; | |
534 | ||
535 | /* Normally there should only be one successor of A and that is B, but | |
536 | partway though the merge of blocks for conditional_execution we'll | |
537 | be merging a TEST block with THEN and ELSE successors. Free the | |
538 | whole lot of them and hope the caller knows what they're doing. */ | |
539 | while (a->succ) | |
540 | remove_edge (a->succ); | |
541 | ||
542 | /* Adjust the edges out of B for the new owner. */ | |
543 | for (e = b->succ; e; e = e->succ_next) | |
544 | e->src = a; | |
545 | a->succ = b->succ; | |
546 | a->flags |= b->flags; | |
547 | ||
548 | /* B hasn't quite yet ceased to exist. Attempt to prevent mishap. */ | |
549 | b->pred = b->succ = NULL; | |
550 | a->global_live_at_end = b->global_live_at_end; | |
551 | ||
552 | expunge_block (b); | |
553 | } | |
554 | ||
ca6c03ca | 555 | /* Blocks A and B are to be merged into a single block A. The insns |
bc35512f | 556 | are already contiguous. */ |
ca6c03ca | 557 | |
bc35512f JH |
558 | static void |
559 | rtl_merge_blocks (basic_block a, basic_block b) | |
ca6c03ca | 560 | { |
5f0d2358 | 561 | rtx b_head = b->head, b_end = b->end, a_end = a->end; |
ca6c03ca JH |
562 | rtx del_first = NULL_RTX, del_last = NULL_RTX; |
563 | int b_empty = 0; | |
564 | ||
565 | /* If there was a CODE_LABEL beginning B, delete it. */ | |
ca6c03ca JH |
566 | if (GET_CODE (b_head) == CODE_LABEL) |
567 | { | |
568 | /* Detect basic blocks with nothing but a label. This can happen | |
569 | in particular at the end of a function. */ | |
570 | if (b_head == b_end) | |
571 | b_empty = 1; | |
5f0d2358 | 572 | |
ca6c03ca JH |
573 | del_first = del_last = b_head; |
574 | b_head = NEXT_INSN (b_head); | |
575 | } | |
576 | ||
5f0d2358 RK |
577 | /* Delete the basic block note and handle blocks containing just that |
578 | note. */ | |
ca6c03ca JH |
579 | if (NOTE_INSN_BASIC_BLOCK_P (b_head)) |
580 | { | |
581 | if (b_head == b_end) | |
582 | b_empty = 1; | |
583 | if (! del_last) | |
584 | del_first = b_head; | |
5f0d2358 | 585 | |
ca6c03ca JH |
586 | del_last = b_head; |
587 | b_head = NEXT_INSN (b_head); | |
588 | } | |
589 | ||
590 | /* If there was a jump out of A, delete it. */ | |
ca6c03ca JH |
591 | if (GET_CODE (a_end) == JUMP_INSN) |
592 | { | |
593 | rtx prev; | |
594 | ||
595 | for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev)) | |
596 | if (GET_CODE (prev) != NOTE | |
597 | || NOTE_LINE_NUMBER (prev) == NOTE_INSN_BASIC_BLOCK | |
598 | || prev == a->head) | |
599 | break; | |
600 | ||
601 | del_first = a_end; | |
602 | ||
603 | #ifdef HAVE_cc0 | |
604 | /* If this was a conditional jump, we need to also delete | |
605 | the insn that set cc0. */ | |
606 | if (only_sets_cc0_p (prev)) | |
607 | { | |
608 | rtx tmp = prev; | |
5f0d2358 | 609 | |
ca6c03ca JH |
610 | prev = prev_nonnote_insn (prev); |
611 | if (!prev) | |
612 | prev = a->head; | |
613 | del_first = tmp; | |
614 | } | |
615 | #endif | |
616 | ||
617 | a_end = PREV_INSN (del_first); | |
618 | } | |
619 | else if (GET_CODE (NEXT_INSN (a_end)) == BARRIER) | |
620 | del_first = NEXT_INSN (a_end); | |
621 | ||
bc35512f | 622 | update_cfg_after_block_merging (a, b); |
ca6c03ca JH |
623 | |
624 | /* Delete everything marked above as well as crap that might be | |
625 | hanging out between the two blocks. */ | |
626 | delete_insn_chain (del_first, del_last); | |
627 | ||
628 | /* Reassociate the insns of B with A. */ | |
629 | if (!b_empty) | |
630 | { | |
ba4f7968 | 631 | rtx x; |
5f0d2358 | 632 | |
ba4f7968 JH |
633 | for (x = a_end; x != b_end; x = NEXT_INSN (x)) |
634 | set_block_for_insn (x, a); | |
5f0d2358 | 635 | |
ba4f7968 | 636 | set_block_for_insn (b_end, a); |
5f0d2358 | 637 | |
ca6c03ca JH |
638 | a_end = b_end; |
639 | } | |
5f0d2358 | 640 | |
ca6c03ca JH |
641 | a->end = a_end; |
642 | } | |
bc35512f JH |
643 | |
644 | /* Return true when block A and B can be merged. */ | |
645 | static bool | |
646 | rtl_can_merge_blocks (basic_block a,basic_block b) | |
647 | { | |
648 | /* There must be exactly one edge in between the blocks. */ | |
649 | return (a->succ && !a->succ->succ_next && a->succ->dest == b | |
650 | && !b->pred->pred_next && a != b | |
651 | /* Must be simple edge. */ | |
652 | && !(a->succ->flags & EDGE_COMPLEX) | |
653 | && a->next_bb == b | |
654 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR | |
655 | /* If the jump insn has side effects, | |
656 | we can't kill the edge. */ | |
657 | && (GET_CODE (a->end) != JUMP_INSN | |
658 | || (flow2_completed | |
659 | ? simplejump_p (a->end) : onlyjump_p (a->end)))); | |
660 | } | |
ca6c03ca | 661 | \f |
5f0d2358 RK |
662 | /* Return the label in the head of basic block BLOCK. Create one if it doesn't |
663 | exist. */ | |
ca6c03ca JH |
664 | |
665 | rtx | |
d329e058 | 666 | block_label (basic_block block) |
ca6c03ca JH |
667 | { |
668 | if (block == EXIT_BLOCK_PTR) | |
669 | return NULL_RTX; | |
5f0d2358 | 670 | |
ca6c03ca JH |
671 | if (GET_CODE (block->head) != CODE_LABEL) |
672 | { | |
673 | block->head = emit_label_before (gen_label_rtx (), block->head); | |
ca6c03ca | 674 | } |
5f0d2358 | 675 | |
ca6c03ca JH |
676 | return block->head; |
677 | } | |
678 | ||
679 | /* Attempt to perform edge redirection by replacing possibly complex jump | |
5f0d2358 RK |
680 | instruction by unconditional jump or removing jump completely. This can |
681 | apply only if all edges now point to the same block. The parameters and | |
682 | return values are equivalent to redirect_edge_and_branch. */ | |
ca6c03ca JH |
683 | |
684 | static bool | |
bc35512f | 685 | try_redirect_by_replacing_jump (edge e, basic_block target, bool in_cfglayout) |
ca6c03ca JH |
686 | { |
687 | basic_block src = e->src; | |
688 | rtx insn = src->end, kill_from; | |
689 | edge tmp; | |
e1233a7d | 690 | rtx set; |
ca6c03ca JH |
691 | int fallthru = 0; |
692 | ||
693 | /* Verify that all targets will be TARGET. */ | |
694 | for (tmp = src->succ; tmp; tmp = tmp->succ_next) | |
695 | if (tmp->dest != target && tmp != e) | |
696 | break; | |
5f0d2358 | 697 | |
ca6c03ca JH |
698 | if (tmp || !onlyjump_p (insn)) |
699 | return false; | |
e1233a7d | 700 | if ((!optimize || flow2_completed) && tablejump_p (insn, NULL, NULL)) |
1b6763cf | 701 | return false; |
ca6c03ca JH |
702 | |
703 | /* Avoid removing branch with side effects. */ | |
704 | set = single_set (insn); | |
705 | if (!set || side_effects_p (set)) | |
706 | return false; | |
707 | ||
708 | /* In case we zap a conditional jump, we'll need to kill | |
709 | the cc0 setter too. */ | |
710 | kill_from = insn; | |
711 | #ifdef HAVE_cc0 | |
712 | if (reg_mentioned_p (cc0_rtx, PATTERN (insn))) | |
713 | kill_from = PREV_INSN (insn); | |
714 | #endif | |
715 | ||
716 | /* See if we can create the fallthru edge. */ | |
bc35512f | 717 | if (in_cfglayout || can_fallthru (src, target)) |
ca6c03ca JH |
718 | { |
719 | if (rtl_dump_file) | |
720 | fprintf (rtl_dump_file, "Removing jump %i.\n", INSN_UID (insn)); | |
721 | fallthru = 1; | |
722 | ||
eaec9b3d | 723 | /* Selectively unlink whole insn chain. */ |
bc35512f JH |
724 | if (in_cfglayout) |
725 | { | |
726 | rtx insn = src->rbi->footer; | |
727 | ||
728 | delete_insn_chain (kill_from, src->end); | |
729 | ||
730 | /* Remove barriers but keep jumptables. */ | |
731 | while (insn) | |
732 | { | |
733 | if (GET_CODE (insn) == BARRIER) | |
734 | { | |
735 | if (PREV_INSN (insn)) | |
736 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
737 | else | |
738 | src->rbi->footer = NEXT_INSN (insn); | |
739 | if (NEXT_INSN (insn)) | |
740 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
741 | } | |
742 | if (GET_CODE (insn) == CODE_LABEL) | |
743 | break; | |
744 | insn = NEXT_INSN (insn); | |
745 | } | |
746 | } | |
747 | else | |
748 | delete_insn_chain (kill_from, PREV_INSN (target->head)); | |
ca6c03ca | 749 | } |
5f0d2358 | 750 | |
ca6c03ca JH |
751 | /* If this already is simplejump, redirect it. */ |
752 | else if (simplejump_p (insn)) | |
753 | { | |
754 | if (e->dest == target) | |
755 | return false; | |
756 | if (rtl_dump_file) | |
757 | fprintf (rtl_dump_file, "Redirecting jump %i from %i to %i.\n", | |
0b17ab2f | 758 | INSN_UID (insn), e->dest->index, target->index); |
6ee3c8e4 JJ |
759 | if (!redirect_jump (insn, block_label (target), 0)) |
760 | { | |
761 | if (target == EXIT_BLOCK_PTR) | |
762 | return false; | |
763 | abort (); | |
764 | } | |
ca6c03ca | 765 | } |
5f0d2358 | 766 | |
6ee3c8e4 JJ |
767 | /* Cannot do anything for target exit block. */ |
768 | else if (target == EXIT_BLOCK_PTR) | |
769 | return false; | |
770 | ||
ca6c03ca JH |
771 | /* Or replace possibly complicated jump insn by simple jump insn. */ |
772 | else | |
773 | { | |
774 | rtx target_label = block_label (target); | |
eb5b8ad4 | 775 | rtx barrier, label, table; |
ca6c03ca | 776 | |
09eb1aab | 777 | emit_jump_insn_after (gen_jump (target_label), insn); |
ca6c03ca JH |
778 | JUMP_LABEL (src->end) = target_label; |
779 | LABEL_NUSES (target_label)++; | |
780 | if (rtl_dump_file) | |
781 | fprintf (rtl_dump_file, "Replacing insn %i by jump %i\n", | |
782 | INSN_UID (insn), INSN_UID (src->end)); | |
783 | ||
4da2eb6b | 784 | |
ca6c03ca JH |
785 | delete_insn_chain (kill_from, insn); |
786 | ||
4da2eb6b RH |
787 | /* Recognize a tablejump that we are converting to a |
788 | simple jump and remove its associated CODE_LABEL | |
789 | and ADDR_VEC or ADDR_DIFF_VEC. */ | |
eb5b8ad4 | 790 | if (tablejump_p (insn, &label, &table)) |
4da2eb6b | 791 | delete_insn_chain (label, table); |
eb5b8ad4 | 792 | |
ca6c03ca JH |
793 | barrier = next_nonnote_insn (src->end); |
794 | if (!barrier || GET_CODE (barrier) != BARRIER) | |
795 | emit_barrier_after (src->end); | |
796 | } | |
797 | ||
798 | /* Keep only one edge out and set proper flags. */ | |
799 | while (src->succ->succ_next) | |
800 | remove_edge (src->succ); | |
801 | e = src->succ; | |
802 | if (fallthru) | |
803 | e->flags = EDGE_FALLTHRU; | |
804 | else | |
805 | e->flags = 0; | |
5f0d2358 | 806 | |
ca6c03ca JH |
807 | e->probability = REG_BR_PROB_BASE; |
808 | e->count = src->count; | |
809 | ||
810 | /* We don't want a block to end on a line-number note since that has | |
811 | the potential of changing the code between -g and not -g. */ | |
812 | while (GET_CODE (e->src->end) == NOTE | |
813 | && NOTE_LINE_NUMBER (e->src->end) >= 0) | |
814 | delete_insn (e->src->end); | |
815 | ||
816 | if (e->dest != target) | |
817 | redirect_edge_succ (e, target); | |
5f0d2358 | 818 | |
ca6c03ca JH |
819 | return true; |
820 | } | |
821 | ||
822 | /* Return last loop_beg note appearing after INSN, before start of next | |
823 | basic block. Return INSN if there are no such notes. | |
824 | ||
09da1532 | 825 | When emitting jump to redirect a fallthru edge, it should always appear |
5f0d2358 RK |
826 | after the LOOP_BEG notes, as loop optimizer expect loop to either start by |
827 | fallthru edge or jump following the LOOP_BEG note jumping to the loop exit | |
828 | test. */ | |
ca6c03ca JH |
829 | |
830 | static rtx | |
d329e058 | 831 | last_loop_beg_note (rtx insn) |
ca6c03ca JH |
832 | { |
833 | rtx last = insn; | |
5f0d2358 RK |
834 | |
835 | for (insn = NEXT_INSN (insn); insn && GET_CODE (insn) == NOTE | |
836 | && NOTE_LINE_NUMBER (insn) != NOTE_INSN_BASIC_BLOCK; | |
837 | insn = NEXT_INSN (insn)) | |
838 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
839 | last = insn; | |
840 | ||
ca6c03ca JH |
841 | return last; |
842 | } | |
843 | ||
bc35512f | 844 | /* Redirect edge representing branch of (un)conditional jump or tablejump. */ |
9ee634e3 | 845 | static bool |
bc35512f | 846 | redirect_branch_edge (edge e, basic_block target) |
ca6c03ca JH |
847 | { |
848 | rtx tmp; | |
849 | rtx old_label = e->dest->head; | |
850 | basic_block src = e->src; | |
851 | rtx insn = src->end; | |
852 | ||
ca6c03ca JH |
853 | /* We can only redirect non-fallthru edges of jump insn. */ |
854 | if (e->flags & EDGE_FALLTHRU) | |
855 | return false; | |
5f0d2358 | 856 | else if (GET_CODE (insn) != JUMP_INSN) |
ca6c03ca JH |
857 | return false; |
858 | ||
859 | /* Recognize a tablejump and adjust all matching cases. */ | |
e1233a7d | 860 | if (tablejump_p (insn, NULL, &tmp)) |
ca6c03ca JH |
861 | { |
862 | rtvec vec; | |
863 | int j; | |
864 | rtx new_label = block_label (target); | |
865 | ||
6ee3c8e4 JJ |
866 | if (target == EXIT_BLOCK_PTR) |
867 | return false; | |
ca6c03ca JH |
868 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) |
869 | vec = XVEC (PATTERN (tmp), 0); | |
870 | else | |
871 | vec = XVEC (PATTERN (tmp), 1); | |
872 | ||
873 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
874 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
875 | { | |
876 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (Pmode, new_label); | |
877 | --LABEL_NUSES (old_label); | |
878 | ++LABEL_NUSES (new_label); | |
879 | } | |
880 | ||
f9da5064 | 881 | /* Handle casesi dispatch insns. */ |
ca6c03ca JH |
882 | if ((tmp = single_set (insn)) != NULL |
883 | && SET_DEST (tmp) == pc_rtx | |
884 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
885 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF | |
886 | && XEXP (XEXP (SET_SRC (tmp), 2), 0) == old_label) | |
887 | { | |
888 | XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (VOIDmode, | |
889 | new_label); | |
890 | --LABEL_NUSES (old_label); | |
891 | ++LABEL_NUSES (new_label); | |
892 | } | |
893 | } | |
894 | else | |
895 | { | |
896 | /* ?? We may play the games with moving the named labels from | |
897 | one basic block to the other in case only one computed_jump is | |
898 | available. */ | |
5f0d2358 RK |
899 | if (computed_jump_p (insn) |
900 | /* A return instruction can't be redirected. */ | |
901 | || returnjump_p (insn)) | |
ca6c03ca JH |
902 | return false; |
903 | ||
904 | /* If the insn doesn't go where we think, we're confused. */ | |
6ee3c8e4 | 905 | if (JUMP_LABEL (insn) != old_label) |
a3623c48 | 906 | abort (); |
6ee3c8e4 JJ |
907 | |
908 | /* If the substitution doesn't succeed, die. This can happen | |
909 | if the back end emitted unrecognizable instructions or if | |
910 | target is exit block on some arches. */ | |
911 | if (!redirect_jump (insn, block_label (target), 0)) | |
912 | { | |
913 | if (target == EXIT_BLOCK_PTR) | |
914 | return false; | |
915 | abort (); | |
916 | } | |
ca6c03ca JH |
917 | } |
918 | ||
919 | if (rtl_dump_file) | |
920 | fprintf (rtl_dump_file, "Edge %i->%i redirected to %i\n", | |
0b17ab2f | 921 | e->src->index, e->dest->index, target->index); |
5f0d2358 | 922 | |
ca6c03ca JH |
923 | if (e->dest != target) |
924 | redirect_edge_succ_nodup (e, target); | |
bc35512f JH |
925 | return true; |
926 | } | |
927 | ||
928 | /* Attempt to change code to redirect edge E to TARGET. Don't do that on | |
929 | expense of adding new instructions or reordering basic blocks. | |
930 | ||
931 | Function can be also called with edge destination equivalent to the TARGET. | |
932 | Then it should try the simplifications and do nothing if none is possible. | |
933 | ||
934 | Return true if transformation succeeded. We still return false in case E | |
935 | already destinated TARGET and we didn't managed to simplify instruction | |
936 | stream. */ | |
937 | ||
938 | static bool | |
939 | rtl_redirect_edge_and_branch (e, target) | |
940 | edge e; | |
941 | basic_block target; | |
942 | { | |
943 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) | |
944 | return false; | |
945 | ||
946 | if (try_redirect_by_replacing_jump (e, target, false)) | |
947 | return true; | |
948 | ||
949 | /* Do this fast path late, as we want above code to simplify for cases | |
950 | where called on single edge leaving basic block containing nontrivial | |
951 | jump insn. */ | |
952 | else if (e->dest == target) | |
953 | return false; | |
954 | else if (!redirect_branch_edge (e, target)) | |
955 | return false; | |
5f0d2358 | 956 | |
ca6c03ca JH |
957 | return true; |
958 | } | |
959 | ||
4fe9b91c | 960 | /* Like force_nonfallthru below, but additionally performs redirection |
ca6c03ca JH |
961 | Used by redirect_edge_and_branch_force. */ |
962 | ||
cb9a1d9b | 963 | basic_block |
d329e058 | 964 | force_nonfallthru_and_redirect (edge e, basic_block target) |
ca6c03ca | 965 | { |
a3716585 | 966 | basic_block jump_block, new_bb = NULL, src = e->src; |
ca6c03ca JH |
967 | rtx note; |
968 | edge new_edge; | |
a3716585 | 969 | int abnormal_edge_flags = 0; |
ca6c03ca | 970 | |
cb9a1d9b JH |
971 | /* In the case the last instruction is conditional jump to the next |
972 | instruction, first redirect the jump itself and then continue | |
b20b352b | 973 | by creating a basic block afterwards to redirect fallthru edge. */ |
cb9a1d9b JH |
974 | if (e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR |
975 | && any_condjump_p (e->src->end) | |
cde1d5bf | 976 | /* When called from cfglayout, fallthru edges do not |
e0bb17a8 | 977 | necessarily go to the next block. */ |
cde1d5bf | 978 | && e->src->next_bb == e->dest |
cb9a1d9b JH |
979 | && JUMP_LABEL (e->src->end) == e->dest->head) |
980 | { | |
981 | rtx note; | |
58e6ae30 | 982 | edge b = unchecked_make_edge (e->src, target, 0); |
cb9a1d9b JH |
983 | |
984 | if (!redirect_jump (e->src->end, block_label (target), 0)) | |
985 | abort (); | |
986 | note = find_reg_note (e->src->end, REG_BR_PROB, NULL_RTX); | |
987 | if (note) | |
988 | { | |
989 | int prob = INTVAL (XEXP (note, 0)); | |
990 | ||
991 | b->probability = prob; | |
992 | b->count = e->count * prob / REG_BR_PROB_BASE; | |
993 | e->probability -= e->probability; | |
994 | e->count -= b->count; | |
995 | if (e->probability < 0) | |
996 | e->probability = 0; | |
997 | if (e->count < 0) | |
998 | e->count = 0; | |
999 | } | |
1000 | } | |
1001 | ||
ca6c03ca | 1002 | if (e->flags & EDGE_ABNORMAL) |
a3716585 JH |
1003 | { |
1004 | /* Irritating special case - fallthru edge to the same block as abnormal | |
1005 | edge. | |
1006 | We can't redirect abnormal edge, but we still can split the fallthru | |
d329e058 | 1007 | one and create separate abnormal edge to original destination. |
a3716585 JH |
1008 | This allows bb-reorder to make such edge non-fallthru. */ |
1009 | if (e->dest != target) | |
1010 | abort (); | |
1011 | abnormal_edge_flags = e->flags & ~(EDGE_FALLTHRU | EDGE_CAN_FALLTHRU); | |
1012 | e->flags &= EDGE_FALLTHRU | EDGE_CAN_FALLTHRU; | |
1013 | } | |
5f0d2358 | 1014 | else if (!(e->flags & EDGE_FALLTHRU)) |
ca6c03ca | 1015 | abort (); |
24c545ff BS |
1016 | else if (e->src == ENTRY_BLOCK_PTR) |
1017 | { | |
1018 | /* We can't redirect the entry block. Create an empty block at the | |
1019 | start of the function which we use to add the new jump. */ | |
1020 | edge *pe1; | |
918ed612 | 1021 | basic_block bb = create_basic_block (e->dest->head, NULL, ENTRY_BLOCK_PTR); |
24c545ff BS |
1022 | |
1023 | /* Change the existing edge's source to be the new block, and add | |
1024 | a new edge from the entry block to the new block. */ | |
1025 | e->src = bb; | |
1026 | for (pe1 = &ENTRY_BLOCK_PTR->succ; *pe1; pe1 = &(*pe1)->succ_next) | |
1027 | if (*pe1 == e) | |
1028 | { | |
1029 | *pe1 = e->succ_next; | |
1030 | break; | |
1031 | } | |
1032 | e->succ_next = 0; | |
1033 | bb->succ = e; | |
1034 | make_single_succ_edge (ENTRY_BLOCK_PTR, bb, EDGE_FALLTHRU); | |
1035 | } | |
1036 | ||
a3716585 | 1037 | if (e->src->succ->succ_next || abnormal_edge_flags) |
ca6c03ca JH |
1038 | { |
1039 | /* Create the new structures. */ | |
31a78298 RH |
1040 | |
1041 | /* Position the new block correctly relative to loop notes. */ | |
ca6c03ca | 1042 | note = last_loop_beg_note (e->src->end); |
31a78298 RH |
1043 | note = NEXT_INSN (note); |
1044 | ||
1045 | /* ... and ADDR_VECs. */ | |
1046 | if (note != NULL | |
1047 | && GET_CODE (note) == CODE_LABEL | |
1048 | && NEXT_INSN (note) | |
1049 | && GET_CODE (NEXT_INSN (note)) == JUMP_INSN | |
1050 | && (GET_CODE (PATTERN (NEXT_INSN (note))) == ADDR_DIFF_VEC | |
1051 | || GET_CODE (PATTERN (NEXT_INSN (note))) == ADDR_VEC)) | |
1052 | note = NEXT_INSN (NEXT_INSN (note)); | |
1053 | ||
1054 | jump_block = create_basic_block (note, NULL, e->src); | |
ca6c03ca JH |
1055 | jump_block->count = e->count; |
1056 | jump_block->frequency = EDGE_FREQUENCY (e); | |
1057 | jump_block->loop_depth = target->loop_depth; | |
1058 | ||
1059 | if (target->global_live_at_start) | |
1060 | { | |
5f0d2358 RK |
1061 | jump_block->global_live_at_start |
1062 | = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
1063 | jump_block->global_live_at_end | |
1064 | = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
ca6c03ca JH |
1065 | COPY_REG_SET (jump_block->global_live_at_start, |
1066 | target->global_live_at_start); | |
1067 | COPY_REG_SET (jump_block->global_live_at_end, | |
1068 | target->global_live_at_start); | |
1069 | } | |
1070 | ||
1071 | /* Wire edge in. */ | |
1072 | new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU); | |
1073 | new_edge->probability = e->probability; | |
1074 | new_edge->count = e->count; | |
1075 | ||
1076 | /* Redirect old edge. */ | |
1077 | redirect_edge_pred (e, jump_block); | |
1078 | e->probability = REG_BR_PROB_BASE; | |
1079 | ||
1080 | new_bb = jump_block; | |
1081 | } | |
1082 | else | |
1083 | jump_block = e->src; | |
5f0d2358 | 1084 | |
ca6c03ca JH |
1085 | e->flags &= ~EDGE_FALLTHRU; |
1086 | if (target == EXIT_BLOCK_PTR) | |
1087 | { | |
1088 | if (HAVE_return) | |
1089 | emit_jump_insn_after (gen_return (), jump_block->end); | |
1090 | else | |
1091 | abort (); | |
1092 | } | |
1093 | else | |
1094 | { | |
1095 | rtx label = block_label (target); | |
1096 | emit_jump_insn_after (gen_jump (label), jump_block->end); | |
1097 | JUMP_LABEL (jump_block->end) = label; | |
1098 | LABEL_NUSES (label)++; | |
1099 | } | |
5f0d2358 | 1100 | |
ca6c03ca JH |
1101 | emit_barrier_after (jump_block->end); |
1102 | redirect_edge_succ_nodup (e, target); | |
1103 | ||
a3716585 JH |
1104 | if (abnormal_edge_flags) |
1105 | make_edge (src, target, abnormal_edge_flags); | |
1106 | ||
ca6c03ca JH |
1107 | return new_bb; |
1108 | } | |
1109 | ||
1110 | /* Edge E is assumed to be fallthru edge. Emit needed jump instruction | |
1111 | (and possibly create new basic block) to make edge non-fallthru. | |
1112 | Return newly created BB or NULL if none. */ | |
5f0d2358 | 1113 | |
ca6c03ca | 1114 | basic_block |
d329e058 | 1115 | force_nonfallthru (edge e) |
ca6c03ca JH |
1116 | { |
1117 | return force_nonfallthru_and_redirect (e, e->dest); | |
1118 | } | |
1119 | ||
1120 | /* Redirect edge even at the expense of creating new jump insn or | |
1121 | basic block. Return new basic block if created, NULL otherwise. | |
eaec9b3d | 1122 | Abort if conversion is impossible. */ |
ca6c03ca | 1123 | |
9ee634e3 | 1124 | static basic_block |
d329e058 | 1125 | rtl_redirect_edge_and_branch_force (edge e, basic_block target) |
ca6c03ca | 1126 | { |
5f0d2358 RK |
1127 | if (redirect_edge_and_branch (e, target) |
1128 | || e->dest == target) | |
ca6c03ca JH |
1129 | return NULL; |
1130 | ||
1131 | /* In case the edge redirection failed, try to force it to be non-fallthru | |
1132 | and redirect newly created simplejump. */ | |
5f0d2358 | 1133 | return force_nonfallthru_and_redirect (e, target); |
ca6c03ca JH |
1134 | } |
1135 | ||
1136 | /* The given edge should potentially be a fallthru edge. If that is in | |
1137 | fact true, delete the jump and barriers that are in the way. */ | |
1138 | ||
1139 | void | |
d329e058 | 1140 | tidy_fallthru_edge (edge e, basic_block b, basic_block c) |
ca6c03ca JH |
1141 | { |
1142 | rtx q; | |
1143 | ||
1144 | /* ??? In a late-running flow pass, other folks may have deleted basic | |
1145 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
1146 | and the target label. They ought to be chastized and fixed. | |
1147 | ||
1148 | We can also wind up with a sequence of undeletable labels between | |
1149 | one block and the next. | |
1150 | ||
1151 | So search through a sequence of barriers, labels, and notes for | |
1152 | the head of block C and assert that we really do fall through. */ | |
1153 | ||
9c0a0632 RH |
1154 | for (q = NEXT_INSN (b->end); q != c->head; q = NEXT_INSN (q)) |
1155 | if (INSN_P (q)) | |
1156 | return; | |
ca6c03ca JH |
1157 | |
1158 | /* Remove what will soon cease being the jump insn from the source block. | |
1159 | If block B consisted only of this single jump, turn it into a deleted | |
1160 | note. */ | |
1161 | q = b->end; | |
1162 | if (GET_CODE (q) == JUMP_INSN | |
1163 | && onlyjump_p (q) | |
1164 | && (any_uncondjump_p (q) | |
1165 | || (b->succ == e && e->succ_next == NULL))) | |
1166 | { | |
1167 | #ifdef HAVE_cc0 | |
1168 | /* If this was a conditional jump, we need to also delete | |
1169 | the insn that set cc0. */ | |
1170 | if (any_condjump_p (q) && only_sets_cc0_p (PREV_INSN (q))) | |
1171 | q = PREV_INSN (q); | |
1172 | #endif | |
1173 | ||
1174 | q = PREV_INSN (q); | |
1175 | ||
1176 | /* We don't want a block to end on a line-number note since that has | |
1177 | the potential of changing the code between -g and not -g. */ | |
1178 | while (GET_CODE (q) == NOTE && NOTE_LINE_NUMBER (q) >= 0) | |
1179 | q = PREV_INSN (q); | |
1180 | } | |
1181 | ||
1182 | /* Selectively unlink the sequence. */ | |
1183 | if (q != PREV_INSN (c->head)) | |
1184 | delete_insn_chain (NEXT_INSN (q), PREV_INSN (c->head)); | |
1185 | ||
1186 | e->flags |= EDGE_FALLTHRU; | |
1187 | } | |
1188 | ||
1189 | /* Fix up edges that now fall through, or rather should now fall through | |
1190 | but previously required a jump around now deleted blocks. Simplify | |
1191 | the search by only examining blocks numerically adjacent, since this | |
1192 | is how find_basic_blocks created them. */ | |
1193 | ||
1194 | void | |
d329e058 | 1195 | tidy_fallthru_edges (void) |
ca6c03ca | 1196 | { |
e0082a72 ZD |
1197 | basic_block b, c; |
1198 | ||
1199 | if (ENTRY_BLOCK_PTR->next_bb == EXIT_BLOCK_PTR) | |
1200 | return; | |
ca6c03ca | 1201 | |
e0082a72 | 1202 | FOR_BB_BETWEEN (b, ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR->prev_bb, next_bb) |
ca6c03ca | 1203 | { |
ca6c03ca JH |
1204 | edge s; |
1205 | ||
e0082a72 ZD |
1206 | c = b->next_bb; |
1207 | ||
ca6c03ca JH |
1208 | /* We care about simple conditional or unconditional jumps with |
1209 | a single successor. | |
1210 | ||
1211 | If we had a conditional branch to the next instruction when | |
1212 | find_basic_blocks was called, then there will only be one | |
1213 | out edge for the block which ended with the conditional | |
1214 | branch (since we do not create duplicate edges). | |
1215 | ||
1216 | Furthermore, the edge will be marked as a fallthru because we | |
1217 | merge the flags for the duplicate edges. So we do not want to | |
1218 | check that the edge is not a FALLTHRU edge. */ | |
5f0d2358 | 1219 | |
ca6c03ca JH |
1220 | if ((s = b->succ) != NULL |
1221 | && ! (s->flags & EDGE_COMPLEX) | |
1222 | && s->succ_next == NULL | |
1223 | && s->dest == c | |
1224 | /* If the jump insn has side effects, we can't tidy the edge. */ | |
1225 | && (GET_CODE (b->end) != JUMP_INSN | |
1226 | || onlyjump_p (b->end))) | |
1227 | tidy_fallthru_edge (s, b, c); | |
1228 | } | |
1229 | } | |
1230 | \f | |
1231 | /* Helper function for split_edge. Return true in case edge BB2 to BB1 | |
1232 | is back edge of syntactic loop. */ | |
1233 | ||
1234 | static bool | |
d329e058 | 1235 | back_edge_of_syntactic_loop_p (basic_block bb1, basic_block bb2) |
ca6c03ca JH |
1236 | { |
1237 | rtx insn; | |
1238 | int count = 0; | |
bf77398c | 1239 | basic_block bb; |
ca6c03ca | 1240 | |
bf77398c | 1241 | if (bb1 == bb2) |
0b17ab2f | 1242 | return true; |
355e4ec4 | 1243 | |
bf77398c ZD |
1244 | /* ??? Could we guarantee that bb indices are monotone, so that we could |
1245 | just compare them? */ | |
1246 | for (bb = bb1; bb && bb != bb2; bb = bb->next_bb) | |
1247 | continue; | |
1248 | ||
1249 | if (!bb) | |
1250 | return false; | |
1251 | ||
ca6c03ca JH |
1252 | for (insn = bb1->end; insn != bb2->head && count >= 0; |
1253 | insn = NEXT_INSN (insn)) | |
1254 | if (GET_CODE (insn) == NOTE) | |
1255 | { | |
1256 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
1257 | count++; | |
5f0d2358 | 1258 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) |
ca6c03ca JH |
1259 | count--; |
1260 | } | |
1261 | ||
1262 | return count >= 0; | |
1263 | } | |
1264 | ||
1265 | /* Split a (typically critical) edge. Return the new block. | |
1266 | Abort on abnormal edges. | |
1267 | ||
1268 | ??? The code generally expects to be called on critical edges. | |
1269 | The case of a block ending in an unconditional jump to a | |
1270 | block with multiple predecessors is not handled optimally. */ | |
1271 | ||
8ce33230 | 1272 | static basic_block |
d329e058 | 1273 | rtl_split_edge (edge edge_in) |
ca6c03ca JH |
1274 | { |
1275 | basic_block bb; | |
ca6c03ca JH |
1276 | rtx before; |
1277 | ||
1278 | /* Abnormal edges cannot be split. */ | |
1279 | if ((edge_in->flags & EDGE_ABNORMAL) != 0) | |
1280 | abort (); | |
1281 | ||
1282 | /* We are going to place the new block in front of edge destination. | |
eaec9b3d | 1283 | Avoid existence of fallthru predecessors. */ |
ca6c03ca JH |
1284 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) |
1285 | { | |
1286 | edge e; | |
5f0d2358 | 1287 | |
ca6c03ca JH |
1288 | for (e = edge_in->dest->pred; e; e = e->pred_next) |
1289 | if (e->flags & EDGE_FALLTHRU) | |
1290 | break; | |
1291 | ||
1292 | if (e) | |
1293 | force_nonfallthru (e); | |
1294 | } | |
1295 | ||
1296 | /* Create the basic block note. | |
1297 | ||
f63d1bf7 | 1298 | Where we place the note can have a noticeable impact on the generated |
ca6c03ca JH |
1299 | code. Consider this cfg: |
1300 | ||
1301 | E | |
1302 | | | |
1303 | 0 | |
1304 | / \ | |
1305 | +->1-->2--->E | |
1306 | | | | |
1307 | +--+ | |
1308 | ||
1309 | If we need to insert an insn on the edge from block 0 to block 1, | |
1310 | we want to ensure the instructions we insert are outside of any | |
1311 | loop notes that physically sit between block 0 and block 1. Otherwise | |
1312 | we confuse the loop optimizer into thinking the loop is a phony. */ | |
1313 | ||
1314 | if (edge_in->dest != EXIT_BLOCK_PTR | |
1315 | && PREV_INSN (edge_in->dest->head) | |
1316 | && GET_CODE (PREV_INSN (edge_in->dest->head)) == NOTE | |
5f0d2358 RK |
1317 | && (NOTE_LINE_NUMBER (PREV_INSN (edge_in->dest->head)) |
1318 | == NOTE_INSN_LOOP_BEG) | |
ca6c03ca JH |
1319 | && !back_edge_of_syntactic_loop_p (edge_in->dest, edge_in->src)) |
1320 | before = PREV_INSN (edge_in->dest->head); | |
1321 | else if (edge_in->dest != EXIT_BLOCK_PTR) | |
1322 | before = edge_in->dest->head; | |
1323 | else | |
1324 | before = NULL_RTX; | |
1325 | ||
918ed612 | 1326 | bb = create_basic_block (before, NULL, edge_in->dest->prev_bb); |
ca6c03ca JH |
1327 | bb->count = edge_in->count; |
1328 | bb->frequency = EDGE_FREQUENCY (edge_in); | |
1329 | ||
1330 | /* ??? This info is likely going to be out of date very soon. */ | |
1331 | if (edge_in->dest->global_live_at_start) | |
1332 | { | |
1333 | bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
1334 | bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
5f0d2358 RK |
1335 | COPY_REG_SET (bb->global_live_at_start, |
1336 | edge_in->dest->global_live_at_start); | |
1337 | COPY_REG_SET (bb->global_live_at_end, | |
1338 | edge_in->dest->global_live_at_start); | |
ca6c03ca JH |
1339 | } |
1340 | ||
4977bab6 | 1341 | make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU); |
ca6c03ca | 1342 | |
4d6922ee | 1343 | /* For non-fallthru edges, we must adjust the predecessor's |
ca6c03ca JH |
1344 | jump instruction to target our new block. */ |
1345 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1346 | { | |
1347 | if (!redirect_edge_and_branch (edge_in, bb)) | |
1348 | abort (); | |
1349 | } | |
1350 | else | |
1351 | redirect_edge_succ (edge_in, bb); | |
1352 | ||
1353 | return bb; | |
1354 | } | |
1355 | ||
1356 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1357 | The new instructions and basic blocks (if any) will not appear in the | |
1358 | CFG until commit_edge_insertions is called. */ | |
1359 | ||
1360 | void | |
d329e058 | 1361 | insert_insn_on_edge (rtx pattern, edge e) |
ca6c03ca JH |
1362 | { |
1363 | /* We cannot insert instructions on an abnormal critical edge. | |
1364 | It will be easier to find the culprit if we die now. */ | |
1365 | if ((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e)) | |
1366 | abort (); | |
1367 | ||
1368 | if (e->insns == NULL_RTX) | |
1369 | start_sequence (); | |
1370 | else | |
1371 | push_to_sequence (e->insns); | |
1372 | ||
1373 | emit_insn (pattern); | |
1374 | ||
1375 | e->insns = get_insns (); | |
1376 | end_sequence (); | |
1377 | } | |
1378 | ||
ff25ef99 ZD |
1379 | /* Called from safe_insert_insn_on_edge through note_stores, marks live |
1380 | registers that are killed by the store. */ | |
1381 | static void | |
1382 | mark_killed_regs (rtx reg, rtx set ATTRIBUTE_UNUSED, void *data) | |
1383 | { | |
1384 | regset killed = data; | |
1385 | int regno, i; | |
1386 | ||
1387 | if (GET_CODE (reg) == SUBREG) | |
1388 | reg = SUBREG_REG (reg); | |
1389 | if (!REG_P (reg)) | |
1390 | return; | |
1391 | regno = REGNO (reg); | |
1392 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1393 | SET_REGNO_REG_SET (killed, regno); | |
1394 | else | |
1395 | { | |
73383a81 | 1396 | for (i = 0; i < (int) HARD_REGNO_NREGS (regno, GET_MODE (reg)); i++) |
ff25ef99 ZD |
1397 | SET_REGNO_REG_SET (killed, regno + i); |
1398 | } | |
1399 | } | |
1400 | ||
1401 | /* Similar to insert_insn_on_edge, tries to put INSN to edge E. Additionally | |
1402 | it checks whether this will not clobber the registers that are live on the | |
e0bb17a8 | 1403 | edge (i.e. it requires liveness information to be up-to-date) and if there |
ff25ef99 | 1404 | are some, then it tries to save and restore them. Returns true if |
e0bb17a8 | 1405 | successful. */ |
ff25ef99 ZD |
1406 | bool |
1407 | safe_insert_insn_on_edge (rtx insn, edge e) | |
1408 | { | |
1409 | rtx x; | |
1410 | regset_head killed_head; | |
1411 | regset killed = INITIALIZE_REG_SET (killed_head); | |
1412 | rtx save_regs = NULL_RTX; | |
1413 | int regno, noccmode; | |
1414 | enum machine_mode mode; | |
1415 | ||
1416 | #ifdef AVOID_CCMODE_COPIES | |
1417 | noccmode = true; | |
1418 | #else | |
1419 | noccmode = false; | |
1420 | #endif | |
1421 | ||
1422 | for (x = insn; x; x = NEXT_INSN (x)) | |
1423 | if (INSN_P (x)) | |
1424 | note_stores (PATTERN (x), mark_killed_regs, killed); | |
1425 | bitmap_operation (killed, killed, e->dest->global_live_at_start, | |
1426 | BITMAP_AND); | |
1427 | ||
1428 | EXECUTE_IF_SET_IN_REG_SET (killed, 0, regno, | |
1429 | { | |
1430 | mode = regno < FIRST_PSEUDO_REGISTER | |
1431 | ? reg_raw_mode[regno] | |
1432 | : GET_MODE (regno_reg_rtx[regno]); | |
1433 | if (mode == VOIDmode) | |
1434 | return false; | |
1435 | ||
1436 | if (noccmode && mode == CCmode) | |
1437 | return false; | |
1438 | ||
1439 | save_regs = alloc_EXPR_LIST (0, | |
1440 | alloc_EXPR_LIST (0, | |
1441 | gen_reg_rtx (mode), | |
1442 | gen_raw_REG (mode, regno)), | |
1443 | save_regs); | |
1444 | }); | |
1445 | ||
1446 | if (save_regs) | |
1447 | { | |
1448 | rtx from, to; | |
1449 | ||
1450 | start_sequence (); | |
1451 | for (x = save_regs; x; x = XEXP (x, 1)) | |
1452 | { | |
1453 | from = XEXP (XEXP (x, 0), 1); | |
1454 | to = XEXP (XEXP (x, 0), 0); | |
1455 | emit_move_insn (to, from); | |
1456 | } | |
1457 | emit_insn (insn); | |
1458 | for (x = save_regs; x; x = XEXP (x, 1)) | |
1459 | { | |
1460 | from = XEXP (XEXP (x, 0), 0); | |
1461 | to = XEXP (XEXP (x, 0), 1); | |
1462 | emit_move_insn (to, from); | |
1463 | } | |
1464 | insn = get_insns (); | |
1465 | end_sequence (); | |
1466 | free_EXPR_LIST_list (&save_regs); | |
1467 | } | |
1468 | insert_insn_on_edge (insn, e); | |
1469 | ||
1470 | FREE_REG_SET (killed); | |
1471 | return true; | |
1472 | } | |
1473 | ||
ca6c03ca JH |
1474 | /* Update the CFG for the instructions queued on edge E. */ |
1475 | ||
1476 | static void | |
d329e058 | 1477 | commit_one_edge_insertion (edge e, int watch_calls) |
ca6c03ca JH |
1478 | { |
1479 | rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last; | |
eae4bc56 | 1480 | basic_block bb = NULL; |
ca6c03ca JH |
1481 | |
1482 | /* Pull the insns off the edge now since the edge might go away. */ | |
1483 | insns = e->insns; | |
1484 | e->insns = NULL_RTX; | |
1485 | ||
3dec4024 JH |
1486 | /* Special case -- avoid inserting code between call and storing |
1487 | its return value. */ | |
1488 | if (watch_calls && (e->flags & EDGE_FALLTHRU) && !e->dest->pred->pred_next | |
1489 | && e->src != ENTRY_BLOCK_PTR | |
1490 | && GET_CODE (e->src->end) == CALL_INSN) | |
ca6c03ca | 1491 | { |
3dec4024 | 1492 | rtx next = next_nonnote_insn (e->src->end); |
ca6c03ca | 1493 | |
3dec4024 JH |
1494 | after = e->dest->head; |
1495 | /* The first insn after the call may be a stack pop, skip it. */ | |
1496 | while (next | |
1497 | && keep_with_call_p (next)) | |
f87c27b4 KH |
1498 | { |
1499 | after = next; | |
3dec4024 JH |
1500 | next = next_nonnote_insn (next); |
1501 | } | |
1502 | bb = e->dest; | |
ca6c03ca | 1503 | } |
3dec4024 | 1504 | if (!before && !after) |
ca6c03ca | 1505 | { |
3dec4024 JH |
1506 | /* Figure out where to put these things. If the destination has |
1507 | one predecessor, insert there. Except for the exit block. */ | |
1508 | if (e->dest->pred->pred_next == NULL && e->dest != EXIT_BLOCK_PTR) | |
ca6c03ca | 1509 | { |
3dec4024 JH |
1510 | bb = e->dest; |
1511 | ||
1512 | /* Get the location correct wrt a code label, and "nice" wrt | |
1513 | a basic block note, and before everything else. */ | |
1514 | tmp = bb->head; | |
1515 | if (GET_CODE (tmp) == CODE_LABEL) | |
1516 | tmp = NEXT_INSN (tmp); | |
1517 | if (NOTE_INSN_BASIC_BLOCK_P (tmp)) | |
1518 | tmp = NEXT_INSN (tmp); | |
1519 | if (tmp == bb->head) | |
1520 | before = tmp; | |
1521 | else if (tmp) | |
1522 | after = PREV_INSN (tmp); | |
1523 | else | |
1524 | after = get_last_insn (); | |
1525 | } | |
1526 | ||
1527 | /* If the source has one successor and the edge is not abnormal, | |
1528 | insert there. Except for the entry block. */ | |
1529 | else if ((e->flags & EDGE_ABNORMAL) == 0 | |
1530 | && e->src->succ->succ_next == NULL | |
1531 | && e->src != ENTRY_BLOCK_PTR) | |
1532 | { | |
1533 | bb = e->src; | |
1534 | ||
1535 | /* It is possible to have a non-simple jump here. Consider a target | |
1536 | where some forms of unconditional jumps clobber a register. This | |
1537 | happens on the fr30 for example. | |
1538 | ||
1539 | We know this block has a single successor, so we can just emit | |
1540 | the queued insns before the jump. */ | |
1541 | if (GET_CODE (bb->end) == JUMP_INSN) | |
1542 | for (before = bb->end; | |
1543 | GET_CODE (PREV_INSN (before)) == NOTE | |
1544 | && NOTE_LINE_NUMBER (PREV_INSN (before)) == | |
1545 | NOTE_INSN_LOOP_BEG; before = PREV_INSN (before)) | |
1546 | ; | |
1547 | else | |
1548 | { | |
1549 | /* We'd better be fallthru, or we've lost track of what's what. */ | |
1550 | if ((e->flags & EDGE_FALLTHRU) == 0) | |
1551 | abort (); | |
ca6c03ca | 1552 | |
3dec4024 JH |
1553 | after = bb->end; |
1554 | } | |
1555 | } | |
1556 | /* Otherwise we must split the edge. */ | |
1557 | else | |
1558 | { | |
1559 | bb = split_edge (e); | |
ca6c03ca JH |
1560 | after = bb->end; |
1561 | } | |
1562 | } | |
1563 | ||
ca6c03ca JH |
1564 | /* Now that we've found the spot, do the insertion. */ |
1565 | ||
1566 | if (before) | |
1567 | { | |
2f937369 | 1568 | emit_insn_before (insns, before); |
ca6c03ca JH |
1569 | last = prev_nonnote_insn (before); |
1570 | } | |
1571 | else | |
2f937369 | 1572 | last = emit_insn_after (insns, after); |
ca6c03ca JH |
1573 | |
1574 | if (returnjump_p (last)) | |
1575 | { | |
1576 | /* ??? Remove all outgoing edges from BB and add one for EXIT. | |
1577 | This is not currently a problem because this only happens | |
3dec4024 JH |
1578 | for the (single) epilogue, which already has a fallthru edge |
1579 | to EXIT. */ | |
ca6c03ca JH |
1580 | |
1581 | e = bb->succ; | |
1582 | if (e->dest != EXIT_BLOCK_PTR | |
3dec4024 | 1583 | || e->succ_next != NULL || (e->flags & EDGE_FALLTHRU) == 0) |
ca6c03ca | 1584 | abort (); |
ca6c03ca | 1585 | |
5f0d2358 | 1586 | e->flags &= ~EDGE_FALLTHRU; |
ca6c03ca | 1587 | emit_barrier_after (last); |
0b17ab2f | 1588 | |
ca6c03ca JH |
1589 | if (before) |
1590 | delete_insn (before); | |
1591 | } | |
1592 | else if (GET_CODE (last) == JUMP_INSN) | |
1593 | abort (); | |
5f0d2358 | 1594 | |
9dca2ad5 JH |
1595 | /* Mark the basic block for find_sub_basic_blocks. */ |
1596 | bb->aux = &bb->aux; | |
ca6c03ca JH |
1597 | } |
1598 | ||
1599 | /* Update the CFG for all queued instructions. */ | |
1600 | ||
1601 | void | |
d329e058 | 1602 | commit_edge_insertions (void) |
ca6c03ca | 1603 | { |
ca6c03ca | 1604 | basic_block bb; |
9dca2ad5 | 1605 | sbitmap blocks; |
9809a362 | 1606 | bool changed = false; |
ca6c03ca JH |
1607 | |
1608 | #ifdef ENABLE_CHECKING | |
1609 | verify_flow_info (); | |
1610 | #endif | |
1611 | ||
e0082a72 | 1612 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
ca6c03ca JH |
1613 | { |
1614 | edge e, next; | |
1615 | ||
1616 | for (e = bb->succ; e; e = next) | |
1617 | { | |
1618 | next = e->succ_next; | |
1619 | if (e->insns) | |
9809a362 JH |
1620 | { |
1621 | changed = true; | |
1622 | commit_one_edge_insertion (e, false); | |
1623 | } | |
3dec4024 | 1624 | } |
3dec4024 | 1625 | } |
9dca2ad5 | 1626 | |
9809a362 JH |
1627 | if (!changed) |
1628 | return; | |
1629 | ||
9dca2ad5 JH |
1630 | blocks = sbitmap_alloc (last_basic_block); |
1631 | sbitmap_zero (blocks); | |
1632 | FOR_EACH_BB (bb) | |
1633 | if (bb->aux) | |
1634 | { | |
1635 | SET_BIT (blocks, bb->index); | |
1636 | /* Check for forgotten bb->aux values before commit_edge_insertions | |
1637 | call. */ | |
1638 | if (bb->aux != &bb->aux) | |
1639 | abort (); | |
1640 | bb->aux = NULL; | |
1641 | } | |
1642 | find_many_sub_basic_blocks (blocks); | |
1643 | sbitmap_free (blocks); | |
3dec4024 JH |
1644 | } |
1645 | \f | |
1646 | /* Update the CFG for all queued instructions, taking special care of inserting | |
1647 | code on edges between call and storing its return value. */ | |
1648 | ||
1649 | void | |
d329e058 | 1650 | commit_edge_insertions_watch_calls (void) |
3dec4024 | 1651 | { |
3dec4024 | 1652 | basic_block bb; |
9809a362 JH |
1653 | sbitmap blocks; |
1654 | bool changed = false; | |
3dec4024 JH |
1655 | |
1656 | #ifdef ENABLE_CHECKING | |
1657 | verify_flow_info (); | |
1658 | #endif | |
1659 | ||
e0082a72 | 1660 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
3dec4024 JH |
1661 | { |
1662 | edge e, next; | |
1663 | ||
1664 | for (e = bb->succ; e; e = next) | |
1665 | { | |
1666 | next = e->succ_next; | |
1667 | if (e->insns) | |
9809a362 JH |
1668 | { |
1669 | changed = true; | |
1670 | commit_one_edge_insertion (e, true); | |
1671 | } | |
ca6c03ca | 1672 | } |
ca6c03ca | 1673 | } |
9809a362 JH |
1674 | |
1675 | if (!changed) | |
1676 | return; | |
1677 | ||
1678 | blocks = sbitmap_alloc (last_basic_block); | |
1679 | sbitmap_zero (blocks); | |
1680 | FOR_EACH_BB (bb) | |
1681 | if (bb->aux) | |
1682 | { | |
1683 | SET_BIT (blocks, bb->index); | |
1684 | /* Check for forgotten bb->aux values before commit_edge_insertions | |
1685 | call. */ | |
1686 | if (bb->aux != &bb->aux) | |
1687 | abort (); | |
1688 | bb->aux = NULL; | |
1689 | } | |
1690 | find_many_sub_basic_blocks (blocks); | |
1691 | sbitmap_free (blocks); | |
ca6c03ca JH |
1692 | } |
1693 | \f | |
1694 | /* Print out one basic block with live information at start and end. */ | |
1695 | ||
10e9fecc | 1696 | static void |
d329e058 | 1697 | rtl_dump_bb (basic_block bb, FILE *outf) |
ca6c03ca JH |
1698 | { |
1699 | rtx insn; | |
1700 | rtx last; | |
ca6c03ca JH |
1701 | |
1702 | fputs (";; Registers live at start:", outf); | |
1703 | dump_regset (bb->global_live_at_start, outf); | |
1704 | putc ('\n', outf); | |
1705 | ||
5f0d2358 | 1706 | for (insn = bb->head, last = NEXT_INSN (bb->end); insn != last; |
ca6c03ca JH |
1707 | insn = NEXT_INSN (insn)) |
1708 | print_rtl_single (outf, insn); | |
1709 | ||
1710 | fputs (";; Registers live at end:", outf); | |
1711 | dump_regset (bb->global_live_at_end, outf); | |
1712 | putc ('\n', outf); | |
ca6c03ca JH |
1713 | } |
1714 | \f | |
1715 | /* Like print_rtl, but also print out live information for the start of each | |
1716 | basic block. */ | |
1717 | ||
1718 | void | |
d329e058 | 1719 | print_rtl_with_bb (FILE *outf, rtx rtx_first) |
ca6c03ca | 1720 | { |
b3694847 | 1721 | rtx tmp_rtx; |
ca6c03ca JH |
1722 | |
1723 | if (rtx_first == 0) | |
1724 | fprintf (outf, "(nil)\n"); | |
1725 | else | |
1726 | { | |
ca6c03ca JH |
1727 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
1728 | int max_uid = get_max_uid (); | |
5f0d2358 RK |
1729 | basic_block *start |
1730 | = (basic_block *) xcalloc (max_uid, sizeof (basic_block)); | |
1731 | basic_block *end | |
1732 | = (basic_block *) xcalloc (max_uid, sizeof (basic_block)); | |
1733 | enum bb_state *in_bb_p | |
1734 | = (enum bb_state *) xcalloc (max_uid, sizeof (enum bb_state)); | |
ca6c03ca | 1735 | |
e0082a72 ZD |
1736 | basic_block bb; |
1737 | ||
1738 | FOR_EACH_BB_REVERSE (bb) | |
ca6c03ca | 1739 | { |
ca6c03ca JH |
1740 | rtx x; |
1741 | ||
1742 | start[INSN_UID (bb->head)] = bb; | |
1743 | end[INSN_UID (bb->end)] = bb; | |
1744 | for (x = bb->head; x != NULL_RTX; x = NEXT_INSN (x)) | |
1745 | { | |
1746 | enum bb_state state = IN_MULTIPLE_BB; | |
5f0d2358 | 1747 | |
ca6c03ca JH |
1748 | if (in_bb_p[INSN_UID (x)] == NOT_IN_BB) |
1749 | state = IN_ONE_BB; | |
1750 | in_bb_p[INSN_UID (x)] = state; | |
1751 | ||
1752 | if (x == bb->end) | |
1753 | break; | |
1754 | } | |
1755 | } | |
1756 | ||
1757 | for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) | |
1758 | { | |
1759 | int did_output; | |
ca6c03ca JH |
1760 | |
1761 | if ((bb = start[INSN_UID (tmp_rtx)]) != NULL) | |
1762 | { | |
1763 | fprintf (outf, ";; Start of basic block %d, registers live:", | |
0b17ab2f | 1764 | bb->index); |
ca6c03ca JH |
1765 | dump_regset (bb->global_live_at_start, outf); |
1766 | putc ('\n', outf); | |
1767 | } | |
1768 | ||
1769 | if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB | |
1770 | && GET_CODE (tmp_rtx) != NOTE | |
1771 | && GET_CODE (tmp_rtx) != BARRIER) | |
1772 | fprintf (outf, ";; Insn is not within a basic block\n"); | |
1773 | else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB) | |
1774 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); | |
1775 | ||
1776 | did_output = print_rtl_single (outf, tmp_rtx); | |
1777 | ||
1778 | if ((bb = end[INSN_UID (tmp_rtx)]) != NULL) | |
1779 | { | |
1780 | fprintf (outf, ";; End of basic block %d, registers live:\n", | |
0b17ab2f | 1781 | bb->index); |
ca6c03ca JH |
1782 | dump_regset (bb->global_live_at_end, outf); |
1783 | putc ('\n', outf); | |
1784 | } | |
1785 | ||
1786 | if (did_output) | |
1787 | putc ('\n', outf); | |
1788 | } | |
1789 | ||
1790 | free (start); | |
1791 | free (end); | |
1792 | free (in_bb_p); | |
1793 | } | |
1794 | ||
1795 | if (current_function_epilogue_delay_list != 0) | |
1796 | { | |
1797 | fprintf (outf, "\n;; Insns in epilogue delay list:\n\n"); | |
1798 | for (tmp_rtx = current_function_epilogue_delay_list; tmp_rtx != 0; | |
1799 | tmp_rtx = XEXP (tmp_rtx, 1)) | |
1800 | print_rtl_single (outf, XEXP (tmp_rtx, 0)); | |
1801 | } | |
1802 | } | |
1803 | \f | |
b446e5a2 | 1804 | void |
d329e058 | 1805 | update_br_prob_note (basic_block bb) |
b446e5a2 JH |
1806 | { |
1807 | rtx note; | |
1808 | if (GET_CODE (bb->end) != JUMP_INSN) | |
1809 | return; | |
1810 | note = find_reg_note (bb->end, REG_BR_PROB, NULL_RTX); | |
1811 | if (!note || INTVAL (XEXP (note, 0)) == BRANCH_EDGE (bb)->probability) | |
1812 | return; | |
1813 | XEXP (note, 0) = GEN_INT (BRANCH_EDGE (bb)->probability); | |
1814 | } | |
1815 | \f | |
10e9fecc JH |
1816 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
1817 | cfglayout RTL. | |
ca6c03ca JH |
1818 | |
1819 | Currently it does following checks: | |
1820 | ||
1821 | - test head/end pointers | |
1822 | - overlapping of basic blocks | |
ca6c03ca | 1823 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) |
f63d1bf7 | 1824 | - tails of basic blocks (ensure that boundary is necessary) |
ca6c03ca JH |
1825 | - scans body of the basic block for JUMP_INSN, CODE_LABEL |
1826 | and NOTE_INSN_BASIC_BLOCK | |
ca6c03ca JH |
1827 | |
1828 | In future it can be extended check a lot of other stuff as well | |
1829 | (reachability of basic blocks, life information, etc. etc.). */ | |
10e9fecc | 1830 | static int |
d329e058 | 1831 | rtl_verify_flow_info_1 (void) |
ca6c03ca JH |
1832 | { |
1833 | const int max_uid = get_max_uid (); | |
ca6c03ca | 1834 | rtx last_head = get_last_insn (); |
10e9fecc | 1835 | basic_block *bb_info; |
ca6c03ca | 1836 | rtx x; |
10e9fecc | 1837 | int err = 0; |
918ed612 | 1838 | basic_block bb, last_bb_seen; |
ca6c03ca JH |
1839 | |
1840 | bb_info = (basic_block *) xcalloc (max_uid, sizeof (basic_block)); | |
ca6c03ca | 1841 | |
918ed612 ZD |
1842 | /* Check bb chain & numbers. */ |
1843 | last_bb_seen = ENTRY_BLOCK_PTR; | |
918ed612 | 1844 | |
e0082a72 | 1845 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1846 | { |
ca6c03ca JH |
1847 | rtx head = bb->head; |
1848 | rtx end = bb->end; | |
1849 | ||
1850 | /* Verify the end of the basic block is in the INSN chain. */ | |
1851 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) | |
1852 | if (x == end) | |
1853 | break; | |
5f0d2358 | 1854 | |
ca6c03ca JH |
1855 | if (!x) |
1856 | { | |
1f978f5f | 1857 | error ("end insn %d for block %d not found in the insn stream", |
0b17ab2f | 1858 | INSN_UID (end), bb->index); |
ca6c03ca JH |
1859 | err = 1; |
1860 | } | |
1861 | ||
1862 | /* Work backwards from the end to the head of the basic block | |
1863 | to verify the head is in the RTL chain. */ | |
1864 | for (; x != NULL_RTX; x = PREV_INSN (x)) | |
1865 | { | |
1866 | /* While walking over the insn chain, verify insns appear | |
1867 | in only one basic block and initialize the BB_INFO array | |
1868 | used by other passes. */ | |
1869 | if (bb_info[INSN_UID (x)] != NULL) | |
1870 | { | |
1f978f5f | 1871 | error ("insn %d is in multiple basic blocks (%d and %d)", |
0b17ab2f | 1872 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); |
ca6c03ca JH |
1873 | err = 1; |
1874 | } | |
5f0d2358 | 1875 | |
ca6c03ca JH |
1876 | bb_info[INSN_UID (x)] = bb; |
1877 | ||
1878 | if (x == head) | |
1879 | break; | |
1880 | } | |
1881 | if (!x) | |
1882 | { | |
1f978f5f | 1883 | error ("head insn %d for block %d not found in the insn stream", |
0b17ab2f | 1884 | INSN_UID (head), bb->index); |
ca6c03ca JH |
1885 | err = 1; |
1886 | } | |
1887 | ||
1888 | last_head = x; | |
1889 | } | |
1890 | ||
1891 | /* Now check the basic blocks (boundaries etc.) */ | |
e0082a72 | 1892 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1893 | { |
3dec4024 | 1894 | int n_fallthru = 0, n_eh = 0, n_call = 0, n_abnormal = 0, n_branch = 0; |
3cf54412 | 1895 | edge e, fallthru = NULL; |
5a1a3e5e | 1896 | rtx note; |
ca6c03ca | 1897 | |
5a1a3e5e | 1898 | if (INSN_P (bb->end) |
1e3881c2 | 1899 | && (note = find_reg_note (bb->end, REG_BR_PROB, NULL_RTX)) |
3e638a90 | 1900 | && bb->succ && bb->succ->succ_next |
1e3881c2 | 1901 | && any_condjump_p (bb->end)) |
5a1a3e5e | 1902 | { |
5a1a3e5e JH |
1903 | if (INTVAL (XEXP (note, 0)) != BRANCH_EDGE (bb)->probability) |
1904 | { | |
0108ae51 | 1905 | error ("verify_flow_info: REG_BR_PROB does not match cfg %wi %i", |
5a1a3e5e JH |
1906 | INTVAL (XEXP (note, 0)), BRANCH_EDGE (bb)->probability); |
1907 | err = 1; | |
1908 | } | |
1909 | } | |
5f0d2358 | 1910 | for (e = bb->succ; e; e = e->succ_next) |
ca6c03ca | 1911 | { |
ca6c03ca | 1912 | if (e->flags & EDGE_FALLTHRU) |
3cf54412 | 1913 | n_fallthru++, fallthru = e; |
3dec4024 | 1914 | |
35b07080 | 1915 | if ((e->flags & ~(EDGE_DFS_BACK | EDGE_CAN_FALLTHRU | EDGE_IRREDUCIBLE_LOOP)) == 0) |
3dec4024 JH |
1916 | n_branch++; |
1917 | ||
1918 | if (e->flags & EDGE_ABNORMAL_CALL) | |
1919 | n_call++; | |
1920 | ||
1921 | if (e->flags & EDGE_EH) | |
1922 | n_eh++; | |
1923 | else if (e->flags & EDGE_ABNORMAL) | |
1924 | n_abnormal++; | |
ca6c03ca | 1925 | } |
5f0d2358 | 1926 | |
a2877a09 JH |
1927 | if (n_eh && GET_CODE (PATTERN (bb->end)) != RESX |
1928 | && !find_reg_note (bb->end, REG_EH_REGION, NULL_RTX)) | |
3dec4024 | 1929 | { |
0b17ab2f | 1930 | error ("Missing REG_EH_REGION note in the end of bb %i", bb->index); |
3dec4024 JH |
1931 | err = 1; |
1932 | } | |
1933 | if (n_branch | |
1934 | && (GET_CODE (bb->end) != JUMP_INSN | |
1935 | || (n_branch > 1 && (any_uncondjump_p (bb->end) | |
1936 | || any_condjump_p (bb->end))))) | |
1937 | { | |
0b17ab2f | 1938 | error ("Too many outgoing branch edges from bb %i", bb->index); |
3dec4024 JH |
1939 | err = 1; |
1940 | } | |
1941 | if (n_fallthru && any_uncondjump_p (bb->end)) | |
1942 | { | |
0b17ab2f | 1943 | error ("Fallthru edge after unconditional jump %i", bb->index); |
3dec4024 JH |
1944 | err = 1; |
1945 | } | |
1946 | if (n_branch != 1 && any_uncondjump_p (bb->end)) | |
1947 | { | |
0b17ab2f | 1948 | error ("Wrong amount of branch edges after unconditional jump %i", bb->index); |
3dec4024 JH |
1949 | err = 1; |
1950 | } | |
1951 | if (n_branch != 1 && any_condjump_p (bb->end) | |
3cf54412 | 1952 | && JUMP_LABEL (bb->end) != fallthru->dest->head) |
3dec4024 | 1953 | { |
0b17ab2f | 1954 | error ("Wrong amount of branch edges after conditional jump %i", bb->index); |
3dec4024 JH |
1955 | err = 1; |
1956 | } | |
1957 | if (n_call && GET_CODE (bb->end) != CALL_INSN) | |
1958 | { | |
0b17ab2f | 1959 | error ("Call edges for non-call insn in bb %i", bb->index); |
3dec4024 JH |
1960 | err = 1; |
1961 | } | |
1962 | if (n_abnormal | |
1963 | && (GET_CODE (bb->end) != CALL_INSN && n_call != n_abnormal) | |
1964 | && (GET_CODE (bb->end) != JUMP_INSN | |
1965 | || any_condjump_p (bb->end) | |
1966 | || any_uncondjump_p (bb->end))) | |
1967 | { | |
0b17ab2f | 1968 | error ("Abnormal edges for no purpose in bb %i", bb->index); |
3dec4024 JH |
1969 | err = 1; |
1970 | } | |
f87c27b4 | 1971 | |
5f0d2358 | 1972 | for (x = bb->head; x != NEXT_INSN (bb->end); x = NEXT_INSN (x)) |
ba4f7968 | 1973 | if (BLOCK_FOR_INSN (x) != bb) |
5f0d2358 RK |
1974 | { |
1975 | debug_rtx (x); | |
1976 | if (! BLOCK_FOR_INSN (x)) | |
1977 | error | |
1978 | ("insn %d inside basic block %d but block_for_insn is NULL", | |
0b17ab2f | 1979 | INSN_UID (x), bb->index); |
5f0d2358 RK |
1980 | else |
1981 | error | |
1982 | ("insn %d inside basic block %d but block_for_insn is %i", | |
0b17ab2f | 1983 | INSN_UID (x), bb->index, BLOCK_FOR_INSN (x)->index); |
5f0d2358 RK |
1984 | |
1985 | err = 1; | |
1986 | } | |
ca6c03ca JH |
1987 | |
1988 | /* OK pointers are correct. Now check the header of basic | |
1989 | block. It ought to contain optional CODE_LABEL followed | |
1990 | by NOTE_BASIC_BLOCK. */ | |
1991 | x = bb->head; | |
1992 | if (GET_CODE (x) == CODE_LABEL) | |
1993 | { | |
1994 | if (bb->end == x) | |
1995 | { | |
1996 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 1997 | bb->index); |
ca6c03ca JH |
1998 | err = 1; |
1999 | } | |
5f0d2358 | 2000 | |
ca6c03ca JH |
2001 | x = NEXT_INSN (x); |
2002 | } | |
5f0d2358 | 2003 | |
ca6c03ca JH |
2004 | if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb) |
2005 | { | |
2006 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 2007 | bb->index); |
ca6c03ca JH |
2008 | err = 1; |
2009 | } | |
2010 | ||
2011 | if (bb->end == x) | |
5f0d2358 RK |
2012 | /* Do checks for empty blocks her. e */ |
2013 | ; | |
ca6c03ca | 2014 | else |
5f0d2358 RK |
2015 | for (x = NEXT_INSN (x); x; x = NEXT_INSN (x)) |
2016 | { | |
2017 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2018 | { | |
2019 | error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d", | |
0b17ab2f | 2020 | INSN_UID (x), bb->index); |
5f0d2358 RK |
2021 | err = 1; |
2022 | } | |
2023 | ||
2024 | if (x == bb->end) | |
2025 | break; | |
ca6c03ca | 2026 | |
83fd323c | 2027 | if (control_flow_insn_p (x)) |
5f0d2358 | 2028 | { |
0b17ab2f | 2029 | error ("in basic block %d:", bb->index); |
5f0d2358 RK |
2030 | fatal_insn ("flow control insn inside a basic block", x); |
2031 | } | |
2032 | } | |
ca6c03ca JH |
2033 | } |
2034 | ||
10e9fecc JH |
2035 | /* Clean up. */ |
2036 | free (bb_info); | |
2037 | return err; | |
2038 | } | |
5f0d2358 | 2039 | |
10e9fecc JH |
2040 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
2041 | cfglayout RTL. | |
5f0d2358 | 2042 | |
10e9fecc JH |
2043 | Currently it does following checks: |
2044 | - all checks of rtl_verify_flow_info_1 | |
2045 | - check that all insns are in the basic blocks | |
2046 | (except the switch handling code, barriers and notes) | |
2047 | - check that all returns are followed by barriers | |
2048 | - check that all fallthru edge points to the adjacent blocks. */ | |
2049 | static int | |
d329e058 | 2050 | rtl_verify_flow_info (void) |
10e9fecc JH |
2051 | { |
2052 | basic_block bb; | |
2053 | int err = rtl_verify_flow_info_1 (); | |
2054 | rtx x; | |
2055 | int num_bb_notes; | |
2056 | const rtx rtx_first = get_insns (); | |
2057 | basic_block last_bb_seen = ENTRY_BLOCK_PTR, curr_bb = NULL; | |
ca6c03ca | 2058 | |
10e9fecc JH |
2059 | FOR_EACH_BB_REVERSE (bb) |
2060 | { | |
2061 | edge e; | |
2062 | for (e = bb->succ; e; e = e->succ_next) | |
2063 | if (e->flags & EDGE_FALLTHRU) | |
2064 | break; | |
2065 | if (!e) | |
2066 | { | |
2067 | rtx insn; | |
2068 | ||
2069 | /* Ensure existence of barrier in BB with no fallthru edges. */ | |
2070 | for (insn = bb->end; !insn || GET_CODE (insn) != BARRIER; | |
2071 | insn = NEXT_INSN (insn)) | |
2072 | if (!insn | |
2073 | || (GET_CODE (insn) == NOTE | |
2074 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_BASIC_BLOCK)) | |
2075 | { | |
2076 | error ("missing barrier after block %i", bb->index); | |
2077 | err = 1; | |
2078 | break; | |
2079 | } | |
2080 | } | |
2081 | else if (e->src != ENTRY_BLOCK_PTR | |
2082 | && e->dest != EXIT_BLOCK_PTR) | |
2083 | { | |
2084 | rtx insn; | |
2085 | ||
2086 | if (e->src->next_bb != e->dest) | |
2087 | { | |
2088 | error | |
2089 | ("verify_flow_info: Incorrect blocks for fallthru %i->%i", | |
2090 | e->src->index, e->dest->index); | |
2091 | err = 1; | |
2092 | } | |
2093 | else | |
2094 | for (insn = NEXT_INSN (e->src->end); insn != e->dest->head; | |
2095 | insn = NEXT_INSN (insn)) | |
2096 | if (GET_CODE (insn) == BARRIER | |
2097 | #ifndef CASE_DROPS_THROUGH | |
2098 | || INSN_P (insn) | |
2099 | #else | |
2100 | || (INSN_P (insn) && ! JUMP_TABLE_DATA_P (insn)) | |
2101 | #endif | |
2102 | ) | |
2103 | { | |
2104 | error ("verify_flow_info: Incorrect fallthru %i->%i", | |
2105 | e->src->index, e->dest->index); | |
2106 | fatal_insn ("wrong insn in the fallthru edge", insn); | |
2107 | err = 1; | |
2108 | } | |
2109 | } | |
2110 | } | |
ca6c03ca | 2111 | |
ca6c03ca | 2112 | num_bb_notes = 0; |
e0082a72 ZD |
2113 | last_bb_seen = ENTRY_BLOCK_PTR; |
2114 | ||
5f0d2358 | 2115 | for (x = rtx_first; x; x = NEXT_INSN (x)) |
ca6c03ca JH |
2116 | { |
2117 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2118 | { | |
bf77398c | 2119 | bb = NOTE_BASIC_BLOCK (x); |
5f0d2358 | 2120 | |
ca6c03ca | 2121 | num_bb_notes++; |
e0082a72 | 2122 | if (bb != last_bb_seen->next_bb) |
10e9fecc | 2123 | internal_error ("basic blocks not laid down consecutively"); |
ca6c03ca | 2124 | |
10e9fecc | 2125 | curr_bb = last_bb_seen = bb; |
ca6c03ca JH |
2126 | } |
2127 | ||
10e9fecc | 2128 | if (!curr_bb) |
ca6c03ca JH |
2129 | { |
2130 | switch (GET_CODE (x)) | |
2131 | { | |
2132 | case BARRIER: | |
2133 | case NOTE: | |
2134 | break; | |
2135 | ||
2136 | case CODE_LABEL: | |
2137 | /* An addr_vec is placed outside any block block. */ | |
2138 | if (NEXT_INSN (x) | |
2139 | && GET_CODE (NEXT_INSN (x)) == JUMP_INSN | |
2140 | && (GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_DIFF_VEC | |
2141 | || GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_VEC)) | |
5f0d2358 | 2142 | x = NEXT_INSN (x); |
ca6c03ca JH |
2143 | |
2144 | /* But in any case, non-deletable labels can appear anywhere. */ | |
2145 | break; | |
2146 | ||
2147 | default: | |
1f978f5f | 2148 | fatal_insn ("insn outside basic block", x); |
ca6c03ca JH |
2149 | } |
2150 | } | |
2151 | ||
2152 | if (INSN_P (x) | |
2153 | && GET_CODE (x) == JUMP_INSN | |
2154 | && returnjump_p (x) && ! condjump_p (x) | |
2155 | && ! (NEXT_INSN (x) && GET_CODE (NEXT_INSN (x)) == BARRIER)) | |
1f978f5f | 2156 | fatal_insn ("return not followed by barrier", x); |
10e9fecc JH |
2157 | if (curr_bb && x == curr_bb->end) |
2158 | curr_bb = NULL; | |
ca6c03ca JH |
2159 | } |
2160 | ||
0b17ab2f | 2161 | if (num_bb_notes != n_basic_blocks) |
ca6c03ca | 2162 | internal_error |
0b17ab2f RH |
2163 | ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)", |
2164 | num_bb_notes, n_basic_blocks); | |
ca6c03ca | 2165 | |
10e9fecc | 2166 | return err; |
ca6c03ca JH |
2167 | } |
2168 | \f | |
eaec9b3d | 2169 | /* Assume that the preceding pass has possibly eliminated jump instructions |
ca6c03ca JH |
2170 | or converted the unconditional jumps. Eliminate the edges from CFG. |
2171 | Return true if any edges are eliminated. */ | |
2172 | ||
2173 | bool | |
d329e058 | 2174 | purge_dead_edges (basic_block bb) |
ca6c03ca JH |
2175 | { |
2176 | edge e, next; | |
89753b3a | 2177 | rtx insn = bb->end, note; |
ca6c03ca JH |
2178 | bool purged = false; |
2179 | ||
70da1d03 JH |
2180 | /* If this instruction cannot trap, remove REG_EH_REGION notes. */ |
2181 | if (GET_CODE (insn) == INSN | |
2182 | && (note = find_reg_note (insn, REG_EH_REGION, NULL))) | |
2183 | { | |
2184 | rtx eqnote; | |
2185 | ||
2186 | if (! may_trap_p (PATTERN (insn)) | |
2187 | || ((eqnote = find_reg_equal_equiv_note (insn)) | |
2188 | && ! may_trap_p (XEXP (eqnote, 0)))) | |
2189 | remove_note (insn, note); | |
2190 | } | |
2191 | ||
546c093e RH |
2192 | /* Cleanup abnormal edges caused by exceptions or non-local gotos. */ |
2193 | for (e = bb->succ; e; e = next) | |
2194 | { | |
2195 | next = e->succ_next; | |
2196 | if (e->flags & EDGE_EH) | |
2197 | { | |
2198 | if (can_throw_internal (bb->end)) | |
2199 | continue; | |
2200 | } | |
2201 | else if (e->flags & EDGE_ABNORMAL_CALL) | |
2202 | { | |
2203 | if (GET_CODE (bb->end) == CALL_INSN | |
2204 | && (! (note = find_reg_note (insn, REG_EH_REGION, NULL)) | |
2205 | || INTVAL (XEXP (note, 0)) >= 0)) | |
2206 | continue; | |
2207 | } | |
2208 | else | |
2209 | continue; | |
2210 | ||
2211 | remove_edge (e); | |
2212 | bb->flags |= BB_DIRTY; | |
2213 | purged = true; | |
2214 | } | |
5f0d2358 | 2215 | |
ca6c03ca JH |
2216 | if (GET_CODE (insn) == JUMP_INSN) |
2217 | { | |
2218 | rtx note; | |
2219 | edge b,f; | |
5f0d2358 | 2220 | |
ca6c03ca JH |
2221 | /* We do care only about conditional jumps and simplejumps. */ |
2222 | if (!any_condjump_p (insn) | |
2223 | && !returnjump_p (insn) | |
2224 | && !simplejump_p (insn)) | |
c51d95ec | 2225 | return purged; |
5f0d2358 | 2226 | |
5a1a3e5e JH |
2227 | /* Branch probability/prediction notes are defined only for |
2228 | condjumps. We've possibly turned condjump into simplejump. */ | |
2229 | if (simplejump_p (insn)) | |
2230 | { | |
2231 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2232 | if (note) | |
2233 | remove_note (insn, note); | |
2234 | while ((note = find_reg_note (insn, REG_BR_PRED, NULL))) | |
2235 | remove_note (insn, note); | |
2236 | } | |
2237 | ||
ca6c03ca JH |
2238 | for (e = bb->succ; e; e = next) |
2239 | { | |
2240 | next = e->succ_next; | |
2241 | ||
7fcd7218 JH |
2242 | /* Avoid abnormal flags to leak from computed jumps turned |
2243 | into simplejumps. */ | |
f87c27b4 | 2244 | |
0e1638d4 | 2245 | e->flags &= ~EDGE_ABNORMAL; |
7fcd7218 | 2246 | |
5a566bed MM |
2247 | /* See if this edge is one we should keep. */ |
2248 | if ((e->flags & EDGE_FALLTHRU) && any_condjump_p (insn)) | |
2249 | /* A conditional jump can fall through into the next | |
2250 | block, so we should keep the edge. */ | |
ca6c03ca | 2251 | continue; |
5f0d2358 RK |
2252 | else if (e->dest != EXIT_BLOCK_PTR |
2253 | && e->dest->head == JUMP_LABEL (insn)) | |
5a566bed MM |
2254 | /* If the destination block is the target of the jump, |
2255 | keep the edge. */ | |
2256 | continue; | |
2257 | else if (e->dest == EXIT_BLOCK_PTR && returnjump_p (insn)) | |
2258 | /* If the destination block is the exit block, and this | |
2259 | instruction is a return, then keep the edge. */ | |
ca6c03ca | 2260 | continue; |
5a566bed MM |
2261 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) |
2262 | /* Keep the edges that correspond to exceptions thrown by | |
2263 | this instruction. */ | |
ca6c03ca | 2264 | continue; |
5f0d2358 | 2265 | |
5a566bed | 2266 | /* We do not need this edge. */ |
c51d95ec | 2267 | bb->flags |= BB_DIRTY; |
ca6c03ca JH |
2268 | purged = true; |
2269 | remove_edge (e); | |
2270 | } | |
5f0d2358 | 2271 | |
ca6c03ca | 2272 | if (!bb->succ || !purged) |
c51d95ec | 2273 | return purged; |
5f0d2358 | 2274 | |
ca6c03ca | 2275 | if (rtl_dump_file) |
0b17ab2f | 2276 | fprintf (rtl_dump_file, "Purged edges from bb %i\n", bb->index); |
5f0d2358 | 2277 | |
ca6c03ca JH |
2278 | if (!optimize) |
2279 | return purged; | |
2280 | ||
2281 | /* Redistribute probabilities. */ | |
2282 | if (!bb->succ->succ_next) | |
2283 | { | |
2284 | bb->succ->probability = REG_BR_PROB_BASE; | |
2285 | bb->succ->count = bb->count; | |
f87c27b4 | 2286 | } |
ca6c03ca JH |
2287 | else |
2288 | { | |
2289 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2290 | if (!note) | |
2291 | return purged; | |
5f0d2358 | 2292 | |
ca6c03ca JH |
2293 | b = BRANCH_EDGE (bb); |
2294 | f = FALLTHRU_EDGE (bb); | |
2295 | b->probability = INTVAL (XEXP (note, 0)); | |
2296 | f->probability = REG_BR_PROB_BASE - b->probability; | |
2297 | b->count = bb->count * b->probability / REG_BR_PROB_BASE; | |
2298 | f->count = bb->count * f->probability / REG_BR_PROB_BASE; | |
2299 | } | |
5f0d2358 | 2300 | |
ca6c03ca JH |
2301 | return purged; |
2302 | } | |
1722c2c8 RH |
2303 | else if (GET_CODE (insn) == CALL_INSN && SIBLING_CALL_P (insn)) |
2304 | { | |
2305 | /* First, there should not be any EH or ABCALL edges resulting | |
2306 | from non-local gotos and the like. If there were, we shouldn't | |
2307 | have created the sibcall in the first place. Second, there | |
2308 | should of course never have been a fallthru edge. */ | |
2309 | if (!bb->succ || bb->succ->succ_next) | |
2310 | abort (); | |
792bb204 | 2311 | if (bb->succ->flags != (EDGE_SIBCALL | EDGE_ABNORMAL)) |
1722c2c8 RH |
2312 | abort (); |
2313 | ||
2314 | return 0; | |
2315 | } | |
ca6c03ca | 2316 | |
ca6c03ca JH |
2317 | /* If we don't see a jump insn, we don't know exactly why the block would |
2318 | have been broken at this point. Look for a simple, non-fallthru edge, | |
2319 | as these are only created by conditional branches. If we find such an | |
2320 | edge we know that there used to be a jump here and can then safely | |
2321 | remove all non-fallthru edges. */ | |
2322 | for (e = bb->succ; e && (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU)); | |
5f0d2358 RK |
2323 | e = e->succ_next) |
2324 | ; | |
2325 | ||
ca6c03ca JH |
2326 | if (!e) |
2327 | return purged; | |
5f0d2358 | 2328 | |
ca6c03ca JH |
2329 | for (e = bb->succ; e; e = next) |
2330 | { | |
2331 | next = e->succ_next; | |
2332 | if (!(e->flags & EDGE_FALLTHRU)) | |
c51d95ec JH |
2333 | { |
2334 | bb->flags |= BB_DIRTY; | |
2335 | remove_edge (e); | |
2336 | purged = true; | |
2337 | } | |
ca6c03ca | 2338 | } |
5f0d2358 | 2339 | |
ca6c03ca JH |
2340 | if (!bb->succ || bb->succ->succ_next) |
2341 | abort (); | |
5f0d2358 | 2342 | |
ca6c03ca JH |
2343 | bb->succ->probability = REG_BR_PROB_BASE; |
2344 | bb->succ->count = bb->count; | |
2345 | ||
2346 | if (rtl_dump_file) | |
2347 | fprintf (rtl_dump_file, "Purged non-fallthru edges from bb %i\n", | |
0b17ab2f | 2348 | bb->index); |
ca6c03ca JH |
2349 | return purged; |
2350 | } | |
2351 | ||
5f0d2358 RK |
2352 | /* Search all basic blocks for potentially dead edges and purge them. Return |
2353 | true if some edge has been eliminated. */ | |
ca6c03ca JH |
2354 | |
2355 | bool | |
d329e058 | 2356 | purge_all_dead_edges (int update_life_p) |
ca6c03ca | 2357 | { |
e0082a72 | 2358 | int purged = false; |
710af899 | 2359 | sbitmap blocks = 0; |
e0082a72 | 2360 | basic_block bb; |
473fb060 JH |
2361 | |
2362 | if (update_life_p) | |
2363 | { | |
d55bc081 | 2364 | blocks = sbitmap_alloc (last_basic_block); |
473fb060 JH |
2365 | sbitmap_zero (blocks); |
2366 | } | |
5f0d2358 | 2367 | |
e0082a72 | 2368 | FOR_EACH_BB (bb) |
473fb060 | 2369 | { |
e0082a72 | 2370 | bool purged_here = purge_dead_edges (bb); |
5f0d2358 | 2371 | |
473fb060 JH |
2372 | purged |= purged_here; |
2373 | if (purged_here && update_life_p) | |
e0082a72 | 2374 | SET_BIT (blocks, bb->index); |
473fb060 | 2375 | } |
5f0d2358 | 2376 | |
473fb060 JH |
2377 | if (update_life_p && purged) |
2378 | update_life_info (blocks, UPDATE_LIFE_GLOBAL, | |
2379 | PROP_DEATH_NOTES | PROP_SCAN_DEAD_CODE | |
2380 | | PROP_KILL_DEAD_CODE); | |
5f0d2358 | 2381 | |
473fb060 JH |
2382 | if (update_life_p) |
2383 | sbitmap_free (blocks); | |
ca6c03ca JH |
2384 | return purged; |
2385 | } | |
9ee634e3 JH |
2386 | |
2387 | /* Same as split_block but update cfg_layout structures. */ | |
2388 | static edge | |
d329e058 | 2389 | cfg_layout_split_block (basic_block bb, void *insnp) |
9ee634e3 JH |
2390 | { |
2391 | rtx insn = insnp; | |
2392 | ||
2393 | edge fallthru = rtl_split_block (bb, insn); | |
2394 | ||
bc35512f JH |
2395 | fallthru->dest->rbi->footer = fallthru->src->rbi->footer; |
2396 | fallthru->src->rbi->footer = NULL; | |
9ee634e3 JH |
2397 | return fallthru; |
2398 | } | |
2399 | ||
2400 | ||
2401 | /* Redirect Edge to DEST. */ | |
2402 | static bool | |
d329e058 | 2403 | cfg_layout_redirect_edge_and_branch (edge e, basic_block dest) |
9ee634e3 JH |
2404 | { |
2405 | basic_block src = e->src; | |
9ee634e3 JH |
2406 | bool ret; |
2407 | ||
bc35512f JH |
2408 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
2409 | return false; | |
2410 | ||
2411 | if (e->src != ENTRY_BLOCK_PTR | |
2412 | && try_redirect_by_replacing_jump (e, dest, true)) | |
2413 | return true; | |
2414 | ||
2415 | if (e->dest == dest) | |
2416 | return true; | |
2417 | ||
2418 | if (e->src == ENTRY_BLOCK_PTR | |
2419 | && (e->flags & EDGE_FALLTHRU) && !(e->flags & EDGE_COMPLEX)) | |
2420 | { | |
2421 | if (rtl_dump_file) | |
2422 | fprintf (rtl_dump_file, "Redirecting entry edge from bb %i to %i\n", | |
2423 | e->src->index, dest->index); | |
2424 | ||
2425 | redirect_edge_succ (e, dest); | |
2426 | return true; | |
2427 | } | |
2428 | ||
9ee634e3 JH |
2429 | /* Redirect_edge_and_branch may decide to turn branch into fallthru edge |
2430 | in the case the basic block appears to be in sequence. Avoid this | |
2431 | transformation. */ | |
2432 | ||
9ee634e3 JH |
2433 | if (e->flags & EDGE_FALLTHRU) |
2434 | { | |
2435 | /* Redirect any branch edges unified with the fallthru one. */ | |
2436 | if (GET_CODE (src->end) == JUMP_INSN | |
2437 | && JUMP_LABEL (src->end) == e->dest->head) | |
2438 | { | |
2439 | if (!redirect_jump (src->end, block_label (dest), 0)) | |
2440 | abort (); | |
2441 | } | |
2442 | /* In case we are redirecting fallthru edge to the branch edge | |
2443 | of conditional jump, remove it. */ | |
2444 | if (src->succ->succ_next | |
2445 | && !src->succ->succ_next->succ_next) | |
2446 | { | |
2447 | edge s = e->succ_next ? e->succ_next : src->succ; | |
2448 | if (s->dest == dest | |
2449 | && any_condjump_p (src->end) | |
2450 | && onlyjump_p (src->end)) | |
2451 | delete_insn (src->end); | |
2452 | } | |
2453 | redirect_edge_succ_nodup (e, dest); | |
bc35512f JH |
2454 | if (rtl_dump_file) |
2455 | fprintf (rtl_dump_file, "Fallthru edge %i->%i redirected to %i\n", | |
2456 | e->src->index, e->dest->index, dest->index); | |
9ee634e3 JH |
2457 | |
2458 | ret = true; | |
2459 | } | |
2460 | else | |
bc35512f | 2461 | ret = redirect_branch_edge (e, dest); |
9ee634e3 JH |
2462 | |
2463 | /* We don't want simplejumps in the insn stream during cfglayout. */ | |
2464 | if (simplejump_p (src->end)) | |
bc35512f | 2465 | abort (); |
9ee634e3 JH |
2466 | |
2467 | return ret; | |
2468 | } | |
2469 | ||
2470 | /* Simple wrapper as we always can redirect fallthru edges. */ | |
2471 | static basic_block | |
d329e058 | 2472 | cfg_layout_redirect_edge_and_branch_force (edge e, basic_block dest) |
9ee634e3 JH |
2473 | { |
2474 | if (!cfg_layout_redirect_edge_and_branch (e, dest)) | |
2475 | abort (); | |
2476 | return NULL; | |
2477 | } | |
2478 | ||
2479 | /* Same as flow_delete_block but update cfg_layout structures. */ | |
2480 | static void | |
d329e058 | 2481 | cfg_layout_delete_block (basic_block bb) |
9ee634e3 JH |
2482 | { |
2483 | rtx insn, next, prev = PREV_INSN (bb->head), *to, remaints; | |
2484 | ||
bc35512f | 2485 | if (bb->rbi->header) |
9ee634e3 JH |
2486 | { |
2487 | next = bb->head; | |
2488 | if (prev) | |
bc35512f | 2489 | NEXT_INSN (prev) = bb->rbi->header; |
9ee634e3 | 2490 | else |
bc35512f JH |
2491 | set_first_insn (bb->rbi->header); |
2492 | PREV_INSN (bb->rbi->header) = prev; | |
2493 | insn = bb->rbi->header; | |
9ee634e3 JH |
2494 | while (NEXT_INSN (insn)) |
2495 | insn = NEXT_INSN (insn); | |
2496 | NEXT_INSN (insn) = next; | |
2497 | PREV_INSN (next) = insn; | |
2498 | } | |
2499 | next = NEXT_INSN (bb->end); | |
bc35512f | 2500 | if (bb->rbi->footer) |
9ee634e3 | 2501 | { |
bc35512f JH |
2502 | insn = bb->rbi->footer; |
2503 | while (insn) | |
2504 | { | |
2505 | if (GET_CODE (insn) == BARRIER) | |
2506 | { | |
2507 | if (PREV_INSN (insn)) | |
2508 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
2509 | else | |
2510 | bb->rbi->footer = NEXT_INSN (insn); | |
2511 | if (NEXT_INSN (insn)) | |
2512 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
2513 | } | |
2514 | if (GET_CODE (insn) == CODE_LABEL) | |
2515 | break; | |
2516 | insn = NEXT_INSN (insn); | |
2517 | } | |
2518 | if (bb->rbi->footer) | |
2519 | { | |
2520 | insn = bb->end; | |
2521 | NEXT_INSN (insn) = bb->rbi->footer; | |
2522 | PREV_INSN (bb->rbi->footer) = insn; | |
2523 | while (NEXT_INSN (insn)) | |
2524 | insn = NEXT_INSN (insn); | |
2525 | NEXT_INSN (insn) = next; | |
2526 | if (next) | |
2527 | PREV_INSN (next) = insn; | |
2528 | else | |
2529 | set_last_insn (insn); | |
2530 | } | |
9ee634e3 JH |
2531 | } |
2532 | if (bb->next_bb != EXIT_BLOCK_PTR) | |
bc35512f | 2533 | to = &bb->next_bb->rbi->header; |
9ee634e3 JH |
2534 | else |
2535 | to = &cfg_layout_function_footer; | |
2536 | rtl_delete_block (bb); | |
2537 | ||
2538 | if (prev) | |
2539 | prev = NEXT_INSN (prev); | |
d329e058 | 2540 | else |
9ee634e3 JH |
2541 | prev = get_insns (); |
2542 | if (next) | |
2543 | next = PREV_INSN (next); | |
d329e058 | 2544 | else |
9ee634e3 JH |
2545 | next = get_last_insn (); |
2546 | ||
2547 | if (next && NEXT_INSN (next) != prev) | |
2548 | { | |
2549 | remaints = unlink_insn_chain (prev, next); | |
2550 | insn = remaints; | |
2551 | while (NEXT_INSN (insn)) | |
2552 | insn = NEXT_INSN (insn); | |
2553 | NEXT_INSN (insn) = *to; | |
2554 | if (*to) | |
2555 | PREV_INSN (*to) = insn; | |
2556 | *to = remaints; | |
2557 | } | |
2558 | } | |
2559 | ||
bc35512f JH |
2560 | /* return true when blocks A and B can be safely merged. */ |
2561 | static bool | |
2562 | cfg_layout_can_merge_blocks_p (basic_block a, basic_block b) | |
2563 | { | |
2564 | /* There must be exactly one edge in between the blocks. */ | |
2565 | return (a->succ && !a->succ->succ_next && a->succ->dest == b | |
2566 | && !b->pred->pred_next && a != b | |
2567 | /* Must be simple edge. */ | |
2568 | && !(a->succ->flags & EDGE_COMPLEX) | |
2569 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR | |
2570 | /* If the jump insn has side effects, | |
2571 | we can't kill the edge. */ | |
2572 | && (GET_CODE (a->end) != JUMP_INSN | |
2573 | || (flow2_completed | |
2574 | ? simplejump_p (a->end) : onlyjump_p (a->end)))); | |
2575 | } | |
2576 | ||
2577 | /* Merge block A and B, abort when it is not possible. */ | |
2578 | static void | |
2579 | cfg_layout_merge_blocks (basic_block a, basic_block b) | |
2580 | { | |
2581 | #ifdef ENABLE_CHECKING | |
2582 | if (!cfg_layout_can_merge_blocks_p (a, b)) | |
2583 | abort (); | |
2584 | #endif | |
2585 | ||
2586 | /* If there was a CODE_LABEL beginning B, delete it. */ | |
2587 | if (GET_CODE (b->head) == CODE_LABEL) | |
2588 | delete_insn (b->head); | |
2589 | ||
2590 | /* We should have fallthru edge in a, or we can do dummy redirection to get | |
2591 | it cleaned up. */ | |
2592 | if (GET_CODE (a->end) == JUMP_INSN) | |
2593 | redirect_edge_and_branch (a->succ, b); | |
2594 | if (GET_CODE (a->end) == JUMP_INSN) | |
2595 | abort (); | |
2596 | ||
2597 | /* Possible line number notes should appear in between. */ | |
2598 | if (b->rbi->header) | |
2599 | { | |
2600 | rtx first = a->end, last; | |
2601 | ||
2602 | last = emit_insn_after (b->rbi->header, a->end); | |
2603 | delete_insn_chain (NEXT_INSN (first), last); | |
2604 | b->rbi->header = NULL; | |
2605 | } | |
2606 | ||
2607 | /* In the case basic blocks are not adjacent, move them around. */ | |
2608 | if (NEXT_INSN (a->end) != b->head) | |
2609 | { | |
2610 | rtx first = unlink_insn_chain (b->head, b->end); | |
2611 | ||
2612 | emit_insn_after (first, a->end); | |
2613 | /* Skip possible DELETED_LABEL insn. */ | |
2614 | if (!NOTE_INSN_BASIC_BLOCK_P (first)) | |
2615 | first = NEXT_INSN (first); | |
2616 | if (!NOTE_INSN_BASIC_BLOCK_P (first)) | |
2617 | abort (); | |
2618 | b->head = NULL; | |
2619 | delete_insn (first); | |
2620 | } | |
2621 | /* Otherwise just re-associate the instructions. */ | |
2622 | else | |
2623 | { | |
2624 | rtx insn; | |
2625 | ||
2626 | for (insn = b->head; insn != NEXT_INSN (b->end); insn = NEXT_INSN (insn)) | |
2627 | set_block_for_insn (insn, a); | |
2628 | insn = b->head; | |
2629 | /* Skip possible DELETED_LABEL insn. */ | |
2630 | if (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
2631 | insn = NEXT_INSN (insn); | |
2632 | if (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
2633 | abort (); | |
2634 | b->head = NULL; | |
2635 | a->end = b->end; | |
2636 | delete_insn (insn); | |
2637 | } | |
2638 | ||
2639 | /* Possible tablejumps and barriers should appear after the block. */ | |
2640 | if (b->rbi->footer) | |
2641 | { | |
2642 | if (!a->rbi->footer) | |
2643 | a->rbi->footer = b->rbi->footer; | |
2644 | else | |
2645 | { | |
2646 | rtx last = a->rbi->footer; | |
2647 | ||
2648 | while (NEXT_INSN (last)) | |
2649 | last = NEXT_INSN (last); | |
2650 | NEXT_INSN (last) = b->rbi->footer; | |
2651 | PREV_INSN (b->rbi->footer) = last; | |
2652 | } | |
2653 | b->rbi->footer = NULL; | |
2654 | } | |
2655 | ||
2656 | if (rtl_dump_file) | |
2657 | fprintf (rtl_dump_file, "Merged blocks %d and %d.\n", | |
2658 | a->index, b->index); | |
2659 | ||
2660 | update_cfg_after_block_merging (a, b); | |
2661 | } | |
2662 | ||
2663 | /* Split edge E. */ | |
2664 | static basic_block | |
2665 | cfg_layout_split_edge (edge e) | |
2666 | { | |
2667 | edge new_e; | |
2668 | basic_block new_bb = | |
2669 | create_basic_block (e->src != ENTRY_BLOCK_PTR | |
2670 | ? NEXT_INSN (e->src-> end) : get_insns (), | |
2671 | NULL_RTX, e->src); | |
2672 | ||
2673 | new_bb->count = e->count; | |
2674 | new_bb->frequency = EDGE_FREQUENCY (e); | |
2675 | ||
2676 | new_e = make_edge (new_bb, e->dest, EDGE_FALLTHRU); | |
2677 | new_e->probability = REG_BR_PROB_BASE; | |
2678 | new_e->count = e->count; | |
2679 | redirect_edge_and_branch_force (e, new_bb); | |
2680 | ||
2681 | return new_bb; | |
2682 | } | |
2683 | ||
9ee634e3 JH |
2684 | /* Implementation of CFG manipulation for linearized RTL. */ |
2685 | struct cfg_hooks rtl_cfg_hooks = { | |
2686 | rtl_verify_flow_info, | |
10e9fecc | 2687 | rtl_dump_bb, |
bc35512f | 2688 | rtl_create_basic_block, |
9ee634e3 JH |
2689 | rtl_redirect_edge_and_branch, |
2690 | rtl_redirect_edge_and_branch_force, | |
2691 | rtl_delete_block, | |
2692 | rtl_split_block, | |
bc35512f JH |
2693 | rtl_can_merge_blocks, /* can_merge_blocks_p */ |
2694 | rtl_merge_blocks, | |
9ee634e3 JH |
2695 | rtl_split_edge |
2696 | }; | |
2697 | ||
2698 | /* Implementation of CFG manipulation for cfg layout RTL, where | |
2699 | basic block connected via fallthru edges does not have to be adjacent. | |
2700 | This representation will hopefully become the default one in future | |
2701 | version of the compiler. */ | |
2702 | struct cfg_hooks cfg_layout_rtl_cfg_hooks = { | |
bc35512f | 2703 | rtl_verify_flow_info_1, |
10e9fecc | 2704 | rtl_dump_bb, |
bc35512f | 2705 | cfg_layout_create_basic_block, |
9ee634e3 JH |
2706 | cfg_layout_redirect_edge_and_branch, |
2707 | cfg_layout_redirect_edge_and_branch_force, | |
2708 | cfg_layout_delete_block, | |
2709 | cfg_layout_split_block, | |
bc35512f JH |
2710 | cfg_layout_can_merge_blocks_p, |
2711 | cfg_layout_merge_blocks, | |
2712 | cfg_layout_split_edge | |
9ee634e3 | 2713 | }; |