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Commit | Line | Data |
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ca6c03ca JH |
1 | /* Control flow graph manipulation code for GNU compiler. |
2 | Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, | |
d9221e01 | 3 | 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc. |
ca6c03ca JH |
4 | |
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it under | |
8 | the terms of the GNU General Public License as published by the Free | |
9 | Software Foundation; either version 2, or (at your option) any later | |
10 | version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING. If not, write to the Free | |
19 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA | |
20 | 02111-1307, USA. */ | |
21 | ||
5f0d2358 RK |
22 | /* This file contains low level functions to manipulate the CFG and analyze it |
23 | that are aware of the RTL intermediate language. | |
ca6c03ca JH |
24 | |
25 | Available functionality: | |
bc35512f | 26 | - Basic CFG/RTL manipulation API documented in cfghooks.h |
5f0d2358 | 27 | - CFG-aware instruction chain manipulation |
ca6c03ca | 28 | delete_insn, delete_insn_chain |
bc35512f JH |
29 | - Edge splitting and committing to edges |
30 | insert_insn_on_edge, commit_edge_insertions | |
31 | - CFG updating after insn simplification | |
32 | purge_dead_edges, purge_all_dead_edges | |
33 | ||
34 | Functions not supposed for generic use: | |
5f0d2358 | 35 | - Infrastructure to determine quickly basic block for insn |
ca6c03ca | 36 | compute_bb_for_insn, update_bb_for_insn, set_block_for_insn, |
5f0d2358 | 37 | - Edge redirection with updating and optimizing of insn chain |
bc35512f | 38 | block_label, tidy_fallthru_edge, force_nonfallthru */ |
ca6c03ca JH |
39 | \f |
40 | #include "config.h" | |
41 | #include "system.h" | |
4977bab6 ZW |
42 | #include "coretypes.h" |
43 | #include "tm.h" | |
ca6c03ca JH |
44 | #include "tree.h" |
45 | #include "rtl.h" | |
46 | #include "hard-reg-set.h" | |
47 | #include "basic-block.h" | |
48 | #include "regs.h" | |
49 | #include "flags.h" | |
50 | #include "output.h" | |
51 | #include "function.h" | |
52 | #include "except.h" | |
53 | #include "toplev.h" | |
54 | #include "tm_p.h" | |
55 | #include "obstack.h" | |
0a2ed1f1 | 56 | #include "insn-config.h" |
9ee634e3 | 57 | #include "cfglayout.h" |
ff25ef99 | 58 | #include "expr.h" |
9fb32434 | 59 | #include "target.h" |
ca6c03ca | 60 | |
ca6c03ca | 61 | |
ca6c03ca JH |
62 | /* The labels mentioned in non-jump rtl. Valid during find_basic_blocks. */ |
63 | /* ??? Should probably be using LABEL_NUSES instead. It would take a | |
64 | bit of surgery to be able to use or co-opt the routines in jump. */ | |
ca6c03ca | 65 | rtx label_value_list; |
ca6c03ca | 66 | |
d329e058 AJ |
67 | static int can_delete_note_p (rtx); |
68 | static int can_delete_label_p (rtx); | |
69 | static void commit_one_edge_insertion (edge, int); | |
d329e058 AJ |
70 | static rtx last_loop_beg_note (rtx); |
71 | static bool back_edge_of_syntactic_loop_p (basic_block, basic_block); | |
72 | basic_block force_nonfallthru_and_redirect (edge, basic_block); | |
73 | static basic_block rtl_split_edge (edge); | |
f470c378 | 74 | static bool rtl_move_block_after (basic_block, basic_block); |
d329e058 | 75 | static int rtl_verify_flow_info (void); |
f470c378 | 76 | static basic_block cfg_layout_split_block (basic_block, void *); |
6de9cd9a | 77 | static edge cfg_layout_redirect_edge_and_branch (edge, basic_block); |
d329e058 AJ |
78 | static basic_block cfg_layout_redirect_edge_and_branch_force (edge, basic_block); |
79 | static void cfg_layout_delete_block (basic_block); | |
80 | static void rtl_delete_block (basic_block); | |
81 | static basic_block rtl_redirect_edge_and_branch_force (edge, basic_block); | |
6de9cd9a | 82 | static edge rtl_redirect_edge_and_branch (edge, basic_block); |
f470c378 ZD |
83 | static basic_block rtl_split_block (basic_block, void *); |
84 | static void rtl_dump_bb (basic_block, FILE *, int); | |
d329e058 | 85 | static int rtl_verify_flow_info_1 (void); |
ff25ef99 | 86 | static void mark_killed_regs (rtx, rtx, void *); |
f470c378 | 87 | static void rtl_make_forwarder_block (edge); |
ca6c03ca JH |
88 | \f |
89 | /* Return true if NOTE is not one of the ones that must be kept paired, | |
5f0d2358 | 90 | so that we may simply delete it. */ |
ca6c03ca JH |
91 | |
92 | static int | |
d329e058 | 93 | can_delete_note_p (rtx note) |
ca6c03ca JH |
94 | { |
95 | return (NOTE_LINE_NUMBER (note) == NOTE_INSN_DELETED | |
969d70ca | 96 | || NOTE_LINE_NUMBER (note) == NOTE_INSN_BASIC_BLOCK |
07a236b6 | 97 | || NOTE_LINE_NUMBER (note) == NOTE_INSN_UNLIKELY_EXECUTED_CODE); |
ca6c03ca JH |
98 | } |
99 | ||
100 | /* True if a given label can be deleted. */ | |
101 | ||
102 | static int | |
d329e058 | 103 | can_delete_label_p (rtx label) |
ca6c03ca | 104 | { |
5f0d2358 RK |
105 | return (!LABEL_PRESERVE_P (label) |
106 | /* User declared labels must be preserved. */ | |
107 | && LABEL_NAME (label) == 0 | |
108 | && !in_expr_list_p (forced_labels, label) | |
6a58eee9 | 109 | && !in_expr_list_p (label_value_list, label)); |
ca6c03ca JH |
110 | } |
111 | ||
112 | /* Delete INSN by patching it out. Return the next insn. */ | |
113 | ||
114 | rtx | |
d329e058 | 115 | delete_insn (rtx insn) |
ca6c03ca JH |
116 | { |
117 | rtx next = NEXT_INSN (insn); | |
118 | rtx note; | |
119 | bool really_delete = true; | |
120 | ||
4b4bf941 | 121 | if (LABEL_P (insn)) |
ca6c03ca JH |
122 | { |
123 | /* Some labels can't be directly removed from the INSN chain, as they | |
f87c27b4 | 124 | might be references via variables, constant pool etc. |
ca6c03ca JH |
125 | Convert them to the special NOTE_INSN_DELETED_LABEL note. */ |
126 | if (! can_delete_label_p (insn)) | |
127 | { | |
128 | const char *name = LABEL_NAME (insn); | |
129 | ||
130 | really_delete = false; | |
131 | PUT_CODE (insn, NOTE); | |
132 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED_LABEL; | |
6773e15f | 133 | NOTE_DELETED_LABEL_NAME (insn) = name; |
ca6c03ca | 134 | } |
5f0d2358 | 135 | |
ca6c03ca JH |
136 | remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels); |
137 | } | |
138 | ||
139 | if (really_delete) | |
140 | { | |
cda94cbb RH |
141 | /* If this insn has already been deleted, something is very wrong. */ |
142 | if (INSN_DELETED_P (insn)) | |
143 | abort (); | |
ca6c03ca JH |
144 | remove_insn (insn); |
145 | INSN_DELETED_P (insn) = 1; | |
146 | } | |
147 | ||
148 | /* If deleting a jump, decrement the use count of the label. Deleting | |
149 | the label itself should happen in the normal course of block merging. */ | |
4b4bf941 | 150 | if (JUMP_P (insn) |
ca6c03ca | 151 | && JUMP_LABEL (insn) |
4b4bf941 | 152 | && LABEL_P (JUMP_LABEL (insn))) |
ca6c03ca JH |
153 | LABEL_NUSES (JUMP_LABEL (insn))--; |
154 | ||
155 | /* Also if deleting an insn that references a label. */ | |
9295a326 JZ |
156 | else |
157 | { | |
158 | while ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)) != NULL_RTX | |
4b4bf941 | 159 | && LABEL_P (XEXP (note, 0))) |
9295a326 JZ |
160 | { |
161 | LABEL_NUSES (XEXP (note, 0))--; | |
162 | remove_note (insn, note); | |
163 | } | |
164 | } | |
ca6c03ca | 165 | |
4b4bf941 | 166 | if (JUMP_P (insn) |
ca6c03ca JH |
167 | && (GET_CODE (PATTERN (insn)) == ADDR_VEC |
168 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)) | |
169 | { | |
170 | rtx pat = PATTERN (insn); | |
171 | int diff_vec_p = GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC; | |
172 | int len = XVECLEN (pat, diff_vec_p); | |
173 | int i; | |
174 | ||
175 | for (i = 0; i < len; i++) | |
a124fcda RH |
176 | { |
177 | rtx label = XEXP (XVECEXP (pat, diff_vec_p, i), 0); | |
178 | ||
179 | /* When deleting code in bulk (e.g. removing many unreachable | |
180 | blocks) we can delete a label that's a target of the vector | |
181 | before deleting the vector itself. */ | |
4b4bf941 | 182 | if (!NOTE_P (label)) |
a124fcda RH |
183 | LABEL_NUSES (label)--; |
184 | } | |
ca6c03ca JH |
185 | } |
186 | ||
187 | return next; | |
188 | } | |
189 | ||
3dec4024 JH |
190 | /* Like delete_insn but also purge dead edges from BB. */ |
191 | rtx | |
d329e058 | 192 | delete_insn_and_edges (rtx insn) |
3dec4024 JH |
193 | { |
194 | rtx x; | |
195 | bool purge = false; | |
196 | ||
ba4f7968 | 197 | if (INSN_P (insn) |
3dec4024 | 198 | && BLOCK_FOR_INSN (insn) |
a813c111 | 199 | && BB_END (BLOCK_FOR_INSN (insn)) == insn) |
3dec4024 JH |
200 | purge = true; |
201 | x = delete_insn (insn); | |
202 | if (purge) | |
203 | purge_dead_edges (BLOCK_FOR_INSN (insn)); | |
204 | return x; | |
205 | } | |
206 | ||
ca6c03ca JH |
207 | /* Unlink a chain of insns between START and FINISH, leaving notes |
208 | that must be paired. */ | |
209 | ||
210 | void | |
d329e058 | 211 | delete_insn_chain (rtx start, rtx finish) |
ca6c03ca | 212 | { |
ca6c03ca JH |
213 | rtx next; |
214 | ||
5f0d2358 RK |
215 | /* Unchain the insns one by one. It would be quicker to delete all of these |
216 | with a single unchaining, rather than one at a time, but we need to keep | |
217 | the NOTE's. */ | |
ca6c03ca JH |
218 | while (1) |
219 | { | |
220 | next = NEXT_INSN (start); | |
4b4bf941 | 221 | if (NOTE_P (start) && !can_delete_note_p (start)) |
ca6c03ca JH |
222 | ; |
223 | else | |
224 | next = delete_insn (start); | |
225 | ||
226 | if (start == finish) | |
227 | break; | |
228 | start = next; | |
229 | } | |
230 | } | |
3dec4024 JH |
231 | |
232 | /* Like delete_insn but also purge dead edges from BB. */ | |
233 | void | |
d329e058 | 234 | delete_insn_chain_and_edges (rtx first, rtx last) |
3dec4024 JH |
235 | { |
236 | bool purge = false; | |
237 | ||
ba4f7968 | 238 | if (INSN_P (last) |
3dec4024 | 239 | && BLOCK_FOR_INSN (last) |
a813c111 | 240 | && BB_END (BLOCK_FOR_INSN (last)) == last) |
3dec4024 JH |
241 | purge = true; |
242 | delete_insn_chain (first, last); | |
243 | if (purge) | |
244 | purge_dead_edges (BLOCK_FOR_INSN (last)); | |
245 | } | |
ca6c03ca | 246 | \f |
5f0d2358 RK |
247 | /* Create a new basic block consisting of the instructions between HEAD and END |
248 | inclusive. This function is designed to allow fast BB construction - reuses | |
249 | the note and basic block struct in BB_NOTE, if any and do not grow | |
250 | BASIC_BLOCK chain and should be used directly only by CFG construction code. | |
251 | END can be NULL in to create new empty basic block before HEAD. Both END | |
918ed612 ZD |
252 | and HEAD can be NULL to create basic block at the end of INSN chain. |
253 | AFTER is the basic block we should be put after. */ | |
ca6c03ca JH |
254 | |
255 | basic_block | |
d329e058 | 256 | create_basic_block_structure (rtx head, rtx end, rtx bb_note, basic_block after) |
ca6c03ca JH |
257 | { |
258 | basic_block bb; | |
259 | ||
260 | if (bb_note | |
ca6c03ca JH |
261 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL |
262 | && bb->aux == NULL) | |
263 | { | |
264 | /* If we found an existing note, thread it back onto the chain. */ | |
265 | ||
266 | rtx after; | |
267 | ||
4b4bf941 | 268 | if (LABEL_P (head)) |
ca6c03ca JH |
269 | after = head; |
270 | else | |
271 | { | |
272 | after = PREV_INSN (head); | |
273 | head = bb_note; | |
274 | } | |
275 | ||
276 | if (after != bb_note && NEXT_INSN (after) != bb_note) | |
ba4f7968 | 277 | reorder_insns_nobb (bb_note, bb_note, after); |
ca6c03ca JH |
278 | } |
279 | else | |
280 | { | |
281 | /* Otherwise we must create a note and a basic block structure. */ | |
282 | ||
283 | bb = alloc_block (); | |
284 | ||
285 | if (!head && !end) | |
5f0d2358 RK |
286 | head = end = bb_note |
287 | = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); | |
4b4bf941 | 288 | else if (LABEL_P (head) && end) |
ca6c03ca JH |
289 | { |
290 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); | |
291 | if (head == end) | |
292 | end = bb_note; | |
293 | } | |
294 | else | |
295 | { | |
296 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); | |
297 | head = bb_note; | |
298 | if (!end) | |
299 | end = head; | |
300 | } | |
5f0d2358 | 301 | |
ca6c03ca JH |
302 | NOTE_BASIC_BLOCK (bb_note) = bb; |
303 | } | |
304 | ||
305 | /* Always include the bb note in the block. */ | |
306 | if (NEXT_INSN (end) == bb_note) | |
307 | end = bb_note; | |
308 | ||
a813c111 SB |
309 | BB_HEAD (bb) = head; |
310 | BB_END (bb) = end; | |
852c6ec7 | 311 | bb->index = last_basic_block++; |
38c1593d | 312 | bb->flags = BB_NEW; |
918ed612 | 313 | link_block (bb, after); |
852c6ec7 | 314 | BASIC_BLOCK (bb->index) = bb; |
ba4f7968 | 315 | update_bb_for_insn (bb); |
076c7ab8 | 316 | BB_SET_PARTITION (bb, BB_UNPARTITIONED); |
ca6c03ca JH |
317 | |
318 | /* Tag the block so that we know it has been used when considering | |
319 | other basic block notes. */ | |
320 | bb->aux = bb; | |
321 | ||
322 | return bb; | |
323 | } | |
324 | ||
5f0d2358 | 325 | /* Create new basic block consisting of instructions in between HEAD and END |
918ed612 | 326 | and place it to the BB chain after block AFTER. END can be NULL in to |
5f0d2358 RK |
327 | create new empty basic block before HEAD. Both END and HEAD can be NULL to |
328 | create basic block at the end of INSN chain. */ | |
ca6c03ca | 329 | |
bc35512f JH |
330 | static basic_block |
331 | rtl_create_basic_block (void *headp, void *endp, basic_block after) | |
ca6c03ca | 332 | { |
bc35512f | 333 | rtx head = headp, end = endp; |
ca6c03ca | 334 | basic_block bb; |
0b17ab2f | 335 | |
7eca0767 JH |
336 | /* Grow the basic block array if needed. */ |
337 | if ((size_t) last_basic_block >= VARRAY_SIZE (basic_block_info)) | |
338 | { | |
339 | size_t new_size = last_basic_block + (last_basic_block + 3) / 4; | |
340 | VARRAY_GROW (basic_block_info, new_size); | |
341 | } | |
0b17ab2f | 342 | |
bf77398c | 343 | n_basic_blocks++; |
ca6c03ca | 344 | |
852c6ec7 | 345 | bb = create_basic_block_structure (head, end, NULL, after); |
ca6c03ca JH |
346 | bb->aux = NULL; |
347 | return bb; | |
348 | } | |
bc35512f JH |
349 | |
350 | static basic_block | |
351 | cfg_layout_create_basic_block (void *head, void *end, basic_block after) | |
352 | { | |
353 | basic_block newbb = rtl_create_basic_block (head, end, after); | |
354 | ||
6de9cd9a | 355 | initialize_bb_rbi (newbb); |
bc35512f JH |
356 | return newbb; |
357 | } | |
ca6c03ca JH |
358 | \f |
359 | /* Delete the insns in a (non-live) block. We physically delete every | |
360 | non-deleted-note insn, and update the flow graph appropriately. | |
361 | ||
362 | Return nonzero if we deleted an exception handler. */ | |
363 | ||
364 | /* ??? Preserving all such notes strikes me as wrong. It would be nice | |
365 | to post-process the stream to remove empty blocks, loops, ranges, etc. */ | |
366 | ||
f0fda11c | 367 | static void |
d329e058 | 368 | rtl_delete_block (basic_block b) |
ca6c03ca | 369 | { |
ca6c03ca JH |
370 | rtx insn, end, tmp; |
371 | ||
372 | /* If the head of this block is a CODE_LABEL, then it might be the | |
373 | label for an exception handler which can't be reached. | |
374 | ||
375 | We need to remove the label from the exception_handler_label list | |
376 | and remove the associated NOTE_INSN_EH_REGION_BEG and | |
377 | NOTE_INSN_EH_REGION_END notes. */ | |
378 | ||
a813c111 | 379 | insn = BB_HEAD (b); |
ca6c03ca | 380 | |
4b4bf941 | 381 | if (LABEL_P (insn)) |
ca6c03ca JH |
382 | maybe_remove_eh_handler (insn); |
383 | ||
384 | /* Include any jump table following the basic block. */ | |
a813c111 | 385 | end = BB_END (b); |
e1233a7d | 386 | if (tablejump_p (end, NULL, &tmp)) |
ca6c03ca JH |
387 | end = tmp; |
388 | ||
389 | /* Include any barrier that may follow the basic block. */ | |
390 | tmp = next_nonnote_insn (end); | |
4b4bf941 | 391 | if (tmp && BARRIER_P (tmp)) |
ca6c03ca JH |
392 | end = tmp; |
393 | ||
394 | /* Selectively delete the entire chain. */ | |
a813c111 | 395 | BB_HEAD (b) = NULL; |
ca6c03ca | 396 | delete_insn_chain (insn, end); |
ca6c03ca JH |
397 | } |
398 | \f | |
852c6ec7 | 399 | /* Records the basic block struct in BLOCK_FOR_INSN for every insn. */ |
ca6c03ca JH |
400 | |
401 | void | |
d329e058 | 402 | compute_bb_for_insn (void) |
ca6c03ca | 403 | { |
e0082a72 | 404 | basic_block bb; |
ca6c03ca | 405 | |
e0082a72 | 406 | FOR_EACH_BB (bb) |
ca6c03ca | 407 | { |
a813c111 | 408 | rtx end = BB_END (bb); |
5f0d2358 | 409 | rtx insn; |
ca6c03ca | 410 | |
a813c111 | 411 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
ca6c03ca | 412 | { |
ba4f7968 | 413 | BLOCK_FOR_INSN (insn) = bb; |
ca6c03ca JH |
414 | if (insn == end) |
415 | break; | |
ca6c03ca JH |
416 | } |
417 | } | |
418 | } | |
419 | ||
420 | /* Release the basic_block_for_insn array. */ | |
421 | ||
422 | void | |
d329e058 | 423 | free_bb_for_insn (void) |
ca6c03ca | 424 | { |
ba4f7968 JH |
425 | rtx insn; |
426 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) | |
4b4bf941 | 427 | if (!BARRIER_P (insn)) |
ba4f7968 | 428 | BLOCK_FOR_INSN (insn) = NULL; |
ca6c03ca JH |
429 | } |
430 | ||
91278841 AP |
431 | /* Return RTX to emit after when we want to emit code on the entry of function. */ |
432 | rtx | |
433 | entry_of_function (void) | |
434 | { | |
435 | return (n_basic_blocks ? BB_HEAD (ENTRY_BLOCK_PTR->next_bb) : get_insns ()); | |
436 | } | |
437 | ||
ca6c03ca JH |
438 | /* Update insns block within BB. */ |
439 | ||
440 | void | |
d329e058 | 441 | update_bb_for_insn (basic_block bb) |
ca6c03ca JH |
442 | { |
443 | rtx insn; | |
444 | ||
a813c111 | 445 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
ca6c03ca | 446 | { |
4b4bf941 | 447 | if (!BARRIER_P (insn)) |
bcc53e2a | 448 | set_block_for_insn (insn, bb); |
a813c111 | 449 | if (insn == BB_END (bb)) |
ca6c03ca JH |
450 | break; |
451 | } | |
452 | } | |
ca6c03ca | 453 | \f |
f470c378 ZD |
454 | /* Creates a new basic block just after basic block B by splitting |
455 | everything after specified instruction I. */ | |
ca6c03ca | 456 | |
f470c378 | 457 | static basic_block |
d329e058 | 458 | rtl_split_block (basic_block bb, void *insnp) |
ca6c03ca JH |
459 | { |
460 | basic_block new_bb; | |
9ee634e3 | 461 | rtx insn = insnp; |
f470c378 | 462 | edge e; |
ca6c03ca | 463 | |
f470c378 ZD |
464 | if (!insn) |
465 | { | |
466 | insn = first_insn_after_basic_block_note (bb); | |
467 | ||
468 | if (insn) | |
469 | insn = PREV_INSN (insn); | |
470 | else | |
471 | insn = get_last_insn (); | |
472 | } | |
473 | ||
474 | /* We probably should check type of the insn so that we do not create | |
475 | inconsistent cfg. It is checked in verify_flow_info anyway, so do not | |
476 | bother. */ | |
477 | if (insn == BB_END (bb)) | |
478 | emit_note_after (NOTE_INSN_DELETED, insn); | |
ca6c03ca JH |
479 | |
480 | /* Create the new basic block. */ | |
a813c111 | 481 | new_bb = create_basic_block (NEXT_INSN (insn), BB_END (bb), bb); |
076c7ab8 | 482 | BB_COPY_PARTITION (new_bb, bb); |
a813c111 | 483 | BB_END (bb) = insn; |
ca6c03ca JH |
484 | |
485 | /* Redirect the outgoing edges. */ | |
486 | new_bb->succ = bb->succ; | |
487 | bb->succ = NULL; | |
488 | for (e = new_bb->succ; e; e = e->succ_next) | |
489 | e->src = new_bb; | |
490 | ||
ca6c03ca JH |
491 | if (bb->global_live_at_start) |
492 | { | |
493 | new_bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
494 | new_bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
495 | COPY_REG_SET (new_bb->global_live_at_end, bb->global_live_at_end); | |
496 | ||
497 | /* We now have to calculate which registers are live at the end | |
498 | of the split basic block and at the start of the new basic | |
499 | block. Start with those registers that are known to be live | |
500 | at the end of the original basic block and get | |
501 | propagate_block to determine which registers are live. */ | |
502 | COPY_REG_SET (new_bb->global_live_at_start, bb->global_live_at_end); | |
503 | propagate_block (new_bb, new_bb->global_live_at_start, NULL, NULL, 0); | |
504 | COPY_REG_SET (bb->global_live_at_end, | |
505 | new_bb->global_live_at_start); | |
0a2ed1f1 JH |
506 | #ifdef HAVE_conditional_execution |
507 | /* In the presence of conditional execution we are not able to update | |
508 | liveness precisely. */ | |
509 | if (reload_completed) | |
510 | { | |
511 | bb->flags |= BB_DIRTY; | |
512 | new_bb->flags |= BB_DIRTY; | |
513 | } | |
514 | #endif | |
ca6c03ca JH |
515 | } |
516 | ||
f470c378 | 517 | return new_bb; |
bc35512f JH |
518 | } |
519 | ||
ca6c03ca | 520 | /* Blocks A and B are to be merged into a single block A. The insns |
bc35512f | 521 | are already contiguous. */ |
ca6c03ca | 522 | |
bc35512f JH |
523 | static void |
524 | rtl_merge_blocks (basic_block a, basic_block b) | |
ca6c03ca | 525 | { |
a813c111 | 526 | rtx b_head = BB_HEAD (b), b_end = BB_END (b), a_end = BB_END (a); |
ca6c03ca JH |
527 | rtx del_first = NULL_RTX, del_last = NULL_RTX; |
528 | int b_empty = 0; | |
529 | ||
530 | /* If there was a CODE_LABEL beginning B, delete it. */ | |
4b4bf941 | 531 | if (LABEL_P (b_head)) |
ca6c03ca JH |
532 | { |
533 | /* Detect basic blocks with nothing but a label. This can happen | |
534 | in particular at the end of a function. */ | |
535 | if (b_head == b_end) | |
536 | b_empty = 1; | |
5f0d2358 | 537 | |
ca6c03ca JH |
538 | del_first = del_last = b_head; |
539 | b_head = NEXT_INSN (b_head); | |
540 | } | |
541 | ||
5f0d2358 RK |
542 | /* Delete the basic block note and handle blocks containing just that |
543 | note. */ | |
ca6c03ca JH |
544 | if (NOTE_INSN_BASIC_BLOCK_P (b_head)) |
545 | { | |
546 | if (b_head == b_end) | |
547 | b_empty = 1; | |
548 | if (! del_last) | |
549 | del_first = b_head; | |
5f0d2358 | 550 | |
ca6c03ca JH |
551 | del_last = b_head; |
552 | b_head = NEXT_INSN (b_head); | |
553 | } | |
554 | ||
555 | /* If there was a jump out of A, delete it. */ | |
4b4bf941 | 556 | if (JUMP_P (a_end)) |
ca6c03ca JH |
557 | { |
558 | rtx prev; | |
559 | ||
560 | for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev)) | |
4b4bf941 | 561 | if (!NOTE_P (prev) |
ca6c03ca | 562 | || NOTE_LINE_NUMBER (prev) == NOTE_INSN_BASIC_BLOCK |
a813c111 | 563 | || prev == BB_HEAD (a)) |
ca6c03ca JH |
564 | break; |
565 | ||
566 | del_first = a_end; | |
567 | ||
568 | #ifdef HAVE_cc0 | |
569 | /* If this was a conditional jump, we need to also delete | |
570 | the insn that set cc0. */ | |
571 | if (only_sets_cc0_p (prev)) | |
572 | { | |
573 | rtx tmp = prev; | |
5f0d2358 | 574 | |
ca6c03ca JH |
575 | prev = prev_nonnote_insn (prev); |
576 | if (!prev) | |
a813c111 | 577 | prev = BB_HEAD (a); |
ca6c03ca JH |
578 | del_first = tmp; |
579 | } | |
580 | #endif | |
581 | ||
582 | a_end = PREV_INSN (del_first); | |
583 | } | |
4b4bf941 | 584 | else if (BARRIER_P (NEXT_INSN (a_end))) |
ca6c03ca JH |
585 | del_first = NEXT_INSN (a_end); |
586 | ||
ca6c03ca JH |
587 | /* Delete everything marked above as well as crap that might be |
588 | hanging out between the two blocks. */ | |
f470c378 | 589 | BB_HEAD (b) = NULL; |
ca6c03ca JH |
590 | delete_insn_chain (del_first, del_last); |
591 | ||
592 | /* Reassociate the insns of B with A. */ | |
593 | if (!b_empty) | |
594 | { | |
ba4f7968 | 595 | rtx x; |
5f0d2358 | 596 | |
ba4f7968 JH |
597 | for (x = a_end; x != b_end; x = NEXT_INSN (x)) |
598 | set_block_for_insn (x, a); | |
5f0d2358 | 599 | |
ba4f7968 | 600 | set_block_for_insn (b_end, a); |
5f0d2358 | 601 | |
ca6c03ca JH |
602 | a_end = b_end; |
603 | } | |
5f0d2358 | 604 | |
a813c111 | 605 | BB_END (a) = a_end; |
ca6c03ca | 606 | } |
bc35512f JH |
607 | |
608 | /* Return true when block A and B can be merged. */ | |
609 | static bool | |
610 | rtl_can_merge_blocks (basic_block a,basic_block b) | |
611 | { | |
750054a2 CT |
612 | /* If we are partitioning hot/cold basic blocks, we don't want to |
613 | mess up unconditional or indirect jumps that cross between hot | |
076c7ab8 ZW |
614 | and cold sections. |
615 | ||
8e8d5162 CT |
616 | Basic block partitioning may result in some jumps that appear to |
617 | be optimizable (or blocks that appear to be mergeable), but which really | |
618 | must be left untouched (they are required to make it safely across | |
619 | partition boundaries). See the comments at the top of | |
620 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ | |
076c7ab8 | 621 | |
750054a2 CT |
622 | if (flag_reorder_blocks_and_partition |
623 | && (find_reg_note (BB_END (a), REG_CROSSING_JUMP, NULL_RTX) | |
624 | || find_reg_note (BB_END (b), REG_CROSSING_JUMP, NULL_RTX) | |
076c7ab8 ZW |
625 | || BB_PARTITION (a) != BB_PARTITION (b))) |
626 | return false; | |
750054a2 | 627 | |
bc35512f JH |
628 | /* There must be exactly one edge in between the blocks. */ |
629 | return (a->succ && !a->succ->succ_next && a->succ->dest == b | |
630 | && !b->pred->pred_next && a != b | |
631 | /* Must be simple edge. */ | |
632 | && !(a->succ->flags & EDGE_COMPLEX) | |
633 | && a->next_bb == b | |
634 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR | |
635 | /* If the jump insn has side effects, | |
636 | we can't kill the edge. */ | |
4b4bf941 | 637 | && (!JUMP_P (BB_END (a)) |
e24e7211 | 638 | || (reload_completed |
a813c111 | 639 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f | 640 | } |
ca6c03ca | 641 | \f |
5f0d2358 RK |
642 | /* Return the label in the head of basic block BLOCK. Create one if it doesn't |
643 | exist. */ | |
ca6c03ca JH |
644 | |
645 | rtx | |
d329e058 | 646 | block_label (basic_block block) |
ca6c03ca JH |
647 | { |
648 | if (block == EXIT_BLOCK_PTR) | |
649 | return NULL_RTX; | |
5f0d2358 | 650 | |
4b4bf941 | 651 | if (!LABEL_P (BB_HEAD (block))) |
ca6c03ca | 652 | { |
a813c111 | 653 | BB_HEAD (block) = emit_label_before (gen_label_rtx (), BB_HEAD (block)); |
ca6c03ca | 654 | } |
5f0d2358 | 655 | |
a813c111 | 656 | return BB_HEAD (block); |
ca6c03ca JH |
657 | } |
658 | ||
659 | /* Attempt to perform edge redirection by replacing possibly complex jump | |
5f0d2358 RK |
660 | instruction by unconditional jump or removing jump completely. This can |
661 | apply only if all edges now point to the same block. The parameters and | |
662 | return values are equivalent to redirect_edge_and_branch. */ | |
ca6c03ca | 663 | |
6de9cd9a | 664 | edge |
bc35512f | 665 | try_redirect_by_replacing_jump (edge e, basic_block target, bool in_cfglayout) |
ca6c03ca JH |
666 | { |
667 | basic_block src = e->src; | |
a813c111 | 668 | rtx insn = BB_END (src), kill_from; |
ca6c03ca | 669 | edge tmp; |
e1233a7d | 670 | rtx set; |
ca6c03ca JH |
671 | int fallthru = 0; |
672 | ||
750054a2 CT |
673 | |
674 | /* If we are partitioning hot/cold basic blocks, we don't want to | |
675 | mess up unconditional or indirect jumps that cross between hot | |
8e8d5162 CT |
676 | and cold sections. |
677 | ||
678 | Basic block partitioning may result in some jumps that appear to | |
679 | be optimizable (or blocks that appear to be mergeable), but which really | |
680 | must be left untouched (they are required to make it safely across | |
681 | partition boundaries). See the comments at the top of | |
682 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ | |
750054a2 CT |
683 | |
684 | if (flag_reorder_blocks_and_partition | |
9fb32434 | 685 | && (find_reg_note (insn, REG_CROSSING_JUMP, NULL_RTX) |
076c7ab8 | 686 | || BB_PARTITION (src) != BB_PARTITION (target))) |
9cf84a3c | 687 | return NULL; |
750054a2 | 688 | |
ca6c03ca JH |
689 | /* Verify that all targets will be TARGET. */ |
690 | for (tmp = src->succ; tmp; tmp = tmp->succ_next) | |
691 | if (tmp->dest != target && tmp != e) | |
692 | break; | |
5f0d2358 | 693 | |
ca6c03ca | 694 | if (tmp || !onlyjump_p (insn)) |
6de9cd9a | 695 | return NULL; |
3348b696 | 696 | if ((!optimize || reload_completed) && tablejump_p (insn, NULL, NULL)) |
6de9cd9a | 697 | return NULL; |
ca6c03ca JH |
698 | |
699 | /* Avoid removing branch with side effects. */ | |
700 | set = single_set (insn); | |
701 | if (!set || side_effects_p (set)) | |
6de9cd9a | 702 | return NULL; |
ca6c03ca JH |
703 | |
704 | /* In case we zap a conditional jump, we'll need to kill | |
705 | the cc0 setter too. */ | |
706 | kill_from = insn; | |
707 | #ifdef HAVE_cc0 | |
708 | if (reg_mentioned_p (cc0_rtx, PATTERN (insn))) | |
709 | kill_from = PREV_INSN (insn); | |
710 | #endif | |
711 | ||
712 | /* See if we can create the fallthru edge. */ | |
bc35512f | 713 | if (in_cfglayout || can_fallthru (src, target)) |
ca6c03ca | 714 | { |
c263766c RH |
715 | if (dump_file) |
716 | fprintf (dump_file, "Removing jump %i.\n", INSN_UID (insn)); | |
ca6c03ca JH |
717 | fallthru = 1; |
718 | ||
eaec9b3d | 719 | /* Selectively unlink whole insn chain. */ |
bc35512f JH |
720 | if (in_cfglayout) |
721 | { | |
722 | rtx insn = src->rbi->footer; | |
723 | ||
a813c111 | 724 | delete_insn_chain (kill_from, BB_END (src)); |
bc35512f JH |
725 | |
726 | /* Remove barriers but keep jumptables. */ | |
727 | while (insn) | |
728 | { | |
4b4bf941 | 729 | if (BARRIER_P (insn)) |
bc35512f JH |
730 | { |
731 | if (PREV_INSN (insn)) | |
732 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
733 | else | |
734 | src->rbi->footer = NEXT_INSN (insn); | |
735 | if (NEXT_INSN (insn)) | |
736 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
737 | } | |
4b4bf941 | 738 | if (LABEL_P (insn)) |
bc35512f JH |
739 | break; |
740 | insn = NEXT_INSN (insn); | |
741 | } | |
742 | } | |
743 | else | |
a813c111 | 744 | delete_insn_chain (kill_from, PREV_INSN (BB_HEAD (target))); |
ca6c03ca | 745 | } |
5f0d2358 | 746 | |
ca6c03ca JH |
747 | /* If this already is simplejump, redirect it. */ |
748 | else if (simplejump_p (insn)) | |
749 | { | |
750 | if (e->dest == target) | |
6de9cd9a | 751 | return NULL; |
c263766c RH |
752 | if (dump_file) |
753 | fprintf (dump_file, "Redirecting jump %i from %i to %i.\n", | |
0b17ab2f | 754 | INSN_UID (insn), e->dest->index, target->index); |
6ee3c8e4 JJ |
755 | if (!redirect_jump (insn, block_label (target), 0)) |
756 | { | |
757 | if (target == EXIT_BLOCK_PTR) | |
6de9cd9a | 758 | return NULL; |
6ee3c8e4 JJ |
759 | abort (); |
760 | } | |
ca6c03ca | 761 | } |
5f0d2358 | 762 | |
6ee3c8e4 JJ |
763 | /* Cannot do anything for target exit block. */ |
764 | else if (target == EXIT_BLOCK_PTR) | |
6de9cd9a | 765 | return NULL; |
6ee3c8e4 | 766 | |
ca6c03ca JH |
767 | /* Or replace possibly complicated jump insn by simple jump insn. */ |
768 | else | |
769 | { | |
770 | rtx target_label = block_label (target); | |
eb5b8ad4 | 771 | rtx barrier, label, table; |
ca6c03ca | 772 | |
09eb1aab | 773 | emit_jump_insn_after (gen_jump (target_label), insn); |
a813c111 | 774 | JUMP_LABEL (BB_END (src)) = target_label; |
ca6c03ca | 775 | LABEL_NUSES (target_label)++; |
c263766c RH |
776 | if (dump_file) |
777 | fprintf (dump_file, "Replacing insn %i by jump %i\n", | |
a813c111 | 778 | INSN_UID (insn), INSN_UID (BB_END (src))); |
ca6c03ca | 779 | |
4da2eb6b | 780 | |
ca6c03ca JH |
781 | delete_insn_chain (kill_from, insn); |
782 | ||
4da2eb6b RH |
783 | /* Recognize a tablejump that we are converting to a |
784 | simple jump and remove its associated CODE_LABEL | |
785 | and ADDR_VEC or ADDR_DIFF_VEC. */ | |
3348b696 | 786 | if (tablejump_p (insn, &label, &table)) |
4da2eb6b | 787 | delete_insn_chain (label, table); |
eb5b8ad4 | 788 | |
a813c111 | 789 | barrier = next_nonnote_insn (BB_END (src)); |
4b4bf941 | 790 | if (!barrier || !BARRIER_P (barrier)) |
a813c111 | 791 | emit_barrier_after (BB_END (src)); |
5d693491 JZ |
792 | else |
793 | { | |
a813c111 | 794 | if (barrier != NEXT_INSN (BB_END (src))) |
5d693491 JZ |
795 | { |
796 | /* Move the jump before barrier so that the notes | |
797 | which originally were or were created before jump table are | |
798 | inside the basic block. */ | |
a813c111 | 799 | rtx new_insn = BB_END (src); |
5d693491 JZ |
800 | rtx tmp; |
801 | ||
a813c111 | 802 | for (tmp = NEXT_INSN (BB_END (src)); tmp != barrier; |
5d693491 JZ |
803 | tmp = NEXT_INSN (tmp)) |
804 | set_block_for_insn (tmp, src); | |
805 | ||
806 | NEXT_INSN (PREV_INSN (new_insn)) = NEXT_INSN (new_insn); | |
807 | PREV_INSN (NEXT_INSN (new_insn)) = PREV_INSN (new_insn); | |
808 | ||
809 | NEXT_INSN (new_insn) = barrier; | |
810 | NEXT_INSN (PREV_INSN (barrier)) = new_insn; | |
811 | ||
812 | PREV_INSN (new_insn) = PREV_INSN (barrier); | |
813 | PREV_INSN (barrier) = new_insn; | |
814 | } | |
815 | } | |
ca6c03ca JH |
816 | } |
817 | ||
818 | /* Keep only one edge out and set proper flags. */ | |
819 | while (src->succ->succ_next) | |
820 | remove_edge (src->succ); | |
821 | e = src->succ; | |
822 | if (fallthru) | |
823 | e->flags = EDGE_FALLTHRU; | |
824 | else | |
825 | e->flags = 0; | |
5f0d2358 | 826 | |
ca6c03ca JH |
827 | e->probability = REG_BR_PROB_BASE; |
828 | e->count = src->count; | |
829 | ||
830 | /* We don't want a block to end on a line-number note since that has | |
831 | the potential of changing the code between -g and not -g. */ | |
4b4bf941 | 832 | while (NOTE_P (BB_END (e->src)) |
a813c111 SB |
833 | && NOTE_LINE_NUMBER (BB_END (e->src)) >= 0) |
834 | delete_insn (BB_END (e->src)); | |
ca6c03ca JH |
835 | |
836 | if (e->dest != target) | |
837 | redirect_edge_succ (e, target); | |
5f0d2358 | 838 | |
6de9cd9a | 839 | return e; |
ca6c03ca JH |
840 | } |
841 | ||
842 | /* Return last loop_beg note appearing after INSN, before start of next | |
843 | basic block. Return INSN if there are no such notes. | |
844 | ||
09da1532 | 845 | When emitting jump to redirect a fallthru edge, it should always appear |
5f0d2358 RK |
846 | after the LOOP_BEG notes, as loop optimizer expect loop to either start by |
847 | fallthru edge or jump following the LOOP_BEG note jumping to the loop exit | |
848 | test. */ | |
ca6c03ca JH |
849 | |
850 | static rtx | |
d329e058 | 851 | last_loop_beg_note (rtx insn) |
ca6c03ca JH |
852 | { |
853 | rtx last = insn; | |
5f0d2358 | 854 | |
4b4bf941 | 855 | for (insn = NEXT_INSN (insn); insn && NOTE_P (insn) |
5f0d2358 RK |
856 | && NOTE_LINE_NUMBER (insn) != NOTE_INSN_BASIC_BLOCK; |
857 | insn = NEXT_INSN (insn)) | |
858 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
859 | last = insn; | |
860 | ||
ca6c03ca JH |
861 | return last; |
862 | } | |
863 | ||
6de9cd9a DN |
864 | /* Redirect edge representing branch of (un)conditional jump or tablejump, |
865 | NULL on failure */ | |
866 | static edge | |
bc35512f | 867 | redirect_branch_edge (edge e, basic_block target) |
ca6c03ca JH |
868 | { |
869 | rtx tmp; | |
a813c111 | 870 | rtx old_label = BB_HEAD (e->dest); |
ca6c03ca | 871 | basic_block src = e->src; |
a813c111 | 872 | rtx insn = BB_END (src); |
ca6c03ca | 873 | |
ca6c03ca JH |
874 | /* We can only redirect non-fallthru edges of jump insn. */ |
875 | if (e->flags & EDGE_FALLTHRU) | |
6de9cd9a | 876 | return NULL; |
4b4bf941 | 877 | else if (!JUMP_P (insn)) |
6de9cd9a | 878 | return NULL; |
ca6c03ca JH |
879 | |
880 | /* Recognize a tablejump and adjust all matching cases. */ | |
e1233a7d | 881 | if (tablejump_p (insn, NULL, &tmp)) |
ca6c03ca JH |
882 | { |
883 | rtvec vec; | |
884 | int j; | |
885 | rtx new_label = block_label (target); | |
886 | ||
6ee3c8e4 | 887 | if (target == EXIT_BLOCK_PTR) |
6de9cd9a | 888 | return NULL; |
ca6c03ca JH |
889 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) |
890 | vec = XVEC (PATTERN (tmp), 0); | |
891 | else | |
892 | vec = XVEC (PATTERN (tmp), 1); | |
893 | ||
894 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
895 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
896 | { | |
897 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (Pmode, new_label); | |
898 | --LABEL_NUSES (old_label); | |
899 | ++LABEL_NUSES (new_label); | |
900 | } | |
901 | ||
f9da5064 | 902 | /* Handle casesi dispatch insns. */ |
ca6c03ca JH |
903 | if ((tmp = single_set (insn)) != NULL |
904 | && SET_DEST (tmp) == pc_rtx | |
905 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
906 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF | |
907 | && XEXP (XEXP (SET_SRC (tmp), 2), 0) == old_label) | |
908 | { | |
909 | XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (VOIDmode, | |
910 | new_label); | |
911 | --LABEL_NUSES (old_label); | |
912 | ++LABEL_NUSES (new_label); | |
913 | } | |
914 | } | |
915 | else | |
916 | { | |
917 | /* ?? We may play the games with moving the named labels from | |
918 | one basic block to the other in case only one computed_jump is | |
919 | available. */ | |
5f0d2358 RK |
920 | if (computed_jump_p (insn) |
921 | /* A return instruction can't be redirected. */ | |
922 | || returnjump_p (insn)) | |
6de9cd9a | 923 | return NULL; |
ca6c03ca JH |
924 | |
925 | /* If the insn doesn't go where we think, we're confused. */ | |
6ee3c8e4 | 926 | if (JUMP_LABEL (insn) != old_label) |
a3623c48 | 927 | abort (); |
6ee3c8e4 JJ |
928 | |
929 | /* If the substitution doesn't succeed, die. This can happen | |
930 | if the back end emitted unrecognizable instructions or if | |
931 | target is exit block on some arches. */ | |
932 | if (!redirect_jump (insn, block_label (target), 0)) | |
933 | { | |
934 | if (target == EXIT_BLOCK_PTR) | |
6de9cd9a | 935 | return NULL; |
6ee3c8e4 JJ |
936 | abort (); |
937 | } | |
ca6c03ca JH |
938 | } |
939 | ||
c263766c RH |
940 | if (dump_file) |
941 | fprintf (dump_file, "Edge %i->%i redirected to %i\n", | |
0b17ab2f | 942 | e->src->index, e->dest->index, target->index); |
5f0d2358 | 943 | |
ca6c03ca | 944 | if (e->dest != target) |
6de9cd9a DN |
945 | e = redirect_edge_succ_nodup (e, target); |
946 | return e; | |
bc35512f JH |
947 | } |
948 | ||
949 | /* Attempt to change code to redirect edge E to TARGET. Don't do that on | |
950 | expense of adding new instructions or reordering basic blocks. | |
951 | ||
952 | Function can be also called with edge destination equivalent to the TARGET. | |
953 | Then it should try the simplifications and do nothing if none is possible. | |
954 | ||
6de9cd9a DN |
955 | Return edge representing the branch if transformation succeeded. Return NULL |
956 | on failure. | |
957 | We still return NULL in case E already destinated TARGET and we didn't | |
958 | managed to simplify instruction stream. */ | |
bc35512f | 959 | |
6de9cd9a | 960 | static edge |
5671bf27 | 961 | rtl_redirect_edge_and_branch (edge e, basic_block target) |
bc35512f | 962 | { |
6de9cd9a | 963 | edge ret; |
f345f21a JH |
964 | basic_block src = e->src; |
965 | ||
bc35512f | 966 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
6de9cd9a | 967 | return NULL; |
bc35512f | 968 | |
3348b696 | 969 | if (e->dest == target) |
6de9cd9a | 970 | return e; |
3348b696 | 971 | |
6de9cd9a | 972 | if ((ret = try_redirect_by_replacing_jump (e, target, false)) != NULL) |
f345f21a JH |
973 | { |
974 | src->flags |= BB_DIRTY; | |
6de9cd9a | 975 | return ret; |
f345f21a | 976 | } |
bc35512f | 977 | |
6de9cd9a DN |
978 | ret = redirect_branch_edge (e, target); |
979 | if (!ret) | |
980 | return NULL; | |
5f0d2358 | 981 | |
f345f21a | 982 | src->flags |= BB_DIRTY; |
6de9cd9a | 983 | return ret; |
ca6c03ca JH |
984 | } |
985 | ||
4fe9b91c | 986 | /* Like force_nonfallthru below, but additionally performs redirection |
ca6c03ca JH |
987 | Used by redirect_edge_and_branch_force. */ |
988 | ||
cb9a1d9b | 989 | basic_block |
d329e058 | 990 | force_nonfallthru_and_redirect (edge e, basic_block target) |
ca6c03ca | 991 | { |
a3716585 | 992 | basic_block jump_block, new_bb = NULL, src = e->src; |
ca6c03ca JH |
993 | rtx note; |
994 | edge new_edge; | |
a3716585 | 995 | int abnormal_edge_flags = 0; |
ca6c03ca | 996 | |
cb9a1d9b JH |
997 | /* In the case the last instruction is conditional jump to the next |
998 | instruction, first redirect the jump itself and then continue | |
b20b352b | 999 | by creating a basic block afterwards to redirect fallthru edge. */ |
cb9a1d9b | 1000 | if (e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR |
a813c111 | 1001 | && any_condjump_p (BB_END (e->src)) |
cde1d5bf | 1002 | /* When called from cfglayout, fallthru edges do not |
e0bb17a8 | 1003 | necessarily go to the next block. */ |
cde1d5bf | 1004 | && e->src->next_bb == e->dest |
a813c111 | 1005 | && JUMP_LABEL (BB_END (e->src)) == BB_HEAD (e->dest)) |
cb9a1d9b JH |
1006 | { |
1007 | rtx note; | |
58e6ae30 | 1008 | edge b = unchecked_make_edge (e->src, target, 0); |
cb9a1d9b | 1009 | |
a813c111 | 1010 | if (!redirect_jump (BB_END (e->src), block_label (target), 0)) |
cb9a1d9b | 1011 | abort (); |
a813c111 | 1012 | note = find_reg_note (BB_END (e->src), REG_BR_PROB, NULL_RTX); |
cb9a1d9b JH |
1013 | if (note) |
1014 | { | |
1015 | int prob = INTVAL (XEXP (note, 0)); | |
1016 | ||
1017 | b->probability = prob; | |
1018 | b->count = e->count * prob / REG_BR_PROB_BASE; | |
1019 | e->probability -= e->probability; | |
1020 | e->count -= b->count; | |
1021 | if (e->probability < 0) | |
1022 | e->probability = 0; | |
1023 | if (e->count < 0) | |
1024 | e->count = 0; | |
1025 | } | |
1026 | } | |
1027 | ||
ca6c03ca | 1028 | if (e->flags & EDGE_ABNORMAL) |
a3716585 JH |
1029 | { |
1030 | /* Irritating special case - fallthru edge to the same block as abnormal | |
1031 | edge. | |
1032 | We can't redirect abnormal edge, but we still can split the fallthru | |
d329e058 | 1033 | one and create separate abnormal edge to original destination. |
a3716585 JH |
1034 | This allows bb-reorder to make such edge non-fallthru. */ |
1035 | if (e->dest != target) | |
1036 | abort (); | |
1037 | abnormal_edge_flags = e->flags & ~(EDGE_FALLTHRU | EDGE_CAN_FALLTHRU); | |
1038 | e->flags &= EDGE_FALLTHRU | EDGE_CAN_FALLTHRU; | |
1039 | } | |
5f0d2358 | 1040 | else if (!(e->flags & EDGE_FALLTHRU)) |
ca6c03ca | 1041 | abort (); |
24c545ff BS |
1042 | else if (e->src == ENTRY_BLOCK_PTR) |
1043 | { | |
1044 | /* We can't redirect the entry block. Create an empty block at the | |
1045 | start of the function which we use to add the new jump. */ | |
1046 | edge *pe1; | |
a813c111 | 1047 | basic_block bb = create_basic_block (BB_HEAD (e->dest), NULL, ENTRY_BLOCK_PTR); |
24c545ff BS |
1048 | |
1049 | /* Change the existing edge's source to be the new block, and add | |
1050 | a new edge from the entry block to the new block. */ | |
1051 | e->src = bb; | |
1052 | for (pe1 = &ENTRY_BLOCK_PTR->succ; *pe1; pe1 = &(*pe1)->succ_next) | |
1053 | if (*pe1 == e) | |
1054 | { | |
1055 | *pe1 = e->succ_next; | |
1056 | break; | |
1057 | } | |
1058 | e->succ_next = 0; | |
1059 | bb->succ = e; | |
1060 | make_single_succ_edge (ENTRY_BLOCK_PTR, bb, EDGE_FALLTHRU); | |
1061 | } | |
1062 | ||
a3716585 | 1063 | if (e->src->succ->succ_next || abnormal_edge_flags) |
ca6c03ca JH |
1064 | { |
1065 | /* Create the new structures. */ | |
31a78298 | 1066 | |
79019985 RH |
1067 | /* If the old block ended with a tablejump, skip its table |
1068 | by searching forward from there. Otherwise start searching | |
1069 | forward from the last instruction of the old block. */ | |
a813c111 SB |
1070 | if (!tablejump_p (BB_END (e->src), NULL, ¬e)) |
1071 | note = BB_END (e->src); | |
79019985 | 1072 | |
31a78298 | 1073 | /* Position the new block correctly relative to loop notes. */ |
79019985 | 1074 | note = last_loop_beg_note (note); |
31a78298 RH |
1075 | note = NEXT_INSN (note); |
1076 | ||
31a78298 | 1077 | jump_block = create_basic_block (note, NULL, e->src); |
ca6c03ca JH |
1078 | jump_block->count = e->count; |
1079 | jump_block->frequency = EDGE_FREQUENCY (e); | |
1080 | jump_block->loop_depth = target->loop_depth; | |
1081 | ||
1082 | if (target->global_live_at_start) | |
1083 | { | |
5f0d2358 RK |
1084 | jump_block->global_live_at_start |
1085 | = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
1086 | jump_block->global_live_at_end | |
1087 | = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
ca6c03ca JH |
1088 | COPY_REG_SET (jump_block->global_live_at_start, |
1089 | target->global_live_at_start); | |
1090 | COPY_REG_SET (jump_block->global_live_at_end, | |
1091 | target->global_live_at_start); | |
1092 | } | |
1093 | ||
750054a2 CT |
1094 | /* Make sure new block ends up in correct hot/cold section. */ |
1095 | ||
076c7ab8 | 1096 | BB_COPY_PARTITION (jump_block, e->src); |
9fb32434 CT |
1097 | if (flag_reorder_blocks_and_partition |
1098 | && targetm.have_named_sections) | |
750054a2 | 1099 | { |
076c7ab8 | 1100 | if (BB_PARTITION (jump_block) == BB_COLD_PARTITION) |
750054a2 CT |
1101 | { |
1102 | rtx bb_note, new_note; | |
1103 | for (bb_note = BB_HEAD (jump_block); | |
1104 | bb_note && bb_note != NEXT_INSN (BB_END (jump_block)); | |
1105 | bb_note = NEXT_INSN (bb_note)) | |
4b4bf941 | 1106 | if (NOTE_P (bb_note) |
750054a2 CT |
1107 | && NOTE_LINE_NUMBER (bb_note) == NOTE_INSN_BASIC_BLOCK) |
1108 | break; | |
1109 | new_note = emit_note_after (NOTE_INSN_UNLIKELY_EXECUTED_CODE, | |
1110 | bb_note); | |
1111 | NOTE_BASIC_BLOCK (new_note) = jump_block; | |
750054a2 | 1112 | } |
4b4bf941 | 1113 | if (JUMP_P (BB_END (jump_block)) |
750054a2 | 1114 | && !any_condjump_p (BB_END (jump_block)) |
bd454efd | 1115 | && (jump_block->succ->flags & EDGE_CROSSING)) |
750054a2 CT |
1116 | REG_NOTES (BB_END (jump_block)) = gen_rtx_EXPR_LIST |
1117 | (REG_CROSSING_JUMP, NULL_RTX, | |
1118 | REG_NOTES (BB_END (jump_block))); | |
1119 | } | |
1120 | ||
ca6c03ca JH |
1121 | /* Wire edge in. */ |
1122 | new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU); | |
1123 | new_edge->probability = e->probability; | |
1124 | new_edge->count = e->count; | |
1125 | ||
1126 | /* Redirect old edge. */ | |
1127 | redirect_edge_pred (e, jump_block); | |
1128 | e->probability = REG_BR_PROB_BASE; | |
1129 | ||
1130 | new_bb = jump_block; | |
1131 | } | |
1132 | else | |
1133 | jump_block = e->src; | |
5f0d2358 | 1134 | |
ca6c03ca JH |
1135 | e->flags &= ~EDGE_FALLTHRU; |
1136 | if (target == EXIT_BLOCK_PTR) | |
1137 | { | |
cf22ce3c | 1138 | #ifdef HAVE_return |
a813c111 | 1139 | emit_jump_insn_after (gen_return (), BB_END (jump_block)); |
cf22ce3c | 1140 | #else |
ca6c03ca | 1141 | abort (); |
cf22ce3c | 1142 | #endif |
ca6c03ca JH |
1143 | } |
1144 | else | |
1145 | { | |
1146 | rtx label = block_label (target); | |
a813c111 SB |
1147 | emit_jump_insn_after (gen_jump (label), BB_END (jump_block)); |
1148 | JUMP_LABEL (BB_END (jump_block)) = label; | |
ca6c03ca JH |
1149 | LABEL_NUSES (label)++; |
1150 | } | |
5f0d2358 | 1151 | |
a813c111 | 1152 | emit_barrier_after (BB_END (jump_block)); |
ca6c03ca JH |
1153 | redirect_edge_succ_nodup (e, target); |
1154 | ||
a3716585 JH |
1155 | if (abnormal_edge_flags) |
1156 | make_edge (src, target, abnormal_edge_flags); | |
1157 | ||
ca6c03ca JH |
1158 | return new_bb; |
1159 | } | |
1160 | ||
1161 | /* Edge E is assumed to be fallthru edge. Emit needed jump instruction | |
1162 | (and possibly create new basic block) to make edge non-fallthru. | |
1163 | Return newly created BB or NULL if none. */ | |
5f0d2358 | 1164 | |
ca6c03ca | 1165 | basic_block |
d329e058 | 1166 | force_nonfallthru (edge e) |
ca6c03ca JH |
1167 | { |
1168 | return force_nonfallthru_and_redirect (e, e->dest); | |
1169 | } | |
1170 | ||
1171 | /* Redirect edge even at the expense of creating new jump insn or | |
1172 | basic block. Return new basic block if created, NULL otherwise. | |
eaec9b3d | 1173 | Abort if conversion is impossible. */ |
ca6c03ca | 1174 | |
9ee634e3 | 1175 | static basic_block |
d329e058 | 1176 | rtl_redirect_edge_and_branch_force (edge e, basic_block target) |
ca6c03ca | 1177 | { |
5f0d2358 RK |
1178 | if (redirect_edge_and_branch (e, target) |
1179 | || e->dest == target) | |
ca6c03ca JH |
1180 | return NULL; |
1181 | ||
1182 | /* In case the edge redirection failed, try to force it to be non-fallthru | |
1183 | and redirect newly created simplejump. */ | |
5f0d2358 | 1184 | return force_nonfallthru_and_redirect (e, target); |
ca6c03ca JH |
1185 | } |
1186 | ||
1187 | /* The given edge should potentially be a fallthru edge. If that is in | |
1188 | fact true, delete the jump and barriers that are in the way. */ | |
1189 | ||
f470c378 ZD |
1190 | static void |
1191 | rtl_tidy_fallthru_edge (edge e) | |
ca6c03ca JH |
1192 | { |
1193 | rtx q; | |
f470c378 ZD |
1194 | basic_block b = e->src, c = b->next_bb; |
1195 | ||
ca6c03ca JH |
1196 | /* ??? In a late-running flow pass, other folks may have deleted basic |
1197 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
1198 | and the target label. They ought to be chastized and fixed. | |
1199 | ||
1200 | We can also wind up with a sequence of undeletable labels between | |
1201 | one block and the next. | |
1202 | ||
1203 | So search through a sequence of barriers, labels, and notes for | |
1204 | the head of block C and assert that we really do fall through. */ | |
1205 | ||
a813c111 | 1206 | for (q = NEXT_INSN (BB_END (b)); q != BB_HEAD (c); q = NEXT_INSN (q)) |
9c0a0632 RH |
1207 | if (INSN_P (q)) |
1208 | return; | |
ca6c03ca JH |
1209 | |
1210 | /* Remove what will soon cease being the jump insn from the source block. | |
1211 | If block B consisted only of this single jump, turn it into a deleted | |
1212 | note. */ | |
a813c111 | 1213 | q = BB_END (b); |
4b4bf941 | 1214 | if (JUMP_P (q) |
ca6c03ca JH |
1215 | && onlyjump_p (q) |
1216 | && (any_uncondjump_p (q) | |
1217 | || (b->succ == e && e->succ_next == NULL))) | |
1218 | { | |
1219 | #ifdef HAVE_cc0 | |
1220 | /* If this was a conditional jump, we need to also delete | |
1221 | the insn that set cc0. */ | |
1222 | if (any_condjump_p (q) && only_sets_cc0_p (PREV_INSN (q))) | |
1223 | q = PREV_INSN (q); | |
1224 | #endif | |
1225 | ||
1226 | q = PREV_INSN (q); | |
1227 | ||
1228 | /* We don't want a block to end on a line-number note since that has | |
1229 | the potential of changing the code between -g and not -g. */ | |
4b4bf941 | 1230 | while (NOTE_P (q) && NOTE_LINE_NUMBER (q) >= 0) |
ca6c03ca JH |
1231 | q = PREV_INSN (q); |
1232 | } | |
1233 | ||
1234 | /* Selectively unlink the sequence. */ | |
a813c111 SB |
1235 | if (q != PREV_INSN (BB_HEAD (c))) |
1236 | delete_insn_chain (NEXT_INSN (q), PREV_INSN (BB_HEAD (c))); | |
ca6c03ca JH |
1237 | |
1238 | e->flags |= EDGE_FALLTHRU; | |
1239 | } | |
ca6c03ca JH |
1240 | \f |
1241 | /* Helper function for split_edge. Return true in case edge BB2 to BB1 | |
1242 | is back edge of syntactic loop. */ | |
1243 | ||
1244 | static bool | |
d329e058 | 1245 | back_edge_of_syntactic_loop_p (basic_block bb1, basic_block bb2) |
ca6c03ca JH |
1246 | { |
1247 | rtx insn; | |
1248 | int count = 0; | |
bf77398c | 1249 | basic_block bb; |
ca6c03ca | 1250 | |
bf77398c | 1251 | if (bb1 == bb2) |
0b17ab2f | 1252 | return true; |
355e4ec4 | 1253 | |
bf77398c ZD |
1254 | /* ??? Could we guarantee that bb indices are monotone, so that we could |
1255 | just compare them? */ | |
1256 | for (bb = bb1; bb && bb != bb2; bb = bb->next_bb) | |
1257 | continue; | |
1258 | ||
1259 | if (!bb) | |
1260 | return false; | |
1261 | ||
a813c111 | 1262 | for (insn = BB_END (bb1); insn != BB_HEAD (bb2) && count >= 0; |
ca6c03ca | 1263 | insn = NEXT_INSN (insn)) |
4b4bf941 | 1264 | if (NOTE_P (insn)) |
ca6c03ca JH |
1265 | { |
1266 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
1267 | count++; | |
5f0d2358 | 1268 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) |
ca6c03ca JH |
1269 | count--; |
1270 | } | |
1271 | ||
1272 | return count >= 0; | |
1273 | } | |
1274 | ||
f470c378 ZD |
1275 | /* Should move basic block BB after basic block AFTER. NIY. */ |
1276 | ||
1277 | static bool | |
1278 | rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED, | |
1279 | basic_block after ATTRIBUTE_UNUSED) | |
1280 | { | |
1281 | return false; | |
1282 | } | |
1283 | ||
ca6c03ca JH |
1284 | /* Split a (typically critical) edge. Return the new block. |
1285 | Abort on abnormal edges. | |
1286 | ||
1287 | ??? The code generally expects to be called on critical edges. | |
1288 | The case of a block ending in an unconditional jump to a | |
1289 | block with multiple predecessors is not handled optimally. */ | |
1290 | ||
8ce33230 | 1291 | static basic_block |
d329e058 | 1292 | rtl_split_edge (edge edge_in) |
ca6c03ca JH |
1293 | { |
1294 | basic_block bb; | |
ca6c03ca JH |
1295 | rtx before; |
1296 | ||
1297 | /* Abnormal edges cannot be split. */ | |
1298 | if ((edge_in->flags & EDGE_ABNORMAL) != 0) | |
1299 | abort (); | |
1300 | ||
1301 | /* We are going to place the new block in front of edge destination. | |
eaec9b3d | 1302 | Avoid existence of fallthru predecessors. */ |
ca6c03ca JH |
1303 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) |
1304 | { | |
1305 | edge e; | |
5f0d2358 | 1306 | |
ca6c03ca JH |
1307 | for (e = edge_in->dest->pred; e; e = e->pred_next) |
1308 | if (e->flags & EDGE_FALLTHRU) | |
1309 | break; | |
1310 | ||
1311 | if (e) | |
1312 | force_nonfallthru (e); | |
1313 | } | |
1314 | ||
1315 | /* Create the basic block note. | |
1316 | ||
f63d1bf7 | 1317 | Where we place the note can have a noticeable impact on the generated |
ca6c03ca JH |
1318 | code. Consider this cfg: |
1319 | ||
1320 | E | |
1321 | | | |
1322 | 0 | |
1323 | / \ | |
1324 | +->1-->2--->E | |
1325 | | | | |
1326 | +--+ | |
1327 | ||
1328 | If we need to insert an insn on the edge from block 0 to block 1, | |
1329 | we want to ensure the instructions we insert are outside of any | |
1330 | loop notes that physically sit between block 0 and block 1. Otherwise | |
1331 | we confuse the loop optimizer into thinking the loop is a phony. */ | |
1332 | ||
1333 | if (edge_in->dest != EXIT_BLOCK_PTR | |
a813c111 | 1334 | && PREV_INSN (BB_HEAD (edge_in->dest)) |
4b4bf941 | 1335 | && NOTE_P (PREV_INSN (BB_HEAD (edge_in->dest))) |
a813c111 | 1336 | && (NOTE_LINE_NUMBER (PREV_INSN (BB_HEAD (edge_in->dest))) |
5f0d2358 | 1337 | == NOTE_INSN_LOOP_BEG) |
ca6c03ca | 1338 | && !back_edge_of_syntactic_loop_p (edge_in->dest, edge_in->src)) |
a813c111 | 1339 | before = PREV_INSN (BB_HEAD (edge_in->dest)); |
ca6c03ca | 1340 | else if (edge_in->dest != EXIT_BLOCK_PTR) |
a813c111 | 1341 | before = BB_HEAD (edge_in->dest); |
ca6c03ca JH |
1342 | else |
1343 | before = NULL_RTX; | |
1344 | ||
623a66fa R |
1345 | /* If this is a fall through edge to the exit block, the blocks might be |
1346 | not adjacent, and the right place is the after the source. */ | |
1347 | if (edge_in->flags & EDGE_FALLTHRU && edge_in->dest == EXIT_BLOCK_PTR) | |
1348 | { | |
1349 | before = NEXT_INSN (BB_END (edge_in->src)); | |
1350 | if (before | |
4b4bf941 | 1351 | && NOTE_P (before) |
623a66fa R |
1352 | && NOTE_LINE_NUMBER (before) == NOTE_INSN_LOOP_END) |
1353 | before = NEXT_INSN (before); | |
1354 | bb = create_basic_block (before, NULL, edge_in->src); | |
076c7ab8 | 1355 | BB_COPY_PARTITION (bb, edge_in->src); |
623a66fa R |
1356 | } |
1357 | else | |
9fb32434 CT |
1358 | { |
1359 | bb = create_basic_block (before, NULL, edge_in->dest->prev_bb); | |
076c7ab8 ZW |
1360 | /* ??? Why not edge_in->dest->prev_bb here? */ |
1361 | BB_COPY_PARTITION (bb, edge_in->dest); | |
9fb32434 | 1362 | } |
ca6c03ca JH |
1363 | |
1364 | /* ??? This info is likely going to be out of date very soon. */ | |
1365 | if (edge_in->dest->global_live_at_start) | |
1366 | { | |
1367 | bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
1368 | bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
5f0d2358 RK |
1369 | COPY_REG_SET (bb->global_live_at_start, |
1370 | edge_in->dest->global_live_at_start); | |
1371 | COPY_REG_SET (bb->global_live_at_end, | |
1372 | edge_in->dest->global_live_at_start); | |
ca6c03ca JH |
1373 | } |
1374 | ||
4977bab6 | 1375 | make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU); |
ca6c03ca | 1376 | |
4d6922ee | 1377 | /* For non-fallthru edges, we must adjust the predecessor's |
ca6c03ca JH |
1378 | jump instruction to target our new block. */ |
1379 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1380 | { | |
1381 | if (!redirect_edge_and_branch (edge_in, bb)) | |
1382 | abort (); | |
1383 | } | |
1384 | else | |
1385 | redirect_edge_succ (edge_in, bb); | |
1386 | ||
1387 | return bb; | |
1388 | } | |
1389 | ||
1390 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1391 | The new instructions and basic blocks (if any) will not appear in the | |
1392 | CFG until commit_edge_insertions is called. */ | |
1393 | ||
1394 | void | |
d329e058 | 1395 | insert_insn_on_edge (rtx pattern, edge e) |
ca6c03ca JH |
1396 | { |
1397 | /* We cannot insert instructions on an abnormal critical edge. | |
1398 | It will be easier to find the culprit if we die now. */ | |
1399 | if ((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e)) | |
1400 | abort (); | |
1401 | ||
6de9cd9a | 1402 | if (e->insns.r == NULL_RTX) |
ca6c03ca JH |
1403 | start_sequence (); |
1404 | else | |
6de9cd9a | 1405 | push_to_sequence (e->insns.r); |
ca6c03ca JH |
1406 | |
1407 | emit_insn (pattern); | |
1408 | ||
6de9cd9a | 1409 | e->insns.r = get_insns (); |
ca6c03ca JH |
1410 | end_sequence (); |
1411 | } | |
1412 | ||
ff25ef99 ZD |
1413 | /* Called from safe_insert_insn_on_edge through note_stores, marks live |
1414 | registers that are killed by the store. */ | |
1415 | static void | |
1416 | mark_killed_regs (rtx reg, rtx set ATTRIBUTE_UNUSED, void *data) | |
1417 | { | |
1418 | regset killed = data; | |
1419 | int regno, i; | |
1420 | ||
1421 | if (GET_CODE (reg) == SUBREG) | |
1422 | reg = SUBREG_REG (reg); | |
1423 | if (!REG_P (reg)) | |
1424 | return; | |
1425 | regno = REGNO (reg); | |
1426 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1427 | SET_REGNO_REG_SET (killed, regno); | |
1428 | else | |
1429 | { | |
66fd46b6 | 1430 | for (i = 0; i < (int) hard_regno_nregs[regno][GET_MODE (reg)]; i++) |
ff25ef99 ZD |
1431 | SET_REGNO_REG_SET (killed, regno + i); |
1432 | } | |
1433 | } | |
1434 | ||
1435 | /* Similar to insert_insn_on_edge, tries to put INSN to edge E. Additionally | |
1436 | it checks whether this will not clobber the registers that are live on the | |
e0bb17a8 | 1437 | edge (i.e. it requires liveness information to be up-to-date) and if there |
ff25ef99 | 1438 | are some, then it tries to save and restore them. Returns true if |
e0bb17a8 | 1439 | successful. */ |
ff25ef99 ZD |
1440 | bool |
1441 | safe_insert_insn_on_edge (rtx insn, edge e) | |
1442 | { | |
1443 | rtx x; | |
1444 | regset_head killed_head; | |
1445 | regset killed = INITIALIZE_REG_SET (killed_head); | |
1446 | rtx save_regs = NULL_RTX; | |
1447 | int regno, noccmode; | |
1448 | enum machine_mode mode; | |
1449 | ||
1450 | #ifdef AVOID_CCMODE_COPIES | |
1451 | noccmode = true; | |
1452 | #else | |
1453 | noccmode = false; | |
1454 | #endif | |
1455 | ||
1456 | for (x = insn; x; x = NEXT_INSN (x)) | |
1457 | if (INSN_P (x)) | |
1458 | note_stores (PATTERN (x), mark_killed_regs, killed); | |
1459 | bitmap_operation (killed, killed, e->dest->global_live_at_start, | |
1460 | BITMAP_AND); | |
1461 | ||
1462 | EXECUTE_IF_SET_IN_REG_SET (killed, 0, regno, | |
1463 | { | |
1464 | mode = regno < FIRST_PSEUDO_REGISTER | |
1465 | ? reg_raw_mode[regno] | |
1466 | : GET_MODE (regno_reg_rtx[regno]); | |
1467 | if (mode == VOIDmode) | |
1468 | return false; | |
1469 | ||
1470 | if (noccmode && mode == CCmode) | |
1471 | return false; | |
1472 | ||
1473 | save_regs = alloc_EXPR_LIST (0, | |
1474 | alloc_EXPR_LIST (0, | |
1475 | gen_reg_rtx (mode), | |
1476 | gen_raw_REG (mode, regno)), | |
1477 | save_regs); | |
1478 | }); | |
1479 | ||
1480 | if (save_regs) | |
1481 | { | |
1482 | rtx from, to; | |
1483 | ||
1484 | start_sequence (); | |
1485 | for (x = save_regs; x; x = XEXP (x, 1)) | |
1486 | { | |
1487 | from = XEXP (XEXP (x, 0), 1); | |
1488 | to = XEXP (XEXP (x, 0), 0); | |
1489 | emit_move_insn (to, from); | |
1490 | } | |
1491 | emit_insn (insn); | |
1492 | for (x = save_regs; x; x = XEXP (x, 1)) | |
1493 | { | |
1494 | from = XEXP (XEXP (x, 0), 0); | |
1495 | to = XEXP (XEXP (x, 0), 1); | |
1496 | emit_move_insn (to, from); | |
1497 | } | |
1498 | insn = get_insns (); | |
1499 | end_sequence (); | |
1500 | free_EXPR_LIST_list (&save_regs); | |
1501 | } | |
1502 | insert_insn_on_edge (insn, e); | |
1503 | ||
1504 | FREE_REG_SET (killed); | |
1505 | return true; | |
1506 | } | |
1507 | ||
ca6c03ca JH |
1508 | /* Update the CFG for the instructions queued on edge E. */ |
1509 | ||
1510 | static void | |
d329e058 | 1511 | commit_one_edge_insertion (edge e, int watch_calls) |
ca6c03ca JH |
1512 | { |
1513 | rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last; | |
eae4bc56 | 1514 | basic_block bb = NULL; |
ca6c03ca JH |
1515 | |
1516 | /* Pull the insns off the edge now since the edge might go away. */ | |
6de9cd9a DN |
1517 | insns = e->insns.r; |
1518 | e->insns.r = NULL_RTX; | |
ca6c03ca | 1519 | |
3dec4024 JH |
1520 | /* Special case -- avoid inserting code between call and storing |
1521 | its return value. */ | |
1522 | if (watch_calls && (e->flags & EDGE_FALLTHRU) && !e->dest->pred->pred_next | |
1523 | && e->src != ENTRY_BLOCK_PTR | |
4b4bf941 | 1524 | && CALL_P (BB_END (e->src))) |
ca6c03ca | 1525 | { |
a813c111 | 1526 | rtx next = next_nonnote_insn (BB_END (e->src)); |
ca6c03ca | 1527 | |
a813c111 | 1528 | after = BB_HEAD (e->dest); |
3dec4024 JH |
1529 | /* The first insn after the call may be a stack pop, skip it. */ |
1530 | while (next | |
1531 | && keep_with_call_p (next)) | |
f87c27b4 KH |
1532 | { |
1533 | after = next; | |
3dec4024 JH |
1534 | next = next_nonnote_insn (next); |
1535 | } | |
1536 | bb = e->dest; | |
ca6c03ca | 1537 | } |
3dec4024 | 1538 | if (!before && !after) |
ca6c03ca | 1539 | { |
3dec4024 JH |
1540 | /* Figure out where to put these things. If the destination has |
1541 | one predecessor, insert there. Except for the exit block. */ | |
1542 | if (e->dest->pred->pred_next == NULL && e->dest != EXIT_BLOCK_PTR) | |
ca6c03ca | 1543 | { |
3dec4024 JH |
1544 | bb = e->dest; |
1545 | ||
1546 | /* Get the location correct wrt a code label, and "nice" wrt | |
1547 | a basic block note, and before everything else. */ | |
a813c111 | 1548 | tmp = BB_HEAD (bb); |
4b4bf941 | 1549 | if (LABEL_P (tmp)) |
3dec4024 JH |
1550 | tmp = NEXT_INSN (tmp); |
1551 | if (NOTE_INSN_BASIC_BLOCK_P (tmp)) | |
1552 | tmp = NEXT_INSN (tmp); | |
750054a2 | 1553 | if (tmp |
4b4bf941 | 1554 | && NOTE_P (tmp) |
750054a2 CT |
1555 | && NOTE_LINE_NUMBER (tmp) == NOTE_INSN_UNLIKELY_EXECUTED_CODE) |
1556 | tmp = NEXT_INSN (tmp); | |
a813c111 | 1557 | if (tmp == BB_HEAD (bb)) |
3dec4024 JH |
1558 | before = tmp; |
1559 | else if (tmp) | |
1560 | after = PREV_INSN (tmp); | |
1561 | else | |
1562 | after = get_last_insn (); | |
1563 | } | |
1564 | ||
1565 | /* If the source has one successor and the edge is not abnormal, | |
1566 | insert there. Except for the entry block. */ | |
1567 | else if ((e->flags & EDGE_ABNORMAL) == 0 | |
1568 | && e->src->succ->succ_next == NULL | |
1569 | && e->src != ENTRY_BLOCK_PTR) | |
1570 | { | |
1571 | bb = e->src; | |
1572 | ||
1573 | /* It is possible to have a non-simple jump here. Consider a target | |
1574 | where some forms of unconditional jumps clobber a register. This | |
1575 | happens on the fr30 for example. | |
1576 | ||
1577 | We know this block has a single successor, so we can just emit | |
1578 | the queued insns before the jump. */ | |
4b4bf941 | 1579 | if (JUMP_P (BB_END (bb))) |
a813c111 | 1580 | for (before = BB_END (bb); |
4b4bf941 | 1581 | NOTE_P (PREV_INSN (before)) |
3dec4024 JH |
1582 | && NOTE_LINE_NUMBER (PREV_INSN (before)) == |
1583 | NOTE_INSN_LOOP_BEG; before = PREV_INSN (before)) | |
1584 | ; | |
1585 | else | |
1586 | { | |
1587 | /* We'd better be fallthru, or we've lost track of what's what. */ | |
1588 | if ((e->flags & EDGE_FALLTHRU) == 0) | |
1589 | abort (); | |
ca6c03ca | 1590 | |
a813c111 | 1591 | after = BB_END (bb); |
3dec4024 JH |
1592 | } |
1593 | } | |
1594 | /* Otherwise we must split the edge. */ | |
1595 | else | |
1596 | { | |
1597 | bb = split_edge (e); | |
a813c111 | 1598 | after = BB_END (bb); |
750054a2 | 1599 | |
750054a2 | 1600 | if (flag_reorder_blocks_and_partition |
9fb32434 | 1601 | && targetm.have_named_sections |
750054a2 | 1602 | && e->src != ENTRY_BLOCK_PTR |
076c7ab8 | 1603 | && BB_PARTITION (e->src) == BB_COLD_PARTITION |
bd454efd | 1604 | && !(e->flags & EDGE_CROSSING)) |
750054a2 CT |
1605 | { |
1606 | rtx bb_note, new_note, cur_insn; | |
1607 | ||
1608 | bb_note = NULL_RTX; | |
1609 | for (cur_insn = BB_HEAD (bb); cur_insn != NEXT_INSN (BB_END (bb)); | |
1610 | cur_insn = NEXT_INSN (cur_insn)) | |
4b4bf941 | 1611 | if (NOTE_P (cur_insn) |
750054a2 CT |
1612 | && NOTE_LINE_NUMBER (cur_insn) == NOTE_INSN_BASIC_BLOCK) |
1613 | { | |
1614 | bb_note = cur_insn; | |
1615 | break; | |
1616 | } | |
1617 | ||
1618 | new_note = emit_note_after (NOTE_INSN_UNLIKELY_EXECUTED_CODE, | |
1619 | bb_note); | |
1620 | NOTE_BASIC_BLOCK (new_note) = bb; | |
4b4bf941 | 1621 | if (JUMP_P (BB_END (bb)) |
750054a2 | 1622 | && !any_condjump_p (BB_END (bb)) |
bd454efd | 1623 | && (bb->succ->flags & EDGE_CROSSING)) |
750054a2 CT |
1624 | REG_NOTES (BB_END (bb)) = gen_rtx_EXPR_LIST |
1625 | (REG_CROSSING_JUMP, NULL_RTX, REG_NOTES (BB_END (bb))); | |
1626 | if (after == bb_note) | |
1627 | after = new_note; | |
1628 | } | |
ca6c03ca JH |
1629 | } |
1630 | } | |
1631 | ||
ca6c03ca JH |
1632 | /* Now that we've found the spot, do the insertion. */ |
1633 | ||
1634 | if (before) | |
1635 | { | |
2f937369 | 1636 | emit_insn_before (insns, before); |
ca6c03ca JH |
1637 | last = prev_nonnote_insn (before); |
1638 | } | |
1639 | else | |
2f937369 | 1640 | last = emit_insn_after (insns, after); |
ca6c03ca JH |
1641 | |
1642 | if (returnjump_p (last)) | |
1643 | { | |
1644 | /* ??? Remove all outgoing edges from BB and add one for EXIT. | |
1645 | This is not currently a problem because this only happens | |
3dec4024 JH |
1646 | for the (single) epilogue, which already has a fallthru edge |
1647 | to EXIT. */ | |
ca6c03ca JH |
1648 | |
1649 | e = bb->succ; | |
1650 | if (e->dest != EXIT_BLOCK_PTR | |
3dec4024 | 1651 | || e->succ_next != NULL || (e->flags & EDGE_FALLTHRU) == 0) |
ca6c03ca | 1652 | abort (); |
ca6c03ca | 1653 | |
5f0d2358 | 1654 | e->flags &= ~EDGE_FALLTHRU; |
ca6c03ca | 1655 | emit_barrier_after (last); |
0b17ab2f | 1656 | |
ca6c03ca JH |
1657 | if (before) |
1658 | delete_insn (before); | |
1659 | } | |
4b4bf941 | 1660 | else if (JUMP_P (last)) |
ca6c03ca | 1661 | abort (); |
5f0d2358 | 1662 | |
9dca2ad5 JH |
1663 | /* Mark the basic block for find_sub_basic_blocks. */ |
1664 | bb->aux = &bb->aux; | |
ca6c03ca JH |
1665 | } |
1666 | ||
1667 | /* Update the CFG for all queued instructions. */ | |
1668 | ||
1669 | void | |
d329e058 | 1670 | commit_edge_insertions (void) |
ca6c03ca | 1671 | { |
ca6c03ca | 1672 | basic_block bb; |
9dca2ad5 | 1673 | sbitmap blocks; |
9809a362 | 1674 | bool changed = false; |
ca6c03ca JH |
1675 | |
1676 | #ifdef ENABLE_CHECKING | |
1677 | verify_flow_info (); | |
1678 | #endif | |
1679 | ||
e0082a72 | 1680 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
ca6c03ca JH |
1681 | { |
1682 | edge e, next; | |
1683 | ||
1684 | for (e = bb->succ; e; e = next) | |
1685 | { | |
1686 | next = e->succ_next; | |
6de9cd9a | 1687 | if (e->insns.r) |
9809a362 | 1688 | { |
6de9cd9a DN |
1689 | changed = true; |
1690 | commit_one_edge_insertion (e, false); | |
9809a362 | 1691 | } |
3dec4024 | 1692 | } |
3dec4024 | 1693 | } |
9dca2ad5 | 1694 | |
9809a362 JH |
1695 | if (!changed) |
1696 | return; | |
1697 | ||
9dca2ad5 JH |
1698 | blocks = sbitmap_alloc (last_basic_block); |
1699 | sbitmap_zero (blocks); | |
1700 | FOR_EACH_BB (bb) | |
1701 | if (bb->aux) | |
1702 | { | |
1703 | SET_BIT (blocks, bb->index); | |
1704 | /* Check for forgotten bb->aux values before commit_edge_insertions | |
1705 | call. */ | |
1706 | if (bb->aux != &bb->aux) | |
1707 | abort (); | |
1708 | bb->aux = NULL; | |
1709 | } | |
1710 | find_many_sub_basic_blocks (blocks); | |
1711 | sbitmap_free (blocks); | |
3dec4024 JH |
1712 | } |
1713 | \f | |
1714 | /* Update the CFG for all queued instructions, taking special care of inserting | |
1715 | code on edges between call and storing its return value. */ | |
1716 | ||
1717 | void | |
d329e058 | 1718 | commit_edge_insertions_watch_calls (void) |
3dec4024 | 1719 | { |
3dec4024 | 1720 | basic_block bb; |
9809a362 JH |
1721 | sbitmap blocks; |
1722 | bool changed = false; | |
3dec4024 JH |
1723 | |
1724 | #ifdef ENABLE_CHECKING | |
1725 | verify_flow_info (); | |
1726 | #endif | |
1727 | ||
e0082a72 | 1728 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
3dec4024 JH |
1729 | { |
1730 | edge e, next; | |
1731 | ||
1732 | for (e = bb->succ; e; e = next) | |
1733 | { | |
1734 | next = e->succ_next; | |
6de9cd9a | 1735 | if (e->insns.r) |
9809a362 JH |
1736 | { |
1737 | changed = true; | |
1738 | commit_one_edge_insertion (e, true); | |
1739 | } | |
ca6c03ca | 1740 | } |
ca6c03ca | 1741 | } |
9809a362 JH |
1742 | |
1743 | if (!changed) | |
1744 | return; | |
1745 | ||
1746 | blocks = sbitmap_alloc (last_basic_block); | |
1747 | sbitmap_zero (blocks); | |
1748 | FOR_EACH_BB (bb) | |
1749 | if (bb->aux) | |
1750 | { | |
1751 | SET_BIT (blocks, bb->index); | |
1752 | /* Check for forgotten bb->aux values before commit_edge_insertions | |
1753 | call. */ | |
1754 | if (bb->aux != &bb->aux) | |
1755 | abort (); | |
1756 | bb->aux = NULL; | |
1757 | } | |
1758 | find_many_sub_basic_blocks (blocks); | |
1759 | sbitmap_free (blocks); | |
ca6c03ca JH |
1760 | } |
1761 | \f | |
f470c378 ZD |
1762 | /* Print out RTL-specific basic block information (live information |
1763 | at start and end). */ | |
ca6c03ca | 1764 | |
10e9fecc | 1765 | static void |
f470c378 | 1766 | rtl_dump_bb (basic_block bb, FILE *outf, int indent) |
ca6c03ca JH |
1767 | { |
1768 | rtx insn; | |
1769 | rtx last; | |
f470c378 | 1770 | char *s_indent; |
ca6c03ca | 1771 | |
400e39e3 KH |
1772 | s_indent = alloca ((size_t) indent + 1); |
1773 | memset (s_indent, ' ', (size_t) indent); | |
f470c378 ZD |
1774 | s_indent[indent] = '\0'; |
1775 | ||
1776 | fprintf (outf, ";;%s Registers live at start: ", s_indent); | |
ca6c03ca JH |
1777 | dump_regset (bb->global_live_at_start, outf); |
1778 | putc ('\n', outf); | |
1779 | ||
a813c111 | 1780 | for (insn = BB_HEAD (bb), last = NEXT_INSN (BB_END (bb)); insn != last; |
ca6c03ca JH |
1781 | insn = NEXT_INSN (insn)) |
1782 | print_rtl_single (outf, insn); | |
1783 | ||
f470c378 | 1784 | fprintf (outf, ";;%s Registers live at end: ", s_indent); |
ca6c03ca JH |
1785 | dump_regset (bb->global_live_at_end, outf); |
1786 | putc ('\n', outf); | |
ca6c03ca JH |
1787 | } |
1788 | \f | |
1789 | /* Like print_rtl, but also print out live information for the start of each | |
1790 | basic block. */ | |
1791 | ||
1792 | void | |
d329e058 | 1793 | print_rtl_with_bb (FILE *outf, rtx rtx_first) |
ca6c03ca | 1794 | { |
b3694847 | 1795 | rtx tmp_rtx; |
ca6c03ca JH |
1796 | |
1797 | if (rtx_first == 0) | |
1798 | fprintf (outf, "(nil)\n"); | |
1799 | else | |
1800 | { | |
ca6c03ca JH |
1801 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
1802 | int max_uid = get_max_uid (); | |
703ad42b KG |
1803 | basic_block *start = xcalloc (max_uid, sizeof (basic_block)); |
1804 | basic_block *end = xcalloc (max_uid, sizeof (basic_block)); | |
1805 | enum bb_state *in_bb_p = xcalloc (max_uid, sizeof (enum bb_state)); | |
ca6c03ca | 1806 | |
e0082a72 ZD |
1807 | basic_block bb; |
1808 | ||
1809 | FOR_EACH_BB_REVERSE (bb) | |
ca6c03ca | 1810 | { |
ca6c03ca JH |
1811 | rtx x; |
1812 | ||
a813c111 SB |
1813 | start[INSN_UID (BB_HEAD (bb))] = bb; |
1814 | end[INSN_UID (BB_END (bb))] = bb; | |
1815 | for (x = BB_HEAD (bb); x != NULL_RTX; x = NEXT_INSN (x)) | |
ca6c03ca JH |
1816 | { |
1817 | enum bb_state state = IN_MULTIPLE_BB; | |
5f0d2358 | 1818 | |
ca6c03ca JH |
1819 | if (in_bb_p[INSN_UID (x)] == NOT_IN_BB) |
1820 | state = IN_ONE_BB; | |
1821 | in_bb_p[INSN_UID (x)] = state; | |
1822 | ||
a813c111 | 1823 | if (x == BB_END (bb)) |
ca6c03ca JH |
1824 | break; |
1825 | } | |
1826 | } | |
1827 | ||
1828 | for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) | |
1829 | { | |
1830 | int did_output; | |
ca6c03ca JH |
1831 | |
1832 | if ((bb = start[INSN_UID (tmp_rtx)]) != NULL) | |
1833 | { | |
1834 | fprintf (outf, ";; Start of basic block %d, registers live:", | |
0b17ab2f | 1835 | bb->index); |
ca6c03ca JH |
1836 | dump_regset (bb->global_live_at_start, outf); |
1837 | putc ('\n', outf); | |
1838 | } | |
1839 | ||
1840 | if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB | |
4b4bf941 JQ |
1841 | && !NOTE_P (tmp_rtx) |
1842 | && !BARRIER_P (tmp_rtx)) | |
ca6c03ca JH |
1843 | fprintf (outf, ";; Insn is not within a basic block\n"); |
1844 | else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB) | |
1845 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); | |
1846 | ||
1847 | did_output = print_rtl_single (outf, tmp_rtx); | |
1848 | ||
1849 | if ((bb = end[INSN_UID (tmp_rtx)]) != NULL) | |
1850 | { | |
1851 | fprintf (outf, ";; End of basic block %d, registers live:\n", | |
0b17ab2f | 1852 | bb->index); |
ca6c03ca JH |
1853 | dump_regset (bb->global_live_at_end, outf); |
1854 | putc ('\n', outf); | |
1855 | } | |
1856 | ||
1857 | if (did_output) | |
1858 | putc ('\n', outf); | |
1859 | } | |
1860 | ||
1861 | free (start); | |
1862 | free (end); | |
1863 | free (in_bb_p); | |
1864 | } | |
1865 | ||
1866 | if (current_function_epilogue_delay_list != 0) | |
1867 | { | |
1868 | fprintf (outf, "\n;; Insns in epilogue delay list:\n\n"); | |
1869 | for (tmp_rtx = current_function_epilogue_delay_list; tmp_rtx != 0; | |
1870 | tmp_rtx = XEXP (tmp_rtx, 1)) | |
1871 | print_rtl_single (outf, XEXP (tmp_rtx, 0)); | |
1872 | } | |
1873 | } | |
1874 | \f | |
b446e5a2 | 1875 | void |
d329e058 | 1876 | update_br_prob_note (basic_block bb) |
b446e5a2 JH |
1877 | { |
1878 | rtx note; | |
4b4bf941 | 1879 | if (!JUMP_P (BB_END (bb))) |
b446e5a2 | 1880 | return; |
a813c111 | 1881 | note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX); |
b446e5a2 JH |
1882 | if (!note || INTVAL (XEXP (note, 0)) == BRANCH_EDGE (bb)->probability) |
1883 | return; | |
1884 | XEXP (note, 0) = GEN_INT (BRANCH_EDGE (bb)->probability); | |
1885 | } | |
1886 | \f | |
10e9fecc JH |
1887 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
1888 | cfglayout RTL. | |
ca6c03ca JH |
1889 | |
1890 | Currently it does following checks: | |
1891 | ||
1892 | - test head/end pointers | |
1893 | - overlapping of basic blocks | |
ca6c03ca | 1894 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) |
f63d1bf7 | 1895 | - tails of basic blocks (ensure that boundary is necessary) |
ca6c03ca JH |
1896 | - scans body of the basic block for JUMP_INSN, CODE_LABEL |
1897 | and NOTE_INSN_BASIC_BLOCK | |
750054a2 | 1898 | - verify that no fall_thru edge crosses hot/cold partition boundaries |
ca6c03ca JH |
1899 | |
1900 | In future it can be extended check a lot of other stuff as well | |
1901 | (reachability of basic blocks, life information, etc. etc.). */ | |
f470c378 | 1902 | |
10e9fecc | 1903 | static int |
d329e058 | 1904 | rtl_verify_flow_info_1 (void) |
ca6c03ca JH |
1905 | { |
1906 | const int max_uid = get_max_uid (); | |
ca6c03ca | 1907 | rtx last_head = get_last_insn (); |
10e9fecc | 1908 | basic_block *bb_info; |
ca6c03ca | 1909 | rtx x; |
10e9fecc | 1910 | int err = 0; |
918ed612 | 1911 | basic_block bb, last_bb_seen; |
ca6c03ca | 1912 | |
703ad42b | 1913 | bb_info = xcalloc (max_uid, sizeof (basic_block)); |
ca6c03ca | 1914 | |
918ed612 ZD |
1915 | /* Check bb chain & numbers. */ |
1916 | last_bb_seen = ENTRY_BLOCK_PTR; | |
918ed612 | 1917 | |
e0082a72 | 1918 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1919 | { |
a813c111 SB |
1920 | rtx head = BB_HEAD (bb); |
1921 | rtx end = BB_END (bb); | |
ca6c03ca JH |
1922 | |
1923 | /* Verify the end of the basic block is in the INSN chain. */ | |
1924 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) | |
1925 | if (x == end) | |
1926 | break; | |
5f0d2358 | 1927 | |
ca6c03ca JH |
1928 | if (!x) |
1929 | { | |
1f978f5f | 1930 | error ("end insn %d for block %d not found in the insn stream", |
0b17ab2f | 1931 | INSN_UID (end), bb->index); |
ca6c03ca JH |
1932 | err = 1; |
1933 | } | |
1934 | ||
1935 | /* Work backwards from the end to the head of the basic block | |
1936 | to verify the head is in the RTL chain. */ | |
1937 | for (; x != NULL_RTX; x = PREV_INSN (x)) | |
1938 | { | |
1939 | /* While walking over the insn chain, verify insns appear | |
1940 | in only one basic block and initialize the BB_INFO array | |
1941 | used by other passes. */ | |
1942 | if (bb_info[INSN_UID (x)] != NULL) | |
1943 | { | |
1f978f5f | 1944 | error ("insn %d is in multiple basic blocks (%d and %d)", |
0b17ab2f | 1945 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); |
ca6c03ca JH |
1946 | err = 1; |
1947 | } | |
5f0d2358 | 1948 | |
ca6c03ca JH |
1949 | bb_info[INSN_UID (x)] = bb; |
1950 | ||
1951 | if (x == head) | |
1952 | break; | |
1953 | } | |
1954 | if (!x) | |
1955 | { | |
1f978f5f | 1956 | error ("head insn %d for block %d not found in the insn stream", |
0b17ab2f | 1957 | INSN_UID (head), bb->index); |
ca6c03ca JH |
1958 | err = 1; |
1959 | } | |
1960 | ||
1961 | last_head = x; | |
1962 | } | |
1963 | ||
1964 | /* Now check the basic blocks (boundaries etc.) */ | |
e0082a72 | 1965 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1966 | { |
3dec4024 | 1967 | int n_fallthru = 0, n_eh = 0, n_call = 0, n_abnormal = 0, n_branch = 0; |
3cf54412 | 1968 | edge e, fallthru = NULL; |
5a1a3e5e | 1969 | rtx note; |
ca6c03ca | 1970 | |
a813c111 SB |
1971 | if (INSN_P (BB_END (bb)) |
1972 | && (note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX)) | |
3e638a90 | 1973 | && bb->succ && bb->succ->succ_next |
a813c111 | 1974 | && any_condjump_p (BB_END (bb))) |
5a1a3e5e | 1975 | { |
5a1a3e5e JH |
1976 | if (INTVAL (XEXP (note, 0)) != BRANCH_EDGE (bb)->probability) |
1977 | { | |
0108ae51 | 1978 | error ("verify_flow_info: REG_BR_PROB does not match cfg %wi %i", |
5a1a3e5e JH |
1979 | INTVAL (XEXP (note, 0)), BRANCH_EDGE (bb)->probability); |
1980 | err = 1; | |
1981 | } | |
1982 | } | |
5f0d2358 | 1983 | for (e = bb->succ; e; e = e->succ_next) |
ca6c03ca | 1984 | { |
ca6c03ca | 1985 | if (e->flags & EDGE_FALLTHRU) |
750054a2 CT |
1986 | { |
1987 | n_fallthru++, fallthru = e; | |
bd454efd | 1988 | if ((e->flags & EDGE_CROSSING) |
076c7ab8 | 1989 | || (BB_PARTITION (e->src) != BB_PARTITION (e->dest) |
9fb32434 CT |
1990 | && e->src != ENTRY_BLOCK_PTR |
1991 | && e->dest != EXIT_BLOCK_PTR)) | |
1992 | { | |
750054a2 CT |
1993 | error ("Fallthru edge crosses section boundary (bb %i)", |
1994 | e->src->index); | |
1995 | err = 1; | |
1996 | } | |
1997 | } | |
3dec4024 | 1998 | |
65f43cdf ZD |
1999 | if ((e->flags & ~(EDGE_DFS_BACK |
2000 | | EDGE_CAN_FALLTHRU | |
2001 | | EDGE_IRREDUCIBLE_LOOP | |
2002 | | EDGE_LOOP_EXIT)) == 0) | |
3dec4024 JH |
2003 | n_branch++; |
2004 | ||
2005 | if (e->flags & EDGE_ABNORMAL_CALL) | |
2006 | n_call++; | |
2007 | ||
2008 | if (e->flags & EDGE_EH) | |
2009 | n_eh++; | |
2010 | else if (e->flags & EDGE_ABNORMAL) | |
2011 | n_abnormal++; | |
ca6c03ca | 2012 | } |
5f0d2358 | 2013 | |
a813c111 SB |
2014 | if (n_eh && GET_CODE (PATTERN (BB_END (bb))) != RESX |
2015 | && !find_reg_note (BB_END (bb), REG_EH_REGION, NULL_RTX)) | |
3dec4024 | 2016 | { |
0b17ab2f | 2017 | error ("Missing REG_EH_REGION note in the end of bb %i", bb->index); |
3dec4024 JH |
2018 | err = 1; |
2019 | } | |
2020 | if (n_branch | |
4b4bf941 | 2021 | && (!JUMP_P (BB_END (bb)) |
a813c111 SB |
2022 | || (n_branch > 1 && (any_uncondjump_p (BB_END (bb)) |
2023 | || any_condjump_p (BB_END (bb)))))) | |
3dec4024 | 2024 | { |
0b17ab2f | 2025 | error ("Too many outgoing branch edges from bb %i", bb->index); |
3dec4024 JH |
2026 | err = 1; |
2027 | } | |
a813c111 | 2028 | if (n_fallthru && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 2029 | { |
0b17ab2f | 2030 | error ("Fallthru edge after unconditional jump %i", bb->index); |
3dec4024 JH |
2031 | err = 1; |
2032 | } | |
a813c111 | 2033 | if (n_branch != 1 && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 2034 | { |
0b17ab2f | 2035 | error ("Wrong amount of branch edges after unconditional jump %i", bb->index); |
3dec4024 JH |
2036 | err = 1; |
2037 | } | |
a813c111 SB |
2038 | if (n_branch != 1 && any_condjump_p (BB_END (bb)) |
2039 | && JUMP_LABEL (BB_END (bb)) != BB_HEAD (fallthru->dest)) | |
3dec4024 | 2040 | { |
0b17ab2f | 2041 | error ("Wrong amount of branch edges after conditional jump %i", bb->index); |
3dec4024 JH |
2042 | err = 1; |
2043 | } | |
4b4bf941 | 2044 | if (n_call && !CALL_P (BB_END (bb))) |
3dec4024 | 2045 | { |
0b17ab2f | 2046 | error ("Call edges for non-call insn in bb %i", bb->index); |
3dec4024 JH |
2047 | err = 1; |
2048 | } | |
2049 | if (n_abnormal | |
4b4bf941 JQ |
2050 | && (!CALL_P (BB_END (bb)) && n_call != n_abnormal) |
2051 | && (!JUMP_P (BB_END (bb)) | |
a813c111 SB |
2052 | || any_condjump_p (BB_END (bb)) |
2053 | || any_uncondjump_p (BB_END (bb)))) | |
3dec4024 | 2054 | { |
0b17ab2f | 2055 | error ("Abnormal edges for no purpose in bb %i", bb->index); |
3dec4024 JH |
2056 | err = 1; |
2057 | } | |
f87c27b4 | 2058 | |
a813c111 | 2059 | for (x = BB_HEAD (bb); x != NEXT_INSN (BB_END (bb)); x = NEXT_INSN (x)) |
ba4f7968 | 2060 | if (BLOCK_FOR_INSN (x) != bb) |
5f0d2358 RK |
2061 | { |
2062 | debug_rtx (x); | |
2063 | if (! BLOCK_FOR_INSN (x)) | |
2064 | error | |
2065 | ("insn %d inside basic block %d but block_for_insn is NULL", | |
0b17ab2f | 2066 | INSN_UID (x), bb->index); |
5f0d2358 RK |
2067 | else |
2068 | error | |
2069 | ("insn %d inside basic block %d but block_for_insn is %i", | |
0b17ab2f | 2070 | INSN_UID (x), bb->index, BLOCK_FOR_INSN (x)->index); |
5f0d2358 RK |
2071 | |
2072 | err = 1; | |
2073 | } | |
ca6c03ca JH |
2074 | |
2075 | /* OK pointers are correct. Now check the header of basic | |
2076 | block. It ought to contain optional CODE_LABEL followed | |
2077 | by NOTE_BASIC_BLOCK. */ | |
a813c111 | 2078 | x = BB_HEAD (bb); |
4b4bf941 | 2079 | if (LABEL_P (x)) |
ca6c03ca | 2080 | { |
a813c111 | 2081 | if (BB_END (bb) == x) |
ca6c03ca JH |
2082 | { |
2083 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 2084 | bb->index); |
ca6c03ca JH |
2085 | err = 1; |
2086 | } | |
5f0d2358 | 2087 | |
ca6c03ca JH |
2088 | x = NEXT_INSN (x); |
2089 | } | |
5f0d2358 | 2090 | |
ca6c03ca JH |
2091 | if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb) |
2092 | { | |
2093 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 2094 | bb->index); |
ca6c03ca JH |
2095 | err = 1; |
2096 | } | |
2097 | ||
a813c111 | 2098 | if (BB_END (bb) == x) |
5f0d2358 RK |
2099 | /* Do checks for empty blocks her. e */ |
2100 | ; | |
ca6c03ca | 2101 | else |
5f0d2358 RK |
2102 | for (x = NEXT_INSN (x); x; x = NEXT_INSN (x)) |
2103 | { | |
2104 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2105 | { | |
2106 | error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d", | |
0b17ab2f | 2107 | INSN_UID (x), bb->index); |
5f0d2358 RK |
2108 | err = 1; |
2109 | } | |
2110 | ||
a813c111 | 2111 | if (x == BB_END (bb)) |
5f0d2358 | 2112 | break; |
ca6c03ca | 2113 | |
83fd323c | 2114 | if (control_flow_insn_p (x)) |
5f0d2358 | 2115 | { |
0b17ab2f | 2116 | error ("in basic block %d:", bb->index); |
5f0d2358 RK |
2117 | fatal_insn ("flow control insn inside a basic block", x); |
2118 | } | |
2119 | } | |
ca6c03ca JH |
2120 | } |
2121 | ||
10e9fecc JH |
2122 | /* Clean up. */ |
2123 | free (bb_info); | |
2124 | return err; | |
2125 | } | |
5f0d2358 | 2126 | |
10e9fecc JH |
2127 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
2128 | cfglayout RTL. | |
5f0d2358 | 2129 | |
10e9fecc JH |
2130 | Currently it does following checks: |
2131 | - all checks of rtl_verify_flow_info_1 | |
2132 | - check that all insns are in the basic blocks | |
2133 | (except the switch handling code, barriers and notes) | |
2134 | - check that all returns are followed by barriers | |
2135 | - check that all fallthru edge points to the adjacent blocks. */ | |
2136 | static int | |
d329e058 | 2137 | rtl_verify_flow_info (void) |
10e9fecc JH |
2138 | { |
2139 | basic_block bb; | |
2140 | int err = rtl_verify_flow_info_1 (); | |
2141 | rtx x; | |
2142 | int num_bb_notes; | |
2143 | const rtx rtx_first = get_insns (); | |
2144 | basic_block last_bb_seen = ENTRY_BLOCK_PTR, curr_bb = NULL; | |
ca6c03ca | 2145 | |
10e9fecc JH |
2146 | FOR_EACH_BB_REVERSE (bb) |
2147 | { | |
2148 | edge e; | |
2149 | for (e = bb->succ; e; e = e->succ_next) | |
2150 | if (e->flags & EDGE_FALLTHRU) | |
2151 | break; | |
2152 | if (!e) | |
2153 | { | |
2154 | rtx insn; | |
2155 | ||
2156 | /* Ensure existence of barrier in BB with no fallthru edges. */ | |
4b4bf941 | 2157 | for (insn = BB_END (bb); !insn || !BARRIER_P (insn); |
10e9fecc JH |
2158 | insn = NEXT_INSN (insn)) |
2159 | if (!insn | |
4b4bf941 | 2160 | || (NOTE_P (insn) |
10e9fecc JH |
2161 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_BASIC_BLOCK)) |
2162 | { | |
2163 | error ("missing barrier after block %i", bb->index); | |
2164 | err = 1; | |
2165 | break; | |
2166 | } | |
2167 | } | |
2168 | else if (e->src != ENTRY_BLOCK_PTR | |
2169 | && e->dest != EXIT_BLOCK_PTR) | |
2170 | { | |
2171 | rtx insn; | |
2172 | ||
2173 | if (e->src->next_bb != e->dest) | |
2174 | { | |
2175 | error | |
2176 | ("verify_flow_info: Incorrect blocks for fallthru %i->%i", | |
2177 | e->src->index, e->dest->index); | |
2178 | err = 1; | |
2179 | } | |
2180 | else | |
a813c111 | 2181 | for (insn = NEXT_INSN (BB_END (e->src)); insn != BB_HEAD (e->dest); |
10e9fecc | 2182 | insn = NEXT_INSN (insn)) |
4b4bf941 | 2183 | if (BARRIER_P (insn) |
10e9fecc JH |
2184 | #ifndef CASE_DROPS_THROUGH |
2185 | || INSN_P (insn) | |
2186 | #else | |
2187 | || (INSN_P (insn) && ! JUMP_TABLE_DATA_P (insn)) | |
2188 | #endif | |
2189 | ) | |
2190 | { | |
2191 | error ("verify_flow_info: Incorrect fallthru %i->%i", | |
2192 | e->src->index, e->dest->index); | |
2193 | fatal_insn ("wrong insn in the fallthru edge", insn); | |
2194 | err = 1; | |
2195 | } | |
2196 | } | |
2197 | } | |
ca6c03ca | 2198 | |
ca6c03ca | 2199 | num_bb_notes = 0; |
e0082a72 ZD |
2200 | last_bb_seen = ENTRY_BLOCK_PTR; |
2201 | ||
5f0d2358 | 2202 | for (x = rtx_first; x; x = NEXT_INSN (x)) |
ca6c03ca JH |
2203 | { |
2204 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2205 | { | |
bf77398c | 2206 | bb = NOTE_BASIC_BLOCK (x); |
5f0d2358 | 2207 | |
ca6c03ca | 2208 | num_bb_notes++; |
e0082a72 | 2209 | if (bb != last_bb_seen->next_bb) |
10e9fecc | 2210 | internal_error ("basic blocks not laid down consecutively"); |
ca6c03ca | 2211 | |
10e9fecc | 2212 | curr_bb = last_bb_seen = bb; |
ca6c03ca JH |
2213 | } |
2214 | ||
10e9fecc | 2215 | if (!curr_bb) |
ca6c03ca JH |
2216 | { |
2217 | switch (GET_CODE (x)) | |
2218 | { | |
2219 | case BARRIER: | |
2220 | case NOTE: | |
2221 | break; | |
2222 | ||
2223 | case CODE_LABEL: | |
666c27b9 | 2224 | /* An addr_vec is placed outside any basic block. */ |
ca6c03ca | 2225 | if (NEXT_INSN (x) |
4b4bf941 | 2226 | && JUMP_P (NEXT_INSN (x)) |
ca6c03ca JH |
2227 | && (GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_DIFF_VEC |
2228 | || GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_VEC)) | |
5f0d2358 | 2229 | x = NEXT_INSN (x); |
ca6c03ca JH |
2230 | |
2231 | /* But in any case, non-deletable labels can appear anywhere. */ | |
2232 | break; | |
2233 | ||
2234 | default: | |
1f978f5f | 2235 | fatal_insn ("insn outside basic block", x); |
ca6c03ca JH |
2236 | } |
2237 | } | |
2238 | ||
2239 | if (INSN_P (x) | |
4b4bf941 | 2240 | && JUMP_P (x) |
ca6c03ca | 2241 | && returnjump_p (x) && ! condjump_p (x) |
4b4bf941 | 2242 | && ! (NEXT_INSN (x) && BARRIER_P (NEXT_INSN (x)))) |
1f978f5f | 2243 | fatal_insn ("return not followed by barrier", x); |
a813c111 | 2244 | if (curr_bb && x == BB_END (curr_bb)) |
10e9fecc | 2245 | curr_bb = NULL; |
ca6c03ca JH |
2246 | } |
2247 | ||
0b17ab2f | 2248 | if (num_bb_notes != n_basic_blocks) |
ca6c03ca | 2249 | internal_error |
0b17ab2f RH |
2250 | ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)", |
2251 | num_bb_notes, n_basic_blocks); | |
ca6c03ca | 2252 | |
10e9fecc | 2253 | return err; |
ca6c03ca JH |
2254 | } |
2255 | \f | |
eaec9b3d | 2256 | /* Assume that the preceding pass has possibly eliminated jump instructions |
ca6c03ca JH |
2257 | or converted the unconditional jumps. Eliminate the edges from CFG. |
2258 | Return true if any edges are eliminated. */ | |
2259 | ||
2260 | bool | |
d329e058 | 2261 | purge_dead_edges (basic_block bb) |
ca6c03ca JH |
2262 | { |
2263 | edge e, next; | |
a813c111 | 2264 | rtx insn = BB_END (bb), note; |
ca6c03ca JH |
2265 | bool purged = false; |
2266 | ||
70da1d03 | 2267 | /* If this instruction cannot trap, remove REG_EH_REGION notes. */ |
4b4bf941 | 2268 | if (NONJUMP_INSN_P (insn) |
70da1d03 JH |
2269 | && (note = find_reg_note (insn, REG_EH_REGION, NULL))) |
2270 | { | |
2271 | rtx eqnote; | |
2272 | ||
2273 | if (! may_trap_p (PATTERN (insn)) | |
2274 | || ((eqnote = find_reg_equal_equiv_note (insn)) | |
2275 | && ! may_trap_p (XEXP (eqnote, 0)))) | |
2276 | remove_note (insn, note); | |
2277 | } | |
2278 | ||
546c093e RH |
2279 | /* Cleanup abnormal edges caused by exceptions or non-local gotos. */ |
2280 | for (e = bb->succ; e; e = next) | |
2281 | { | |
2282 | next = e->succ_next; | |
2283 | if (e->flags & EDGE_EH) | |
2284 | { | |
a813c111 | 2285 | if (can_throw_internal (BB_END (bb))) |
546c093e RH |
2286 | continue; |
2287 | } | |
2288 | else if (e->flags & EDGE_ABNORMAL_CALL) | |
2289 | { | |
4b4bf941 | 2290 | if (CALL_P (BB_END (bb)) |
546c093e RH |
2291 | && (! (note = find_reg_note (insn, REG_EH_REGION, NULL)) |
2292 | || INTVAL (XEXP (note, 0)) >= 0)) | |
2293 | continue; | |
2294 | } | |
2295 | else | |
2296 | continue; | |
2297 | ||
2298 | remove_edge (e); | |
2299 | bb->flags |= BB_DIRTY; | |
2300 | purged = true; | |
2301 | } | |
5f0d2358 | 2302 | |
4b4bf941 | 2303 | if (JUMP_P (insn)) |
ca6c03ca JH |
2304 | { |
2305 | rtx note; | |
2306 | edge b,f; | |
5f0d2358 | 2307 | |
ca6c03ca JH |
2308 | /* We do care only about conditional jumps and simplejumps. */ |
2309 | if (!any_condjump_p (insn) | |
2310 | && !returnjump_p (insn) | |
2311 | && !simplejump_p (insn)) | |
c51d95ec | 2312 | return purged; |
5f0d2358 | 2313 | |
5a1a3e5e JH |
2314 | /* Branch probability/prediction notes are defined only for |
2315 | condjumps. We've possibly turned condjump into simplejump. */ | |
2316 | if (simplejump_p (insn)) | |
2317 | { | |
2318 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2319 | if (note) | |
2320 | remove_note (insn, note); | |
2321 | while ((note = find_reg_note (insn, REG_BR_PRED, NULL))) | |
2322 | remove_note (insn, note); | |
2323 | } | |
2324 | ||
ca6c03ca JH |
2325 | for (e = bb->succ; e; e = next) |
2326 | { | |
2327 | next = e->succ_next; | |
2328 | ||
7fcd7218 JH |
2329 | /* Avoid abnormal flags to leak from computed jumps turned |
2330 | into simplejumps. */ | |
f87c27b4 | 2331 | |
0e1638d4 | 2332 | e->flags &= ~EDGE_ABNORMAL; |
7fcd7218 | 2333 | |
5a566bed MM |
2334 | /* See if this edge is one we should keep. */ |
2335 | if ((e->flags & EDGE_FALLTHRU) && any_condjump_p (insn)) | |
2336 | /* A conditional jump can fall through into the next | |
2337 | block, so we should keep the edge. */ | |
ca6c03ca | 2338 | continue; |
5f0d2358 | 2339 | else if (e->dest != EXIT_BLOCK_PTR |
a813c111 | 2340 | && BB_HEAD (e->dest) == JUMP_LABEL (insn)) |
5a566bed MM |
2341 | /* If the destination block is the target of the jump, |
2342 | keep the edge. */ | |
2343 | continue; | |
2344 | else if (e->dest == EXIT_BLOCK_PTR && returnjump_p (insn)) | |
2345 | /* If the destination block is the exit block, and this | |
2346 | instruction is a return, then keep the edge. */ | |
ca6c03ca | 2347 | continue; |
5a566bed MM |
2348 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) |
2349 | /* Keep the edges that correspond to exceptions thrown by | |
0b75beaa EB |
2350 | this instruction and rematerialize the EDGE_ABNORMAL |
2351 | flag we just cleared above. */ | |
2352 | { | |
2353 | e->flags |= EDGE_ABNORMAL; | |
2354 | continue; | |
2355 | } | |
5f0d2358 | 2356 | |
5a566bed | 2357 | /* We do not need this edge. */ |
c51d95ec | 2358 | bb->flags |= BB_DIRTY; |
ca6c03ca JH |
2359 | purged = true; |
2360 | remove_edge (e); | |
2361 | } | |
5f0d2358 | 2362 | |
ca6c03ca | 2363 | if (!bb->succ || !purged) |
c51d95ec | 2364 | return purged; |
5f0d2358 | 2365 | |
c263766c RH |
2366 | if (dump_file) |
2367 | fprintf (dump_file, "Purged edges from bb %i\n", bb->index); | |
5f0d2358 | 2368 | |
ca6c03ca JH |
2369 | if (!optimize) |
2370 | return purged; | |
2371 | ||
2372 | /* Redistribute probabilities. */ | |
2373 | if (!bb->succ->succ_next) | |
2374 | { | |
2375 | bb->succ->probability = REG_BR_PROB_BASE; | |
2376 | bb->succ->count = bb->count; | |
f87c27b4 | 2377 | } |
ca6c03ca JH |
2378 | else |
2379 | { | |
2380 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2381 | if (!note) | |
2382 | return purged; | |
5f0d2358 | 2383 | |
ca6c03ca JH |
2384 | b = BRANCH_EDGE (bb); |
2385 | f = FALLTHRU_EDGE (bb); | |
2386 | b->probability = INTVAL (XEXP (note, 0)); | |
2387 | f->probability = REG_BR_PROB_BASE - b->probability; | |
2388 | b->count = bb->count * b->probability / REG_BR_PROB_BASE; | |
2389 | f->count = bb->count * f->probability / REG_BR_PROB_BASE; | |
2390 | } | |
5f0d2358 | 2391 | |
ca6c03ca JH |
2392 | return purged; |
2393 | } | |
4b4bf941 | 2394 | else if (CALL_P (insn) && SIBLING_CALL_P (insn)) |
1722c2c8 RH |
2395 | { |
2396 | /* First, there should not be any EH or ABCALL edges resulting | |
2397 | from non-local gotos and the like. If there were, we shouldn't | |
2398 | have created the sibcall in the first place. Second, there | |
2399 | should of course never have been a fallthru edge. */ | |
2400 | if (!bb->succ || bb->succ->succ_next) | |
2401 | abort (); | |
792bb204 | 2402 | if (bb->succ->flags != (EDGE_SIBCALL | EDGE_ABNORMAL)) |
1722c2c8 RH |
2403 | abort (); |
2404 | ||
2405 | return 0; | |
2406 | } | |
ca6c03ca | 2407 | |
ca6c03ca JH |
2408 | /* If we don't see a jump insn, we don't know exactly why the block would |
2409 | have been broken at this point. Look for a simple, non-fallthru edge, | |
2410 | as these are only created by conditional branches. If we find such an | |
2411 | edge we know that there used to be a jump here and can then safely | |
2412 | remove all non-fallthru edges. */ | |
2413 | for (e = bb->succ; e && (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU)); | |
5f0d2358 RK |
2414 | e = e->succ_next) |
2415 | ; | |
2416 | ||
ca6c03ca JH |
2417 | if (!e) |
2418 | return purged; | |
5f0d2358 | 2419 | |
ca6c03ca JH |
2420 | for (e = bb->succ; e; e = next) |
2421 | { | |
2422 | next = e->succ_next; | |
2423 | if (!(e->flags & EDGE_FALLTHRU)) | |
c51d95ec JH |
2424 | { |
2425 | bb->flags |= BB_DIRTY; | |
2426 | remove_edge (e); | |
2427 | purged = true; | |
2428 | } | |
ca6c03ca | 2429 | } |
5f0d2358 | 2430 | |
ca6c03ca JH |
2431 | if (!bb->succ || bb->succ->succ_next) |
2432 | abort (); | |
5f0d2358 | 2433 | |
ca6c03ca JH |
2434 | bb->succ->probability = REG_BR_PROB_BASE; |
2435 | bb->succ->count = bb->count; | |
2436 | ||
c263766c RH |
2437 | if (dump_file) |
2438 | fprintf (dump_file, "Purged non-fallthru edges from bb %i\n", | |
0b17ab2f | 2439 | bb->index); |
ca6c03ca JH |
2440 | return purged; |
2441 | } | |
2442 | ||
5f0d2358 RK |
2443 | /* Search all basic blocks for potentially dead edges and purge them. Return |
2444 | true if some edge has been eliminated. */ | |
ca6c03ca JH |
2445 | |
2446 | bool | |
d329e058 | 2447 | purge_all_dead_edges (int update_life_p) |
ca6c03ca | 2448 | { |
e0082a72 | 2449 | int purged = false; |
710af899 | 2450 | sbitmap blocks = 0; |
e0082a72 | 2451 | basic_block bb; |
473fb060 JH |
2452 | |
2453 | if (update_life_p) | |
2454 | { | |
d55bc081 | 2455 | blocks = sbitmap_alloc (last_basic_block); |
473fb060 JH |
2456 | sbitmap_zero (blocks); |
2457 | } | |
5f0d2358 | 2458 | |
e0082a72 | 2459 | FOR_EACH_BB (bb) |
473fb060 | 2460 | { |
e0082a72 | 2461 | bool purged_here = purge_dead_edges (bb); |
5f0d2358 | 2462 | |
473fb060 JH |
2463 | purged |= purged_here; |
2464 | if (purged_here && update_life_p) | |
e0082a72 | 2465 | SET_BIT (blocks, bb->index); |
473fb060 | 2466 | } |
5f0d2358 | 2467 | |
473fb060 JH |
2468 | if (update_life_p && purged) |
2469 | update_life_info (blocks, UPDATE_LIFE_GLOBAL, | |
2470 | PROP_DEATH_NOTES | PROP_SCAN_DEAD_CODE | |
2471 | | PROP_KILL_DEAD_CODE); | |
5f0d2358 | 2472 | |
473fb060 JH |
2473 | if (update_life_p) |
2474 | sbitmap_free (blocks); | |
ca6c03ca JH |
2475 | return purged; |
2476 | } | |
9ee634e3 JH |
2477 | |
2478 | /* Same as split_block but update cfg_layout structures. */ | |
f470c378 ZD |
2479 | |
2480 | static basic_block | |
d329e058 | 2481 | cfg_layout_split_block (basic_block bb, void *insnp) |
9ee634e3 JH |
2482 | { |
2483 | rtx insn = insnp; | |
f470c378 | 2484 | basic_block new_bb = rtl_split_block (bb, insn); |
9ee634e3 | 2485 | |
f470c378 ZD |
2486 | new_bb->rbi->footer = bb->rbi->footer; |
2487 | bb->rbi->footer = NULL; | |
9ee634e3 | 2488 | |
f470c378 | 2489 | return new_bb; |
9ee634e3 JH |
2490 | } |
2491 | ||
2492 | ||
2493 | /* Redirect Edge to DEST. */ | |
6de9cd9a | 2494 | static edge |
d329e058 | 2495 | cfg_layout_redirect_edge_and_branch (edge e, basic_block dest) |
9ee634e3 JH |
2496 | { |
2497 | basic_block src = e->src; | |
6de9cd9a | 2498 | edge ret; |
9ee634e3 | 2499 | |
bc35512f | 2500 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
6de9cd9a | 2501 | return NULL; |
bc35512f | 2502 | |
3348b696 | 2503 | if (e->dest == dest) |
6de9cd9a | 2504 | return e; |
bc35512f | 2505 | |
3348b696 | 2506 | if (e->src != ENTRY_BLOCK_PTR |
6de9cd9a | 2507 | && (ret = try_redirect_by_replacing_jump (e, dest, true))) |
f345f21a JH |
2508 | { |
2509 | src->flags |= BB_DIRTY; | |
6de9cd9a | 2510 | return ret; |
f345f21a | 2511 | } |
bc35512f JH |
2512 | |
2513 | if (e->src == ENTRY_BLOCK_PTR | |
2514 | && (e->flags & EDGE_FALLTHRU) && !(e->flags & EDGE_COMPLEX)) | |
2515 | { | |
c263766c RH |
2516 | if (dump_file) |
2517 | fprintf (dump_file, "Redirecting entry edge from bb %i to %i\n", | |
bc35512f JH |
2518 | e->src->index, dest->index); |
2519 | ||
f345f21a | 2520 | e->src->flags |= BB_DIRTY; |
bc35512f | 2521 | redirect_edge_succ (e, dest); |
6de9cd9a | 2522 | return e; |
bc35512f JH |
2523 | } |
2524 | ||
9ee634e3 JH |
2525 | /* Redirect_edge_and_branch may decide to turn branch into fallthru edge |
2526 | in the case the basic block appears to be in sequence. Avoid this | |
2527 | transformation. */ | |
2528 | ||
9ee634e3 JH |
2529 | if (e->flags & EDGE_FALLTHRU) |
2530 | { | |
2531 | /* Redirect any branch edges unified with the fallthru one. */ | |
4b4bf941 | 2532 | if (JUMP_P (BB_END (src)) |
432f982f JH |
2533 | && label_is_jump_target_p (BB_HEAD (e->dest), |
2534 | BB_END (src))) | |
9ee634e3 | 2535 | { |
c263766c RH |
2536 | if (dump_file) |
2537 | fprintf (dump_file, "Fallthru edge unified with branch " | |
432f982f JH |
2538 | "%i->%i redirected to %i\n", |
2539 | e->src->index, e->dest->index, dest->index); | |
2540 | e->flags &= ~EDGE_FALLTHRU; | |
2541 | if (!redirect_branch_edge (e, dest)) | |
9ee634e3 | 2542 | abort (); |
432f982f | 2543 | e->flags |= EDGE_FALLTHRU; |
f345f21a | 2544 | e->src->flags |= BB_DIRTY; |
6de9cd9a | 2545 | return e; |
9ee634e3 JH |
2546 | } |
2547 | /* In case we are redirecting fallthru edge to the branch edge | |
2548 | of conditional jump, remove it. */ | |
2549 | if (src->succ->succ_next | |
2550 | && !src->succ->succ_next->succ_next) | |
2551 | { | |
2552 | edge s = e->succ_next ? e->succ_next : src->succ; | |
2553 | if (s->dest == dest | |
a813c111 SB |
2554 | && any_condjump_p (BB_END (src)) |
2555 | && onlyjump_p (BB_END (src))) | |
2556 | delete_insn (BB_END (src)); | |
9ee634e3 | 2557 | } |
6de9cd9a | 2558 | ret = redirect_edge_succ_nodup (e, dest); |
c263766c RH |
2559 | if (dump_file) |
2560 | fprintf (dump_file, "Fallthru edge %i->%i redirected to %i\n", | |
bc35512f | 2561 | e->src->index, e->dest->index, dest->index); |
9ee634e3 JH |
2562 | } |
2563 | else | |
bc35512f | 2564 | ret = redirect_branch_edge (e, dest); |
9ee634e3 JH |
2565 | |
2566 | /* We don't want simplejumps in the insn stream during cfglayout. */ | |
a813c111 | 2567 | if (simplejump_p (BB_END (src))) |
bc35512f | 2568 | abort (); |
9ee634e3 | 2569 | |
f345f21a | 2570 | src->flags |= BB_DIRTY; |
9ee634e3 JH |
2571 | return ret; |
2572 | } | |
2573 | ||
2574 | /* Simple wrapper as we always can redirect fallthru edges. */ | |
2575 | static basic_block | |
d329e058 | 2576 | cfg_layout_redirect_edge_and_branch_force (edge e, basic_block dest) |
9ee634e3 JH |
2577 | { |
2578 | if (!cfg_layout_redirect_edge_and_branch (e, dest)) | |
2579 | abort (); | |
2580 | return NULL; | |
2581 | } | |
2582 | ||
f470c378 ZD |
2583 | /* Same as delete_basic_block but update cfg_layout structures. */ |
2584 | ||
9ee634e3 | 2585 | static void |
d329e058 | 2586 | cfg_layout_delete_block (basic_block bb) |
9ee634e3 | 2587 | { |
a813c111 | 2588 | rtx insn, next, prev = PREV_INSN (BB_HEAD (bb)), *to, remaints; |
9ee634e3 | 2589 | |
bc35512f | 2590 | if (bb->rbi->header) |
9ee634e3 | 2591 | { |
a813c111 | 2592 | next = BB_HEAD (bb); |
9ee634e3 | 2593 | if (prev) |
bc35512f | 2594 | NEXT_INSN (prev) = bb->rbi->header; |
9ee634e3 | 2595 | else |
bc35512f JH |
2596 | set_first_insn (bb->rbi->header); |
2597 | PREV_INSN (bb->rbi->header) = prev; | |
2598 | insn = bb->rbi->header; | |
9ee634e3 JH |
2599 | while (NEXT_INSN (insn)) |
2600 | insn = NEXT_INSN (insn); | |
2601 | NEXT_INSN (insn) = next; | |
2602 | PREV_INSN (next) = insn; | |
2603 | } | |
a813c111 | 2604 | next = NEXT_INSN (BB_END (bb)); |
bc35512f | 2605 | if (bb->rbi->footer) |
9ee634e3 | 2606 | { |
bc35512f JH |
2607 | insn = bb->rbi->footer; |
2608 | while (insn) | |
2609 | { | |
4b4bf941 | 2610 | if (BARRIER_P (insn)) |
bc35512f JH |
2611 | { |
2612 | if (PREV_INSN (insn)) | |
2613 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
2614 | else | |
2615 | bb->rbi->footer = NEXT_INSN (insn); | |
2616 | if (NEXT_INSN (insn)) | |
2617 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
2618 | } | |
4b4bf941 | 2619 | if (LABEL_P (insn)) |
bc35512f JH |
2620 | break; |
2621 | insn = NEXT_INSN (insn); | |
2622 | } | |
2623 | if (bb->rbi->footer) | |
2624 | { | |
a813c111 | 2625 | insn = BB_END (bb); |
bc35512f JH |
2626 | NEXT_INSN (insn) = bb->rbi->footer; |
2627 | PREV_INSN (bb->rbi->footer) = insn; | |
2628 | while (NEXT_INSN (insn)) | |
2629 | insn = NEXT_INSN (insn); | |
2630 | NEXT_INSN (insn) = next; | |
2631 | if (next) | |
2632 | PREV_INSN (next) = insn; | |
2633 | else | |
2634 | set_last_insn (insn); | |
2635 | } | |
9ee634e3 JH |
2636 | } |
2637 | if (bb->next_bb != EXIT_BLOCK_PTR) | |
bc35512f | 2638 | to = &bb->next_bb->rbi->header; |
9ee634e3 JH |
2639 | else |
2640 | to = &cfg_layout_function_footer; | |
2641 | rtl_delete_block (bb); | |
2642 | ||
2643 | if (prev) | |
2644 | prev = NEXT_INSN (prev); | |
d329e058 | 2645 | else |
9ee634e3 JH |
2646 | prev = get_insns (); |
2647 | if (next) | |
2648 | next = PREV_INSN (next); | |
d329e058 | 2649 | else |
9ee634e3 JH |
2650 | next = get_last_insn (); |
2651 | ||
2652 | if (next && NEXT_INSN (next) != prev) | |
2653 | { | |
2654 | remaints = unlink_insn_chain (prev, next); | |
2655 | insn = remaints; | |
2656 | while (NEXT_INSN (insn)) | |
2657 | insn = NEXT_INSN (insn); | |
2658 | NEXT_INSN (insn) = *to; | |
2659 | if (*to) | |
2660 | PREV_INSN (*to) = insn; | |
2661 | *to = remaints; | |
2662 | } | |
2663 | } | |
2664 | ||
beb235f8 | 2665 | /* Return true when blocks A and B can be safely merged. */ |
bc35512f JH |
2666 | static bool |
2667 | cfg_layout_can_merge_blocks_p (basic_block a, basic_block b) | |
2668 | { | |
750054a2 CT |
2669 | /* If we are partitioning hot/cold basic blocks, we don't want to |
2670 | mess up unconditional or indirect jumps that cross between hot | |
076c7ab8 ZW |
2671 | and cold sections. |
2672 | ||
8e8d5162 CT |
2673 | Basic block partitioning may result in some jumps that appear to |
2674 | be optimizable (or blocks that appear to be mergeable), but which really | |
2675 | must be left untouched (they are required to make it safely across | |
2676 | partition boundaries). See the comments at the top of | |
2677 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ | |
2678 | ||
750054a2 CT |
2679 | if (flag_reorder_blocks_and_partition |
2680 | && (find_reg_note (BB_END (a), REG_CROSSING_JUMP, NULL_RTX) | |
2681 | || find_reg_note (BB_END (b), REG_CROSSING_JUMP, NULL_RTX) | |
076c7ab8 ZW |
2682 | || BB_PARTITION (a) != BB_PARTITION (b))) |
2683 | return false; | |
750054a2 | 2684 | |
bc35512f JH |
2685 | /* There must be exactly one edge in between the blocks. */ |
2686 | return (a->succ && !a->succ->succ_next && a->succ->dest == b | |
2687 | && !b->pred->pred_next && a != b | |
2688 | /* Must be simple edge. */ | |
2689 | && !(a->succ->flags & EDGE_COMPLEX) | |
2690 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR | |
2691 | /* If the jump insn has side effects, | |
2692 | we can't kill the edge. */ | |
4b4bf941 | 2693 | && (!JUMP_P (BB_END (a)) |
e24e7211 | 2694 | || (reload_completed |
a813c111 | 2695 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f JH |
2696 | } |
2697 | ||
2698 | /* Merge block A and B, abort when it is not possible. */ | |
2699 | static void | |
2700 | cfg_layout_merge_blocks (basic_block a, basic_block b) | |
2701 | { | |
2702 | #ifdef ENABLE_CHECKING | |
2703 | if (!cfg_layout_can_merge_blocks_p (a, b)) | |
2704 | abort (); | |
2705 | #endif | |
2706 | ||
2707 | /* If there was a CODE_LABEL beginning B, delete it. */ | |
4b4bf941 | 2708 | if (LABEL_P (BB_HEAD (b))) |
a813c111 | 2709 | delete_insn (BB_HEAD (b)); |
bc35512f JH |
2710 | |
2711 | /* We should have fallthru edge in a, or we can do dummy redirection to get | |
2712 | it cleaned up. */ | |
4b4bf941 | 2713 | if (JUMP_P (BB_END (a))) |
3348b696 | 2714 | try_redirect_by_replacing_jump (a->succ, b, true); |
4b4bf941 | 2715 | if (JUMP_P (BB_END (a))) |
bc35512f JH |
2716 | abort (); |
2717 | ||
2718 | /* Possible line number notes should appear in between. */ | |
2719 | if (b->rbi->header) | |
2720 | { | |
a813c111 | 2721 | rtx first = BB_END (a), last; |
bc35512f | 2722 | |
a813c111 | 2723 | last = emit_insn_after (b->rbi->header, BB_END (a)); |
bc35512f JH |
2724 | delete_insn_chain (NEXT_INSN (first), last); |
2725 | b->rbi->header = NULL; | |
2726 | } | |
2727 | ||
2728 | /* In the case basic blocks are not adjacent, move them around. */ | |
a813c111 | 2729 | if (NEXT_INSN (BB_END (a)) != BB_HEAD (b)) |
bc35512f | 2730 | { |
a813c111 | 2731 | rtx first = unlink_insn_chain (BB_HEAD (b), BB_END (b)); |
bc35512f | 2732 | |
a813c111 | 2733 | emit_insn_after (first, BB_END (a)); |
bc35512f JH |
2734 | /* Skip possible DELETED_LABEL insn. */ |
2735 | if (!NOTE_INSN_BASIC_BLOCK_P (first)) | |
2736 | first = NEXT_INSN (first); | |
2737 | if (!NOTE_INSN_BASIC_BLOCK_P (first)) | |
2738 | abort (); | |
a813c111 | 2739 | BB_HEAD (b) = NULL; |
bc35512f JH |
2740 | delete_insn (first); |
2741 | } | |
2742 | /* Otherwise just re-associate the instructions. */ | |
2743 | else | |
2744 | { | |
2745 | rtx insn; | |
2746 | ||
a813c111 SB |
2747 | for (insn = BB_HEAD (b); |
2748 | insn != NEXT_INSN (BB_END (b)); | |
2749 | insn = NEXT_INSN (insn)) | |
bc35512f | 2750 | set_block_for_insn (insn, a); |
a813c111 | 2751 | insn = BB_HEAD (b); |
bc35512f JH |
2752 | /* Skip possible DELETED_LABEL insn. */ |
2753 | if (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
2754 | insn = NEXT_INSN (insn); | |
2755 | if (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
2756 | abort (); | |
a813c111 SB |
2757 | BB_HEAD (b) = NULL; |
2758 | BB_END (a) = BB_END (b); | |
bc35512f JH |
2759 | delete_insn (insn); |
2760 | } | |
2761 | ||
2762 | /* Possible tablejumps and barriers should appear after the block. */ | |
2763 | if (b->rbi->footer) | |
2764 | { | |
2765 | if (!a->rbi->footer) | |
2766 | a->rbi->footer = b->rbi->footer; | |
2767 | else | |
2768 | { | |
2769 | rtx last = a->rbi->footer; | |
2770 | ||
2771 | while (NEXT_INSN (last)) | |
2772 | last = NEXT_INSN (last); | |
2773 | NEXT_INSN (last) = b->rbi->footer; | |
2774 | PREV_INSN (b->rbi->footer) = last; | |
2775 | } | |
2776 | b->rbi->footer = NULL; | |
2777 | } | |
2778 | ||
c263766c RH |
2779 | if (dump_file) |
2780 | fprintf (dump_file, "Merged blocks %d and %d.\n", | |
bc35512f | 2781 | a->index, b->index); |
bc35512f JH |
2782 | } |
2783 | ||
2784 | /* Split edge E. */ | |
f470c378 | 2785 | |
bc35512f JH |
2786 | static basic_block |
2787 | cfg_layout_split_edge (edge e) | |
2788 | { | |
2789 | edge new_e; | |
2790 | basic_block new_bb = | |
2791 | create_basic_block (e->src != ENTRY_BLOCK_PTR | |
a813c111 | 2792 | ? NEXT_INSN (BB_END (e->src)) : get_insns (), |
bc35512f JH |
2793 | NULL_RTX, e->src); |
2794 | ||
af874237 JW |
2795 | /* ??? This info is likely going to be out of date very soon, but we must |
2796 | create it to avoid getting an ICE later. */ | |
2797 | if (e->dest->global_live_at_start) | |
2798 | { | |
2799 | new_bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
2800 | new_bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
2801 | COPY_REG_SET (new_bb->global_live_at_start, | |
2802 | e->dest->global_live_at_start); | |
2803 | COPY_REG_SET (new_bb->global_live_at_end, | |
2804 | e->dest->global_live_at_start); | |
2805 | } | |
2806 | ||
bc35512f | 2807 | new_e = make_edge (new_bb, e->dest, EDGE_FALLTHRU); |
bc35512f JH |
2808 | redirect_edge_and_branch_force (e, new_bb); |
2809 | ||
2810 | return new_bb; | |
2811 | } | |
2812 | ||
f470c378 ZD |
2813 | /* Do postprocessing after making a forwarder block joined by edge FALLTHRU. */ |
2814 | ||
2815 | static void | |
2816 | rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED) | |
2817 | { | |
2818 | } | |
2819 | ||
6de9cd9a DN |
2820 | /* Return 1 if BB ends with a call, possibly followed by some |
2821 | instructions that must stay with the call, 0 otherwise. */ | |
2822 | ||
2823 | static bool | |
2824 | rtl_block_ends_with_call_p (basic_block bb) | |
2825 | { | |
2826 | rtx insn = BB_END (bb); | |
2827 | ||
4b4bf941 | 2828 | while (!CALL_P (insn) |
6de9cd9a DN |
2829 | && insn != BB_HEAD (bb) |
2830 | && keep_with_call_p (insn)) | |
2831 | insn = PREV_INSN (insn); | |
4b4bf941 | 2832 | return (CALL_P (insn)); |
6de9cd9a DN |
2833 | } |
2834 | ||
2835 | /* Return 1 if BB ends with a conditional branch, 0 otherwise. */ | |
2836 | ||
2837 | static bool | |
2838 | rtl_block_ends_with_condjump_p (basic_block bb) | |
2839 | { | |
2840 | return any_condjump_p (BB_END (bb)); | |
2841 | } | |
2842 | ||
2843 | /* Return true if we need to add fake edge to exit. | |
2844 | Helper function for rtl_flow_call_edges_add. */ | |
2845 | ||
2846 | static bool | |
2847 | need_fake_edge_p (rtx insn) | |
2848 | { | |
2849 | if (!INSN_P (insn)) | |
2850 | return false; | |
2851 | ||
4b4bf941 | 2852 | if ((CALL_P (insn) |
6de9cd9a DN |
2853 | && !SIBLING_CALL_P (insn) |
2854 | && !find_reg_note (insn, REG_NORETURN, NULL) | |
2855 | && !find_reg_note (insn, REG_ALWAYS_RETURN, NULL) | |
2856 | && !CONST_OR_PURE_CALL_P (insn))) | |
2857 | return true; | |
2858 | ||
2859 | return ((GET_CODE (PATTERN (insn)) == ASM_OPERANDS | |
2860 | && MEM_VOLATILE_P (PATTERN (insn))) | |
2861 | || (GET_CODE (PATTERN (insn)) == PARALLEL | |
2862 | && asm_noperands (insn) != -1 | |
2863 | && MEM_VOLATILE_P (XVECEXP (PATTERN (insn), 0, 0))) | |
2864 | || GET_CODE (PATTERN (insn)) == ASM_INPUT); | |
2865 | } | |
2866 | ||
2867 | /* Add fake edges to the function exit for any non constant and non noreturn | |
2868 | calls, volatile inline assembly in the bitmap of blocks specified by | |
2869 | BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks | |
2870 | that were split. | |
2871 | ||
2872 | The goal is to expose cases in which entering a basic block does not imply | |
2873 | that all subsequent instructions must be executed. */ | |
2874 | ||
2875 | static int | |
2876 | rtl_flow_call_edges_add (sbitmap blocks) | |
2877 | { | |
2878 | int i; | |
2879 | int blocks_split = 0; | |
2880 | int last_bb = last_basic_block; | |
2881 | bool check_last_block = false; | |
2882 | ||
2883 | if (n_basic_blocks == 0) | |
2884 | return 0; | |
2885 | ||
2886 | if (! blocks) | |
2887 | check_last_block = true; | |
2888 | else | |
2889 | check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index); | |
2890 | ||
2891 | /* In the last basic block, before epilogue generation, there will be | |
2892 | a fallthru edge to EXIT. Special care is required if the last insn | |
2893 | of the last basic block is a call because make_edge folds duplicate | |
2894 | edges, which would result in the fallthru edge also being marked | |
2895 | fake, which would result in the fallthru edge being removed by | |
2896 | remove_fake_edges, which would result in an invalid CFG. | |
2897 | ||
2898 | Moreover, we can't elide the outgoing fake edge, since the block | |
2899 | profiler needs to take this into account in order to solve the minimal | |
2900 | spanning tree in the case that the call doesn't return. | |
2901 | ||
2902 | Handle this by adding a dummy instruction in a new last basic block. */ | |
2903 | if (check_last_block) | |
2904 | { | |
2905 | basic_block bb = EXIT_BLOCK_PTR->prev_bb; | |
2906 | rtx insn = BB_END (bb); | |
2907 | ||
2908 | /* Back up past insns that must be kept in the same block as a call. */ | |
2909 | while (insn != BB_HEAD (bb) | |
2910 | && keep_with_call_p (insn)) | |
2911 | insn = PREV_INSN (insn); | |
2912 | ||
2913 | if (need_fake_edge_p (insn)) | |
2914 | { | |
2915 | edge e; | |
2916 | ||
2917 | for (e = bb->succ; e; e = e->succ_next) | |
2918 | if (e->dest == EXIT_BLOCK_PTR) | |
2919 | { | |
2920 | insert_insn_on_edge (gen_rtx_USE (VOIDmode, const0_rtx), e); | |
2921 | commit_edge_insertions (); | |
2922 | break; | |
2923 | } | |
2924 | } | |
2925 | } | |
2926 | ||
2927 | /* Now add fake edges to the function exit for any non constant | |
2928 | calls since there is no way that we can determine if they will | |
2929 | return or not... */ | |
2930 | ||
2931 | for (i = 0; i < last_bb; i++) | |
2932 | { | |
2933 | basic_block bb = BASIC_BLOCK (i); | |
2934 | rtx insn; | |
2935 | rtx prev_insn; | |
2936 | ||
2937 | if (!bb) | |
2938 | continue; | |
2939 | ||
2940 | if (blocks && !TEST_BIT (blocks, i)) | |
2941 | continue; | |
2942 | ||
2943 | for (insn = BB_END (bb); ; insn = prev_insn) | |
2944 | { | |
2945 | prev_insn = PREV_INSN (insn); | |
2946 | if (need_fake_edge_p (insn)) | |
2947 | { | |
2948 | edge e; | |
2949 | rtx split_at_insn = insn; | |
2950 | ||
2951 | /* Don't split the block between a call and an insn that should | |
2952 | remain in the same block as the call. */ | |
4b4bf941 | 2953 | if (CALL_P (insn)) |
6de9cd9a DN |
2954 | while (split_at_insn != BB_END (bb) |
2955 | && keep_with_call_p (NEXT_INSN (split_at_insn))) | |
2956 | split_at_insn = NEXT_INSN (split_at_insn); | |
2957 | ||
2958 | /* The handling above of the final block before the epilogue | |
2959 | should be enough to verify that there is no edge to the exit | |
2960 | block in CFG already. Calling make_edge in such case would | |
2961 | cause us to mark that edge as fake and remove it later. */ | |
2962 | ||
2963 | #ifdef ENABLE_CHECKING | |
2964 | if (split_at_insn == BB_END (bb)) | |
2965 | for (e = bb->succ; e; e = e->succ_next) | |
2966 | if (e->dest == EXIT_BLOCK_PTR) | |
2967 | abort (); | |
2968 | #endif | |
2969 | ||
2970 | /* Note that the following may create a new basic block | |
2971 | and renumber the existing basic blocks. */ | |
2972 | if (split_at_insn != BB_END (bb)) | |
2973 | { | |
2974 | e = split_block (bb, split_at_insn); | |
2975 | if (e) | |
2976 | blocks_split++; | |
2977 | } | |
2978 | ||
2979 | make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE); | |
2980 | } | |
2981 | ||
2982 | if (insn == BB_HEAD (bb)) | |
2983 | break; | |
2984 | } | |
2985 | } | |
2986 | ||
2987 | if (blocks_split) | |
2988 | verify_flow_info (); | |
2989 | ||
2990 | return blocks_split; | |
2991 | } | |
2992 | ||
9ee634e3 JH |
2993 | /* Implementation of CFG manipulation for linearized RTL. */ |
2994 | struct cfg_hooks rtl_cfg_hooks = { | |
f470c378 | 2995 | "rtl", |
9ee634e3 | 2996 | rtl_verify_flow_info, |
10e9fecc | 2997 | rtl_dump_bb, |
bc35512f | 2998 | rtl_create_basic_block, |
9ee634e3 JH |
2999 | rtl_redirect_edge_and_branch, |
3000 | rtl_redirect_edge_and_branch_force, | |
3001 | rtl_delete_block, | |
3002 | rtl_split_block, | |
f470c378 | 3003 | rtl_move_block_after, |
bc35512f JH |
3004 | rtl_can_merge_blocks, /* can_merge_blocks_p */ |
3005 | rtl_merge_blocks, | |
6de9cd9a DN |
3006 | rtl_predict_edge, |
3007 | rtl_predicted_by_p, | |
3008 | NULL, /* can_duplicate_block_p */ | |
3009 | NULL, /* duplicate_block */ | |
f470c378 ZD |
3010 | rtl_split_edge, |
3011 | rtl_make_forwarder_block, | |
6de9cd9a DN |
3012 | rtl_tidy_fallthru_edge, |
3013 | rtl_block_ends_with_call_p, | |
3014 | rtl_block_ends_with_condjump_p, | |
3015 | rtl_flow_call_edges_add | |
9ee634e3 JH |
3016 | }; |
3017 | ||
3018 | /* Implementation of CFG manipulation for cfg layout RTL, where | |
3019 | basic block connected via fallthru edges does not have to be adjacent. | |
3020 | This representation will hopefully become the default one in future | |
3021 | version of the compiler. */ | |
6de9cd9a DN |
3022 | |
3023 | /* We do not want to declare these functions in a header file, since they | |
3024 | should only be used through the cfghooks interface, and we do not want to | |
3025 | move them here since it would require also moving quite a lot of related | |
3026 | code. */ | |
3027 | extern bool cfg_layout_can_duplicate_bb_p (basic_block); | |
3028 | extern basic_block cfg_layout_duplicate_bb (basic_block); | |
3029 | ||
9ee634e3 | 3030 | struct cfg_hooks cfg_layout_rtl_cfg_hooks = { |
f470c378 | 3031 | "cfglayout mode", |
bc35512f | 3032 | rtl_verify_flow_info_1, |
10e9fecc | 3033 | rtl_dump_bb, |
bc35512f | 3034 | cfg_layout_create_basic_block, |
9ee634e3 JH |
3035 | cfg_layout_redirect_edge_and_branch, |
3036 | cfg_layout_redirect_edge_and_branch_force, | |
3037 | cfg_layout_delete_block, | |
3038 | cfg_layout_split_block, | |
f470c378 | 3039 | rtl_move_block_after, |
bc35512f JH |
3040 | cfg_layout_can_merge_blocks_p, |
3041 | cfg_layout_merge_blocks, | |
6de9cd9a DN |
3042 | rtl_predict_edge, |
3043 | rtl_predicted_by_p, | |
3044 | cfg_layout_can_duplicate_bb_p, | |
3045 | cfg_layout_duplicate_bb, | |
f470c378 ZD |
3046 | cfg_layout_split_edge, |
3047 | rtl_make_forwarder_block, | |
6de9cd9a DN |
3048 | NULL, |
3049 | rtl_block_ends_with_call_p, | |
3050 | rtl_block_ends_with_condjump_p, | |
3051 | rtl_flow_call_edges_add | |
9ee634e3 | 3052 | }; |
6de9cd9a | 3053 |