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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 | 141 | /* If this insn has already been deleted, something is very wrong. */ |
341c100f | 142 | gcc_assert (!INSN_DELETED_P (insn)); |
ca6c03ca JH |
143 | remove_insn (insn); |
144 | INSN_DELETED_P (insn) = 1; | |
145 | } | |
146 | ||
147 | /* If deleting a jump, decrement the use count of the label. Deleting | |
148 | the label itself should happen in the normal course of block merging. */ | |
4b4bf941 | 149 | if (JUMP_P (insn) |
ca6c03ca | 150 | && JUMP_LABEL (insn) |
4b4bf941 | 151 | && LABEL_P (JUMP_LABEL (insn))) |
ca6c03ca JH |
152 | LABEL_NUSES (JUMP_LABEL (insn))--; |
153 | ||
154 | /* Also if deleting an insn that references a label. */ | |
9295a326 JZ |
155 | else |
156 | { | |
157 | while ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)) != NULL_RTX | |
4b4bf941 | 158 | && LABEL_P (XEXP (note, 0))) |
9295a326 JZ |
159 | { |
160 | LABEL_NUSES (XEXP (note, 0))--; | |
161 | remove_note (insn, note); | |
162 | } | |
163 | } | |
ca6c03ca | 164 | |
4b4bf941 | 165 | if (JUMP_P (insn) |
ca6c03ca JH |
166 | && (GET_CODE (PATTERN (insn)) == ADDR_VEC |
167 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)) | |
168 | { | |
169 | rtx pat = PATTERN (insn); | |
170 | int diff_vec_p = GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC; | |
171 | int len = XVECLEN (pat, diff_vec_p); | |
172 | int i; | |
173 | ||
174 | for (i = 0; i < len; i++) | |
a124fcda RH |
175 | { |
176 | rtx label = XEXP (XVECEXP (pat, diff_vec_p, i), 0); | |
177 | ||
178 | /* When deleting code in bulk (e.g. removing many unreachable | |
179 | blocks) we can delete a label that's a target of the vector | |
180 | before deleting the vector itself. */ | |
4b4bf941 | 181 | if (!NOTE_P (label)) |
a124fcda RH |
182 | LABEL_NUSES (label)--; |
183 | } | |
ca6c03ca JH |
184 | } |
185 | ||
186 | return next; | |
187 | } | |
188 | ||
3dec4024 JH |
189 | /* Like delete_insn but also purge dead edges from BB. */ |
190 | rtx | |
d329e058 | 191 | delete_insn_and_edges (rtx insn) |
3dec4024 JH |
192 | { |
193 | rtx x; | |
194 | bool purge = false; | |
195 | ||
ba4f7968 | 196 | if (INSN_P (insn) |
3dec4024 | 197 | && BLOCK_FOR_INSN (insn) |
a813c111 | 198 | && BB_END (BLOCK_FOR_INSN (insn)) == insn) |
3dec4024 JH |
199 | purge = true; |
200 | x = delete_insn (insn); | |
201 | if (purge) | |
202 | purge_dead_edges (BLOCK_FOR_INSN (insn)); | |
203 | return x; | |
204 | } | |
205 | ||
ca6c03ca JH |
206 | /* Unlink a chain of insns between START and FINISH, leaving notes |
207 | that must be paired. */ | |
208 | ||
209 | void | |
d329e058 | 210 | delete_insn_chain (rtx start, rtx finish) |
ca6c03ca | 211 | { |
ca6c03ca JH |
212 | rtx next; |
213 | ||
5f0d2358 RK |
214 | /* Unchain the insns one by one. It would be quicker to delete all of these |
215 | with a single unchaining, rather than one at a time, but we need to keep | |
216 | the NOTE's. */ | |
ca6c03ca JH |
217 | while (1) |
218 | { | |
219 | next = NEXT_INSN (start); | |
4b4bf941 | 220 | if (NOTE_P (start) && !can_delete_note_p (start)) |
ca6c03ca JH |
221 | ; |
222 | else | |
223 | next = delete_insn (start); | |
224 | ||
225 | if (start == finish) | |
226 | break; | |
227 | start = next; | |
228 | } | |
229 | } | |
3dec4024 JH |
230 | |
231 | /* Like delete_insn but also purge dead edges from BB. */ | |
232 | void | |
d329e058 | 233 | delete_insn_chain_and_edges (rtx first, rtx last) |
3dec4024 JH |
234 | { |
235 | bool purge = false; | |
236 | ||
ba4f7968 | 237 | if (INSN_P (last) |
3dec4024 | 238 | && BLOCK_FOR_INSN (last) |
a813c111 | 239 | && BB_END (BLOCK_FOR_INSN (last)) == last) |
3dec4024 JH |
240 | purge = true; |
241 | delete_insn_chain (first, last); | |
242 | if (purge) | |
243 | purge_dead_edges (BLOCK_FOR_INSN (last)); | |
244 | } | |
ca6c03ca | 245 | \f |
5f0d2358 RK |
246 | /* Create a new basic block consisting of the instructions between HEAD and END |
247 | inclusive. This function is designed to allow fast BB construction - reuses | |
248 | the note and basic block struct in BB_NOTE, if any and do not grow | |
249 | BASIC_BLOCK chain and should be used directly only by CFG construction code. | |
250 | END can be NULL in to create new empty basic block before HEAD. Both END | |
918ed612 ZD |
251 | and HEAD can be NULL to create basic block at the end of INSN chain. |
252 | AFTER is the basic block we should be put after. */ | |
ca6c03ca JH |
253 | |
254 | basic_block | |
d329e058 | 255 | create_basic_block_structure (rtx head, rtx end, rtx bb_note, basic_block after) |
ca6c03ca JH |
256 | { |
257 | basic_block bb; | |
258 | ||
259 | if (bb_note | |
ca6c03ca JH |
260 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL |
261 | && bb->aux == NULL) | |
262 | { | |
263 | /* If we found an existing note, thread it back onto the chain. */ | |
264 | ||
265 | rtx after; | |
266 | ||
4b4bf941 | 267 | if (LABEL_P (head)) |
ca6c03ca JH |
268 | after = head; |
269 | else | |
270 | { | |
271 | after = PREV_INSN (head); | |
272 | head = bb_note; | |
273 | } | |
274 | ||
275 | if (after != bb_note && NEXT_INSN (after) != bb_note) | |
ba4f7968 | 276 | reorder_insns_nobb (bb_note, bb_note, after); |
ca6c03ca JH |
277 | } |
278 | else | |
279 | { | |
280 | /* Otherwise we must create a note and a basic block structure. */ | |
281 | ||
282 | bb = alloc_block (); | |
283 | ||
284 | if (!head && !end) | |
5f0d2358 RK |
285 | head = end = bb_note |
286 | = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); | |
4b4bf941 | 287 | else if (LABEL_P (head) && end) |
ca6c03ca JH |
288 | { |
289 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); | |
290 | if (head == end) | |
291 | end = bb_note; | |
292 | } | |
293 | else | |
294 | { | |
295 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); | |
296 | head = bb_note; | |
297 | if (!end) | |
298 | end = head; | |
299 | } | |
5f0d2358 | 300 | |
ca6c03ca JH |
301 | NOTE_BASIC_BLOCK (bb_note) = bb; |
302 | } | |
303 | ||
304 | /* Always include the bb note in the block. */ | |
305 | if (NEXT_INSN (end) == bb_note) | |
306 | end = bb_note; | |
307 | ||
a813c111 SB |
308 | BB_HEAD (bb) = head; |
309 | BB_END (bb) = end; | |
852c6ec7 | 310 | bb->index = last_basic_block++; |
38c1593d | 311 | bb->flags = BB_NEW; |
918ed612 | 312 | link_block (bb, after); |
852c6ec7 | 313 | BASIC_BLOCK (bb->index) = bb; |
ba4f7968 | 314 | update_bb_for_insn (bb); |
076c7ab8 | 315 | BB_SET_PARTITION (bb, BB_UNPARTITIONED); |
ca6c03ca JH |
316 | |
317 | /* Tag the block so that we know it has been used when considering | |
318 | other basic block notes. */ | |
319 | bb->aux = bb; | |
320 | ||
321 | return bb; | |
322 | } | |
323 | ||
5f0d2358 | 324 | /* Create new basic block consisting of instructions in between HEAD and END |
918ed612 | 325 | and place it to the BB chain after block AFTER. END can be NULL in to |
5f0d2358 RK |
326 | create new empty basic block before HEAD. Both END and HEAD can be NULL to |
327 | create basic block at the end of INSN chain. */ | |
ca6c03ca | 328 | |
bc35512f JH |
329 | static basic_block |
330 | rtl_create_basic_block (void *headp, void *endp, basic_block after) | |
ca6c03ca | 331 | { |
bc35512f | 332 | rtx head = headp, end = endp; |
ca6c03ca | 333 | basic_block bb; |
0b17ab2f | 334 | |
7eca0767 JH |
335 | /* Grow the basic block array if needed. */ |
336 | if ((size_t) last_basic_block >= VARRAY_SIZE (basic_block_info)) | |
337 | { | |
338 | size_t new_size = last_basic_block + (last_basic_block + 3) / 4; | |
339 | VARRAY_GROW (basic_block_info, new_size); | |
340 | } | |
0b17ab2f | 341 | |
bf77398c | 342 | n_basic_blocks++; |
ca6c03ca | 343 | |
852c6ec7 | 344 | bb = create_basic_block_structure (head, end, NULL, after); |
ca6c03ca JH |
345 | bb->aux = NULL; |
346 | return bb; | |
347 | } | |
bc35512f JH |
348 | |
349 | static basic_block | |
350 | cfg_layout_create_basic_block (void *head, void *end, basic_block after) | |
351 | { | |
352 | basic_block newbb = rtl_create_basic_block (head, end, after); | |
353 | ||
6de9cd9a | 354 | initialize_bb_rbi (newbb); |
bc35512f JH |
355 | return newbb; |
356 | } | |
ca6c03ca JH |
357 | \f |
358 | /* Delete the insns in a (non-live) block. We physically delete every | |
359 | non-deleted-note insn, and update the flow graph appropriately. | |
360 | ||
361 | Return nonzero if we deleted an exception handler. */ | |
362 | ||
363 | /* ??? Preserving all such notes strikes me as wrong. It would be nice | |
364 | to post-process the stream to remove empty blocks, loops, ranges, etc. */ | |
365 | ||
f0fda11c | 366 | static void |
d329e058 | 367 | rtl_delete_block (basic_block b) |
ca6c03ca | 368 | { |
ca6c03ca JH |
369 | rtx insn, end, tmp; |
370 | ||
371 | /* If the head of this block is a CODE_LABEL, then it might be the | |
372 | label for an exception handler which can't be reached. | |
373 | ||
374 | We need to remove the label from the exception_handler_label list | |
375 | and remove the associated NOTE_INSN_EH_REGION_BEG and | |
376 | NOTE_INSN_EH_REGION_END notes. */ | |
377 | ||
a813c111 | 378 | insn = BB_HEAD (b); |
ca6c03ca | 379 | |
4b4bf941 | 380 | if (LABEL_P (insn)) |
ca6c03ca JH |
381 | maybe_remove_eh_handler (insn); |
382 | ||
383 | /* Include any jump table following the basic block. */ | |
a813c111 | 384 | end = BB_END (b); |
e1233a7d | 385 | if (tablejump_p (end, NULL, &tmp)) |
ca6c03ca JH |
386 | end = tmp; |
387 | ||
388 | /* Include any barrier that may follow the basic block. */ | |
389 | tmp = next_nonnote_insn (end); | |
4b4bf941 | 390 | if (tmp && BARRIER_P (tmp)) |
ca6c03ca JH |
391 | end = tmp; |
392 | ||
393 | /* Selectively delete the entire chain. */ | |
a813c111 | 394 | BB_HEAD (b) = NULL; |
ca6c03ca | 395 | delete_insn_chain (insn, end); |
ca6c03ca JH |
396 | } |
397 | \f | |
852c6ec7 | 398 | /* Records the basic block struct in BLOCK_FOR_INSN for every insn. */ |
ca6c03ca JH |
399 | |
400 | void | |
d329e058 | 401 | compute_bb_for_insn (void) |
ca6c03ca | 402 | { |
e0082a72 | 403 | basic_block bb; |
ca6c03ca | 404 | |
e0082a72 | 405 | FOR_EACH_BB (bb) |
ca6c03ca | 406 | { |
a813c111 | 407 | rtx end = BB_END (bb); |
5f0d2358 | 408 | rtx insn; |
ca6c03ca | 409 | |
a813c111 | 410 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
ca6c03ca | 411 | { |
ba4f7968 | 412 | BLOCK_FOR_INSN (insn) = bb; |
ca6c03ca JH |
413 | if (insn == end) |
414 | break; | |
ca6c03ca JH |
415 | } |
416 | } | |
417 | } | |
418 | ||
419 | /* Release the basic_block_for_insn array. */ | |
420 | ||
421 | void | |
d329e058 | 422 | free_bb_for_insn (void) |
ca6c03ca | 423 | { |
ba4f7968 JH |
424 | rtx insn; |
425 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) | |
4b4bf941 | 426 | if (!BARRIER_P (insn)) |
ba4f7968 | 427 | BLOCK_FOR_INSN (insn) = NULL; |
ca6c03ca JH |
428 | } |
429 | ||
91278841 AP |
430 | /* Return RTX to emit after when we want to emit code on the entry of function. */ |
431 | rtx | |
432 | entry_of_function (void) | |
433 | { | |
434 | return (n_basic_blocks ? BB_HEAD (ENTRY_BLOCK_PTR->next_bb) : get_insns ()); | |
435 | } | |
436 | ||
ca6c03ca JH |
437 | /* Update insns block within BB. */ |
438 | ||
439 | void | |
d329e058 | 440 | update_bb_for_insn (basic_block bb) |
ca6c03ca JH |
441 | { |
442 | rtx insn; | |
443 | ||
a813c111 | 444 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
ca6c03ca | 445 | { |
4b4bf941 | 446 | if (!BARRIER_P (insn)) |
bcc53e2a | 447 | set_block_for_insn (insn, bb); |
a813c111 | 448 | if (insn == BB_END (bb)) |
ca6c03ca JH |
449 | break; |
450 | } | |
451 | } | |
ca6c03ca | 452 | \f |
f470c378 ZD |
453 | /* Creates a new basic block just after basic block B by splitting |
454 | everything after specified instruction I. */ | |
ca6c03ca | 455 | |
f470c378 | 456 | static basic_block |
d329e058 | 457 | rtl_split_block (basic_block bb, void *insnp) |
ca6c03ca JH |
458 | { |
459 | basic_block new_bb; | |
9ee634e3 | 460 | rtx insn = insnp; |
f470c378 | 461 | edge e; |
628f6a4e | 462 | edge_iterator ei; |
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. */ | |
628f6a4e BE |
486 | new_bb->succs = bb->succs; |
487 | bb->succs = NULL; | |
488 | FOR_EACH_EDGE (e, ei, new_bb->succs) | |
ca6c03ca JH |
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 | 628 | /* There must be exactly one edge in between the blocks. */ |
628f6a4e BE |
629 | return (EDGE_COUNT (a->succs) == 1 |
630 | && EDGE_SUCC (a, 0)->dest == b | |
631 | && EDGE_COUNT (b->preds) == 1 | |
632 | && a != b | |
bc35512f | 633 | /* Must be simple edge. */ |
628f6a4e | 634 | && !(EDGE_SUCC (a, 0)->flags & EDGE_COMPLEX) |
bc35512f JH |
635 | && a->next_bb == b |
636 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR | |
637 | /* If the jump insn has side effects, | |
638 | we can't kill the edge. */ | |
4b4bf941 | 639 | && (!JUMP_P (BB_END (a)) |
e24e7211 | 640 | || (reload_completed |
a813c111 | 641 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f | 642 | } |
ca6c03ca | 643 | \f |
5f0d2358 RK |
644 | /* Return the label in the head of basic block BLOCK. Create one if it doesn't |
645 | exist. */ | |
ca6c03ca JH |
646 | |
647 | rtx | |
d329e058 | 648 | block_label (basic_block block) |
ca6c03ca JH |
649 | { |
650 | if (block == EXIT_BLOCK_PTR) | |
651 | return NULL_RTX; | |
5f0d2358 | 652 | |
4b4bf941 | 653 | if (!LABEL_P (BB_HEAD (block))) |
ca6c03ca | 654 | { |
a813c111 | 655 | BB_HEAD (block) = emit_label_before (gen_label_rtx (), BB_HEAD (block)); |
ca6c03ca | 656 | } |
5f0d2358 | 657 | |
a813c111 | 658 | return BB_HEAD (block); |
ca6c03ca JH |
659 | } |
660 | ||
661 | /* Attempt to perform edge redirection by replacing possibly complex jump | |
5f0d2358 RK |
662 | instruction by unconditional jump or removing jump completely. This can |
663 | apply only if all edges now point to the same block. The parameters and | |
664 | return values are equivalent to redirect_edge_and_branch. */ | |
ca6c03ca | 665 | |
6de9cd9a | 666 | edge |
bc35512f | 667 | try_redirect_by_replacing_jump (edge e, basic_block target, bool in_cfglayout) |
ca6c03ca JH |
668 | { |
669 | basic_block src = e->src; | |
a813c111 | 670 | rtx insn = BB_END (src), kill_from; |
ca6c03ca | 671 | edge tmp; |
e1233a7d | 672 | rtx set; |
ca6c03ca | 673 | int fallthru = 0; |
628f6a4e | 674 | edge_iterator ei; |
750054a2 CT |
675 | |
676 | /* If we are partitioning hot/cold basic blocks, we don't want to | |
677 | mess up unconditional or indirect jumps that cross between hot | |
8e8d5162 CT |
678 | and cold sections. |
679 | ||
680 | Basic block partitioning may result in some jumps that appear to | |
681 | be optimizable (or blocks that appear to be mergeable), but which really | |
682 | must be left untouched (they are required to make it safely across | |
683 | partition boundaries). See the comments at the top of | |
684 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ | |
750054a2 CT |
685 | |
686 | if (flag_reorder_blocks_and_partition | |
9fb32434 | 687 | && (find_reg_note (insn, REG_CROSSING_JUMP, NULL_RTX) |
076c7ab8 | 688 | || BB_PARTITION (src) != BB_PARTITION (target))) |
9cf84a3c | 689 | return NULL; |
750054a2 | 690 | |
ca6c03ca | 691 | /* Verify that all targets will be TARGET. */ |
628f6a4e | 692 | FOR_EACH_EDGE (tmp, ei, src->succs) |
ca6c03ca JH |
693 | if (tmp->dest != target && tmp != e) |
694 | break; | |
5f0d2358 | 695 | |
ca6c03ca | 696 | if (tmp || !onlyjump_p (insn)) |
6de9cd9a | 697 | return NULL; |
3348b696 | 698 | if ((!optimize || reload_completed) && tablejump_p (insn, NULL, NULL)) |
6de9cd9a | 699 | return NULL; |
ca6c03ca JH |
700 | |
701 | /* Avoid removing branch with side effects. */ | |
702 | set = single_set (insn); | |
703 | if (!set || side_effects_p (set)) | |
6de9cd9a | 704 | return NULL; |
ca6c03ca JH |
705 | |
706 | /* In case we zap a conditional jump, we'll need to kill | |
707 | the cc0 setter too. */ | |
708 | kill_from = insn; | |
709 | #ifdef HAVE_cc0 | |
710 | if (reg_mentioned_p (cc0_rtx, PATTERN (insn))) | |
711 | kill_from = PREV_INSN (insn); | |
712 | #endif | |
713 | ||
714 | /* See if we can create the fallthru edge. */ | |
bc35512f | 715 | if (in_cfglayout || can_fallthru (src, target)) |
ca6c03ca | 716 | { |
c263766c RH |
717 | if (dump_file) |
718 | fprintf (dump_file, "Removing jump %i.\n", INSN_UID (insn)); | |
ca6c03ca JH |
719 | fallthru = 1; |
720 | ||
eaec9b3d | 721 | /* Selectively unlink whole insn chain. */ |
bc35512f JH |
722 | if (in_cfglayout) |
723 | { | |
724 | rtx insn = src->rbi->footer; | |
725 | ||
a813c111 | 726 | delete_insn_chain (kill_from, BB_END (src)); |
bc35512f JH |
727 | |
728 | /* Remove barriers but keep jumptables. */ | |
729 | while (insn) | |
730 | { | |
4b4bf941 | 731 | if (BARRIER_P (insn)) |
bc35512f JH |
732 | { |
733 | if (PREV_INSN (insn)) | |
734 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
735 | else | |
736 | src->rbi->footer = NEXT_INSN (insn); | |
737 | if (NEXT_INSN (insn)) | |
738 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
739 | } | |
4b4bf941 | 740 | if (LABEL_P (insn)) |
bc35512f JH |
741 | break; |
742 | insn = NEXT_INSN (insn); | |
743 | } | |
744 | } | |
745 | else | |
a813c111 | 746 | delete_insn_chain (kill_from, PREV_INSN (BB_HEAD (target))); |
ca6c03ca | 747 | } |
5f0d2358 | 748 | |
ca6c03ca JH |
749 | /* If this already is simplejump, redirect it. */ |
750 | else if (simplejump_p (insn)) | |
751 | { | |
752 | if (e->dest == target) | |
6de9cd9a | 753 | return NULL; |
c263766c RH |
754 | if (dump_file) |
755 | fprintf (dump_file, "Redirecting jump %i from %i to %i.\n", | |
0b17ab2f | 756 | INSN_UID (insn), e->dest->index, target->index); |
6ee3c8e4 JJ |
757 | if (!redirect_jump (insn, block_label (target), 0)) |
758 | { | |
341c100f NS |
759 | gcc_assert (target == EXIT_BLOCK_PTR); |
760 | return NULL; | |
6ee3c8e4 | 761 | } |
ca6c03ca | 762 | } |
5f0d2358 | 763 | |
6ee3c8e4 JJ |
764 | /* Cannot do anything for target exit block. */ |
765 | else if (target == EXIT_BLOCK_PTR) | |
6de9cd9a | 766 | return NULL; |
6ee3c8e4 | 767 | |
ca6c03ca JH |
768 | /* Or replace possibly complicated jump insn by simple jump insn. */ |
769 | else | |
770 | { | |
771 | rtx target_label = block_label (target); | |
eb5b8ad4 | 772 | rtx barrier, label, table; |
ca6c03ca | 773 | |
a7102479 | 774 | emit_jump_insn_after_noloc (gen_jump (target_label), insn); |
a813c111 | 775 | JUMP_LABEL (BB_END (src)) = target_label; |
ca6c03ca | 776 | LABEL_NUSES (target_label)++; |
c263766c RH |
777 | if (dump_file) |
778 | fprintf (dump_file, "Replacing insn %i by jump %i\n", | |
a813c111 | 779 | INSN_UID (insn), INSN_UID (BB_END (src))); |
ca6c03ca | 780 | |
4da2eb6b | 781 | |
ca6c03ca JH |
782 | delete_insn_chain (kill_from, insn); |
783 | ||
4da2eb6b RH |
784 | /* Recognize a tablejump that we are converting to a |
785 | simple jump and remove its associated CODE_LABEL | |
786 | and ADDR_VEC or ADDR_DIFF_VEC. */ | |
3348b696 | 787 | if (tablejump_p (insn, &label, &table)) |
4da2eb6b | 788 | delete_insn_chain (label, table); |
eb5b8ad4 | 789 | |
a813c111 | 790 | barrier = next_nonnote_insn (BB_END (src)); |
4b4bf941 | 791 | if (!barrier || !BARRIER_P (barrier)) |
a813c111 | 792 | emit_barrier_after (BB_END (src)); |
5d693491 JZ |
793 | else |
794 | { | |
a813c111 | 795 | if (barrier != NEXT_INSN (BB_END (src))) |
5d693491 JZ |
796 | { |
797 | /* Move the jump before barrier so that the notes | |
798 | which originally were or were created before jump table are | |
799 | inside the basic block. */ | |
a813c111 | 800 | rtx new_insn = BB_END (src); |
5d693491 JZ |
801 | rtx tmp; |
802 | ||
a813c111 | 803 | for (tmp = NEXT_INSN (BB_END (src)); tmp != barrier; |
5d693491 JZ |
804 | tmp = NEXT_INSN (tmp)) |
805 | set_block_for_insn (tmp, src); | |
806 | ||
807 | NEXT_INSN (PREV_INSN (new_insn)) = NEXT_INSN (new_insn); | |
808 | PREV_INSN (NEXT_INSN (new_insn)) = PREV_INSN (new_insn); | |
809 | ||
810 | NEXT_INSN (new_insn) = barrier; | |
811 | NEXT_INSN (PREV_INSN (barrier)) = new_insn; | |
812 | ||
813 | PREV_INSN (new_insn) = PREV_INSN (barrier); | |
814 | PREV_INSN (barrier) = new_insn; | |
815 | } | |
816 | } | |
ca6c03ca JH |
817 | } |
818 | ||
819 | /* Keep only one edge out and set proper flags. */ | |
628f6a4e BE |
820 | while (EDGE_COUNT (src->succs) > 1) |
821 | remove_edge (e); | |
822 | ||
823 | e = EDGE_SUCC (src, 0); | |
ca6c03ca JH |
824 | if (fallthru) |
825 | e->flags = EDGE_FALLTHRU; | |
826 | else | |
827 | e->flags = 0; | |
5f0d2358 | 828 | |
ca6c03ca JH |
829 | e->probability = REG_BR_PROB_BASE; |
830 | e->count = src->count; | |
831 | ||
832 | /* We don't want a block to end on a line-number note since that has | |
833 | the potential of changing the code between -g and not -g. */ | |
4b4bf941 | 834 | while (NOTE_P (BB_END (e->src)) |
a813c111 SB |
835 | && NOTE_LINE_NUMBER (BB_END (e->src)) >= 0) |
836 | delete_insn (BB_END (e->src)); | |
ca6c03ca JH |
837 | |
838 | if (e->dest != target) | |
839 | redirect_edge_succ (e, target); | |
5f0d2358 | 840 | |
6de9cd9a | 841 | return e; |
ca6c03ca JH |
842 | } |
843 | ||
844 | /* Return last loop_beg note appearing after INSN, before start of next | |
845 | basic block. Return INSN if there are no such notes. | |
846 | ||
09da1532 | 847 | When emitting jump to redirect a fallthru edge, it should always appear |
5f0d2358 RK |
848 | after the LOOP_BEG notes, as loop optimizer expect loop to either start by |
849 | fallthru edge or jump following the LOOP_BEG note jumping to the loop exit | |
850 | test. */ | |
ca6c03ca JH |
851 | |
852 | static rtx | |
d329e058 | 853 | last_loop_beg_note (rtx insn) |
ca6c03ca JH |
854 | { |
855 | rtx last = insn; | |
5f0d2358 | 856 | |
4b4bf941 | 857 | for (insn = NEXT_INSN (insn); insn && NOTE_P (insn) |
5f0d2358 RK |
858 | && NOTE_LINE_NUMBER (insn) != NOTE_INSN_BASIC_BLOCK; |
859 | insn = NEXT_INSN (insn)) | |
860 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
861 | last = insn; | |
862 | ||
ca6c03ca JH |
863 | return last; |
864 | } | |
865 | ||
6de9cd9a DN |
866 | /* Redirect edge representing branch of (un)conditional jump or tablejump, |
867 | NULL on failure */ | |
868 | static edge | |
bc35512f | 869 | redirect_branch_edge (edge e, basic_block target) |
ca6c03ca JH |
870 | { |
871 | rtx tmp; | |
a813c111 | 872 | rtx old_label = BB_HEAD (e->dest); |
ca6c03ca | 873 | basic_block src = e->src; |
a813c111 | 874 | rtx insn = BB_END (src); |
ca6c03ca | 875 | |
ca6c03ca JH |
876 | /* We can only redirect non-fallthru edges of jump insn. */ |
877 | if (e->flags & EDGE_FALLTHRU) | |
6de9cd9a | 878 | return NULL; |
4b4bf941 | 879 | else if (!JUMP_P (insn)) |
6de9cd9a | 880 | return NULL; |
ca6c03ca JH |
881 | |
882 | /* Recognize a tablejump and adjust all matching cases. */ | |
e1233a7d | 883 | if (tablejump_p (insn, NULL, &tmp)) |
ca6c03ca JH |
884 | { |
885 | rtvec vec; | |
886 | int j; | |
887 | rtx new_label = block_label (target); | |
888 | ||
6ee3c8e4 | 889 | if (target == EXIT_BLOCK_PTR) |
6de9cd9a | 890 | return NULL; |
ca6c03ca JH |
891 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) |
892 | vec = XVEC (PATTERN (tmp), 0); | |
893 | else | |
894 | vec = XVEC (PATTERN (tmp), 1); | |
895 | ||
896 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
897 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
898 | { | |
899 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (Pmode, new_label); | |
900 | --LABEL_NUSES (old_label); | |
901 | ++LABEL_NUSES (new_label); | |
902 | } | |
903 | ||
f9da5064 | 904 | /* Handle casesi dispatch insns. */ |
ca6c03ca JH |
905 | if ((tmp = single_set (insn)) != NULL |
906 | && SET_DEST (tmp) == pc_rtx | |
907 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
908 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF | |
909 | && XEXP (XEXP (SET_SRC (tmp), 2), 0) == old_label) | |
910 | { | |
911 | XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (VOIDmode, | |
912 | new_label); | |
913 | --LABEL_NUSES (old_label); | |
914 | ++LABEL_NUSES (new_label); | |
915 | } | |
916 | } | |
917 | else | |
918 | { | |
919 | /* ?? We may play the games with moving the named labels from | |
920 | one basic block to the other in case only one computed_jump is | |
921 | available. */ | |
5f0d2358 RK |
922 | if (computed_jump_p (insn) |
923 | /* A return instruction can't be redirected. */ | |
924 | || returnjump_p (insn)) | |
6de9cd9a | 925 | return NULL; |
ca6c03ca JH |
926 | |
927 | /* If the insn doesn't go where we think, we're confused. */ | |
341c100f | 928 | gcc_assert (JUMP_LABEL (insn) == old_label); |
6ee3c8e4 JJ |
929 | |
930 | /* If the substitution doesn't succeed, die. This can happen | |
931 | if the back end emitted unrecognizable instructions or if | |
932 | target is exit block on some arches. */ | |
933 | if (!redirect_jump (insn, block_label (target), 0)) | |
934 | { | |
341c100f NS |
935 | gcc_assert (target == EXIT_BLOCK_PTR); |
936 | return NULL; | |
6ee3c8e4 | 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); |
341c100f | 1009 | bool redirected; |
cb9a1d9b | 1010 | |
341c100f NS |
1011 | redirected = redirect_jump (BB_END (e->src), block_label (target), 0); |
1012 | gcc_assert (redirected); | |
1013 | ||
a813c111 | 1014 | note = find_reg_note (BB_END (e->src), REG_BR_PROB, NULL_RTX); |
cb9a1d9b JH |
1015 | if (note) |
1016 | { | |
1017 | int prob = INTVAL (XEXP (note, 0)); | |
1018 | ||
1019 | b->probability = prob; | |
1020 | b->count = e->count * prob / REG_BR_PROB_BASE; | |
1021 | e->probability -= e->probability; | |
1022 | e->count -= b->count; | |
1023 | if (e->probability < 0) | |
1024 | e->probability = 0; | |
1025 | if (e->count < 0) | |
1026 | e->count = 0; | |
1027 | } | |
1028 | } | |
1029 | ||
ca6c03ca | 1030 | if (e->flags & EDGE_ABNORMAL) |
a3716585 JH |
1031 | { |
1032 | /* Irritating special case - fallthru edge to the same block as abnormal | |
1033 | edge. | |
1034 | We can't redirect abnormal edge, but we still can split the fallthru | |
d329e058 | 1035 | one and create separate abnormal edge to original destination. |
a3716585 | 1036 | This allows bb-reorder to make such edge non-fallthru. */ |
341c100f | 1037 | gcc_assert (e->dest == target); |
a3716585 JH |
1038 | abnormal_edge_flags = e->flags & ~(EDGE_FALLTHRU | EDGE_CAN_FALLTHRU); |
1039 | e->flags &= EDGE_FALLTHRU | EDGE_CAN_FALLTHRU; | |
1040 | } | |
341c100f | 1041 | else |
24c545ff | 1042 | { |
341c100f NS |
1043 | gcc_assert (e->flags & EDGE_FALLTHRU); |
1044 | if (e->src == ENTRY_BLOCK_PTR) | |
1045 | { | |
1046 | /* We can't redirect the entry block. Create an empty block | |
628f6a4e BE |
1047 | at the start of the function which we use to add the new |
1048 | jump. */ | |
1049 | edge tmp; | |
1050 | edge_iterator ei; | |
1051 | bool found = false; | |
1052 | ||
1053 | basic_block bb = create_basic_block (BB_HEAD (e->dest), NULL, ENTRY_BLOCK_PTR); | |
1054 | ||
341c100f NS |
1055 | /* Change the existing edge's source to be the new block, and add |
1056 | a new edge from the entry block to the new block. */ | |
1057 | e->src = bb; | |
628f6a4e BE |
1058 | for (ei = ei_start (ENTRY_BLOCK_PTR->succs); (tmp = ei_safe_edge (ei)); ) |
1059 | { | |
1060 | if (tmp == e) | |
1061 | { | |
1062 | VEC_ordered_remove (edge, ENTRY_BLOCK_PTR->succs, ei.index); | |
1063 | found = true; | |
1064 | break; | |
1065 | } | |
1066 | else | |
1067 | ei_next (&ei); | |
1068 | } | |
1069 | ||
1070 | gcc_assert (found); | |
1071 | ||
1072 | VEC_safe_insert (edge, bb->succs, 0, e); | |
341c100f NS |
1073 | make_single_succ_edge (ENTRY_BLOCK_PTR, bb, EDGE_FALLTHRU); |
1074 | } | |
24c545ff BS |
1075 | } |
1076 | ||
628f6a4e | 1077 | if (EDGE_COUNT (e->src->succs) >= 2 || abnormal_edge_flags) |
ca6c03ca JH |
1078 | { |
1079 | /* Create the new structures. */ | |
31a78298 | 1080 | |
79019985 RH |
1081 | /* If the old block ended with a tablejump, skip its table |
1082 | by searching forward from there. Otherwise start searching | |
1083 | forward from the last instruction of the old block. */ | |
a813c111 SB |
1084 | if (!tablejump_p (BB_END (e->src), NULL, ¬e)) |
1085 | note = BB_END (e->src); | |
79019985 | 1086 | |
31a78298 | 1087 | /* Position the new block correctly relative to loop notes. */ |
79019985 | 1088 | note = last_loop_beg_note (note); |
31a78298 RH |
1089 | note = NEXT_INSN (note); |
1090 | ||
31a78298 | 1091 | jump_block = create_basic_block (note, NULL, e->src); |
ca6c03ca JH |
1092 | jump_block->count = e->count; |
1093 | jump_block->frequency = EDGE_FREQUENCY (e); | |
1094 | jump_block->loop_depth = target->loop_depth; | |
1095 | ||
1096 | if (target->global_live_at_start) | |
1097 | { | |
5f0d2358 RK |
1098 | jump_block->global_live_at_start |
1099 | = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
1100 | jump_block->global_live_at_end | |
1101 | = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
ca6c03ca JH |
1102 | COPY_REG_SET (jump_block->global_live_at_start, |
1103 | target->global_live_at_start); | |
1104 | COPY_REG_SET (jump_block->global_live_at_end, | |
1105 | target->global_live_at_start); | |
1106 | } | |
1107 | ||
750054a2 CT |
1108 | /* Make sure new block ends up in correct hot/cold section. */ |
1109 | ||
076c7ab8 | 1110 | BB_COPY_PARTITION (jump_block, e->src); |
9fb32434 CT |
1111 | if (flag_reorder_blocks_and_partition |
1112 | && targetm.have_named_sections) | |
750054a2 | 1113 | { |
076c7ab8 | 1114 | if (BB_PARTITION (jump_block) == BB_COLD_PARTITION) |
750054a2 CT |
1115 | { |
1116 | rtx bb_note, new_note; | |
1117 | for (bb_note = BB_HEAD (jump_block); | |
1118 | bb_note && bb_note != NEXT_INSN (BB_END (jump_block)); | |
1119 | bb_note = NEXT_INSN (bb_note)) | |
4b4bf941 | 1120 | if (NOTE_P (bb_note) |
750054a2 CT |
1121 | && NOTE_LINE_NUMBER (bb_note) == NOTE_INSN_BASIC_BLOCK) |
1122 | break; | |
1123 | new_note = emit_note_after (NOTE_INSN_UNLIKELY_EXECUTED_CODE, | |
1124 | bb_note); | |
1125 | NOTE_BASIC_BLOCK (new_note) = jump_block; | |
750054a2 | 1126 | } |
4b4bf941 | 1127 | if (JUMP_P (BB_END (jump_block)) |
750054a2 | 1128 | && !any_condjump_p (BB_END (jump_block)) |
628f6a4e | 1129 | && (EDGE_SUCC (jump_block, 0)->flags & EDGE_CROSSING)) |
750054a2 CT |
1130 | REG_NOTES (BB_END (jump_block)) = gen_rtx_EXPR_LIST |
1131 | (REG_CROSSING_JUMP, NULL_RTX, | |
1132 | REG_NOTES (BB_END (jump_block))); | |
1133 | } | |
1134 | ||
ca6c03ca JH |
1135 | /* Wire edge in. */ |
1136 | new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU); | |
1137 | new_edge->probability = e->probability; | |
1138 | new_edge->count = e->count; | |
1139 | ||
1140 | /* Redirect old edge. */ | |
1141 | redirect_edge_pred (e, jump_block); | |
1142 | e->probability = REG_BR_PROB_BASE; | |
1143 | ||
1144 | new_bb = jump_block; | |
1145 | } | |
1146 | else | |
1147 | jump_block = e->src; | |
5f0d2358 | 1148 | |
ca6c03ca JH |
1149 | e->flags &= ~EDGE_FALLTHRU; |
1150 | if (target == EXIT_BLOCK_PTR) | |
1151 | { | |
cf22ce3c | 1152 | #ifdef HAVE_return |
a7102479 | 1153 | emit_jump_insn_after_noloc (gen_return (), BB_END (jump_block)); |
cf22ce3c | 1154 | #else |
341c100f | 1155 | gcc_unreachable (); |
cf22ce3c | 1156 | #endif |
ca6c03ca JH |
1157 | } |
1158 | else | |
1159 | { | |
1160 | rtx label = block_label (target); | |
a7102479 | 1161 | emit_jump_insn_after_noloc (gen_jump (label), BB_END (jump_block)); |
a813c111 | 1162 | JUMP_LABEL (BB_END (jump_block)) = label; |
ca6c03ca JH |
1163 | LABEL_NUSES (label)++; |
1164 | } | |
5f0d2358 | 1165 | |
a813c111 | 1166 | emit_barrier_after (BB_END (jump_block)); |
ca6c03ca JH |
1167 | redirect_edge_succ_nodup (e, target); |
1168 | ||
a3716585 JH |
1169 | if (abnormal_edge_flags) |
1170 | make_edge (src, target, abnormal_edge_flags); | |
1171 | ||
ca6c03ca JH |
1172 | return new_bb; |
1173 | } | |
1174 | ||
1175 | /* Edge E is assumed to be fallthru edge. Emit needed jump instruction | |
1176 | (and possibly create new basic block) to make edge non-fallthru. | |
1177 | Return newly created BB or NULL if none. */ | |
5f0d2358 | 1178 | |
ca6c03ca | 1179 | basic_block |
d329e058 | 1180 | force_nonfallthru (edge e) |
ca6c03ca JH |
1181 | { |
1182 | return force_nonfallthru_and_redirect (e, e->dest); | |
1183 | } | |
1184 | ||
1185 | /* Redirect edge even at the expense of creating new jump insn or | |
1186 | basic block. Return new basic block if created, NULL otherwise. | |
eaec9b3d | 1187 | Abort if conversion is impossible. */ |
ca6c03ca | 1188 | |
9ee634e3 | 1189 | static basic_block |
d329e058 | 1190 | rtl_redirect_edge_and_branch_force (edge e, basic_block target) |
ca6c03ca | 1191 | { |
5f0d2358 RK |
1192 | if (redirect_edge_and_branch (e, target) |
1193 | || e->dest == target) | |
ca6c03ca JH |
1194 | return NULL; |
1195 | ||
1196 | /* In case the edge redirection failed, try to force it to be non-fallthru | |
1197 | and redirect newly created simplejump. */ | |
5f0d2358 | 1198 | return force_nonfallthru_and_redirect (e, target); |
ca6c03ca JH |
1199 | } |
1200 | ||
1201 | /* The given edge should potentially be a fallthru edge. If that is in | |
1202 | fact true, delete the jump and barriers that are in the way. */ | |
1203 | ||
f470c378 ZD |
1204 | static void |
1205 | rtl_tidy_fallthru_edge (edge e) | |
ca6c03ca JH |
1206 | { |
1207 | rtx q; | |
f470c378 | 1208 | basic_block b = e->src, c = b->next_bb; |
628f6a4e BE |
1209 | edge e2; |
1210 | edge_iterator ei; | |
1211 | ||
1212 | FOR_EACH_EDGE (e2, ei, b->succs) | |
1213 | if (e == e2) | |
1214 | break; | |
f470c378 | 1215 | |
ca6c03ca JH |
1216 | /* ??? In a late-running flow pass, other folks may have deleted basic |
1217 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
1218 | and the target label. They ought to be chastized and fixed. | |
1219 | ||
1220 | We can also wind up with a sequence of undeletable labels between | |
1221 | one block and the next. | |
1222 | ||
1223 | So search through a sequence of barriers, labels, and notes for | |
1224 | the head of block C and assert that we really do fall through. */ | |
1225 | ||
a813c111 | 1226 | for (q = NEXT_INSN (BB_END (b)); q != BB_HEAD (c); q = NEXT_INSN (q)) |
9c0a0632 RH |
1227 | if (INSN_P (q)) |
1228 | return; | |
ca6c03ca JH |
1229 | |
1230 | /* Remove what will soon cease being the jump insn from the source block. | |
1231 | If block B consisted only of this single jump, turn it into a deleted | |
1232 | note. */ | |
a813c111 | 1233 | q = BB_END (b); |
4b4bf941 | 1234 | if (JUMP_P (q) |
ca6c03ca JH |
1235 | && onlyjump_p (q) |
1236 | && (any_uncondjump_p (q) | |
628f6a4e | 1237 | || (EDGE_SUCC (b, 0) == e && ei.index == EDGE_COUNT (b->succs) - 1))) |
ca6c03ca JH |
1238 | { |
1239 | #ifdef HAVE_cc0 | |
1240 | /* If this was a conditional jump, we need to also delete | |
1241 | the insn that set cc0. */ | |
1242 | if (any_condjump_p (q) && only_sets_cc0_p (PREV_INSN (q))) | |
1243 | q = PREV_INSN (q); | |
1244 | #endif | |
1245 | ||
1246 | q = PREV_INSN (q); | |
1247 | ||
1248 | /* We don't want a block to end on a line-number note since that has | |
1249 | the potential of changing the code between -g and not -g. */ | |
4b4bf941 | 1250 | while (NOTE_P (q) && NOTE_LINE_NUMBER (q) >= 0) |
ca6c03ca JH |
1251 | q = PREV_INSN (q); |
1252 | } | |
1253 | ||
1254 | /* Selectively unlink the sequence. */ | |
a813c111 SB |
1255 | if (q != PREV_INSN (BB_HEAD (c))) |
1256 | delete_insn_chain (NEXT_INSN (q), PREV_INSN (BB_HEAD (c))); | |
ca6c03ca JH |
1257 | |
1258 | e->flags |= EDGE_FALLTHRU; | |
1259 | } | |
ca6c03ca JH |
1260 | \f |
1261 | /* Helper function for split_edge. Return true in case edge BB2 to BB1 | |
1262 | is back edge of syntactic loop. */ | |
1263 | ||
1264 | static bool | |
d329e058 | 1265 | back_edge_of_syntactic_loop_p (basic_block bb1, basic_block bb2) |
ca6c03ca JH |
1266 | { |
1267 | rtx insn; | |
1268 | int count = 0; | |
bf77398c | 1269 | basic_block bb; |
ca6c03ca | 1270 | |
bf77398c | 1271 | if (bb1 == bb2) |
0b17ab2f | 1272 | return true; |
355e4ec4 | 1273 | |
bf77398c ZD |
1274 | /* ??? Could we guarantee that bb indices are monotone, so that we could |
1275 | just compare them? */ | |
1276 | for (bb = bb1; bb && bb != bb2; bb = bb->next_bb) | |
1277 | continue; | |
1278 | ||
1279 | if (!bb) | |
1280 | return false; | |
1281 | ||
a813c111 | 1282 | for (insn = BB_END (bb1); insn != BB_HEAD (bb2) && count >= 0; |
ca6c03ca | 1283 | insn = NEXT_INSN (insn)) |
4b4bf941 | 1284 | if (NOTE_P (insn)) |
ca6c03ca JH |
1285 | { |
1286 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
1287 | count++; | |
5f0d2358 | 1288 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) |
ca6c03ca JH |
1289 | count--; |
1290 | } | |
1291 | ||
1292 | return count >= 0; | |
1293 | } | |
1294 | ||
f470c378 ZD |
1295 | /* Should move basic block BB after basic block AFTER. NIY. */ |
1296 | ||
1297 | static bool | |
1298 | rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED, | |
1299 | basic_block after ATTRIBUTE_UNUSED) | |
1300 | { | |
1301 | return false; | |
1302 | } | |
1303 | ||
ca6c03ca JH |
1304 | /* Split a (typically critical) edge. Return the new block. |
1305 | Abort on abnormal edges. | |
1306 | ||
1307 | ??? The code generally expects to be called on critical edges. | |
1308 | The case of a block ending in an unconditional jump to a | |
1309 | block with multiple predecessors is not handled optimally. */ | |
1310 | ||
8ce33230 | 1311 | static basic_block |
d329e058 | 1312 | rtl_split_edge (edge edge_in) |
ca6c03ca JH |
1313 | { |
1314 | basic_block bb; | |
ca6c03ca JH |
1315 | rtx before; |
1316 | ||
1317 | /* Abnormal edges cannot be split. */ | |
341c100f | 1318 | gcc_assert (!(edge_in->flags & EDGE_ABNORMAL)); |
ca6c03ca JH |
1319 | |
1320 | /* We are going to place the new block in front of edge destination. | |
eaec9b3d | 1321 | Avoid existence of fallthru predecessors. */ |
ca6c03ca JH |
1322 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) |
1323 | { | |
1324 | edge e; | |
628f6a4e | 1325 | edge_iterator ei; |
5f0d2358 | 1326 | |
628f6a4e | 1327 | FOR_EACH_EDGE (e, ei, edge_in->dest->preds) |
ca6c03ca JH |
1328 | if (e->flags & EDGE_FALLTHRU) |
1329 | break; | |
1330 | ||
1331 | if (e) | |
1332 | force_nonfallthru (e); | |
1333 | } | |
1334 | ||
1335 | /* Create the basic block note. | |
1336 | ||
f63d1bf7 | 1337 | Where we place the note can have a noticeable impact on the generated |
ca6c03ca JH |
1338 | code. Consider this cfg: |
1339 | ||
1340 | E | |
1341 | | | |
1342 | 0 | |
1343 | / \ | |
1344 | +->1-->2--->E | |
1345 | | | | |
1346 | +--+ | |
1347 | ||
1348 | If we need to insert an insn on the edge from block 0 to block 1, | |
1349 | we want to ensure the instructions we insert are outside of any | |
1350 | loop notes that physically sit between block 0 and block 1. Otherwise | |
1351 | we confuse the loop optimizer into thinking the loop is a phony. */ | |
1352 | ||
1353 | if (edge_in->dest != EXIT_BLOCK_PTR | |
a813c111 | 1354 | && PREV_INSN (BB_HEAD (edge_in->dest)) |
4b4bf941 | 1355 | && NOTE_P (PREV_INSN (BB_HEAD (edge_in->dest))) |
a813c111 | 1356 | && (NOTE_LINE_NUMBER (PREV_INSN (BB_HEAD (edge_in->dest))) |
5f0d2358 | 1357 | == NOTE_INSN_LOOP_BEG) |
ca6c03ca | 1358 | && !back_edge_of_syntactic_loop_p (edge_in->dest, edge_in->src)) |
a813c111 | 1359 | before = PREV_INSN (BB_HEAD (edge_in->dest)); |
ca6c03ca | 1360 | else if (edge_in->dest != EXIT_BLOCK_PTR) |
a813c111 | 1361 | before = BB_HEAD (edge_in->dest); |
ca6c03ca JH |
1362 | else |
1363 | before = NULL_RTX; | |
1364 | ||
623a66fa R |
1365 | /* If this is a fall through edge to the exit block, the blocks might be |
1366 | not adjacent, and the right place is the after the source. */ | |
1367 | if (edge_in->flags & EDGE_FALLTHRU && edge_in->dest == EXIT_BLOCK_PTR) | |
1368 | { | |
1369 | before = NEXT_INSN (BB_END (edge_in->src)); | |
1370 | if (before | |
4b4bf941 | 1371 | && NOTE_P (before) |
623a66fa R |
1372 | && NOTE_LINE_NUMBER (before) == NOTE_INSN_LOOP_END) |
1373 | before = NEXT_INSN (before); | |
1374 | bb = create_basic_block (before, NULL, edge_in->src); | |
076c7ab8 | 1375 | BB_COPY_PARTITION (bb, edge_in->src); |
623a66fa R |
1376 | } |
1377 | else | |
9fb32434 CT |
1378 | { |
1379 | bb = create_basic_block (before, NULL, edge_in->dest->prev_bb); | |
076c7ab8 ZW |
1380 | /* ??? Why not edge_in->dest->prev_bb here? */ |
1381 | BB_COPY_PARTITION (bb, edge_in->dest); | |
9fb32434 | 1382 | } |
ca6c03ca JH |
1383 | |
1384 | /* ??? This info is likely going to be out of date very soon. */ | |
1385 | if (edge_in->dest->global_live_at_start) | |
1386 | { | |
1387 | bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
1388 | bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
5f0d2358 RK |
1389 | COPY_REG_SET (bb->global_live_at_start, |
1390 | edge_in->dest->global_live_at_start); | |
1391 | COPY_REG_SET (bb->global_live_at_end, | |
1392 | edge_in->dest->global_live_at_start); | |
ca6c03ca JH |
1393 | } |
1394 | ||
4977bab6 | 1395 | make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU); |
ca6c03ca | 1396 | |
4d6922ee | 1397 | /* For non-fallthru edges, we must adjust the predecessor's |
ca6c03ca JH |
1398 | jump instruction to target our new block. */ |
1399 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1400 | { | |
341c100f NS |
1401 | edge redirected = redirect_edge_and_branch (edge_in, bb); |
1402 | gcc_assert (redirected); | |
ca6c03ca JH |
1403 | } |
1404 | else | |
1405 | redirect_edge_succ (edge_in, bb); | |
1406 | ||
1407 | return bb; | |
1408 | } | |
1409 | ||
1410 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1411 | The new instructions and basic blocks (if any) will not appear in the | |
1412 | CFG until commit_edge_insertions is called. */ | |
1413 | ||
1414 | void | |
d329e058 | 1415 | insert_insn_on_edge (rtx pattern, edge e) |
ca6c03ca JH |
1416 | { |
1417 | /* We cannot insert instructions on an abnormal critical edge. | |
1418 | It will be easier to find the culprit if we die now. */ | |
341c100f | 1419 | gcc_assert (!((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e))); |
ca6c03ca | 1420 | |
6de9cd9a | 1421 | if (e->insns.r == NULL_RTX) |
ca6c03ca JH |
1422 | start_sequence (); |
1423 | else | |
6de9cd9a | 1424 | push_to_sequence (e->insns.r); |
ca6c03ca JH |
1425 | |
1426 | emit_insn (pattern); | |
1427 | ||
6de9cd9a | 1428 | e->insns.r = get_insns (); |
ca6c03ca JH |
1429 | end_sequence (); |
1430 | } | |
1431 | ||
ff25ef99 ZD |
1432 | /* Called from safe_insert_insn_on_edge through note_stores, marks live |
1433 | registers that are killed by the store. */ | |
1434 | static void | |
1435 | mark_killed_regs (rtx reg, rtx set ATTRIBUTE_UNUSED, void *data) | |
1436 | { | |
1437 | regset killed = data; | |
1438 | int regno, i; | |
1439 | ||
1440 | if (GET_CODE (reg) == SUBREG) | |
1441 | reg = SUBREG_REG (reg); | |
1442 | if (!REG_P (reg)) | |
1443 | return; | |
1444 | regno = REGNO (reg); | |
1445 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1446 | SET_REGNO_REG_SET (killed, regno); | |
1447 | else | |
1448 | { | |
66fd46b6 | 1449 | for (i = 0; i < (int) hard_regno_nregs[regno][GET_MODE (reg)]; i++) |
ff25ef99 ZD |
1450 | SET_REGNO_REG_SET (killed, regno + i); |
1451 | } | |
1452 | } | |
1453 | ||
1454 | /* Similar to insert_insn_on_edge, tries to put INSN to edge E. Additionally | |
1455 | it checks whether this will not clobber the registers that are live on the | |
e0bb17a8 | 1456 | edge (i.e. it requires liveness information to be up-to-date) and if there |
ff25ef99 | 1457 | are some, then it tries to save and restore them. Returns true if |
e0bb17a8 | 1458 | successful. */ |
ff25ef99 ZD |
1459 | bool |
1460 | safe_insert_insn_on_edge (rtx insn, edge e) | |
1461 | { | |
1462 | rtx x; | |
1463 | regset_head killed_head; | |
1464 | regset killed = INITIALIZE_REG_SET (killed_head); | |
1465 | rtx save_regs = NULL_RTX; | |
1466 | int regno, noccmode; | |
1467 | enum machine_mode mode; | |
a2041967 | 1468 | reg_set_iterator rsi; |
ff25ef99 ZD |
1469 | |
1470 | #ifdef AVOID_CCMODE_COPIES | |
1471 | noccmode = true; | |
1472 | #else | |
1473 | noccmode = false; | |
1474 | #endif | |
1475 | ||
1476 | for (x = insn; x; x = NEXT_INSN (x)) | |
1477 | if (INSN_P (x)) | |
1478 | note_stores (PATTERN (x), mark_killed_regs, killed); | |
1479 | bitmap_operation (killed, killed, e->dest->global_live_at_start, | |
1480 | BITMAP_AND); | |
1481 | ||
a2041967 | 1482 | EXECUTE_IF_SET_IN_REG_SET (killed, 0, regno, rsi) |
ff25ef99 ZD |
1483 | { |
1484 | mode = regno < FIRST_PSEUDO_REGISTER | |
1485 | ? reg_raw_mode[regno] | |
1486 | : GET_MODE (regno_reg_rtx[regno]); | |
1487 | if (mode == VOIDmode) | |
1488 | return false; | |
1489 | ||
1490 | if (noccmode && mode == CCmode) | |
1491 | return false; | |
1492 | ||
1493 | save_regs = alloc_EXPR_LIST (0, | |
1494 | alloc_EXPR_LIST (0, | |
1495 | gen_reg_rtx (mode), | |
1496 | gen_raw_REG (mode, regno)), | |
1497 | save_regs); | |
a2041967 | 1498 | } |
ff25ef99 ZD |
1499 | |
1500 | if (save_regs) | |
1501 | { | |
1502 | rtx from, to; | |
1503 | ||
1504 | start_sequence (); | |
1505 | for (x = save_regs; x; x = XEXP (x, 1)) | |
1506 | { | |
1507 | from = XEXP (XEXP (x, 0), 1); | |
1508 | to = XEXP (XEXP (x, 0), 0); | |
1509 | emit_move_insn (to, from); | |
1510 | } | |
1511 | emit_insn (insn); | |
1512 | for (x = save_regs; x; x = XEXP (x, 1)) | |
1513 | { | |
1514 | from = XEXP (XEXP (x, 0), 0); | |
1515 | to = XEXP (XEXP (x, 0), 1); | |
1516 | emit_move_insn (to, from); | |
1517 | } | |
1518 | insn = get_insns (); | |
1519 | end_sequence (); | |
1520 | free_EXPR_LIST_list (&save_regs); | |
1521 | } | |
1522 | insert_insn_on_edge (insn, e); | |
1523 | ||
1524 | FREE_REG_SET (killed); | |
1525 | return true; | |
1526 | } | |
1527 | ||
ca6c03ca JH |
1528 | /* Update the CFG for the instructions queued on edge E. */ |
1529 | ||
1530 | static void | |
d329e058 | 1531 | commit_one_edge_insertion (edge e, int watch_calls) |
ca6c03ca JH |
1532 | { |
1533 | rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last; | |
eae4bc56 | 1534 | basic_block bb = NULL; |
ca6c03ca JH |
1535 | |
1536 | /* Pull the insns off the edge now since the edge might go away. */ | |
6de9cd9a DN |
1537 | insns = e->insns.r; |
1538 | e->insns.r = NULL_RTX; | |
ca6c03ca | 1539 | |
3dec4024 JH |
1540 | /* Special case -- avoid inserting code between call and storing |
1541 | its return value. */ | |
628f6a4e BE |
1542 | if (watch_calls && (e->flags & EDGE_FALLTHRU) |
1543 | && EDGE_COUNT (e->dest->preds) == 1 | |
3dec4024 | 1544 | && e->src != ENTRY_BLOCK_PTR |
4b4bf941 | 1545 | && CALL_P (BB_END (e->src))) |
ca6c03ca | 1546 | { |
a813c111 | 1547 | rtx next = next_nonnote_insn (BB_END (e->src)); |
ca6c03ca | 1548 | |
a813c111 | 1549 | after = BB_HEAD (e->dest); |
3dec4024 JH |
1550 | /* The first insn after the call may be a stack pop, skip it. */ |
1551 | while (next | |
1552 | && keep_with_call_p (next)) | |
f87c27b4 KH |
1553 | { |
1554 | after = next; | |
3dec4024 JH |
1555 | next = next_nonnote_insn (next); |
1556 | } | |
1557 | bb = e->dest; | |
ca6c03ca | 1558 | } |
3dec4024 | 1559 | if (!before && !after) |
ca6c03ca | 1560 | { |
3dec4024 JH |
1561 | /* Figure out where to put these things. If the destination has |
1562 | one predecessor, insert there. Except for the exit block. */ | |
628f6a4e | 1563 | if (EDGE_COUNT (e->dest->preds) == 1 && e->dest != EXIT_BLOCK_PTR) |
ca6c03ca | 1564 | { |
3dec4024 JH |
1565 | bb = e->dest; |
1566 | ||
1567 | /* Get the location correct wrt a code label, and "nice" wrt | |
1568 | a basic block note, and before everything else. */ | |
a813c111 | 1569 | tmp = BB_HEAD (bb); |
4b4bf941 | 1570 | if (LABEL_P (tmp)) |
3dec4024 JH |
1571 | tmp = NEXT_INSN (tmp); |
1572 | if (NOTE_INSN_BASIC_BLOCK_P (tmp)) | |
1573 | tmp = NEXT_INSN (tmp); | |
750054a2 | 1574 | if (tmp |
4b4bf941 | 1575 | && NOTE_P (tmp) |
750054a2 CT |
1576 | && NOTE_LINE_NUMBER (tmp) == NOTE_INSN_UNLIKELY_EXECUTED_CODE) |
1577 | tmp = NEXT_INSN (tmp); | |
a813c111 | 1578 | if (tmp == BB_HEAD (bb)) |
3dec4024 JH |
1579 | before = tmp; |
1580 | else if (tmp) | |
1581 | after = PREV_INSN (tmp); | |
1582 | else | |
1583 | after = get_last_insn (); | |
1584 | } | |
1585 | ||
1586 | /* If the source has one successor and the edge is not abnormal, | |
1587 | insert there. Except for the entry block. */ | |
1588 | else if ((e->flags & EDGE_ABNORMAL) == 0 | |
628f6a4e | 1589 | && EDGE_COUNT (e->src->succs) == 1 |
3dec4024 JH |
1590 | && e->src != ENTRY_BLOCK_PTR) |
1591 | { | |
1592 | bb = e->src; | |
1593 | ||
1594 | /* It is possible to have a non-simple jump here. Consider a target | |
1595 | where some forms of unconditional jumps clobber a register. This | |
1596 | happens on the fr30 for example. | |
1597 | ||
1598 | We know this block has a single successor, so we can just emit | |
1599 | the queued insns before the jump. */ | |
4b4bf941 | 1600 | if (JUMP_P (BB_END (bb))) |
a813c111 | 1601 | for (before = BB_END (bb); |
4b4bf941 | 1602 | NOTE_P (PREV_INSN (before)) |
3dec4024 JH |
1603 | && NOTE_LINE_NUMBER (PREV_INSN (before)) == |
1604 | NOTE_INSN_LOOP_BEG; before = PREV_INSN (before)) | |
1605 | ; | |
1606 | else | |
1607 | { | |
341c100f NS |
1608 | /* We'd better be fallthru, or we've lost track of |
1609 | what's what. */ | |
1610 | gcc_assert (e->flags & EDGE_FALLTHRU); | |
ca6c03ca | 1611 | |
a813c111 | 1612 | after = BB_END (bb); |
3dec4024 JH |
1613 | } |
1614 | } | |
1615 | /* Otherwise we must split the edge. */ | |
1616 | else | |
1617 | { | |
1618 | bb = split_edge (e); | |
a813c111 | 1619 | after = BB_END (bb); |
750054a2 | 1620 | |
750054a2 | 1621 | if (flag_reorder_blocks_and_partition |
9fb32434 | 1622 | && targetm.have_named_sections |
750054a2 | 1623 | && e->src != ENTRY_BLOCK_PTR |
076c7ab8 | 1624 | && BB_PARTITION (e->src) == BB_COLD_PARTITION |
bd454efd | 1625 | && !(e->flags & EDGE_CROSSING)) |
750054a2 CT |
1626 | { |
1627 | rtx bb_note, new_note, cur_insn; | |
1628 | ||
1629 | bb_note = NULL_RTX; | |
1630 | for (cur_insn = BB_HEAD (bb); cur_insn != NEXT_INSN (BB_END (bb)); | |
1631 | cur_insn = NEXT_INSN (cur_insn)) | |
4b4bf941 | 1632 | if (NOTE_P (cur_insn) |
750054a2 CT |
1633 | && NOTE_LINE_NUMBER (cur_insn) == NOTE_INSN_BASIC_BLOCK) |
1634 | { | |
1635 | bb_note = cur_insn; | |
1636 | break; | |
1637 | } | |
1638 | ||
1639 | new_note = emit_note_after (NOTE_INSN_UNLIKELY_EXECUTED_CODE, | |
1640 | bb_note); | |
1641 | NOTE_BASIC_BLOCK (new_note) = bb; | |
4b4bf941 | 1642 | if (JUMP_P (BB_END (bb)) |
750054a2 | 1643 | && !any_condjump_p (BB_END (bb)) |
628f6a4e | 1644 | && (EDGE_SUCC (bb, 0)->flags & EDGE_CROSSING)) |
750054a2 CT |
1645 | REG_NOTES (BB_END (bb)) = gen_rtx_EXPR_LIST |
1646 | (REG_CROSSING_JUMP, NULL_RTX, REG_NOTES (BB_END (bb))); | |
1647 | if (after == bb_note) | |
1648 | after = new_note; | |
1649 | } | |
ca6c03ca JH |
1650 | } |
1651 | } | |
1652 | ||
ca6c03ca JH |
1653 | /* Now that we've found the spot, do the insertion. */ |
1654 | ||
1655 | if (before) | |
1656 | { | |
a7102479 | 1657 | emit_insn_before_noloc (insns, before); |
ca6c03ca JH |
1658 | last = prev_nonnote_insn (before); |
1659 | } | |
1660 | else | |
a7102479 | 1661 | last = emit_insn_after_noloc (insns, after); |
ca6c03ca JH |
1662 | |
1663 | if (returnjump_p (last)) | |
1664 | { | |
1665 | /* ??? Remove all outgoing edges from BB and add one for EXIT. | |
1666 | This is not currently a problem because this only happens | |
3dec4024 JH |
1667 | for the (single) epilogue, which already has a fallthru edge |
1668 | to EXIT. */ | |
ca6c03ca | 1669 | |
628f6a4e | 1670 | e = EDGE_SUCC (bb, 0); |
341c100f | 1671 | gcc_assert (e->dest == EXIT_BLOCK_PTR |
628f6a4e | 1672 | && EDGE_COUNT (bb->succs) == 1 && (e->flags & EDGE_FALLTHRU)); |
ca6c03ca | 1673 | |
5f0d2358 | 1674 | e->flags &= ~EDGE_FALLTHRU; |
ca6c03ca | 1675 | emit_barrier_after (last); |
0b17ab2f | 1676 | |
ca6c03ca JH |
1677 | if (before) |
1678 | delete_insn (before); | |
1679 | } | |
341c100f NS |
1680 | else |
1681 | gcc_assert (!JUMP_P (last)); | |
5f0d2358 | 1682 | |
9dca2ad5 JH |
1683 | /* Mark the basic block for find_sub_basic_blocks. */ |
1684 | bb->aux = &bb->aux; | |
ca6c03ca JH |
1685 | } |
1686 | ||
1687 | /* Update the CFG for all queued instructions. */ | |
1688 | ||
1689 | void | |
d329e058 | 1690 | commit_edge_insertions (void) |
ca6c03ca | 1691 | { |
ca6c03ca | 1692 | basic_block bb; |
9dca2ad5 | 1693 | sbitmap blocks; |
9809a362 | 1694 | bool changed = false; |
ca6c03ca JH |
1695 | |
1696 | #ifdef ENABLE_CHECKING | |
1697 | verify_flow_info (); | |
1698 | #endif | |
1699 | ||
e0082a72 | 1700 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
ca6c03ca | 1701 | { |
628f6a4e BE |
1702 | edge e; |
1703 | edge_iterator ei; | |
ca6c03ca | 1704 | |
628f6a4e BE |
1705 | FOR_EACH_EDGE (e, ei, bb->succs) |
1706 | if (e->insns.r) | |
1707 | { | |
1708 | changed = true; | |
1709 | commit_one_edge_insertion (e, false); | |
1710 | } | |
3dec4024 | 1711 | } |
9dca2ad5 | 1712 | |
9809a362 JH |
1713 | if (!changed) |
1714 | return; | |
1715 | ||
9dca2ad5 JH |
1716 | blocks = sbitmap_alloc (last_basic_block); |
1717 | sbitmap_zero (blocks); | |
1718 | FOR_EACH_BB (bb) | |
1719 | if (bb->aux) | |
1720 | { | |
1721 | SET_BIT (blocks, bb->index); | |
1722 | /* Check for forgotten bb->aux values before commit_edge_insertions | |
1723 | call. */ | |
341c100f | 1724 | gcc_assert (bb->aux == &bb->aux); |
9dca2ad5 JH |
1725 | bb->aux = NULL; |
1726 | } | |
1727 | find_many_sub_basic_blocks (blocks); | |
1728 | sbitmap_free (blocks); | |
3dec4024 JH |
1729 | } |
1730 | \f | |
1731 | /* Update the CFG for all queued instructions, taking special care of inserting | |
1732 | code on edges between call and storing its return value. */ | |
1733 | ||
1734 | void | |
d329e058 | 1735 | commit_edge_insertions_watch_calls (void) |
3dec4024 | 1736 | { |
3dec4024 | 1737 | basic_block bb; |
9809a362 JH |
1738 | sbitmap blocks; |
1739 | bool changed = false; | |
3dec4024 JH |
1740 | |
1741 | #ifdef ENABLE_CHECKING | |
1742 | verify_flow_info (); | |
1743 | #endif | |
1744 | ||
e0082a72 | 1745 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
3dec4024 | 1746 | { |
628f6a4e BE |
1747 | edge e; |
1748 | edge_iterator ei; | |
3dec4024 | 1749 | |
628f6a4e BE |
1750 | FOR_EACH_EDGE (e, ei, bb->succs) |
1751 | if (e->insns.r) | |
1752 | { | |
1753 | changed = true; | |
1754 | commit_one_edge_insertion (e, true); | |
1755 | } | |
ca6c03ca | 1756 | } |
9809a362 JH |
1757 | |
1758 | if (!changed) | |
1759 | return; | |
1760 | ||
1761 | blocks = sbitmap_alloc (last_basic_block); | |
1762 | sbitmap_zero (blocks); | |
1763 | FOR_EACH_BB (bb) | |
1764 | if (bb->aux) | |
1765 | { | |
1766 | SET_BIT (blocks, bb->index); | |
1767 | /* Check for forgotten bb->aux values before commit_edge_insertions | |
1768 | call. */ | |
341c100f | 1769 | gcc_assert (bb->aux == &bb->aux); |
9809a362 JH |
1770 | bb->aux = NULL; |
1771 | } | |
1772 | find_many_sub_basic_blocks (blocks); | |
1773 | sbitmap_free (blocks); | |
ca6c03ca JH |
1774 | } |
1775 | \f | |
f470c378 ZD |
1776 | /* Print out RTL-specific basic block information (live information |
1777 | at start and end). */ | |
ca6c03ca | 1778 | |
10e9fecc | 1779 | static void |
f470c378 | 1780 | rtl_dump_bb (basic_block bb, FILE *outf, int indent) |
ca6c03ca JH |
1781 | { |
1782 | rtx insn; | |
1783 | rtx last; | |
f470c378 | 1784 | char *s_indent; |
ca6c03ca | 1785 | |
400e39e3 KH |
1786 | s_indent = alloca ((size_t) indent + 1); |
1787 | memset (s_indent, ' ', (size_t) indent); | |
f470c378 ZD |
1788 | s_indent[indent] = '\0'; |
1789 | ||
1790 | fprintf (outf, ";;%s Registers live at start: ", s_indent); | |
ca6c03ca JH |
1791 | dump_regset (bb->global_live_at_start, outf); |
1792 | putc ('\n', outf); | |
1793 | ||
a813c111 | 1794 | for (insn = BB_HEAD (bb), last = NEXT_INSN (BB_END (bb)); insn != last; |
ca6c03ca JH |
1795 | insn = NEXT_INSN (insn)) |
1796 | print_rtl_single (outf, insn); | |
1797 | ||
f470c378 | 1798 | fprintf (outf, ";;%s Registers live at end: ", s_indent); |
ca6c03ca JH |
1799 | dump_regset (bb->global_live_at_end, outf); |
1800 | putc ('\n', outf); | |
ca6c03ca JH |
1801 | } |
1802 | \f | |
1803 | /* Like print_rtl, but also print out live information for the start of each | |
1804 | basic block. */ | |
1805 | ||
1806 | void | |
d329e058 | 1807 | print_rtl_with_bb (FILE *outf, rtx rtx_first) |
ca6c03ca | 1808 | { |
b3694847 | 1809 | rtx tmp_rtx; |
ca6c03ca JH |
1810 | |
1811 | if (rtx_first == 0) | |
1812 | fprintf (outf, "(nil)\n"); | |
1813 | else | |
1814 | { | |
ca6c03ca JH |
1815 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
1816 | int max_uid = get_max_uid (); | |
703ad42b KG |
1817 | basic_block *start = xcalloc (max_uid, sizeof (basic_block)); |
1818 | basic_block *end = xcalloc (max_uid, sizeof (basic_block)); | |
1819 | enum bb_state *in_bb_p = xcalloc (max_uid, sizeof (enum bb_state)); | |
ca6c03ca | 1820 | |
e0082a72 ZD |
1821 | basic_block bb; |
1822 | ||
1823 | FOR_EACH_BB_REVERSE (bb) | |
ca6c03ca | 1824 | { |
ca6c03ca JH |
1825 | rtx x; |
1826 | ||
a813c111 SB |
1827 | start[INSN_UID (BB_HEAD (bb))] = bb; |
1828 | end[INSN_UID (BB_END (bb))] = bb; | |
1829 | for (x = BB_HEAD (bb); x != NULL_RTX; x = NEXT_INSN (x)) | |
ca6c03ca JH |
1830 | { |
1831 | enum bb_state state = IN_MULTIPLE_BB; | |
5f0d2358 | 1832 | |
ca6c03ca JH |
1833 | if (in_bb_p[INSN_UID (x)] == NOT_IN_BB) |
1834 | state = IN_ONE_BB; | |
1835 | in_bb_p[INSN_UID (x)] = state; | |
1836 | ||
a813c111 | 1837 | if (x == BB_END (bb)) |
ca6c03ca JH |
1838 | break; |
1839 | } | |
1840 | } | |
1841 | ||
1842 | for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) | |
1843 | { | |
1844 | int did_output; | |
ca6c03ca JH |
1845 | |
1846 | if ((bb = start[INSN_UID (tmp_rtx)]) != NULL) | |
1847 | { | |
1848 | fprintf (outf, ";; Start of basic block %d, registers live:", | |
0b17ab2f | 1849 | bb->index); |
ca6c03ca JH |
1850 | dump_regset (bb->global_live_at_start, outf); |
1851 | putc ('\n', outf); | |
1852 | } | |
1853 | ||
1854 | if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB | |
4b4bf941 JQ |
1855 | && !NOTE_P (tmp_rtx) |
1856 | && !BARRIER_P (tmp_rtx)) | |
ca6c03ca JH |
1857 | fprintf (outf, ";; Insn is not within a basic block\n"); |
1858 | else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB) | |
1859 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); | |
1860 | ||
1861 | did_output = print_rtl_single (outf, tmp_rtx); | |
1862 | ||
1863 | if ((bb = end[INSN_UID (tmp_rtx)]) != NULL) | |
1864 | { | |
1865 | fprintf (outf, ";; End of basic block %d, registers live:\n", | |
0b17ab2f | 1866 | bb->index); |
ca6c03ca JH |
1867 | dump_regset (bb->global_live_at_end, outf); |
1868 | putc ('\n', outf); | |
1869 | } | |
1870 | ||
1871 | if (did_output) | |
1872 | putc ('\n', outf); | |
1873 | } | |
1874 | ||
1875 | free (start); | |
1876 | free (end); | |
1877 | free (in_bb_p); | |
1878 | } | |
1879 | ||
1880 | if (current_function_epilogue_delay_list != 0) | |
1881 | { | |
1882 | fprintf (outf, "\n;; Insns in epilogue delay list:\n\n"); | |
1883 | for (tmp_rtx = current_function_epilogue_delay_list; tmp_rtx != 0; | |
1884 | tmp_rtx = XEXP (tmp_rtx, 1)) | |
1885 | print_rtl_single (outf, XEXP (tmp_rtx, 0)); | |
1886 | } | |
1887 | } | |
1888 | \f | |
b446e5a2 | 1889 | void |
d329e058 | 1890 | update_br_prob_note (basic_block bb) |
b446e5a2 JH |
1891 | { |
1892 | rtx note; | |
4b4bf941 | 1893 | if (!JUMP_P (BB_END (bb))) |
b446e5a2 | 1894 | return; |
a813c111 | 1895 | note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX); |
b446e5a2 JH |
1896 | if (!note || INTVAL (XEXP (note, 0)) == BRANCH_EDGE (bb)->probability) |
1897 | return; | |
1898 | XEXP (note, 0) = GEN_INT (BRANCH_EDGE (bb)->probability); | |
1899 | } | |
1900 | \f | |
10e9fecc JH |
1901 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
1902 | cfglayout RTL. | |
ca6c03ca JH |
1903 | |
1904 | Currently it does following checks: | |
1905 | ||
1906 | - test head/end pointers | |
1907 | - overlapping of basic blocks | |
ca6c03ca | 1908 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) |
f63d1bf7 | 1909 | - tails of basic blocks (ensure that boundary is necessary) |
ca6c03ca JH |
1910 | - scans body of the basic block for JUMP_INSN, CODE_LABEL |
1911 | and NOTE_INSN_BASIC_BLOCK | |
750054a2 | 1912 | - verify that no fall_thru edge crosses hot/cold partition boundaries |
ca6c03ca JH |
1913 | |
1914 | In future it can be extended check a lot of other stuff as well | |
1915 | (reachability of basic blocks, life information, etc. etc.). */ | |
f470c378 | 1916 | |
10e9fecc | 1917 | static int |
d329e058 | 1918 | rtl_verify_flow_info_1 (void) |
ca6c03ca JH |
1919 | { |
1920 | const int max_uid = get_max_uid (); | |
ca6c03ca | 1921 | rtx last_head = get_last_insn (); |
10e9fecc | 1922 | basic_block *bb_info; |
ca6c03ca | 1923 | rtx x; |
10e9fecc | 1924 | int err = 0; |
918ed612 | 1925 | basic_block bb, last_bb_seen; |
ca6c03ca | 1926 | |
703ad42b | 1927 | bb_info = xcalloc (max_uid, sizeof (basic_block)); |
ca6c03ca | 1928 | |
918ed612 ZD |
1929 | /* Check bb chain & numbers. */ |
1930 | last_bb_seen = ENTRY_BLOCK_PTR; | |
918ed612 | 1931 | |
e0082a72 | 1932 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1933 | { |
a813c111 SB |
1934 | rtx head = BB_HEAD (bb); |
1935 | rtx end = BB_END (bb); | |
ca6c03ca JH |
1936 | |
1937 | /* Verify the end of the basic block is in the INSN chain. */ | |
1938 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) | |
1939 | if (x == end) | |
1940 | break; | |
5f0d2358 | 1941 | |
ca6c03ca JH |
1942 | if (!x) |
1943 | { | |
1f978f5f | 1944 | error ("end insn %d for block %d not found in the insn stream", |
0b17ab2f | 1945 | INSN_UID (end), bb->index); |
ca6c03ca JH |
1946 | err = 1; |
1947 | } | |
1948 | ||
1949 | /* Work backwards from the end to the head of the basic block | |
1950 | to verify the head is in the RTL chain. */ | |
1951 | for (; x != NULL_RTX; x = PREV_INSN (x)) | |
1952 | { | |
1953 | /* While walking over the insn chain, verify insns appear | |
1954 | in only one basic block and initialize the BB_INFO array | |
1955 | used by other passes. */ | |
1956 | if (bb_info[INSN_UID (x)] != NULL) | |
1957 | { | |
1f978f5f | 1958 | error ("insn %d is in multiple basic blocks (%d and %d)", |
0b17ab2f | 1959 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); |
ca6c03ca JH |
1960 | err = 1; |
1961 | } | |
5f0d2358 | 1962 | |
ca6c03ca JH |
1963 | bb_info[INSN_UID (x)] = bb; |
1964 | ||
1965 | if (x == head) | |
1966 | break; | |
1967 | } | |
1968 | if (!x) | |
1969 | { | |
1f978f5f | 1970 | error ("head insn %d for block %d not found in the insn stream", |
0b17ab2f | 1971 | INSN_UID (head), bb->index); |
ca6c03ca JH |
1972 | err = 1; |
1973 | } | |
1974 | ||
1975 | last_head = x; | |
1976 | } | |
1977 | ||
1978 | /* Now check the basic blocks (boundaries etc.) */ | |
e0082a72 | 1979 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1980 | { |
3dec4024 | 1981 | int n_fallthru = 0, n_eh = 0, n_call = 0, n_abnormal = 0, n_branch = 0; |
3cf54412 | 1982 | edge e, fallthru = NULL; |
5a1a3e5e | 1983 | rtx note; |
628f6a4e | 1984 | edge_iterator ei; |
ca6c03ca | 1985 | |
a813c111 SB |
1986 | if (INSN_P (BB_END (bb)) |
1987 | && (note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX)) | |
628f6a4e | 1988 | && EDGE_COUNT (bb->succs) >= 2 |
a813c111 | 1989 | && any_condjump_p (BB_END (bb))) |
5a1a3e5e | 1990 | { |
e53de54d JH |
1991 | if (INTVAL (XEXP (note, 0)) != BRANCH_EDGE (bb)->probability |
1992 | && profile_status != PROFILE_ABSENT) | |
5a1a3e5e | 1993 | { |
0108ae51 | 1994 | error ("verify_flow_info: REG_BR_PROB does not match cfg %wi %i", |
5a1a3e5e JH |
1995 | INTVAL (XEXP (note, 0)), BRANCH_EDGE (bb)->probability); |
1996 | err = 1; | |
1997 | } | |
1998 | } | |
628f6a4e | 1999 | FOR_EACH_EDGE (e, ei, bb->succs) |
ca6c03ca | 2000 | { |
ca6c03ca | 2001 | if (e->flags & EDGE_FALLTHRU) |
750054a2 CT |
2002 | { |
2003 | n_fallthru++, fallthru = e; | |
bd454efd | 2004 | if ((e->flags & EDGE_CROSSING) |
076c7ab8 | 2005 | || (BB_PARTITION (e->src) != BB_PARTITION (e->dest) |
9fb32434 CT |
2006 | && e->src != ENTRY_BLOCK_PTR |
2007 | && e->dest != EXIT_BLOCK_PTR)) | |
2008 | { | |
750054a2 CT |
2009 | error ("Fallthru edge crosses section boundary (bb %i)", |
2010 | e->src->index); | |
2011 | err = 1; | |
2012 | } | |
2013 | } | |
3dec4024 | 2014 | |
65f43cdf ZD |
2015 | if ((e->flags & ~(EDGE_DFS_BACK |
2016 | | EDGE_CAN_FALLTHRU | |
2017 | | EDGE_IRREDUCIBLE_LOOP | |
9beb1c84 CT |
2018 | | EDGE_LOOP_EXIT |
2019 | | EDGE_CROSSING)) == 0) | |
3dec4024 JH |
2020 | n_branch++; |
2021 | ||
2022 | if (e->flags & EDGE_ABNORMAL_CALL) | |
2023 | n_call++; | |
2024 | ||
2025 | if (e->flags & EDGE_EH) | |
2026 | n_eh++; | |
2027 | else if (e->flags & EDGE_ABNORMAL) | |
2028 | n_abnormal++; | |
ca6c03ca | 2029 | } |
5f0d2358 | 2030 | |
a813c111 SB |
2031 | if (n_eh && GET_CODE (PATTERN (BB_END (bb))) != RESX |
2032 | && !find_reg_note (BB_END (bb), REG_EH_REGION, NULL_RTX)) | |
3dec4024 | 2033 | { |
0b17ab2f | 2034 | error ("Missing REG_EH_REGION note in the end of bb %i", bb->index); |
3dec4024 JH |
2035 | err = 1; |
2036 | } | |
2037 | if (n_branch | |
4b4bf941 | 2038 | && (!JUMP_P (BB_END (bb)) |
a813c111 SB |
2039 | || (n_branch > 1 && (any_uncondjump_p (BB_END (bb)) |
2040 | || any_condjump_p (BB_END (bb)))))) | |
3dec4024 | 2041 | { |
0b17ab2f | 2042 | error ("Too many outgoing branch edges from bb %i", bb->index); |
3dec4024 JH |
2043 | err = 1; |
2044 | } | |
a813c111 | 2045 | if (n_fallthru && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 2046 | { |
0b17ab2f | 2047 | error ("Fallthru edge after unconditional jump %i", bb->index); |
3dec4024 JH |
2048 | err = 1; |
2049 | } | |
a813c111 | 2050 | if (n_branch != 1 && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 2051 | { |
0b17ab2f | 2052 | error ("Wrong amount of branch edges after unconditional jump %i", bb->index); |
3dec4024 JH |
2053 | err = 1; |
2054 | } | |
a813c111 SB |
2055 | if (n_branch != 1 && any_condjump_p (BB_END (bb)) |
2056 | && JUMP_LABEL (BB_END (bb)) != BB_HEAD (fallthru->dest)) | |
3dec4024 | 2057 | { |
0b17ab2f | 2058 | error ("Wrong amount of branch edges after conditional jump %i", bb->index); |
3dec4024 JH |
2059 | err = 1; |
2060 | } | |
4b4bf941 | 2061 | if (n_call && !CALL_P (BB_END (bb))) |
3dec4024 | 2062 | { |
0b17ab2f | 2063 | error ("Call edges for non-call insn in bb %i", bb->index); |
3dec4024 JH |
2064 | err = 1; |
2065 | } | |
2066 | if (n_abnormal | |
4b4bf941 JQ |
2067 | && (!CALL_P (BB_END (bb)) && n_call != n_abnormal) |
2068 | && (!JUMP_P (BB_END (bb)) | |
a813c111 SB |
2069 | || any_condjump_p (BB_END (bb)) |
2070 | || any_uncondjump_p (BB_END (bb)))) | |
3dec4024 | 2071 | { |
0b17ab2f | 2072 | error ("Abnormal edges for no purpose in bb %i", bb->index); |
3dec4024 JH |
2073 | err = 1; |
2074 | } | |
f87c27b4 | 2075 | |
a813c111 | 2076 | for (x = BB_HEAD (bb); x != NEXT_INSN (BB_END (bb)); x = NEXT_INSN (x)) |
0ca541aa HPN |
2077 | /* We may have a barrier inside a basic block before dead code |
2078 | elimination. They always have a NULL BLOCK_FOR_INSN. */ | |
2079 | if (BLOCK_FOR_INSN (x) != bb | |
2080 | && !(BARRIER_P (x) && BLOCK_FOR_INSN (x) == NULL)) | |
5f0d2358 RK |
2081 | { |
2082 | debug_rtx (x); | |
2083 | if (! BLOCK_FOR_INSN (x)) | |
2084 | error | |
2085 | ("insn %d inside basic block %d but block_for_insn is NULL", | |
0b17ab2f | 2086 | INSN_UID (x), bb->index); |
5f0d2358 RK |
2087 | else |
2088 | error | |
2089 | ("insn %d inside basic block %d but block_for_insn is %i", | |
0b17ab2f | 2090 | INSN_UID (x), bb->index, BLOCK_FOR_INSN (x)->index); |
5f0d2358 RK |
2091 | |
2092 | err = 1; | |
2093 | } | |
ca6c03ca JH |
2094 | |
2095 | /* OK pointers are correct. Now check the header of basic | |
2096 | block. It ought to contain optional CODE_LABEL followed | |
2097 | by NOTE_BASIC_BLOCK. */ | |
a813c111 | 2098 | x = BB_HEAD (bb); |
4b4bf941 | 2099 | if (LABEL_P (x)) |
ca6c03ca | 2100 | { |
a813c111 | 2101 | if (BB_END (bb) == x) |
ca6c03ca JH |
2102 | { |
2103 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 2104 | bb->index); |
ca6c03ca JH |
2105 | err = 1; |
2106 | } | |
5f0d2358 | 2107 | |
ca6c03ca JH |
2108 | x = NEXT_INSN (x); |
2109 | } | |
5f0d2358 | 2110 | |
ca6c03ca JH |
2111 | if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb) |
2112 | { | |
2113 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 2114 | bb->index); |
ca6c03ca JH |
2115 | err = 1; |
2116 | } | |
2117 | ||
a813c111 | 2118 | if (BB_END (bb) == x) |
5f0d2358 RK |
2119 | /* Do checks for empty blocks her. e */ |
2120 | ; | |
ca6c03ca | 2121 | else |
5f0d2358 RK |
2122 | for (x = NEXT_INSN (x); x; x = NEXT_INSN (x)) |
2123 | { | |
2124 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2125 | { | |
2126 | error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d", | |
0b17ab2f | 2127 | INSN_UID (x), bb->index); |
5f0d2358 RK |
2128 | err = 1; |
2129 | } | |
2130 | ||
a813c111 | 2131 | if (x == BB_END (bb)) |
5f0d2358 | 2132 | break; |
ca6c03ca | 2133 | |
83fd323c | 2134 | if (control_flow_insn_p (x)) |
5f0d2358 | 2135 | { |
0b17ab2f | 2136 | error ("in basic block %d:", bb->index); |
5f0d2358 RK |
2137 | fatal_insn ("flow control insn inside a basic block", x); |
2138 | } | |
2139 | } | |
ca6c03ca JH |
2140 | } |
2141 | ||
10e9fecc JH |
2142 | /* Clean up. */ |
2143 | free (bb_info); | |
2144 | return err; | |
2145 | } | |
5f0d2358 | 2146 | |
10e9fecc JH |
2147 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
2148 | cfglayout RTL. | |
5f0d2358 | 2149 | |
10e9fecc JH |
2150 | Currently it does following checks: |
2151 | - all checks of rtl_verify_flow_info_1 | |
2152 | - check that all insns are in the basic blocks | |
2153 | (except the switch handling code, barriers and notes) | |
2154 | - check that all returns are followed by barriers | |
2155 | - check that all fallthru edge points to the adjacent blocks. */ | |
2156 | static int | |
d329e058 | 2157 | rtl_verify_flow_info (void) |
10e9fecc JH |
2158 | { |
2159 | basic_block bb; | |
2160 | int err = rtl_verify_flow_info_1 (); | |
2161 | rtx x; | |
2162 | int num_bb_notes; | |
2163 | const rtx rtx_first = get_insns (); | |
2164 | basic_block last_bb_seen = ENTRY_BLOCK_PTR, curr_bb = NULL; | |
ca6c03ca | 2165 | |
10e9fecc JH |
2166 | FOR_EACH_BB_REVERSE (bb) |
2167 | { | |
2168 | edge e; | |
628f6a4e BE |
2169 | edge_iterator ei; |
2170 | ||
2171 | FOR_EACH_EDGE (e, ei, bb->succs) | |
10e9fecc JH |
2172 | if (e->flags & EDGE_FALLTHRU) |
2173 | break; | |
2174 | if (!e) | |
2175 | { | |
2176 | rtx insn; | |
2177 | ||
2178 | /* Ensure existence of barrier in BB with no fallthru edges. */ | |
4b4bf941 | 2179 | for (insn = BB_END (bb); !insn || !BARRIER_P (insn); |
10e9fecc JH |
2180 | insn = NEXT_INSN (insn)) |
2181 | if (!insn | |
4b4bf941 | 2182 | || (NOTE_P (insn) |
10e9fecc JH |
2183 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_BASIC_BLOCK)) |
2184 | { | |
2185 | error ("missing barrier after block %i", bb->index); | |
2186 | err = 1; | |
2187 | break; | |
2188 | } | |
2189 | } | |
2190 | else if (e->src != ENTRY_BLOCK_PTR | |
2191 | && e->dest != EXIT_BLOCK_PTR) | |
2192 | { | |
2193 | rtx insn; | |
2194 | ||
2195 | if (e->src->next_bb != e->dest) | |
2196 | { | |
2197 | error | |
2198 | ("verify_flow_info: Incorrect blocks for fallthru %i->%i", | |
2199 | e->src->index, e->dest->index); | |
2200 | err = 1; | |
2201 | } | |
2202 | else | |
a813c111 | 2203 | for (insn = NEXT_INSN (BB_END (e->src)); insn != BB_HEAD (e->dest); |
10e9fecc | 2204 | insn = NEXT_INSN (insn)) |
4b4bf941 | 2205 | if (BARRIER_P (insn) |
10e9fecc JH |
2206 | #ifndef CASE_DROPS_THROUGH |
2207 | || INSN_P (insn) | |
2208 | #else | |
2209 | || (INSN_P (insn) && ! JUMP_TABLE_DATA_P (insn)) | |
2210 | #endif | |
2211 | ) | |
2212 | { | |
2213 | error ("verify_flow_info: Incorrect fallthru %i->%i", | |
2214 | e->src->index, e->dest->index); | |
2215 | fatal_insn ("wrong insn in the fallthru edge", insn); | |
2216 | err = 1; | |
2217 | } | |
2218 | } | |
2219 | } | |
ca6c03ca | 2220 | |
ca6c03ca | 2221 | num_bb_notes = 0; |
e0082a72 ZD |
2222 | last_bb_seen = ENTRY_BLOCK_PTR; |
2223 | ||
5f0d2358 | 2224 | for (x = rtx_first; x; x = NEXT_INSN (x)) |
ca6c03ca JH |
2225 | { |
2226 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2227 | { | |
bf77398c | 2228 | bb = NOTE_BASIC_BLOCK (x); |
5f0d2358 | 2229 | |
ca6c03ca | 2230 | num_bb_notes++; |
e0082a72 | 2231 | if (bb != last_bb_seen->next_bb) |
10e9fecc | 2232 | internal_error ("basic blocks not laid down consecutively"); |
ca6c03ca | 2233 | |
10e9fecc | 2234 | curr_bb = last_bb_seen = bb; |
ca6c03ca JH |
2235 | } |
2236 | ||
10e9fecc | 2237 | if (!curr_bb) |
ca6c03ca JH |
2238 | { |
2239 | switch (GET_CODE (x)) | |
2240 | { | |
2241 | case BARRIER: | |
2242 | case NOTE: | |
2243 | break; | |
2244 | ||
2245 | case CODE_LABEL: | |
666c27b9 | 2246 | /* An addr_vec is placed outside any basic block. */ |
ca6c03ca | 2247 | if (NEXT_INSN (x) |
4b4bf941 | 2248 | && JUMP_P (NEXT_INSN (x)) |
ca6c03ca JH |
2249 | && (GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_DIFF_VEC |
2250 | || GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_VEC)) | |
5f0d2358 | 2251 | x = NEXT_INSN (x); |
ca6c03ca JH |
2252 | |
2253 | /* But in any case, non-deletable labels can appear anywhere. */ | |
2254 | break; | |
2255 | ||
2256 | default: | |
1f978f5f | 2257 | fatal_insn ("insn outside basic block", x); |
ca6c03ca JH |
2258 | } |
2259 | } | |
2260 | ||
2261 | if (INSN_P (x) | |
4b4bf941 | 2262 | && JUMP_P (x) |
ca6c03ca | 2263 | && returnjump_p (x) && ! condjump_p (x) |
4b4bf941 | 2264 | && ! (NEXT_INSN (x) && BARRIER_P (NEXT_INSN (x)))) |
1f978f5f | 2265 | fatal_insn ("return not followed by barrier", x); |
a813c111 | 2266 | if (curr_bb && x == BB_END (curr_bb)) |
10e9fecc | 2267 | curr_bb = NULL; |
ca6c03ca JH |
2268 | } |
2269 | ||
0b17ab2f | 2270 | if (num_bb_notes != n_basic_blocks) |
ca6c03ca | 2271 | internal_error |
0b17ab2f RH |
2272 | ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)", |
2273 | num_bb_notes, n_basic_blocks); | |
ca6c03ca | 2274 | |
10e9fecc | 2275 | return err; |
ca6c03ca JH |
2276 | } |
2277 | \f | |
eaec9b3d | 2278 | /* Assume that the preceding pass has possibly eliminated jump instructions |
ca6c03ca JH |
2279 | or converted the unconditional jumps. Eliminate the edges from CFG. |
2280 | Return true if any edges are eliminated. */ | |
2281 | ||
2282 | bool | |
d329e058 | 2283 | purge_dead_edges (basic_block bb) |
ca6c03ca | 2284 | { |
628f6a4e | 2285 | edge e; |
a813c111 | 2286 | rtx insn = BB_END (bb), note; |
ca6c03ca | 2287 | bool purged = false; |
628f6a4e BE |
2288 | bool found; |
2289 | edge_iterator ei; | |
ca6c03ca | 2290 | |
70da1d03 | 2291 | /* If this instruction cannot trap, remove REG_EH_REGION notes. */ |
4b4bf941 | 2292 | if (NONJUMP_INSN_P (insn) |
70da1d03 JH |
2293 | && (note = find_reg_note (insn, REG_EH_REGION, NULL))) |
2294 | { | |
2295 | rtx eqnote; | |
2296 | ||
2297 | if (! may_trap_p (PATTERN (insn)) | |
2298 | || ((eqnote = find_reg_equal_equiv_note (insn)) | |
2299 | && ! may_trap_p (XEXP (eqnote, 0)))) | |
2300 | remove_note (insn, note); | |
2301 | } | |
2302 | ||
546c093e | 2303 | /* Cleanup abnormal edges caused by exceptions or non-local gotos. */ |
628f6a4e | 2304 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
546c093e | 2305 | { |
546c093e RH |
2306 | if (e->flags & EDGE_EH) |
2307 | { | |
a813c111 | 2308 | if (can_throw_internal (BB_END (bb))) |
628f6a4e BE |
2309 | { |
2310 | ei_next (&ei); | |
2311 | continue; | |
2312 | } | |
546c093e RH |
2313 | } |
2314 | else if (e->flags & EDGE_ABNORMAL_CALL) | |
2315 | { | |
4b4bf941 | 2316 | if (CALL_P (BB_END (bb)) |
546c093e RH |
2317 | && (! (note = find_reg_note (insn, REG_EH_REGION, NULL)) |
2318 | || INTVAL (XEXP (note, 0)) >= 0)) | |
628f6a4e BE |
2319 | { |
2320 | ei_next (&ei); | |
2321 | continue; | |
2322 | } | |
546c093e RH |
2323 | } |
2324 | else | |
628f6a4e BE |
2325 | { |
2326 | ei_next (&ei); | |
2327 | continue; | |
2328 | } | |
546c093e RH |
2329 | |
2330 | remove_edge (e); | |
2331 | bb->flags |= BB_DIRTY; | |
2332 | purged = true; | |
2333 | } | |
5f0d2358 | 2334 | |
4b4bf941 | 2335 | if (JUMP_P (insn)) |
ca6c03ca JH |
2336 | { |
2337 | rtx note; | |
2338 | edge b,f; | |
628f6a4e | 2339 | edge_iterator ei; |
5f0d2358 | 2340 | |
ca6c03ca JH |
2341 | /* We do care only about conditional jumps and simplejumps. */ |
2342 | if (!any_condjump_p (insn) | |
2343 | && !returnjump_p (insn) | |
2344 | && !simplejump_p (insn)) | |
c51d95ec | 2345 | return purged; |
5f0d2358 | 2346 | |
5a1a3e5e JH |
2347 | /* Branch probability/prediction notes are defined only for |
2348 | condjumps. We've possibly turned condjump into simplejump. */ | |
2349 | if (simplejump_p (insn)) | |
2350 | { | |
2351 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2352 | if (note) | |
2353 | remove_note (insn, note); | |
2354 | while ((note = find_reg_note (insn, REG_BR_PRED, NULL))) | |
2355 | remove_note (insn, note); | |
2356 | } | |
2357 | ||
628f6a4e | 2358 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
ca6c03ca | 2359 | { |
7fcd7218 JH |
2360 | /* Avoid abnormal flags to leak from computed jumps turned |
2361 | into simplejumps. */ | |
f87c27b4 | 2362 | |
0e1638d4 | 2363 | e->flags &= ~EDGE_ABNORMAL; |
7fcd7218 | 2364 | |
5a566bed MM |
2365 | /* See if this edge is one we should keep. */ |
2366 | if ((e->flags & EDGE_FALLTHRU) && any_condjump_p (insn)) | |
2367 | /* A conditional jump can fall through into the next | |
2368 | block, so we should keep the edge. */ | |
628f6a4e BE |
2369 | { |
2370 | ei_next (&ei); | |
2371 | continue; | |
2372 | } | |
5f0d2358 | 2373 | else if (e->dest != EXIT_BLOCK_PTR |
a813c111 | 2374 | && BB_HEAD (e->dest) == JUMP_LABEL (insn)) |
5a566bed MM |
2375 | /* If the destination block is the target of the jump, |
2376 | keep the edge. */ | |
628f6a4e BE |
2377 | { |
2378 | ei_next (&ei); | |
2379 | continue; | |
2380 | } | |
5a566bed MM |
2381 | else if (e->dest == EXIT_BLOCK_PTR && returnjump_p (insn)) |
2382 | /* If the destination block is the exit block, and this | |
2383 | instruction is a return, then keep the edge. */ | |
628f6a4e BE |
2384 | { |
2385 | ei_next (&ei); | |
2386 | continue; | |
2387 | } | |
5a566bed MM |
2388 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) |
2389 | /* Keep the edges that correspond to exceptions thrown by | |
0b75beaa EB |
2390 | this instruction and rematerialize the EDGE_ABNORMAL |
2391 | flag we just cleared above. */ | |
2392 | { | |
2393 | e->flags |= EDGE_ABNORMAL; | |
628f6a4e | 2394 | ei_next (&ei); |
0b75beaa EB |
2395 | continue; |
2396 | } | |
5f0d2358 | 2397 | |
5a566bed | 2398 | /* We do not need this edge. */ |
c51d95ec | 2399 | bb->flags |= BB_DIRTY; |
ca6c03ca JH |
2400 | purged = true; |
2401 | remove_edge (e); | |
2402 | } | |
5f0d2358 | 2403 | |
628f6a4e | 2404 | if (EDGE_COUNT (bb->succs) == 0 || !purged) |
c51d95ec | 2405 | return purged; |
5f0d2358 | 2406 | |
c263766c RH |
2407 | if (dump_file) |
2408 | fprintf (dump_file, "Purged edges from bb %i\n", bb->index); | |
5f0d2358 | 2409 | |
ca6c03ca JH |
2410 | if (!optimize) |
2411 | return purged; | |
2412 | ||
2413 | /* Redistribute probabilities. */ | |
628f6a4e | 2414 | if (EDGE_COUNT (bb->succs) == 1) |
ca6c03ca | 2415 | { |
628f6a4e BE |
2416 | EDGE_SUCC (bb, 0)->probability = REG_BR_PROB_BASE; |
2417 | EDGE_SUCC (bb, 0)->count = bb->count; | |
f87c27b4 | 2418 | } |
ca6c03ca JH |
2419 | else |
2420 | { | |
2421 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2422 | if (!note) | |
2423 | return purged; | |
5f0d2358 | 2424 | |
ca6c03ca JH |
2425 | b = BRANCH_EDGE (bb); |
2426 | f = FALLTHRU_EDGE (bb); | |
2427 | b->probability = INTVAL (XEXP (note, 0)); | |
2428 | f->probability = REG_BR_PROB_BASE - b->probability; | |
2429 | b->count = bb->count * b->probability / REG_BR_PROB_BASE; | |
2430 | f->count = bb->count * f->probability / REG_BR_PROB_BASE; | |
2431 | } | |
5f0d2358 | 2432 | |
ca6c03ca JH |
2433 | return purged; |
2434 | } | |
4b4bf941 | 2435 | else if (CALL_P (insn) && SIBLING_CALL_P (insn)) |
1722c2c8 RH |
2436 | { |
2437 | /* First, there should not be any EH or ABCALL edges resulting | |
2438 | from non-local gotos and the like. If there were, we shouldn't | |
2439 | have created the sibcall in the first place. Second, there | |
2440 | should of course never have been a fallthru edge. */ | |
628f6a4e BE |
2441 | gcc_assert (EDGE_COUNT (bb->succs) == 1); |
2442 | gcc_assert (EDGE_SUCC (bb, 0)->flags == (EDGE_SIBCALL | EDGE_ABNORMAL)); | |
1722c2c8 RH |
2443 | |
2444 | return 0; | |
2445 | } | |
ca6c03ca | 2446 | |
ca6c03ca JH |
2447 | /* If we don't see a jump insn, we don't know exactly why the block would |
2448 | have been broken at this point. Look for a simple, non-fallthru edge, | |
2449 | as these are only created by conditional branches. If we find such an | |
2450 | edge we know that there used to be a jump here and can then safely | |
2451 | remove all non-fallthru edges. */ | |
628f6a4e BE |
2452 | found = false; |
2453 | FOR_EACH_EDGE (e, ei, bb->succs) | |
2454 | if (! (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU))) | |
2455 | { | |
2456 | found = true; | |
2457 | break; | |
2458 | } | |
5f0d2358 | 2459 | |
628f6a4e | 2460 | if (!found) |
ca6c03ca | 2461 | return purged; |
5f0d2358 | 2462 | |
628f6a4e | 2463 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
ca6c03ca | 2464 | { |
ca6c03ca | 2465 | if (!(e->flags & EDGE_FALLTHRU)) |
c51d95ec JH |
2466 | { |
2467 | bb->flags |= BB_DIRTY; | |
2468 | remove_edge (e); | |
2469 | purged = true; | |
2470 | } | |
628f6a4e BE |
2471 | else |
2472 | ei_next (&ei); | |
ca6c03ca | 2473 | } |
5f0d2358 | 2474 | |
628f6a4e | 2475 | gcc_assert (EDGE_COUNT (bb->succs) == 1); |
5f0d2358 | 2476 | |
628f6a4e BE |
2477 | EDGE_SUCC (bb, 0)->probability = REG_BR_PROB_BASE; |
2478 | EDGE_SUCC (bb, 0)->count = bb->count; | |
ca6c03ca | 2479 | |
c263766c RH |
2480 | if (dump_file) |
2481 | fprintf (dump_file, "Purged non-fallthru edges from bb %i\n", | |
0b17ab2f | 2482 | bb->index); |
ca6c03ca JH |
2483 | return purged; |
2484 | } | |
2485 | ||
5f0d2358 RK |
2486 | /* Search all basic blocks for potentially dead edges and purge them. Return |
2487 | true if some edge has been eliminated. */ | |
ca6c03ca JH |
2488 | |
2489 | bool | |
d329e058 | 2490 | purge_all_dead_edges (int update_life_p) |
ca6c03ca | 2491 | { |
e0082a72 | 2492 | int purged = false; |
710af899 | 2493 | sbitmap blocks = 0; |
e0082a72 | 2494 | basic_block bb; |
473fb060 JH |
2495 | |
2496 | if (update_life_p) | |
2497 | { | |
d55bc081 | 2498 | blocks = sbitmap_alloc (last_basic_block); |
473fb060 JH |
2499 | sbitmap_zero (blocks); |
2500 | } | |
5f0d2358 | 2501 | |
e0082a72 | 2502 | FOR_EACH_BB (bb) |
473fb060 | 2503 | { |
e0082a72 | 2504 | bool purged_here = purge_dead_edges (bb); |
5f0d2358 | 2505 | |
473fb060 JH |
2506 | purged |= purged_here; |
2507 | if (purged_here && update_life_p) | |
e0082a72 | 2508 | SET_BIT (blocks, bb->index); |
473fb060 | 2509 | } |
5f0d2358 | 2510 | |
473fb060 JH |
2511 | if (update_life_p && purged) |
2512 | update_life_info (blocks, UPDATE_LIFE_GLOBAL, | |
2513 | PROP_DEATH_NOTES | PROP_SCAN_DEAD_CODE | |
2514 | | PROP_KILL_DEAD_CODE); | |
5f0d2358 | 2515 | |
473fb060 JH |
2516 | if (update_life_p) |
2517 | sbitmap_free (blocks); | |
ca6c03ca JH |
2518 | return purged; |
2519 | } | |
9ee634e3 JH |
2520 | |
2521 | /* Same as split_block but update cfg_layout structures. */ | |
f470c378 ZD |
2522 | |
2523 | static basic_block | |
d329e058 | 2524 | cfg_layout_split_block (basic_block bb, void *insnp) |
9ee634e3 JH |
2525 | { |
2526 | rtx insn = insnp; | |
f470c378 | 2527 | basic_block new_bb = rtl_split_block (bb, insn); |
9ee634e3 | 2528 | |
f470c378 ZD |
2529 | new_bb->rbi->footer = bb->rbi->footer; |
2530 | bb->rbi->footer = NULL; | |
9ee634e3 | 2531 | |
f470c378 | 2532 | return new_bb; |
9ee634e3 JH |
2533 | } |
2534 | ||
2535 | ||
2536 | /* Redirect Edge to DEST. */ | |
6de9cd9a | 2537 | static edge |
d329e058 | 2538 | cfg_layout_redirect_edge_and_branch (edge e, basic_block dest) |
9ee634e3 JH |
2539 | { |
2540 | basic_block src = e->src; | |
6de9cd9a | 2541 | edge ret; |
9ee634e3 | 2542 | |
bc35512f | 2543 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
6de9cd9a | 2544 | return NULL; |
bc35512f | 2545 | |
3348b696 | 2546 | if (e->dest == dest) |
6de9cd9a | 2547 | return e; |
bc35512f | 2548 | |
3348b696 | 2549 | if (e->src != ENTRY_BLOCK_PTR |
6de9cd9a | 2550 | && (ret = try_redirect_by_replacing_jump (e, dest, true))) |
f345f21a JH |
2551 | { |
2552 | src->flags |= BB_DIRTY; | |
6de9cd9a | 2553 | return ret; |
f345f21a | 2554 | } |
bc35512f JH |
2555 | |
2556 | if (e->src == ENTRY_BLOCK_PTR | |
2557 | && (e->flags & EDGE_FALLTHRU) && !(e->flags & EDGE_COMPLEX)) | |
2558 | { | |
c263766c RH |
2559 | if (dump_file) |
2560 | fprintf (dump_file, "Redirecting entry edge from bb %i to %i\n", | |
bc35512f JH |
2561 | e->src->index, dest->index); |
2562 | ||
f345f21a | 2563 | e->src->flags |= BB_DIRTY; |
bc35512f | 2564 | redirect_edge_succ (e, dest); |
6de9cd9a | 2565 | return e; |
bc35512f JH |
2566 | } |
2567 | ||
9ee634e3 JH |
2568 | /* Redirect_edge_and_branch may decide to turn branch into fallthru edge |
2569 | in the case the basic block appears to be in sequence. Avoid this | |
2570 | transformation. */ | |
2571 | ||
9ee634e3 JH |
2572 | if (e->flags & EDGE_FALLTHRU) |
2573 | { | |
2574 | /* Redirect any branch edges unified with the fallthru one. */ | |
4b4bf941 | 2575 | if (JUMP_P (BB_END (src)) |
432f982f JH |
2576 | && label_is_jump_target_p (BB_HEAD (e->dest), |
2577 | BB_END (src))) | |
9ee634e3 | 2578 | { |
341c100f NS |
2579 | edge redirected; |
2580 | ||
c263766c RH |
2581 | if (dump_file) |
2582 | fprintf (dump_file, "Fallthru edge unified with branch " | |
432f982f JH |
2583 | "%i->%i redirected to %i\n", |
2584 | e->src->index, e->dest->index, dest->index); | |
2585 | e->flags &= ~EDGE_FALLTHRU; | |
341c100f NS |
2586 | redirected = redirect_branch_edge (e, dest); |
2587 | gcc_assert (redirected); | |
432f982f | 2588 | e->flags |= EDGE_FALLTHRU; |
f345f21a | 2589 | e->src->flags |= BB_DIRTY; |
6de9cd9a | 2590 | return e; |
9ee634e3 JH |
2591 | } |
2592 | /* In case we are redirecting fallthru edge to the branch edge | |
2593 | of conditional jump, remove it. */ | |
628f6a4e | 2594 | if (EDGE_COUNT (src->succs) == 2) |
9ee634e3 | 2595 | { |
628f6a4e BE |
2596 | bool found = false; |
2597 | unsigned ix = 0; | |
2598 | edge tmp, s; | |
2599 | edge_iterator ei; | |
2600 | ||
2601 | FOR_EACH_EDGE (tmp, ei, src->succs) | |
2602 | if (e == tmp) | |
2603 | { | |
2604 | found = true; | |
2605 | ix = ei.index; | |
2606 | break; | |
2607 | } | |
2608 | ||
2609 | gcc_assert (found); | |
2610 | ||
2611 | if (EDGE_COUNT (src->succs) > (ix + 1)) | |
2612 | s = EDGE_SUCC (src, ix + 1); | |
2613 | else | |
2614 | s = EDGE_SUCC (src, 0); | |
2615 | ||
9ee634e3 | 2616 | if (s->dest == dest |
a813c111 SB |
2617 | && any_condjump_p (BB_END (src)) |
2618 | && onlyjump_p (BB_END (src))) | |
2619 | delete_insn (BB_END (src)); | |
9ee634e3 | 2620 | } |
6de9cd9a | 2621 | ret = redirect_edge_succ_nodup (e, dest); |
c263766c RH |
2622 | if (dump_file) |
2623 | fprintf (dump_file, "Fallthru edge %i->%i redirected to %i\n", | |
bc35512f | 2624 | e->src->index, e->dest->index, dest->index); |
9ee634e3 JH |
2625 | } |
2626 | else | |
bc35512f | 2627 | ret = redirect_branch_edge (e, dest); |
9ee634e3 JH |
2628 | |
2629 | /* We don't want simplejumps in the insn stream during cfglayout. */ | |
341c100f | 2630 | gcc_assert (!simplejump_p (BB_END (src))); |
9ee634e3 | 2631 | |
f345f21a | 2632 | src->flags |= BB_DIRTY; |
9ee634e3 JH |
2633 | return ret; |
2634 | } | |
2635 | ||
2636 | /* Simple wrapper as we always can redirect fallthru edges. */ | |
2637 | static basic_block | |
d329e058 | 2638 | cfg_layout_redirect_edge_and_branch_force (edge e, basic_block dest) |
9ee634e3 | 2639 | { |
341c100f NS |
2640 | edge redirected = cfg_layout_redirect_edge_and_branch (e, dest); |
2641 | ||
2642 | gcc_assert (redirected); | |
9ee634e3 JH |
2643 | return NULL; |
2644 | } | |
2645 | ||
f470c378 ZD |
2646 | /* Same as delete_basic_block but update cfg_layout structures. */ |
2647 | ||
9ee634e3 | 2648 | static void |
d329e058 | 2649 | cfg_layout_delete_block (basic_block bb) |
9ee634e3 | 2650 | { |
a813c111 | 2651 | rtx insn, next, prev = PREV_INSN (BB_HEAD (bb)), *to, remaints; |
9ee634e3 | 2652 | |
bc35512f | 2653 | if (bb->rbi->header) |
9ee634e3 | 2654 | { |
a813c111 | 2655 | next = BB_HEAD (bb); |
9ee634e3 | 2656 | if (prev) |
bc35512f | 2657 | NEXT_INSN (prev) = bb->rbi->header; |
9ee634e3 | 2658 | else |
bc35512f JH |
2659 | set_first_insn (bb->rbi->header); |
2660 | PREV_INSN (bb->rbi->header) = prev; | |
2661 | insn = bb->rbi->header; | |
9ee634e3 JH |
2662 | while (NEXT_INSN (insn)) |
2663 | insn = NEXT_INSN (insn); | |
2664 | NEXT_INSN (insn) = next; | |
2665 | PREV_INSN (next) = insn; | |
2666 | } | |
a813c111 | 2667 | next = NEXT_INSN (BB_END (bb)); |
bc35512f | 2668 | if (bb->rbi->footer) |
9ee634e3 | 2669 | { |
bc35512f JH |
2670 | insn = bb->rbi->footer; |
2671 | while (insn) | |
2672 | { | |
4b4bf941 | 2673 | if (BARRIER_P (insn)) |
bc35512f JH |
2674 | { |
2675 | if (PREV_INSN (insn)) | |
2676 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
2677 | else | |
2678 | bb->rbi->footer = NEXT_INSN (insn); | |
2679 | if (NEXT_INSN (insn)) | |
2680 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
2681 | } | |
4b4bf941 | 2682 | if (LABEL_P (insn)) |
bc35512f JH |
2683 | break; |
2684 | insn = NEXT_INSN (insn); | |
2685 | } | |
2686 | if (bb->rbi->footer) | |
2687 | { | |
a813c111 | 2688 | insn = BB_END (bb); |
bc35512f JH |
2689 | NEXT_INSN (insn) = bb->rbi->footer; |
2690 | PREV_INSN (bb->rbi->footer) = insn; | |
2691 | while (NEXT_INSN (insn)) | |
2692 | insn = NEXT_INSN (insn); | |
2693 | NEXT_INSN (insn) = next; | |
2694 | if (next) | |
2695 | PREV_INSN (next) = insn; | |
2696 | else | |
2697 | set_last_insn (insn); | |
2698 | } | |
9ee634e3 JH |
2699 | } |
2700 | if (bb->next_bb != EXIT_BLOCK_PTR) | |
bc35512f | 2701 | to = &bb->next_bb->rbi->header; |
9ee634e3 JH |
2702 | else |
2703 | to = &cfg_layout_function_footer; | |
2704 | rtl_delete_block (bb); | |
2705 | ||
2706 | if (prev) | |
2707 | prev = NEXT_INSN (prev); | |
d329e058 | 2708 | else |
9ee634e3 JH |
2709 | prev = get_insns (); |
2710 | if (next) | |
2711 | next = PREV_INSN (next); | |
d329e058 | 2712 | else |
9ee634e3 JH |
2713 | next = get_last_insn (); |
2714 | ||
2715 | if (next && NEXT_INSN (next) != prev) | |
2716 | { | |
2717 | remaints = unlink_insn_chain (prev, next); | |
2718 | insn = remaints; | |
2719 | while (NEXT_INSN (insn)) | |
2720 | insn = NEXT_INSN (insn); | |
2721 | NEXT_INSN (insn) = *to; | |
2722 | if (*to) | |
2723 | PREV_INSN (*to) = insn; | |
2724 | *to = remaints; | |
2725 | } | |
2726 | } | |
2727 | ||
beb235f8 | 2728 | /* Return true when blocks A and B can be safely merged. */ |
bc35512f JH |
2729 | static bool |
2730 | cfg_layout_can_merge_blocks_p (basic_block a, basic_block b) | |
2731 | { | |
750054a2 CT |
2732 | /* If we are partitioning hot/cold basic blocks, we don't want to |
2733 | mess up unconditional or indirect jumps that cross between hot | |
076c7ab8 ZW |
2734 | and cold sections. |
2735 | ||
8e8d5162 CT |
2736 | Basic block partitioning may result in some jumps that appear to |
2737 | be optimizable (or blocks that appear to be mergeable), but which really | |
2738 | must be left untouched (they are required to make it safely across | |
2739 | partition boundaries). See the comments at the top of | |
2740 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ | |
2741 | ||
750054a2 CT |
2742 | if (flag_reorder_blocks_and_partition |
2743 | && (find_reg_note (BB_END (a), REG_CROSSING_JUMP, NULL_RTX) | |
2744 | || find_reg_note (BB_END (b), REG_CROSSING_JUMP, NULL_RTX) | |
076c7ab8 ZW |
2745 | || BB_PARTITION (a) != BB_PARTITION (b))) |
2746 | return false; | |
750054a2 | 2747 | |
bc35512f | 2748 | /* There must be exactly one edge in between the blocks. */ |
628f6a4e BE |
2749 | return (EDGE_COUNT (a->succs) == 1 |
2750 | && EDGE_SUCC (a, 0)->dest == b | |
2751 | && EDGE_COUNT (b->preds) == 1 | |
2752 | && a != b | |
bc35512f | 2753 | /* Must be simple edge. */ |
628f6a4e | 2754 | && !(EDGE_SUCC (a, 0)->flags & EDGE_COMPLEX) |
bc35512f JH |
2755 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR |
2756 | /* If the jump insn has side effects, | |
2757 | we can't kill the edge. */ | |
4b4bf941 | 2758 | && (!JUMP_P (BB_END (a)) |
e24e7211 | 2759 | || (reload_completed |
a813c111 | 2760 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f JH |
2761 | } |
2762 | ||
2763 | /* Merge block A and B, abort when it is not possible. */ | |
2764 | static void | |
2765 | cfg_layout_merge_blocks (basic_block a, basic_block b) | |
2766 | { | |
2767 | #ifdef ENABLE_CHECKING | |
341c100f | 2768 | gcc_assert (cfg_layout_can_merge_blocks_p (a, b)); |
bc35512f JH |
2769 | #endif |
2770 | ||
2771 | /* If there was a CODE_LABEL beginning B, delete it. */ | |
4b4bf941 | 2772 | if (LABEL_P (BB_HEAD (b))) |
a813c111 | 2773 | delete_insn (BB_HEAD (b)); |
bc35512f JH |
2774 | |
2775 | /* We should have fallthru edge in a, or we can do dummy redirection to get | |
2776 | it cleaned up. */ | |
4b4bf941 | 2777 | if (JUMP_P (BB_END (a))) |
628f6a4e | 2778 | try_redirect_by_replacing_jump (EDGE_SUCC (a, 0), b, true); |
341c100f | 2779 | gcc_assert (!JUMP_P (BB_END (a))); |
bc35512f JH |
2780 | |
2781 | /* Possible line number notes should appear in between. */ | |
2782 | if (b->rbi->header) | |
2783 | { | |
a813c111 | 2784 | rtx first = BB_END (a), last; |
bc35512f | 2785 | |
a7102479 | 2786 | last = emit_insn_after_noloc (b->rbi->header, BB_END (a)); |
bc35512f JH |
2787 | delete_insn_chain (NEXT_INSN (first), last); |
2788 | b->rbi->header = NULL; | |
2789 | } | |
2790 | ||
2791 | /* In the case basic blocks are not adjacent, move them around. */ | |
a813c111 | 2792 | if (NEXT_INSN (BB_END (a)) != BB_HEAD (b)) |
bc35512f | 2793 | { |
a813c111 | 2794 | rtx first = unlink_insn_chain (BB_HEAD (b), BB_END (b)); |
bc35512f | 2795 | |
a7102479 | 2796 | emit_insn_after_noloc (first, BB_END (a)); |
bc35512f JH |
2797 | /* Skip possible DELETED_LABEL insn. */ |
2798 | if (!NOTE_INSN_BASIC_BLOCK_P (first)) | |
2799 | first = NEXT_INSN (first); | |
341c100f | 2800 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (first)); |
a813c111 | 2801 | BB_HEAD (b) = NULL; |
bc35512f JH |
2802 | delete_insn (first); |
2803 | } | |
2804 | /* Otherwise just re-associate the instructions. */ | |
2805 | else | |
2806 | { | |
2807 | rtx insn; | |
2808 | ||
a813c111 SB |
2809 | for (insn = BB_HEAD (b); |
2810 | insn != NEXT_INSN (BB_END (b)); | |
2811 | insn = NEXT_INSN (insn)) | |
bc35512f | 2812 | set_block_for_insn (insn, a); |
a813c111 | 2813 | insn = BB_HEAD (b); |
bc35512f JH |
2814 | /* Skip possible DELETED_LABEL insn. */ |
2815 | if (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
2816 | insn = NEXT_INSN (insn); | |
341c100f | 2817 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn)); |
a813c111 SB |
2818 | BB_HEAD (b) = NULL; |
2819 | BB_END (a) = BB_END (b); | |
bc35512f JH |
2820 | delete_insn (insn); |
2821 | } | |
2822 | ||
2823 | /* Possible tablejumps and barriers should appear after the block. */ | |
2824 | if (b->rbi->footer) | |
2825 | { | |
2826 | if (!a->rbi->footer) | |
2827 | a->rbi->footer = b->rbi->footer; | |
2828 | else | |
2829 | { | |
2830 | rtx last = a->rbi->footer; | |
2831 | ||
2832 | while (NEXT_INSN (last)) | |
2833 | last = NEXT_INSN (last); | |
2834 | NEXT_INSN (last) = b->rbi->footer; | |
2835 | PREV_INSN (b->rbi->footer) = last; | |
2836 | } | |
2837 | b->rbi->footer = NULL; | |
2838 | } | |
2839 | ||
c263766c RH |
2840 | if (dump_file) |
2841 | fprintf (dump_file, "Merged blocks %d and %d.\n", | |
bc35512f | 2842 | a->index, b->index); |
bc35512f JH |
2843 | } |
2844 | ||
2845 | /* Split edge E. */ | |
f470c378 | 2846 | |
bc35512f JH |
2847 | static basic_block |
2848 | cfg_layout_split_edge (edge e) | |
2849 | { | |
2850 | edge new_e; | |
2851 | basic_block new_bb = | |
2852 | create_basic_block (e->src != ENTRY_BLOCK_PTR | |
a813c111 | 2853 | ? NEXT_INSN (BB_END (e->src)) : get_insns (), |
bc35512f JH |
2854 | NULL_RTX, e->src); |
2855 | ||
af874237 JW |
2856 | /* ??? This info is likely going to be out of date very soon, but we must |
2857 | create it to avoid getting an ICE later. */ | |
2858 | if (e->dest->global_live_at_start) | |
2859 | { | |
2860 | new_bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
2861 | new_bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack); | |
2862 | COPY_REG_SET (new_bb->global_live_at_start, | |
2863 | e->dest->global_live_at_start); | |
2864 | COPY_REG_SET (new_bb->global_live_at_end, | |
2865 | e->dest->global_live_at_start); | |
2866 | } | |
2867 | ||
bc35512f | 2868 | new_e = make_edge (new_bb, e->dest, EDGE_FALLTHRU); |
bc35512f JH |
2869 | redirect_edge_and_branch_force (e, new_bb); |
2870 | ||
2871 | return new_bb; | |
2872 | } | |
2873 | ||
f470c378 ZD |
2874 | /* Do postprocessing after making a forwarder block joined by edge FALLTHRU. */ |
2875 | ||
2876 | static void | |
2877 | rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED) | |
2878 | { | |
2879 | } | |
2880 | ||
6de9cd9a DN |
2881 | /* Return 1 if BB ends with a call, possibly followed by some |
2882 | instructions that must stay with the call, 0 otherwise. */ | |
2883 | ||
2884 | static bool | |
2885 | rtl_block_ends_with_call_p (basic_block bb) | |
2886 | { | |
2887 | rtx insn = BB_END (bb); | |
2888 | ||
4b4bf941 | 2889 | while (!CALL_P (insn) |
6de9cd9a DN |
2890 | && insn != BB_HEAD (bb) |
2891 | && keep_with_call_p (insn)) | |
2892 | insn = PREV_INSN (insn); | |
4b4bf941 | 2893 | return (CALL_P (insn)); |
6de9cd9a DN |
2894 | } |
2895 | ||
2896 | /* Return 1 if BB ends with a conditional branch, 0 otherwise. */ | |
2897 | ||
2898 | static bool | |
2899 | rtl_block_ends_with_condjump_p (basic_block bb) | |
2900 | { | |
2901 | return any_condjump_p (BB_END (bb)); | |
2902 | } | |
2903 | ||
2904 | /* Return true if we need to add fake edge to exit. | |
2905 | Helper function for rtl_flow_call_edges_add. */ | |
2906 | ||
2907 | static bool | |
2908 | need_fake_edge_p (rtx insn) | |
2909 | { | |
2910 | if (!INSN_P (insn)) | |
2911 | return false; | |
2912 | ||
4b4bf941 | 2913 | if ((CALL_P (insn) |
6de9cd9a DN |
2914 | && !SIBLING_CALL_P (insn) |
2915 | && !find_reg_note (insn, REG_NORETURN, NULL) | |
2916 | && !find_reg_note (insn, REG_ALWAYS_RETURN, NULL) | |
2917 | && !CONST_OR_PURE_CALL_P (insn))) | |
2918 | return true; | |
2919 | ||
2920 | return ((GET_CODE (PATTERN (insn)) == ASM_OPERANDS | |
2921 | && MEM_VOLATILE_P (PATTERN (insn))) | |
2922 | || (GET_CODE (PATTERN (insn)) == PARALLEL | |
2923 | && asm_noperands (insn) != -1 | |
2924 | && MEM_VOLATILE_P (XVECEXP (PATTERN (insn), 0, 0))) | |
2925 | || GET_CODE (PATTERN (insn)) == ASM_INPUT); | |
2926 | } | |
2927 | ||
2928 | /* Add fake edges to the function exit for any non constant and non noreturn | |
2929 | calls, volatile inline assembly in the bitmap of blocks specified by | |
2930 | BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks | |
2931 | that were split. | |
2932 | ||
2933 | The goal is to expose cases in which entering a basic block does not imply | |
2934 | that all subsequent instructions must be executed. */ | |
2935 | ||
2936 | static int | |
2937 | rtl_flow_call_edges_add (sbitmap blocks) | |
2938 | { | |
2939 | int i; | |
2940 | int blocks_split = 0; | |
2941 | int last_bb = last_basic_block; | |
2942 | bool check_last_block = false; | |
2943 | ||
2944 | if (n_basic_blocks == 0) | |
2945 | return 0; | |
2946 | ||
2947 | if (! blocks) | |
2948 | check_last_block = true; | |
2949 | else | |
2950 | check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index); | |
2951 | ||
2952 | /* In the last basic block, before epilogue generation, there will be | |
2953 | a fallthru edge to EXIT. Special care is required if the last insn | |
2954 | of the last basic block is a call because make_edge folds duplicate | |
2955 | edges, which would result in the fallthru edge also being marked | |
2956 | fake, which would result in the fallthru edge being removed by | |
2957 | remove_fake_edges, which would result in an invalid CFG. | |
2958 | ||
2959 | Moreover, we can't elide the outgoing fake edge, since the block | |
2960 | profiler needs to take this into account in order to solve the minimal | |
2961 | spanning tree in the case that the call doesn't return. | |
2962 | ||
2963 | Handle this by adding a dummy instruction in a new last basic block. */ | |
2964 | if (check_last_block) | |
2965 | { | |
2966 | basic_block bb = EXIT_BLOCK_PTR->prev_bb; | |
2967 | rtx insn = BB_END (bb); | |
2968 | ||
2969 | /* Back up past insns that must be kept in the same block as a call. */ | |
2970 | while (insn != BB_HEAD (bb) | |
2971 | && keep_with_call_p (insn)) | |
2972 | insn = PREV_INSN (insn); | |
2973 | ||
2974 | if (need_fake_edge_p (insn)) | |
2975 | { | |
2976 | edge e; | |
628f6a4e | 2977 | edge_iterator ei; |
6de9cd9a | 2978 | |
628f6a4e | 2979 | FOR_EACH_EDGE (e, ei, bb->succs) |
6de9cd9a DN |
2980 | if (e->dest == EXIT_BLOCK_PTR) |
2981 | { | |
2982 | insert_insn_on_edge (gen_rtx_USE (VOIDmode, const0_rtx), e); | |
2983 | commit_edge_insertions (); | |
2984 | break; | |
2985 | } | |
2986 | } | |
2987 | } | |
2988 | ||
2989 | /* Now add fake edges to the function exit for any non constant | |
2990 | calls since there is no way that we can determine if they will | |
2991 | return or not... */ | |
2992 | ||
2993 | for (i = 0; i < last_bb; i++) | |
2994 | { | |
2995 | basic_block bb = BASIC_BLOCK (i); | |
2996 | rtx insn; | |
2997 | rtx prev_insn; | |
2998 | ||
2999 | if (!bb) | |
3000 | continue; | |
3001 | ||
3002 | if (blocks && !TEST_BIT (blocks, i)) | |
3003 | continue; | |
3004 | ||
3005 | for (insn = BB_END (bb); ; insn = prev_insn) | |
3006 | { | |
3007 | prev_insn = PREV_INSN (insn); | |
3008 | if (need_fake_edge_p (insn)) | |
3009 | { | |
3010 | edge e; | |
3011 | rtx split_at_insn = insn; | |
3012 | ||
3013 | /* Don't split the block between a call and an insn that should | |
3014 | remain in the same block as the call. */ | |
4b4bf941 | 3015 | if (CALL_P (insn)) |
6de9cd9a DN |
3016 | while (split_at_insn != BB_END (bb) |
3017 | && keep_with_call_p (NEXT_INSN (split_at_insn))) | |
3018 | split_at_insn = NEXT_INSN (split_at_insn); | |
3019 | ||
3020 | /* The handling above of the final block before the epilogue | |
3021 | should be enough to verify that there is no edge to the exit | |
3022 | block in CFG already. Calling make_edge in such case would | |
3023 | cause us to mark that edge as fake and remove it later. */ | |
3024 | ||
3025 | #ifdef ENABLE_CHECKING | |
3026 | if (split_at_insn == BB_END (bb)) | |
628f6a4e BE |
3027 | { |
3028 | edge_iterator ei; | |
3029 | FOR_EACH_EDGE (e, ei, bb->succs) | |
3030 | gcc_assert (e->dest != EXIT_BLOCK_PTR); | |
3031 | } | |
6de9cd9a DN |
3032 | #endif |
3033 | ||
3034 | /* Note that the following may create a new basic block | |
3035 | and renumber the existing basic blocks. */ | |
3036 | if (split_at_insn != BB_END (bb)) | |
3037 | { | |
3038 | e = split_block (bb, split_at_insn); | |
3039 | if (e) | |
3040 | blocks_split++; | |
3041 | } | |
3042 | ||
3043 | make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE); | |
3044 | } | |
3045 | ||
3046 | if (insn == BB_HEAD (bb)) | |
3047 | break; | |
3048 | } | |
3049 | } | |
3050 | ||
3051 | if (blocks_split) | |
3052 | verify_flow_info (); | |
3053 | ||
3054 | return blocks_split; | |
3055 | } | |
3056 | ||
9ee634e3 JH |
3057 | /* Implementation of CFG manipulation for linearized RTL. */ |
3058 | struct cfg_hooks rtl_cfg_hooks = { | |
f470c378 | 3059 | "rtl", |
9ee634e3 | 3060 | rtl_verify_flow_info, |
10e9fecc | 3061 | rtl_dump_bb, |
bc35512f | 3062 | rtl_create_basic_block, |
9ee634e3 JH |
3063 | rtl_redirect_edge_and_branch, |
3064 | rtl_redirect_edge_and_branch_force, | |
3065 | rtl_delete_block, | |
3066 | rtl_split_block, | |
f470c378 | 3067 | rtl_move_block_after, |
bc35512f JH |
3068 | rtl_can_merge_blocks, /* can_merge_blocks_p */ |
3069 | rtl_merge_blocks, | |
6de9cd9a DN |
3070 | rtl_predict_edge, |
3071 | rtl_predicted_by_p, | |
3072 | NULL, /* can_duplicate_block_p */ | |
3073 | NULL, /* duplicate_block */ | |
f470c378 ZD |
3074 | rtl_split_edge, |
3075 | rtl_make_forwarder_block, | |
6de9cd9a DN |
3076 | rtl_tidy_fallthru_edge, |
3077 | rtl_block_ends_with_call_p, | |
3078 | rtl_block_ends_with_condjump_p, | |
3079 | rtl_flow_call_edges_add | |
9ee634e3 JH |
3080 | }; |
3081 | ||
3082 | /* Implementation of CFG manipulation for cfg layout RTL, where | |
3083 | basic block connected via fallthru edges does not have to be adjacent. | |
3084 | This representation will hopefully become the default one in future | |
3085 | version of the compiler. */ | |
6de9cd9a DN |
3086 | |
3087 | /* We do not want to declare these functions in a header file, since they | |
3088 | should only be used through the cfghooks interface, and we do not want to | |
3089 | move them here since it would require also moving quite a lot of related | |
3090 | code. */ | |
3091 | extern bool cfg_layout_can_duplicate_bb_p (basic_block); | |
3092 | extern basic_block cfg_layout_duplicate_bb (basic_block); | |
3093 | ||
9ee634e3 | 3094 | struct cfg_hooks cfg_layout_rtl_cfg_hooks = { |
f470c378 | 3095 | "cfglayout mode", |
bc35512f | 3096 | rtl_verify_flow_info_1, |
10e9fecc | 3097 | rtl_dump_bb, |
bc35512f | 3098 | cfg_layout_create_basic_block, |
9ee634e3 JH |
3099 | cfg_layout_redirect_edge_and_branch, |
3100 | cfg_layout_redirect_edge_and_branch_force, | |
3101 | cfg_layout_delete_block, | |
3102 | cfg_layout_split_block, | |
f470c378 | 3103 | rtl_move_block_after, |
bc35512f JH |
3104 | cfg_layout_can_merge_blocks_p, |
3105 | cfg_layout_merge_blocks, | |
6de9cd9a DN |
3106 | rtl_predict_edge, |
3107 | rtl_predicted_by_p, | |
3108 | cfg_layout_can_duplicate_bb_p, | |
3109 | cfg_layout_duplicate_bb, | |
f470c378 ZD |
3110 | cfg_layout_split_edge, |
3111 | rtl_make_forwarder_block, | |
6de9cd9a DN |
3112 | NULL, |
3113 | rtl_block_ends_with_call_p, | |
3114 | rtl_block_ends_with_condjump_p, | |
3115 | rtl_flow_call_edges_add | |
9ee634e3 | 3116 | }; |
6de9cd9a | 3117 |