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