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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, | |
7072a650 | 3 | 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 |
6fb5fa3c | 4 | Free Software Foundation, Inc. |
ca6c03ca JH |
5 | |
6 | This file is part of GCC. | |
7 | ||
8 | GCC is free software; you can redistribute it and/or modify it under | |
9 | the terms of the GNU General Public License as published by the Free | |
9dcd6f09 | 10 | Software Foundation; either version 3, or (at your option) any later |
ca6c03ca JH |
11 | version. |
12 | ||
13 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
14 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
19 | along with GCC; see the file COPYING3. If not see |
20 | <http://www.gnu.org/licenses/>. */ | |
ca6c03ca | 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" | |
2a34bece | 56 | #include "insn-attr.h" |
0a2ed1f1 | 57 | #include "insn-config.h" |
9ee634e3 | 58 | #include "cfglayout.h" |
ff25ef99 | 59 | #include "expr.h" |
9fb32434 | 60 | #include "target.h" |
1cb7dfc3 | 61 | #include "cfgloop.h" |
5e2d947c | 62 | #include "ggc.h" |
ef330312 | 63 | #include "tree-pass.h" |
6fb5fa3c | 64 | #include "df.h" |
ca6c03ca | 65 | |
9678086d KG |
66 | static int can_delete_note_p (const_rtx); |
67 | static int can_delete_label_p (const_rtx); | |
d329e058 | 68 | static basic_block rtl_split_edge (edge); |
f470c378 | 69 | static bool rtl_move_block_after (basic_block, basic_block); |
d329e058 | 70 | static int rtl_verify_flow_info (void); |
f470c378 | 71 | static basic_block cfg_layout_split_block (basic_block, void *); |
6de9cd9a | 72 | static edge cfg_layout_redirect_edge_and_branch (edge, basic_block); |
d329e058 AJ |
73 | static basic_block cfg_layout_redirect_edge_and_branch_force (edge, basic_block); |
74 | static void cfg_layout_delete_block (basic_block); | |
75 | static void rtl_delete_block (basic_block); | |
76 | static basic_block rtl_redirect_edge_and_branch_force (edge, basic_block); | |
6de9cd9a | 77 | static edge rtl_redirect_edge_and_branch (edge, basic_block); |
f470c378 | 78 | static basic_block rtl_split_block (basic_block, void *); |
726a989a | 79 | static void rtl_dump_bb (basic_block, FILE *, int, int); |
d329e058 | 80 | static int rtl_verify_flow_info_1 (void); |
f470c378 | 81 | static void rtl_make_forwarder_block (edge); |
ca6c03ca JH |
82 | \f |
83 | /* Return true if NOTE is not one of the ones that must be kept paired, | |
5f0d2358 | 84 | so that we may simply delete it. */ |
ca6c03ca JH |
85 | |
86 | static int | |
9678086d | 87 | can_delete_note_p (const_rtx note) |
ca6c03ca | 88 | { |
cd9c1ca8 RH |
89 | switch (NOTE_KIND (note)) |
90 | { | |
91 | case NOTE_INSN_DELETED: | |
92 | case NOTE_INSN_BASIC_BLOCK: | |
93 | case NOTE_INSN_EPILOGUE_BEG: | |
94 | return true; | |
95 | ||
96 | default: | |
97 | return false; | |
98 | } | |
ca6c03ca JH |
99 | } |
100 | ||
101 | /* True if a given label can be deleted. */ | |
102 | ||
103 | static int | |
9678086d | 104 | can_delete_label_p (const_rtx label) |
ca6c03ca | 105 | { |
5f0d2358 RK |
106 | return (!LABEL_PRESERVE_P (label) |
107 | /* User declared labels must be preserved. */ | |
108 | && LABEL_NAME (label) == 0 | |
610d2478 | 109 | && !in_expr_list_p (forced_labels, label)); |
ca6c03ca JH |
110 | } |
111 | ||
112 | /* Delete INSN by patching it out. Return the next insn. */ | |
113 | ||
114 | rtx | |
d329e058 | 115 | delete_insn (rtx insn) |
ca6c03ca JH |
116 | { |
117 | rtx next = NEXT_INSN (insn); | |
118 | rtx note; | |
119 | bool really_delete = true; | |
120 | ||
4b4bf941 | 121 | if (LABEL_P (insn)) |
ca6c03ca JH |
122 | { |
123 | /* Some labels can't be directly removed from the INSN chain, as they | |
c22cacf3 MS |
124 | might be references via variables, constant pool etc. |
125 | Convert them to the special NOTE_INSN_DELETED_LABEL note. */ | |
ca6c03ca JH |
126 | if (! can_delete_label_p (insn)) |
127 | { | |
128 | const char *name = LABEL_NAME (insn); | |
129 | ||
130 | really_delete = false; | |
131 | PUT_CODE (insn, NOTE); | |
a38e7aa5 | 132 | NOTE_KIND (insn) = NOTE_INSN_DELETED_LABEL; |
6773e15f | 133 | NOTE_DELETED_LABEL_NAME (insn) = name; |
ca6c03ca | 134 | } |
5f0d2358 | 135 | |
ca6c03ca JH |
136 | remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels); |
137 | } | |
138 | ||
139 | if (really_delete) | |
140 | { | |
cda94cbb | 141 | /* If this insn has already been deleted, something is very wrong. */ |
341c100f | 142 | gcc_assert (!INSN_DELETED_P (insn)); |
ca6c03ca JH |
143 | remove_insn (insn); |
144 | INSN_DELETED_P (insn) = 1; | |
145 | } | |
146 | ||
147 | /* If deleting a jump, decrement the use count of the label. Deleting | |
148 | the label itself should happen in the normal course of block merging. */ | |
cf7c4aa6 | 149 | if (JUMP_P (insn)) |
9295a326 | 150 | { |
cf7c4aa6 HPN |
151 | if (JUMP_LABEL (insn) |
152 | && LABEL_P (JUMP_LABEL (insn))) | |
153 | LABEL_NUSES (JUMP_LABEL (insn))--; | |
154 | ||
155 | /* If there are more targets, remove them too. */ | |
156 | while ((note | |
157 | = find_reg_note (insn, REG_LABEL_TARGET, 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 | |
cf7c4aa6 HPN |
165 | /* Also if deleting any insn that references a label as an operand. */ |
166 | while ((note = find_reg_note (insn, REG_LABEL_OPERAND, NULL_RTX)) != NULL_RTX | |
167 | && LABEL_P (XEXP (note, 0))) | |
168 | { | |
169 | LABEL_NUSES (XEXP (note, 0))--; | |
170 | remove_note (insn, note); | |
171 | } | |
172 | ||
481683e1 | 173 | if (JUMP_TABLE_DATA_P (insn)) |
ca6c03ca JH |
174 | { |
175 | rtx pat = PATTERN (insn); | |
176 | int diff_vec_p = GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC; | |
177 | int len = XVECLEN (pat, diff_vec_p); | |
178 | int i; | |
179 | ||
180 | for (i = 0; i < len; i++) | |
a124fcda RH |
181 | { |
182 | rtx label = XEXP (XVECEXP (pat, diff_vec_p, i), 0); | |
183 | ||
184 | /* When deleting code in bulk (e.g. removing many unreachable | |
185 | blocks) we can delete a label that's a target of the vector | |
186 | before deleting the vector itself. */ | |
4b4bf941 | 187 | if (!NOTE_P (label)) |
a124fcda RH |
188 | LABEL_NUSES (label)--; |
189 | } | |
ca6c03ca JH |
190 | } |
191 | ||
192 | return next; | |
193 | } | |
194 | ||
3dec4024 | 195 | /* Like delete_insn but also purge dead edges from BB. */ |
9ed7b221 | 196 | |
3dec4024 | 197 | rtx |
d329e058 | 198 | delete_insn_and_edges (rtx insn) |
3dec4024 JH |
199 | { |
200 | rtx x; | |
201 | bool purge = false; | |
202 | ||
ba4f7968 | 203 | if (INSN_P (insn) |
3dec4024 | 204 | && BLOCK_FOR_INSN (insn) |
a813c111 | 205 | && BB_END (BLOCK_FOR_INSN (insn)) == insn) |
3dec4024 JH |
206 | purge = true; |
207 | x = delete_insn (insn); | |
208 | if (purge) | |
209 | purge_dead_edges (BLOCK_FOR_INSN (insn)); | |
210 | return x; | |
211 | } | |
212 | ||
ca6c03ca | 213 | /* Unlink a chain of insns between START and FINISH, leaving notes |
a7b87f73 ZD |
214 | that must be paired. If CLEAR_BB is true, we set bb field for |
215 | insns that cannot be removed to NULL. */ | |
ca6c03ca JH |
216 | |
217 | void | |
a7b87f73 | 218 | delete_insn_chain (rtx start, rtx finish, bool clear_bb) |
ca6c03ca | 219 | { |
ca6c03ca JH |
220 | rtx next; |
221 | ||
5f0d2358 RK |
222 | /* Unchain the insns one by one. It would be quicker to delete all of these |
223 | with a single unchaining, rather than one at a time, but we need to keep | |
224 | the NOTE's. */ | |
ca6c03ca JH |
225 | while (1) |
226 | { | |
227 | next = NEXT_INSN (start); | |
4b4bf941 | 228 | if (NOTE_P (start) && !can_delete_note_p (start)) |
ca6c03ca JH |
229 | ; |
230 | else | |
231 | next = delete_insn (start); | |
232 | ||
a7b87f73 ZD |
233 | if (clear_bb && !INSN_DELETED_P (start)) |
234 | set_block_for_insn (start, NULL); | |
235 | ||
ca6c03ca JH |
236 | if (start == finish) |
237 | break; | |
238 | start = next; | |
239 | } | |
240 | } | |
241 | \f | |
5f0d2358 RK |
242 | /* Create a new basic block consisting of the instructions between HEAD and END |
243 | inclusive. This function is designed to allow fast BB construction - reuses | |
244 | the note and basic block struct in BB_NOTE, if any and do not grow | |
245 | BASIC_BLOCK chain and should be used directly only by CFG construction code. | |
246 | END can be NULL in to create new empty basic block before HEAD. Both END | |
918ed612 ZD |
247 | and HEAD can be NULL to create basic block at the end of INSN chain. |
248 | AFTER is the basic block we should be put after. */ | |
ca6c03ca JH |
249 | |
250 | basic_block | |
d329e058 | 251 | create_basic_block_structure (rtx head, rtx end, rtx bb_note, basic_block after) |
ca6c03ca JH |
252 | { |
253 | basic_block bb; | |
254 | ||
255 | if (bb_note | |
ca6c03ca JH |
256 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL |
257 | && bb->aux == NULL) | |
258 | { | |
259 | /* If we found an existing note, thread it back onto the chain. */ | |
260 | ||
261 | rtx after; | |
262 | ||
4b4bf941 | 263 | if (LABEL_P (head)) |
ca6c03ca JH |
264 | after = head; |
265 | else | |
266 | { | |
267 | after = PREV_INSN (head); | |
268 | head = bb_note; | |
269 | } | |
270 | ||
271 | if (after != bb_note && NEXT_INSN (after) != bb_note) | |
ba4f7968 | 272 | reorder_insns_nobb (bb_note, bb_note, after); |
ca6c03ca JH |
273 | } |
274 | else | |
275 | { | |
276 | /* Otherwise we must create a note and a basic block structure. */ | |
277 | ||
278 | bb = alloc_block (); | |
279 | ||
5e2d947c | 280 | init_rtl_bb_info (bb); |
ca6c03ca | 281 | if (!head && !end) |
5f0d2358 RK |
282 | head = end = bb_note |
283 | = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); | |
4b4bf941 | 284 | else if (LABEL_P (head) && end) |
ca6c03ca JH |
285 | { |
286 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); | |
287 | if (head == end) | |
288 | end = bb_note; | |
289 | } | |
290 | else | |
291 | { | |
292 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); | |
293 | head = bb_note; | |
294 | if (!end) | |
295 | end = head; | |
296 | } | |
5f0d2358 | 297 | |
ca6c03ca JH |
298 | NOTE_BASIC_BLOCK (bb_note) = bb; |
299 | } | |
300 | ||
301 | /* Always include the bb note in the block. */ | |
302 | if (NEXT_INSN (end) == bb_note) | |
303 | end = bb_note; | |
304 | ||
a813c111 SB |
305 | BB_HEAD (bb) = head; |
306 | BB_END (bb) = end; | |
852c6ec7 | 307 | bb->index = last_basic_block++; |
5e2d947c | 308 | bb->flags = BB_NEW | BB_RTL; |
918ed612 | 309 | link_block (bb, after); |
68f9b844 | 310 | SET_BASIC_BLOCK (bb->index, bb); |
6fb5fa3c | 311 | df_bb_refs_record (bb->index, false); |
ba4f7968 | 312 | update_bb_for_insn (bb); |
076c7ab8 | 313 | BB_SET_PARTITION (bb, BB_UNPARTITIONED); |
ca6c03ca JH |
314 | |
315 | /* Tag the block so that we know it has been used when considering | |
316 | other basic block notes. */ | |
317 | bb->aux = bb; | |
318 | ||
319 | return bb; | |
320 | } | |
321 | ||
5f0d2358 | 322 | /* Create new basic block consisting of instructions in between HEAD and END |
918ed612 | 323 | and place it to the BB chain after block AFTER. END can be NULL in to |
5f0d2358 RK |
324 | create new empty basic block before HEAD. Both END and HEAD can be NULL to |
325 | create basic block at the end of INSN chain. */ | |
ca6c03ca | 326 | |
bc35512f JH |
327 | static basic_block |
328 | rtl_create_basic_block (void *headp, void *endp, basic_block after) | |
ca6c03ca | 329 | { |
ae50c0cb | 330 | rtx head = (rtx) headp, end = (rtx) endp; |
ca6c03ca | 331 | basic_block bb; |
0b17ab2f | 332 | |
7eca0767 | 333 | /* Grow the basic block array if needed. */ |
68f9b844 | 334 | if ((size_t) last_basic_block >= VEC_length (basic_block, basic_block_info)) |
7eca0767 JH |
335 | { |
336 | size_t new_size = last_basic_block + (last_basic_block + 3) / 4; | |
a590ac65 | 337 | VEC_safe_grow_cleared (basic_block, gc, basic_block_info, new_size); |
7eca0767 | 338 | } |
0b17ab2f | 339 | |
bf77398c | 340 | n_basic_blocks++; |
ca6c03ca | 341 | |
852c6ec7 | 342 | bb = create_basic_block_structure (head, end, NULL, after); |
ca6c03ca JH |
343 | bb->aux = NULL; |
344 | return bb; | |
345 | } | |
bc35512f JH |
346 | |
347 | static basic_block | |
348 | cfg_layout_create_basic_block (void *head, void *end, basic_block after) | |
349 | { | |
350 | basic_block newbb = rtl_create_basic_block (head, end, after); | |
351 | ||
bc35512f JH |
352 | return newbb; |
353 | } | |
ca6c03ca JH |
354 | \f |
355 | /* Delete the insns in a (non-live) block. We physically delete every | |
356 | non-deleted-note insn, and update the flow graph appropriately. | |
357 | ||
358 | Return nonzero if we deleted an exception handler. */ | |
359 | ||
360 | /* ??? Preserving all such notes strikes me as wrong. It would be nice | |
361 | to post-process the stream to remove empty blocks, loops, ranges, etc. */ | |
362 | ||
f0fda11c | 363 | static void |
d329e058 | 364 | rtl_delete_block (basic_block b) |
ca6c03ca | 365 | { |
96370780 | 366 | rtx insn, end; |
ca6c03ca JH |
367 | |
368 | /* If the head of this block is a CODE_LABEL, then it might be the | |
f39e46ba SB |
369 | label for an exception handler which can't be reached. We need |
370 | to remove the label from the exception_handler_label list. */ | |
a813c111 | 371 | insn = BB_HEAD (b); |
ca6c03ca | 372 | |
96370780 | 373 | end = get_last_bb_insn (b); |
ca6c03ca JH |
374 | |
375 | /* Selectively delete the entire chain. */ | |
a813c111 | 376 | BB_HEAD (b) = NULL; |
a7b87f73 ZD |
377 | delete_insn_chain (insn, end, true); |
378 | ||
6fb5fa3c DB |
379 | |
380 | if (dump_file) | |
381 | fprintf (dump_file, "deleting block %d\n", b->index); | |
382 | df_bb_delete (b->index); | |
ca6c03ca JH |
383 | } |
384 | \f | |
852c6ec7 | 385 | /* Records the basic block struct in BLOCK_FOR_INSN for every insn. */ |
ca6c03ca JH |
386 | |
387 | void | |
d329e058 | 388 | compute_bb_for_insn (void) |
ca6c03ca | 389 | { |
e0082a72 | 390 | basic_block bb; |
ca6c03ca | 391 | |
e0082a72 | 392 | FOR_EACH_BB (bb) |
ca6c03ca | 393 | { |
a813c111 | 394 | rtx end = BB_END (bb); |
5f0d2358 | 395 | rtx insn; |
ca6c03ca | 396 | |
a813c111 | 397 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
ca6c03ca | 398 | { |
ba4f7968 | 399 | BLOCK_FOR_INSN (insn) = bb; |
ca6c03ca JH |
400 | if (insn == end) |
401 | break; | |
ca6c03ca JH |
402 | } |
403 | } | |
404 | } | |
405 | ||
406 | /* Release the basic_block_for_insn array. */ | |
407 | ||
c2924966 | 408 | unsigned int |
d329e058 | 409 | free_bb_for_insn (void) |
ca6c03ca | 410 | { |
ba4f7968 JH |
411 | rtx insn; |
412 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) | |
4b4bf941 | 413 | if (!BARRIER_P (insn)) |
ba4f7968 | 414 | BLOCK_FOR_INSN (insn) = NULL; |
c2924966 | 415 | return 0; |
ca6c03ca JH |
416 | } |
417 | ||
2a34bece EB |
418 | static unsigned int |
419 | rest_of_pass_free_cfg (void) | |
420 | { | |
421 | #ifdef DELAY_SLOTS | |
422 | /* The resource.c machinery uses DF but the CFG isn't guaranteed to be | |
423 | valid at that point so it would be too late to call df_analyze. */ | |
424 | if (optimize > 0 && flag_delayed_branch) | |
425 | df_analyze (); | |
426 | #endif | |
427 | ||
428 | free_bb_for_insn (); | |
429 | return 0; | |
430 | } | |
431 | ||
8ddbbcae | 432 | struct rtl_opt_pass pass_free_cfg = |
ef330312 | 433 | { |
8ddbbcae JH |
434 | { |
435 | RTL_PASS, | |
e0a42b0f | 436 | "*free_cfg", /* name */ |
ef330312 | 437 | NULL, /* gate */ |
2a34bece | 438 | rest_of_pass_free_cfg, /* execute */ |
ef330312 PB |
439 | NULL, /* sub */ |
440 | NULL, /* next */ | |
441 | 0, /* static_pass_number */ | |
7072a650 | 442 | TV_NONE, /* tv_id */ |
ef330312 PB |
443 | 0, /* properties_required */ |
444 | 0, /* properties_provided */ | |
445 | PROP_cfg, /* properties_destroyed */ | |
446 | 0, /* todo_flags_start */ | |
447 | 0, /* todo_flags_finish */ | |
8ddbbcae | 448 | } |
ef330312 PB |
449 | }; |
450 | ||
91278841 AP |
451 | /* Return RTX to emit after when we want to emit code on the entry of function. */ |
452 | rtx | |
453 | entry_of_function (void) | |
454 | { | |
c22cacf3 | 455 | return (n_basic_blocks > NUM_FIXED_BLOCKS ? |
24bd1a0b | 456 | BB_HEAD (ENTRY_BLOCK_PTR->next_bb) : get_insns ()); |
91278841 AP |
457 | } |
458 | ||
11b904a1 BS |
459 | /* Emit INSN at the entry point of the function, ensuring that it is only |
460 | executed once per function. */ | |
461 | void | |
462 | emit_insn_at_entry (rtx insn) | |
463 | { | |
464 | edge_iterator ei = ei_start (ENTRY_BLOCK_PTR->succs); | |
465 | edge e = ei_safe_edge (ei); | |
5419bc7f | 466 | gcc_assert (e->flags & EDGE_FALLTHRU); |
11b904a1 BS |
467 | |
468 | insert_insn_on_edge (insn, e); | |
469 | commit_edge_insertions (); | |
470 | } | |
471 | ||
6c3d0e31 | 472 | /* Update BLOCK_FOR_INSN of insns between BEGIN and END |
b8698a0f | 473 | (or BARRIER if found) and notify df of the bb change. |
6c3d0e31 SP |
474 | The insn chain range is inclusive |
475 | (i.e. both BEGIN and END will be updated. */ | |
ca6c03ca | 476 | |
6c3d0e31 SP |
477 | static void |
478 | update_bb_for_insn_chain (rtx begin, rtx end, basic_block bb) | |
ca6c03ca JH |
479 | { |
480 | rtx insn; | |
481 | ||
6c3d0e31 SP |
482 | end = NEXT_INSN (end); |
483 | for (insn = begin; insn != end; insn = NEXT_INSN (insn)) | |
63642d5a AO |
484 | if (!BARRIER_P (insn)) |
485 | df_insn_change_bb (insn, bb); | |
ca6c03ca | 486 | } |
6c3d0e31 SP |
487 | |
488 | /* Update BLOCK_FOR_INSN of insns in BB to BB, | |
489 | and notify df of the change. */ | |
490 | ||
491 | void | |
492 | update_bb_for_insn (basic_block bb) | |
493 | { | |
494 | update_bb_for_insn_chain (BB_HEAD (bb), BB_END (bb), bb); | |
495 | } | |
496 | ||
ca6c03ca | 497 | \f |
6fb5fa3c DB |
498 | /* Return the INSN immediately following the NOTE_INSN_BASIC_BLOCK |
499 | note associated with the BLOCK. */ | |
500 | ||
501 | static rtx | |
502 | first_insn_after_basic_block_note (basic_block block) | |
503 | { | |
504 | rtx insn; | |
505 | ||
506 | /* Get the first instruction in the block. */ | |
507 | insn = BB_HEAD (block); | |
508 | ||
509 | if (insn == NULL_RTX) | |
510 | return NULL_RTX; | |
511 | if (LABEL_P (insn)) | |
512 | insn = NEXT_INSN (insn); | |
513 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn)); | |
514 | ||
515 | return NEXT_INSN (insn); | |
516 | } | |
517 | ||
f470c378 ZD |
518 | /* Creates a new basic block just after basic block B by splitting |
519 | everything after specified instruction I. */ | |
ca6c03ca | 520 | |
f470c378 | 521 | static basic_block |
d329e058 | 522 | rtl_split_block (basic_block bb, void *insnp) |
ca6c03ca JH |
523 | { |
524 | basic_block new_bb; | |
ae50c0cb | 525 | rtx insn = (rtx) insnp; |
f470c378 | 526 | edge e; |
628f6a4e | 527 | edge_iterator ei; |
ca6c03ca | 528 | |
f470c378 ZD |
529 | if (!insn) |
530 | { | |
531 | insn = first_insn_after_basic_block_note (bb); | |
532 | ||
533 | if (insn) | |
b5b8b0ac AO |
534 | { |
535 | rtx next = insn; | |
536 | ||
537 | insn = PREV_INSN (insn); | |
538 | ||
539 | /* If the block contains only debug insns, insn would have | |
540 | been NULL in a non-debug compilation, and then we'd end | |
541 | up emitting a DELETED note. For -fcompare-debug | |
542 | stability, emit the note too. */ | |
543 | if (insn != BB_END (bb) | |
544 | && DEBUG_INSN_P (next) | |
545 | && DEBUG_INSN_P (BB_END (bb))) | |
546 | { | |
547 | while (next != BB_END (bb) && DEBUG_INSN_P (next)) | |
548 | next = NEXT_INSN (next); | |
549 | ||
550 | if (next == BB_END (bb)) | |
551 | emit_note_after (NOTE_INSN_DELETED, next); | |
552 | } | |
553 | } | |
f470c378 ZD |
554 | else |
555 | insn = get_last_insn (); | |
556 | } | |
557 | ||
558 | /* We probably should check type of the insn so that we do not create | |
559 | inconsistent cfg. It is checked in verify_flow_info anyway, so do not | |
560 | bother. */ | |
561 | if (insn == BB_END (bb)) | |
562 | emit_note_after (NOTE_INSN_DELETED, insn); | |
ca6c03ca JH |
563 | |
564 | /* Create the new basic block. */ | |
a813c111 | 565 | new_bb = create_basic_block (NEXT_INSN (insn), BB_END (bb), bb); |
076c7ab8 | 566 | BB_COPY_PARTITION (new_bb, bb); |
a813c111 | 567 | BB_END (bb) = insn; |
ca6c03ca JH |
568 | |
569 | /* Redirect the outgoing edges. */ | |
628f6a4e BE |
570 | new_bb->succs = bb->succs; |
571 | bb->succs = NULL; | |
572 | FOR_EACH_EDGE (e, ei, new_bb->succs) | |
ca6c03ca JH |
573 | e->src = new_bb; |
574 | ||
6fb5fa3c DB |
575 | /* The new block starts off being dirty. */ |
576 | df_set_bb_dirty (bb); | |
f470c378 | 577 | return new_bb; |
bc35512f JH |
578 | } |
579 | ||
ca6c03ca | 580 | /* Blocks A and B are to be merged into a single block A. The insns |
bc35512f | 581 | are already contiguous. */ |
ca6c03ca | 582 | |
bc35512f JH |
583 | static void |
584 | rtl_merge_blocks (basic_block a, basic_block b) | |
ca6c03ca | 585 | { |
a813c111 | 586 | rtx b_head = BB_HEAD (b), b_end = BB_END (b), a_end = BB_END (a); |
ca6c03ca | 587 | rtx del_first = NULL_RTX, del_last = NULL_RTX; |
b5b8b0ac | 588 | rtx b_debug_start = b_end, b_debug_end = b_end; |
ca6c03ca JH |
589 | int b_empty = 0; |
590 | ||
6fb5fa3c DB |
591 | if (dump_file) |
592 | fprintf (dump_file, "merging block %d into block %d\n", b->index, a->index); | |
593 | ||
b5b8b0ac AO |
594 | while (DEBUG_INSN_P (b_end)) |
595 | b_end = PREV_INSN (b_debug_start = b_end); | |
596 | ||
ca6c03ca | 597 | /* If there was a CODE_LABEL beginning B, delete it. */ |
4b4bf941 | 598 | if (LABEL_P (b_head)) |
ca6c03ca JH |
599 | { |
600 | /* Detect basic blocks with nothing but a label. This can happen | |
601 | in particular at the end of a function. */ | |
602 | if (b_head == b_end) | |
603 | b_empty = 1; | |
5f0d2358 | 604 | |
ca6c03ca JH |
605 | del_first = del_last = b_head; |
606 | b_head = NEXT_INSN (b_head); | |
607 | } | |
608 | ||
5f0d2358 RK |
609 | /* Delete the basic block note and handle blocks containing just that |
610 | note. */ | |
ca6c03ca JH |
611 | if (NOTE_INSN_BASIC_BLOCK_P (b_head)) |
612 | { | |
613 | if (b_head == b_end) | |
614 | b_empty = 1; | |
615 | if (! del_last) | |
616 | del_first = b_head; | |
5f0d2358 | 617 | |
ca6c03ca JH |
618 | del_last = b_head; |
619 | b_head = NEXT_INSN (b_head); | |
620 | } | |
621 | ||
622 | /* If there was a jump out of A, delete it. */ | |
4b4bf941 | 623 | if (JUMP_P (a_end)) |
ca6c03ca JH |
624 | { |
625 | rtx prev; | |
626 | ||
627 | for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev)) | |
4b4bf941 | 628 | if (!NOTE_P (prev) |
a38e7aa5 | 629 | || NOTE_INSN_BASIC_BLOCK_P (prev) |
a813c111 | 630 | || prev == BB_HEAD (a)) |
ca6c03ca JH |
631 | break; |
632 | ||
633 | del_first = a_end; | |
634 | ||
635 | #ifdef HAVE_cc0 | |
636 | /* If this was a conditional jump, we need to also delete | |
637 | the insn that set cc0. */ | |
638 | if (only_sets_cc0_p (prev)) | |
639 | { | |
640 | rtx tmp = prev; | |
5f0d2358 | 641 | |
ca6c03ca JH |
642 | prev = prev_nonnote_insn (prev); |
643 | if (!prev) | |
a813c111 | 644 | prev = BB_HEAD (a); |
ca6c03ca JH |
645 | del_first = tmp; |
646 | } | |
647 | #endif | |
648 | ||
649 | a_end = PREV_INSN (del_first); | |
650 | } | |
4b4bf941 | 651 | else if (BARRIER_P (NEXT_INSN (a_end))) |
ca6c03ca JH |
652 | del_first = NEXT_INSN (a_end); |
653 | ||
ca6c03ca JH |
654 | /* Delete everything marked above as well as crap that might be |
655 | hanging out between the two blocks. */ | |
f470c378 | 656 | BB_HEAD (b) = NULL; |
a7b87f73 | 657 | delete_insn_chain (del_first, del_last, true); |
ca6c03ca JH |
658 | |
659 | /* Reassociate the insns of B with A. */ | |
660 | if (!b_empty) | |
661 | { | |
b5b8b0ac | 662 | update_bb_for_insn_chain (a_end, b_debug_end, a); |
5f0d2358 | 663 | |
b5b8b0ac AO |
664 | a_end = b_debug_end; |
665 | } | |
666 | else if (b_end != b_debug_end) | |
667 | { | |
668 | /* Move any deleted labels and other notes between the end of A | |
669 | and the debug insns that make up B after the debug insns, | |
670 | bringing the debug insns into A while keeping the notes after | |
671 | the end of A. */ | |
672 | if (NEXT_INSN (a_end) != b_debug_start) | |
673 | reorder_insns_nobb (NEXT_INSN (a_end), PREV_INSN (b_debug_start), | |
674 | b_debug_end); | |
675 | update_bb_for_insn_chain (b_debug_start, b_debug_end, a); | |
676 | a_end = b_debug_end; | |
ca6c03ca | 677 | } |
5f0d2358 | 678 | |
6fb5fa3c | 679 | df_bb_delete (b->index); |
a813c111 | 680 | BB_END (a) = a_end; |
ca6c03ca | 681 | } |
bc35512f | 682 | |
6fb5fa3c | 683 | |
bc35512f | 684 | /* Return true when block A and B can be merged. */ |
9678086d | 685 | |
b48d0358 DN |
686 | static bool |
687 | rtl_can_merge_blocks (basic_block a, basic_block b) | |
bc35512f | 688 | { |
750054a2 CT |
689 | /* If we are partitioning hot/cold basic blocks, we don't want to |
690 | mess up unconditional or indirect jumps that cross between hot | |
076c7ab8 ZW |
691 | and cold sections. |
692 | ||
8e8d5162 | 693 | Basic block partitioning may result in some jumps that appear to |
c22cacf3 MS |
694 | be optimizable (or blocks that appear to be mergeable), but which really |
695 | must be left untouched (they are required to make it safely across | |
696 | partition boundaries). See the comments at the top of | |
8e8d5162 | 697 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
076c7ab8 | 698 | |
87c8b4be | 699 | if (BB_PARTITION (a) != BB_PARTITION (b)) |
076c7ab8 | 700 | return false; |
750054a2 | 701 | |
bc35512f | 702 | /* There must be exactly one edge in between the blocks. */ |
c5cbcccf ZD |
703 | return (single_succ_p (a) |
704 | && single_succ (a) == b | |
705 | && single_pred_p (b) | |
628f6a4e | 706 | && a != b |
bc35512f | 707 | /* Must be simple edge. */ |
c5cbcccf | 708 | && !(single_succ_edge (a)->flags & EDGE_COMPLEX) |
bc35512f JH |
709 | && a->next_bb == b |
710 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR | |
711 | /* If the jump insn has side effects, | |
712 | we can't kill the edge. */ | |
4b4bf941 | 713 | && (!JUMP_P (BB_END (a)) |
e24e7211 | 714 | || (reload_completed |
a813c111 | 715 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f | 716 | } |
ca6c03ca | 717 | \f |
5f0d2358 RK |
718 | /* Return the label in the head of basic block BLOCK. Create one if it doesn't |
719 | exist. */ | |
ca6c03ca JH |
720 | |
721 | rtx | |
d329e058 | 722 | block_label (basic_block block) |
ca6c03ca JH |
723 | { |
724 | if (block == EXIT_BLOCK_PTR) | |
725 | return NULL_RTX; | |
5f0d2358 | 726 | |
4b4bf941 | 727 | if (!LABEL_P (BB_HEAD (block))) |
ca6c03ca | 728 | { |
a813c111 | 729 | BB_HEAD (block) = emit_label_before (gen_label_rtx (), BB_HEAD (block)); |
ca6c03ca | 730 | } |
5f0d2358 | 731 | |
a813c111 | 732 | return BB_HEAD (block); |
ca6c03ca JH |
733 | } |
734 | ||
735 | /* Attempt to perform edge redirection by replacing possibly complex jump | |
5f0d2358 RK |
736 | instruction by unconditional jump or removing jump completely. This can |
737 | apply only if all edges now point to the same block. The parameters and | |
738 | return values are equivalent to redirect_edge_and_branch. */ | |
ca6c03ca | 739 | |
6de9cd9a | 740 | edge |
bc35512f | 741 | try_redirect_by_replacing_jump (edge e, basic_block target, bool in_cfglayout) |
ca6c03ca JH |
742 | { |
743 | basic_block src = e->src; | |
a813c111 | 744 | rtx insn = BB_END (src), kill_from; |
e1233a7d | 745 | rtx set; |
ca6c03ca | 746 | int fallthru = 0; |
750054a2 CT |
747 | |
748 | /* If we are partitioning hot/cold basic blocks, we don't want to | |
749 | mess up unconditional or indirect jumps that cross between hot | |
8e8d5162 CT |
750 | and cold sections. |
751 | ||
752 | Basic block partitioning may result in some jumps that appear to | |
c22cacf3 MS |
753 | be optimizable (or blocks that appear to be mergeable), but which really |
754 | must be left untouched (they are required to make it safely across | |
755 | partition boundaries). See the comments at the top of | |
8e8d5162 | 756 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
c22cacf3 | 757 | |
87c8b4be CT |
758 | if (find_reg_note (insn, REG_CROSSING_JUMP, NULL_RTX) |
759 | || BB_PARTITION (src) != BB_PARTITION (target)) | |
9cf84a3c | 760 | return NULL; |
750054a2 | 761 | |
6a66a8a7 KH |
762 | /* We can replace or remove a complex jump only when we have exactly |
763 | two edges. Also, if we have exactly one outgoing edge, we can | |
764 | redirect that. */ | |
765 | if (EDGE_COUNT (src->succs) >= 3 | |
766 | /* Verify that all targets will be TARGET. Specifically, the | |
767 | edge that is not E must also go to TARGET. */ | |
768 | || (EDGE_COUNT (src->succs) == 2 | |
769 | && EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)) | |
770 | return NULL; | |
5f0d2358 | 771 | |
6a66a8a7 | 772 | if (!onlyjump_p (insn)) |
6de9cd9a | 773 | return NULL; |
3348b696 | 774 | if ((!optimize || reload_completed) && tablejump_p (insn, NULL, NULL)) |
6de9cd9a | 775 | return NULL; |
ca6c03ca JH |
776 | |
777 | /* Avoid removing branch with side effects. */ | |
778 | set = single_set (insn); | |
779 | if (!set || side_effects_p (set)) | |
6de9cd9a | 780 | return NULL; |
ca6c03ca JH |
781 | |
782 | /* In case we zap a conditional jump, we'll need to kill | |
783 | the cc0 setter too. */ | |
784 | kill_from = insn; | |
785 | #ifdef HAVE_cc0 | |
9caea4a7 RS |
786 | if (reg_mentioned_p (cc0_rtx, PATTERN (insn)) |
787 | && only_sets_cc0_p (PREV_INSN (insn))) | |
ca6c03ca JH |
788 | kill_from = PREV_INSN (insn); |
789 | #endif | |
790 | ||
791 | /* See if we can create the fallthru edge. */ | |
bc35512f | 792 | if (in_cfglayout || can_fallthru (src, target)) |
ca6c03ca | 793 | { |
c263766c RH |
794 | if (dump_file) |
795 | fprintf (dump_file, "Removing jump %i.\n", INSN_UID (insn)); | |
ca6c03ca JH |
796 | fallthru = 1; |
797 | ||
eaec9b3d | 798 | /* Selectively unlink whole insn chain. */ |
bc35512f JH |
799 | if (in_cfglayout) |
800 | { | |
370369e1 | 801 | rtx insn = src->il.rtl->footer; |
bc35512f | 802 | |
a7b87f73 | 803 | delete_insn_chain (kill_from, BB_END (src), false); |
bc35512f JH |
804 | |
805 | /* Remove barriers but keep jumptables. */ | |
806 | while (insn) | |
807 | { | |
4b4bf941 | 808 | if (BARRIER_P (insn)) |
bc35512f JH |
809 | { |
810 | if (PREV_INSN (insn)) | |
811 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
812 | else | |
370369e1 | 813 | src->il.rtl->footer = NEXT_INSN (insn); |
bc35512f JH |
814 | if (NEXT_INSN (insn)) |
815 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
816 | } | |
4b4bf941 | 817 | if (LABEL_P (insn)) |
bc35512f JH |
818 | break; |
819 | insn = NEXT_INSN (insn); | |
820 | } | |
821 | } | |
822 | else | |
a7b87f73 ZD |
823 | delete_insn_chain (kill_from, PREV_INSN (BB_HEAD (target)), |
824 | false); | |
ca6c03ca | 825 | } |
5f0d2358 | 826 | |
ca6c03ca JH |
827 | /* If this already is simplejump, redirect it. */ |
828 | else if (simplejump_p (insn)) | |
829 | { | |
830 | if (e->dest == target) | |
6de9cd9a | 831 | return NULL; |
c263766c RH |
832 | if (dump_file) |
833 | fprintf (dump_file, "Redirecting jump %i from %i to %i.\n", | |
0b17ab2f | 834 | INSN_UID (insn), e->dest->index, target->index); |
6ee3c8e4 JJ |
835 | if (!redirect_jump (insn, block_label (target), 0)) |
836 | { | |
341c100f NS |
837 | gcc_assert (target == EXIT_BLOCK_PTR); |
838 | return NULL; | |
6ee3c8e4 | 839 | } |
ca6c03ca | 840 | } |
5f0d2358 | 841 | |
6ee3c8e4 JJ |
842 | /* Cannot do anything for target exit block. */ |
843 | else if (target == EXIT_BLOCK_PTR) | |
6de9cd9a | 844 | return NULL; |
6ee3c8e4 | 845 | |
ca6c03ca JH |
846 | /* Or replace possibly complicated jump insn by simple jump insn. */ |
847 | else | |
848 | { | |
849 | rtx target_label = block_label (target); | |
eb5b8ad4 | 850 | rtx barrier, label, table; |
ca6c03ca | 851 | |
a7102479 | 852 | emit_jump_insn_after_noloc (gen_jump (target_label), insn); |
a813c111 | 853 | JUMP_LABEL (BB_END (src)) = target_label; |
ca6c03ca | 854 | LABEL_NUSES (target_label)++; |
c263766c RH |
855 | if (dump_file) |
856 | fprintf (dump_file, "Replacing insn %i by jump %i\n", | |
a813c111 | 857 | INSN_UID (insn), INSN_UID (BB_END (src))); |
ca6c03ca | 858 | |
4da2eb6b | 859 | |
ba4807a0 LB |
860 | delete_insn_chain (kill_from, insn, false); |
861 | ||
4da2eb6b RH |
862 | /* Recognize a tablejump that we are converting to a |
863 | simple jump and remove its associated CODE_LABEL | |
864 | and ADDR_VEC or ADDR_DIFF_VEC. */ | |
ba4807a0 LB |
865 | if (tablejump_p (insn, &label, &table)) |
866 | delete_insn_chain (label, table, false); | |
eb5b8ad4 | 867 | |
a813c111 | 868 | barrier = next_nonnote_insn (BB_END (src)); |
4b4bf941 | 869 | if (!barrier || !BARRIER_P (barrier)) |
a813c111 | 870 | emit_barrier_after (BB_END (src)); |
5d693491 JZ |
871 | else |
872 | { | |
a813c111 | 873 | if (barrier != NEXT_INSN (BB_END (src))) |
5d693491 JZ |
874 | { |
875 | /* Move the jump before barrier so that the notes | |
876 | which originally were or were created before jump table are | |
877 | inside the basic block. */ | |
a813c111 | 878 | rtx new_insn = BB_END (src); |
5d693491 | 879 | |
6c3d0e31 SP |
880 | update_bb_for_insn_chain (NEXT_INSN (BB_END (src)), |
881 | PREV_INSN (barrier), src); | |
5d693491 JZ |
882 | |
883 | NEXT_INSN (PREV_INSN (new_insn)) = NEXT_INSN (new_insn); | |
884 | PREV_INSN (NEXT_INSN (new_insn)) = PREV_INSN (new_insn); | |
885 | ||
886 | NEXT_INSN (new_insn) = barrier; | |
887 | NEXT_INSN (PREV_INSN (barrier)) = new_insn; | |
888 | ||
889 | PREV_INSN (new_insn) = PREV_INSN (barrier); | |
890 | PREV_INSN (barrier) = new_insn; | |
891 | } | |
892 | } | |
ca6c03ca JH |
893 | } |
894 | ||
895 | /* Keep only one edge out and set proper flags. */ | |
c5cbcccf | 896 | if (!single_succ_p (src)) |
628f6a4e | 897 | remove_edge (e); |
c5cbcccf | 898 | gcc_assert (single_succ_p (src)); |
628f6a4e | 899 | |
c5cbcccf | 900 | e = single_succ_edge (src); |
ca6c03ca JH |
901 | if (fallthru) |
902 | e->flags = EDGE_FALLTHRU; | |
903 | else | |
904 | e->flags = 0; | |
5f0d2358 | 905 | |
ca6c03ca JH |
906 | e->probability = REG_BR_PROB_BASE; |
907 | e->count = src->count; | |
908 | ||
ca6c03ca JH |
909 | if (e->dest != target) |
910 | redirect_edge_succ (e, target); | |
6de9cd9a | 911 | return e; |
ca6c03ca JH |
912 | } |
913 | ||
4e3825db MM |
914 | /* Subroutine of redirect_branch_edge that tries to patch the jump |
915 | instruction INSN so that it reaches block NEW. Do this | |
916 | only when it originally reached block OLD. Return true if this | |
917 | worked or the original target wasn't OLD, return false if redirection | |
918 | doesn't work. */ | |
919 | ||
920 | static bool | |
921 | patch_jump_insn (rtx insn, rtx old_label, basic_block new_bb) | |
ca6c03ca JH |
922 | { |
923 | rtx tmp; | |
ca6c03ca | 924 | /* Recognize a tablejump and adjust all matching cases. */ |
e1233a7d | 925 | if (tablejump_p (insn, NULL, &tmp)) |
ca6c03ca JH |
926 | { |
927 | rtvec vec; | |
928 | int j; | |
4e3825db | 929 | rtx new_label = block_label (new_bb); |
ca6c03ca | 930 | |
4e3825db MM |
931 | if (new_bb == EXIT_BLOCK_PTR) |
932 | return false; | |
ca6c03ca JH |
933 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) |
934 | vec = XVEC (PATTERN (tmp), 0); | |
935 | else | |
936 | vec = XVEC (PATTERN (tmp), 1); | |
937 | ||
938 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
939 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
940 | { | |
941 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (Pmode, new_label); | |
942 | --LABEL_NUSES (old_label); | |
943 | ++LABEL_NUSES (new_label); | |
944 | } | |
945 | ||
f9da5064 | 946 | /* Handle casesi dispatch insns. */ |
ca6c03ca JH |
947 | if ((tmp = single_set (insn)) != NULL |
948 | && SET_DEST (tmp) == pc_rtx | |
949 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
950 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF | |
951 | && XEXP (XEXP (SET_SRC (tmp), 2), 0) == old_label) | |
952 | { | |
4c33cb26 | 953 | XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (Pmode, |
ca6c03ca JH |
954 | new_label); |
955 | --LABEL_NUSES (old_label); | |
956 | ++LABEL_NUSES (new_label); | |
957 | } | |
958 | } | |
1c384bf1 RH |
959 | else if ((tmp = extract_asm_operands (PATTERN (insn))) != NULL) |
960 | { | |
961 | int i, n = ASM_OPERANDS_LABEL_LENGTH (tmp); | |
962 | rtx new_label, note; | |
963 | ||
964 | if (new_bb == EXIT_BLOCK_PTR) | |
965 | return false; | |
966 | new_label = block_label (new_bb); | |
967 | ||
968 | for (i = 0; i < n; ++i) | |
969 | { | |
970 | rtx old_ref = ASM_OPERANDS_LABEL (tmp, i); | |
971 | gcc_assert (GET_CODE (old_ref) == LABEL_REF); | |
972 | if (XEXP (old_ref, 0) == old_label) | |
973 | { | |
974 | ASM_OPERANDS_LABEL (tmp, i) | |
975 | = gen_rtx_LABEL_REF (Pmode, new_label); | |
976 | --LABEL_NUSES (old_label); | |
977 | ++LABEL_NUSES (new_label); | |
978 | } | |
979 | } | |
980 | ||
981 | if (JUMP_LABEL (insn) == old_label) | |
982 | { | |
983 | JUMP_LABEL (insn) = new_label; | |
984 | note = find_reg_note (insn, REG_LABEL_TARGET, new_label); | |
985 | if (note) | |
986 | remove_note (insn, note); | |
987 | } | |
988 | else | |
989 | { | |
990 | note = find_reg_note (insn, REG_LABEL_TARGET, old_label); | |
991 | if (note) | |
992 | remove_note (insn, note); | |
993 | if (JUMP_LABEL (insn) != new_label | |
994 | && !find_reg_note (insn, REG_LABEL_TARGET, new_label)) | |
995 | add_reg_note (insn, REG_LABEL_TARGET, new_label); | |
996 | } | |
997 | } | |
ca6c03ca JH |
998 | else |
999 | { | |
1000 | /* ?? We may play the games with moving the named labels from | |
1001 | one basic block to the other in case only one computed_jump is | |
1002 | available. */ | |
5f0d2358 RK |
1003 | if (computed_jump_p (insn) |
1004 | /* A return instruction can't be redirected. */ | |
1005 | || returnjump_p (insn)) | |
4e3825db | 1006 | return false; |
6ee3c8e4 | 1007 | |
4e3825db | 1008 | if (!currently_expanding_to_rtl || JUMP_LABEL (insn) == old_label) |
6ee3c8e4 | 1009 | { |
4e3825db MM |
1010 | /* If the insn doesn't go where we think, we're confused. */ |
1011 | gcc_assert (JUMP_LABEL (insn) == old_label); | |
1012 | ||
1013 | /* If the substitution doesn't succeed, die. This can happen | |
1014 | if the back end emitted unrecognizable instructions or if | |
1015 | target is exit block on some arches. */ | |
1016 | if (!redirect_jump (insn, block_label (new_bb), 0)) | |
1017 | { | |
1018 | gcc_assert (new_bb == EXIT_BLOCK_PTR); | |
1019 | return false; | |
1020 | } | |
6ee3c8e4 | 1021 | } |
ca6c03ca | 1022 | } |
4e3825db MM |
1023 | return true; |
1024 | } | |
1025 | ||
1026 | ||
1027 | /* Redirect edge representing branch of (un)conditional jump or tablejump, | |
1028 | NULL on failure */ | |
1029 | static edge | |
1030 | redirect_branch_edge (edge e, basic_block target) | |
1031 | { | |
1032 | rtx old_label = BB_HEAD (e->dest); | |
1033 | basic_block src = e->src; | |
1034 | rtx insn = BB_END (src); | |
1035 | ||
1036 | /* We can only redirect non-fallthru edges of jump insn. */ | |
1037 | if (e->flags & EDGE_FALLTHRU) | |
1038 | return NULL; | |
1039 | else if (!JUMP_P (insn) && !currently_expanding_to_rtl) | |
1040 | return NULL; | |
1041 | ||
1042 | if (!currently_expanding_to_rtl) | |
1043 | { | |
1044 | if (!patch_jump_insn (insn, old_label, target)) | |
1045 | return NULL; | |
1046 | } | |
1047 | else | |
1048 | /* When expanding this BB might actually contain multiple | |
1049 | jumps (i.e. not yet split by find_many_sub_basic_blocks). | |
1050 | Redirect all of those that match our label. */ | |
1051 | for (insn = BB_HEAD (src); insn != NEXT_INSN (BB_END (src)); | |
1052 | insn = NEXT_INSN (insn)) | |
1053 | if (JUMP_P (insn) && !patch_jump_insn (insn, old_label, target)) | |
1054 | return NULL; | |
ca6c03ca | 1055 | |
c263766c RH |
1056 | if (dump_file) |
1057 | fprintf (dump_file, "Edge %i->%i redirected to %i\n", | |
0b17ab2f | 1058 | e->src->index, e->dest->index, target->index); |
5f0d2358 | 1059 | |
ca6c03ca | 1060 | if (e->dest != target) |
6de9cd9a | 1061 | e = redirect_edge_succ_nodup (e, target); |
6fb5fa3c | 1062 | |
6de9cd9a | 1063 | return e; |
bc35512f JH |
1064 | } |
1065 | ||
1066 | /* Attempt to change code to redirect edge E to TARGET. Don't do that on | |
1067 | expense of adding new instructions or reordering basic blocks. | |
1068 | ||
1069 | Function can be also called with edge destination equivalent to the TARGET. | |
1070 | Then it should try the simplifications and do nothing if none is possible. | |
1071 | ||
6de9cd9a DN |
1072 | Return edge representing the branch if transformation succeeded. Return NULL |
1073 | on failure. | |
1074 | We still return NULL in case E already destinated TARGET and we didn't | |
1075 | managed to simplify instruction stream. */ | |
bc35512f | 1076 | |
6de9cd9a | 1077 | static edge |
5671bf27 | 1078 | rtl_redirect_edge_and_branch (edge e, basic_block target) |
bc35512f | 1079 | { |
6de9cd9a | 1080 | edge ret; |
f345f21a JH |
1081 | basic_block src = e->src; |
1082 | ||
bc35512f | 1083 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
6de9cd9a | 1084 | return NULL; |
bc35512f | 1085 | |
3348b696 | 1086 | if (e->dest == target) |
6de9cd9a | 1087 | return e; |
3348b696 | 1088 | |
6de9cd9a | 1089 | if ((ret = try_redirect_by_replacing_jump (e, target, false)) != NULL) |
f345f21a | 1090 | { |
6fb5fa3c | 1091 | df_set_bb_dirty (src); |
6de9cd9a | 1092 | return ret; |
f345f21a | 1093 | } |
bc35512f | 1094 | |
6de9cd9a DN |
1095 | ret = redirect_branch_edge (e, target); |
1096 | if (!ret) | |
1097 | return NULL; | |
5f0d2358 | 1098 | |
6fb5fa3c | 1099 | df_set_bb_dirty (src); |
6de9cd9a | 1100 | return ret; |
ca6c03ca JH |
1101 | } |
1102 | ||
4fe9b91c | 1103 | /* Like force_nonfallthru below, but additionally performs redirection |
ca6c03ca JH |
1104 | Used by redirect_edge_and_branch_force. */ |
1105 | ||
9167e1c0 | 1106 | static basic_block |
d329e058 | 1107 | force_nonfallthru_and_redirect (edge e, basic_block target) |
ca6c03ca | 1108 | { |
a3716585 | 1109 | basic_block jump_block, new_bb = NULL, src = e->src; |
ca6c03ca JH |
1110 | rtx note; |
1111 | edge new_edge; | |
a3716585 | 1112 | int abnormal_edge_flags = 0; |
7241571e | 1113 | int loc; |
ca6c03ca | 1114 | |
cb9a1d9b JH |
1115 | /* In the case the last instruction is conditional jump to the next |
1116 | instruction, first redirect the jump itself and then continue | |
b20b352b | 1117 | by creating a basic block afterwards to redirect fallthru edge. */ |
cb9a1d9b | 1118 | if (e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR |
a813c111 | 1119 | && any_condjump_p (BB_END (e->src)) |
a813c111 | 1120 | && JUMP_LABEL (BB_END (e->src)) == BB_HEAD (e->dest)) |
cb9a1d9b JH |
1121 | { |
1122 | rtx note; | |
58e6ae30 | 1123 | edge b = unchecked_make_edge (e->src, target, 0); |
341c100f | 1124 | bool redirected; |
cb9a1d9b | 1125 | |
341c100f NS |
1126 | redirected = redirect_jump (BB_END (e->src), block_label (target), 0); |
1127 | gcc_assert (redirected); | |
c22cacf3 | 1128 | |
a813c111 | 1129 | note = find_reg_note (BB_END (e->src), REG_BR_PROB, NULL_RTX); |
cb9a1d9b JH |
1130 | if (note) |
1131 | { | |
1132 | int prob = INTVAL (XEXP (note, 0)); | |
1133 | ||
1134 | b->probability = prob; | |
1135 | b->count = e->count * prob / REG_BR_PROB_BASE; | |
1136 | e->probability -= e->probability; | |
1137 | e->count -= b->count; | |
1138 | if (e->probability < 0) | |
1139 | e->probability = 0; | |
1140 | if (e->count < 0) | |
1141 | e->count = 0; | |
1142 | } | |
1143 | } | |
1144 | ||
ca6c03ca | 1145 | if (e->flags & EDGE_ABNORMAL) |
a3716585 JH |
1146 | { |
1147 | /* Irritating special case - fallthru edge to the same block as abnormal | |
1148 | edge. | |
1149 | We can't redirect abnormal edge, but we still can split the fallthru | |
d329e058 | 1150 | one and create separate abnormal edge to original destination. |
a3716585 | 1151 | This allows bb-reorder to make such edge non-fallthru. */ |
341c100f | 1152 | gcc_assert (e->dest == target); |
a3716585 JH |
1153 | abnormal_edge_flags = e->flags & ~(EDGE_FALLTHRU | EDGE_CAN_FALLTHRU); |
1154 | e->flags &= EDGE_FALLTHRU | EDGE_CAN_FALLTHRU; | |
1155 | } | |
341c100f | 1156 | else |
24c545ff | 1157 | { |
341c100f NS |
1158 | gcc_assert (e->flags & EDGE_FALLTHRU); |
1159 | if (e->src == ENTRY_BLOCK_PTR) | |
1160 | { | |
1161 | /* We can't redirect the entry block. Create an empty block | |
628f6a4e BE |
1162 | at the start of the function which we use to add the new |
1163 | jump. */ | |
1164 | edge tmp; | |
1165 | edge_iterator ei; | |
1166 | bool found = false; | |
c22cacf3 | 1167 | |
628f6a4e | 1168 | basic_block bb = create_basic_block (BB_HEAD (e->dest), NULL, ENTRY_BLOCK_PTR); |
c22cacf3 | 1169 | |
341c100f NS |
1170 | /* Change the existing edge's source to be the new block, and add |
1171 | a new edge from the entry block to the new block. */ | |
1172 | e->src = bb; | |
628f6a4e BE |
1173 | for (ei = ei_start (ENTRY_BLOCK_PTR->succs); (tmp = ei_safe_edge (ei)); ) |
1174 | { | |
1175 | if (tmp == e) | |
1176 | { | |
865851d0 | 1177 | VEC_unordered_remove (edge, ENTRY_BLOCK_PTR->succs, ei.index); |
628f6a4e BE |
1178 | found = true; |
1179 | break; | |
1180 | } | |
1181 | else | |
1182 | ei_next (&ei); | |
1183 | } | |
c22cacf3 | 1184 | |
628f6a4e | 1185 | gcc_assert (found); |
c22cacf3 | 1186 | |
d4e6fecb | 1187 | VEC_safe_push (edge, gc, bb->succs, e); |
341c100f NS |
1188 | make_single_succ_edge (ENTRY_BLOCK_PTR, bb, EDGE_FALLTHRU); |
1189 | } | |
24c545ff BS |
1190 | } |
1191 | ||
628f6a4e | 1192 | if (EDGE_COUNT (e->src->succs) >= 2 || abnormal_edge_flags) |
ca6c03ca JH |
1193 | { |
1194 | /* Create the new structures. */ | |
31a78298 | 1195 | |
79019985 RH |
1196 | /* If the old block ended with a tablejump, skip its table |
1197 | by searching forward from there. Otherwise start searching | |
1198 | forward from the last instruction of the old block. */ | |
a813c111 SB |
1199 | if (!tablejump_p (BB_END (e->src), NULL, ¬e)) |
1200 | note = BB_END (e->src); | |
31a78298 RH |
1201 | note = NEXT_INSN (note); |
1202 | ||
31a78298 | 1203 | jump_block = create_basic_block (note, NULL, e->src); |
ca6c03ca JH |
1204 | jump_block->count = e->count; |
1205 | jump_block->frequency = EDGE_FREQUENCY (e); | |
1206 | jump_block->loop_depth = target->loop_depth; | |
1207 | ||
750054a2 CT |
1208 | /* Make sure new block ends up in correct hot/cold section. */ |
1209 | ||
076c7ab8 | 1210 | BB_COPY_PARTITION (jump_block, e->src); |
9fb32434 | 1211 | if (flag_reorder_blocks_and_partition |
87c8b4be CT |
1212 | && targetm.have_named_sections |
1213 | && JUMP_P (BB_END (jump_block)) | |
1214 | && !any_condjump_p (BB_END (jump_block)) | |
1215 | && (EDGE_SUCC (jump_block, 0)->flags & EDGE_CROSSING)) | |
65c5f2a6 | 1216 | add_reg_note (BB_END (jump_block), REG_CROSSING_JUMP, NULL_RTX); |
c22cacf3 | 1217 | |
ca6c03ca JH |
1218 | /* Wire edge in. */ |
1219 | new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU); | |
1220 | new_edge->probability = e->probability; | |
1221 | new_edge->count = e->count; | |
1222 | ||
1223 | /* Redirect old edge. */ | |
1224 | redirect_edge_pred (e, jump_block); | |
1225 | e->probability = REG_BR_PROB_BASE; | |
1226 | ||
1227 | new_bb = jump_block; | |
1228 | } | |
1229 | else | |
1230 | jump_block = e->src; | |
5f0d2358 | 1231 | |
7241571e JJ |
1232 | if (e->goto_locus && e->goto_block == NULL) |
1233 | loc = e->goto_locus; | |
1234 | else | |
1235 | loc = 0; | |
ca6c03ca JH |
1236 | e->flags &= ~EDGE_FALLTHRU; |
1237 | if (target == EXIT_BLOCK_PTR) | |
1238 | { | |
cf22ce3c | 1239 | #ifdef HAVE_return |
7241571e | 1240 | emit_jump_insn_after_setloc (gen_return (), BB_END (jump_block), loc); |
cf22ce3c | 1241 | #else |
341c100f | 1242 | gcc_unreachable (); |
cf22ce3c | 1243 | #endif |
ca6c03ca JH |
1244 | } |
1245 | else | |
1246 | { | |
1247 | rtx label = block_label (target); | |
7241571e | 1248 | emit_jump_insn_after_setloc (gen_jump (label), BB_END (jump_block), loc); |
a813c111 | 1249 | JUMP_LABEL (BB_END (jump_block)) = label; |
ca6c03ca JH |
1250 | LABEL_NUSES (label)++; |
1251 | } | |
5f0d2358 | 1252 | |
a813c111 | 1253 | emit_barrier_after (BB_END (jump_block)); |
ca6c03ca JH |
1254 | redirect_edge_succ_nodup (e, target); |
1255 | ||
a3716585 JH |
1256 | if (abnormal_edge_flags) |
1257 | make_edge (src, target, abnormal_edge_flags); | |
1258 | ||
b8698a0f | 1259 | df_mark_solutions_dirty (); |
ca6c03ca JH |
1260 | return new_bb; |
1261 | } | |
1262 | ||
1263 | /* Edge E is assumed to be fallthru edge. Emit needed jump instruction | |
1264 | (and possibly create new basic block) to make edge non-fallthru. | |
1265 | Return newly created BB or NULL if none. */ | |
5f0d2358 | 1266 | |
ca6c03ca | 1267 | basic_block |
d329e058 | 1268 | force_nonfallthru (edge e) |
ca6c03ca JH |
1269 | { |
1270 | return force_nonfallthru_and_redirect (e, e->dest); | |
1271 | } | |
1272 | ||
1273 | /* Redirect edge even at the expense of creating new jump insn or | |
1274 | basic block. Return new basic block if created, NULL otherwise. | |
41806d92 | 1275 | Conversion must be possible. */ |
ca6c03ca | 1276 | |
9ee634e3 | 1277 | static basic_block |
d329e058 | 1278 | rtl_redirect_edge_and_branch_force (edge e, basic_block target) |
ca6c03ca | 1279 | { |
5f0d2358 RK |
1280 | if (redirect_edge_and_branch (e, target) |
1281 | || e->dest == target) | |
ca6c03ca JH |
1282 | return NULL; |
1283 | ||
1284 | /* In case the edge redirection failed, try to force it to be non-fallthru | |
1285 | and redirect newly created simplejump. */ | |
6fb5fa3c | 1286 | df_set_bb_dirty (e->src); |
5f0d2358 | 1287 | return force_nonfallthru_and_redirect (e, target); |
ca6c03ca JH |
1288 | } |
1289 | ||
1290 | /* The given edge should potentially be a fallthru edge. If that is in | |
1291 | fact true, delete the jump and barriers that are in the way. */ | |
1292 | ||
f470c378 ZD |
1293 | static void |
1294 | rtl_tidy_fallthru_edge (edge e) | |
ca6c03ca JH |
1295 | { |
1296 | rtx q; | |
f470c378 ZD |
1297 | basic_block b = e->src, c = b->next_bb; |
1298 | ||
ca6c03ca JH |
1299 | /* ??? In a late-running flow pass, other folks may have deleted basic |
1300 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
0fa2e4df | 1301 | and the target label. They ought to be chastised and fixed. |
ca6c03ca JH |
1302 | |
1303 | We can also wind up with a sequence of undeletable labels between | |
1304 | one block and the next. | |
1305 | ||
1306 | So search through a sequence of barriers, labels, and notes for | |
1307 | the head of block C and assert that we really do fall through. */ | |
1308 | ||
a813c111 | 1309 | for (q = NEXT_INSN (BB_END (b)); q != BB_HEAD (c); q = NEXT_INSN (q)) |
9c0a0632 RH |
1310 | if (INSN_P (q)) |
1311 | return; | |
ca6c03ca JH |
1312 | |
1313 | /* Remove what will soon cease being the jump insn from the source block. | |
1314 | If block B consisted only of this single jump, turn it into a deleted | |
1315 | note. */ | |
a813c111 | 1316 | q = BB_END (b); |
4b4bf941 | 1317 | if (JUMP_P (q) |
ca6c03ca JH |
1318 | && onlyjump_p (q) |
1319 | && (any_uncondjump_p (q) | |
c5cbcccf | 1320 | || single_succ_p (b))) |
ca6c03ca JH |
1321 | { |
1322 | #ifdef HAVE_cc0 | |
1323 | /* If this was a conditional jump, we need to also delete | |
1324 | the insn that set cc0. */ | |
1325 | if (any_condjump_p (q) && only_sets_cc0_p (PREV_INSN (q))) | |
1326 | q = PREV_INSN (q); | |
1327 | #endif | |
1328 | ||
1329 | q = PREV_INSN (q); | |
ca6c03ca JH |
1330 | } |
1331 | ||
1332 | /* Selectively unlink the sequence. */ | |
a813c111 | 1333 | if (q != PREV_INSN (BB_HEAD (c))) |
a7b87f73 | 1334 | delete_insn_chain (NEXT_INSN (q), PREV_INSN (BB_HEAD (c)), false); |
ca6c03ca JH |
1335 | |
1336 | e->flags |= EDGE_FALLTHRU; | |
1337 | } | |
ca6c03ca | 1338 | \f |
f470c378 ZD |
1339 | /* Should move basic block BB after basic block AFTER. NIY. */ |
1340 | ||
1341 | static bool | |
1342 | rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED, | |
1343 | basic_block after ATTRIBUTE_UNUSED) | |
1344 | { | |
1345 | return false; | |
1346 | } | |
1347 | ||
ca6c03ca | 1348 | /* Split a (typically critical) edge. Return the new block. |
41806d92 | 1349 | The edge must not be abnormal. |
ca6c03ca JH |
1350 | |
1351 | ??? The code generally expects to be called on critical edges. | |
1352 | The case of a block ending in an unconditional jump to a | |
1353 | block with multiple predecessors is not handled optimally. */ | |
1354 | ||
8ce33230 | 1355 | static basic_block |
d329e058 | 1356 | rtl_split_edge (edge edge_in) |
ca6c03ca JH |
1357 | { |
1358 | basic_block bb; | |
ca6c03ca JH |
1359 | rtx before; |
1360 | ||
1361 | /* Abnormal edges cannot be split. */ | |
341c100f | 1362 | gcc_assert (!(edge_in->flags & EDGE_ABNORMAL)); |
ca6c03ca JH |
1363 | |
1364 | /* We are going to place the new block in front of edge destination. | |
eaec9b3d | 1365 | Avoid existence of fallthru predecessors. */ |
ca6c03ca JH |
1366 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) |
1367 | { | |
1368 | edge e; | |
628f6a4e | 1369 | edge_iterator ei; |
5f0d2358 | 1370 | |
628f6a4e | 1371 | FOR_EACH_EDGE (e, ei, edge_in->dest->preds) |
ca6c03ca JH |
1372 | if (e->flags & EDGE_FALLTHRU) |
1373 | break; | |
1374 | ||
1375 | if (e) | |
1376 | force_nonfallthru (e); | |
1377 | } | |
1378 | ||
96e82e0a ZD |
1379 | /* Create the basic block note. */ |
1380 | if (edge_in->dest != EXIT_BLOCK_PTR) | |
a813c111 | 1381 | before = BB_HEAD (edge_in->dest); |
ca6c03ca JH |
1382 | else |
1383 | before = NULL_RTX; | |
1384 | ||
623a66fa R |
1385 | /* If this is a fall through edge to the exit block, the blocks might be |
1386 | not adjacent, and the right place is the after the source. */ | |
1387 | if (edge_in->flags & EDGE_FALLTHRU && edge_in->dest == EXIT_BLOCK_PTR) | |
1388 | { | |
1389 | before = NEXT_INSN (BB_END (edge_in->src)); | |
623a66fa | 1390 | bb = create_basic_block (before, NULL, edge_in->src); |
076c7ab8 | 1391 | BB_COPY_PARTITION (bb, edge_in->src); |
623a66fa R |
1392 | } |
1393 | else | |
9fb32434 CT |
1394 | { |
1395 | bb = create_basic_block (before, NULL, edge_in->dest->prev_bb); | |
076c7ab8 ZW |
1396 | /* ??? Why not edge_in->dest->prev_bb here? */ |
1397 | BB_COPY_PARTITION (bb, edge_in->dest); | |
9fb32434 | 1398 | } |
ca6c03ca | 1399 | |
4977bab6 | 1400 | make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU); |
ca6c03ca | 1401 | |
4d6922ee | 1402 | /* For non-fallthru edges, we must adjust the predecessor's |
ca6c03ca JH |
1403 | jump instruction to target our new block. */ |
1404 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1405 | { | |
341c100f NS |
1406 | edge redirected = redirect_edge_and_branch (edge_in, bb); |
1407 | gcc_assert (redirected); | |
ca6c03ca JH |
1408 | } |
1409 | else | |
1410 | redirect_edge_succ (edge_in, bb); | |
1411 | ||
1412 | return bb; | |
1413 | } | |
1414 | ||
1415 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1416 | The new instructions and basic blocks (if any) will not appear in the | |
1417 | CFG until commit_edge_insertions is called. */ | |
1418 | ||
1419 | void | |
d329e058 | 1420 | insert_insn_on_edge (rtx pattern, edge e) |
ca6c03ca JH |
1421 | { |
1422 | /* We cannot insert instructions on an abnormal critical edge. | |
1423 | It will be easier to find the culprit if we die now. */ | |
341c100f | 1424 | gcc_assert (!((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e))); |
ca6c03ca | 1425 | |
6de9cd9a | 1426 | if (e->insns.r == NULL_RTX) |
ca6c03ca JH |
1427 | start_sequence (); |
1428 | else | |
6de9cd9a | 1429 | push_to_sequence (e->insns.r); |
ca6c03ca JH |
1430 | |
1431 | emit_insn (pattern); | |
1432 | ||
6de9cd9a | 1433 | e->insns.r = get_insns (); |
ca6c03ca JH |
1434 | end_sequence (); |
1435 | } | |
1436 | ||
1437 | /* Update the CFG for the instructions queued on edge E. */ | |
1438 | ||
4e3825db | 1439 | void |
2ac66157 | 1440 | commit_one_edge_insertion (edge e) |
ca6c03ca JH |
1441 | { |
1442 | rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last; | |
eae4bc56 | 1443 | basic_block bb = NULL; |
ca6c03ca JH |
1444 | |
1445 | /* Pull the insns off the edge now since the edge might go away. */ | |
6de9cd9a DN |
1446 | insns = e->insns.r; |
1447 | e->insns.r = NULL_RTX; | |
ca6c03ca | 1448 | |
3dec4024 | 1449 | if (!before && !after) |
ca6c03ca | 1450 | { |
3dec4024 | 1451 | /* Figure out where to put these things. If the destination has |
c22cacf3 | 1452 | one predecessor, insert there. Except for the exit block. */ |
c5cbcccf | 1453 | if (single_pred_p (e->dest) && e->dest != EXIT_BLOCK_PTR) |
ca6c03ca | 1454 | { |
3dec4024 JH |
1455 | bb = e->dest; |
1456 | ||
1457 | /* Get the location correct wrt a code label, and "nice" wrt | |
1458 | a basic block note, and before everything else. */ | |
a813c111 | 1459 | tmp = BB_HEAD (bb); |
4b4bf941 | 1460 | if (LABEL_P (tmp)) |
3dec4024 JH |
1461 | tmp = NEXT_INSN (tmp); |
1462 | if (NOTE_INSN_BASIC_BLOCK_P (tmp)) | |
1463 | tmp = NEXT_INSN (tmp); | |
a813c111 | 1464 | if (tmp == BB_HEAD (bb)) |
3dec4024 JH |
1465 | before = tmp; |
1466 | else if (tmp) | |
1467 | after = PREV_INSN (tmp); | |
1468 | else | |
1469 | after = get_last_insn (); | |
1470 | } | |
1471 | ||
1472 | /* If the source has one successor and the edge is not abnormal, | |
c22cacf3 | 1473 | insert there. Except for the entry block. */ |
3dec4024 | 1474 | else if ((e->flags & EDGE_ABNORMAL) == 0 |
c5cbcccf | 1475 | && single_succ_p (e->src) |
3dec4024 JH |
1476 | && e->src != ENTRY_BLOCK_PTR) |
1477 | { | |
1478 | bb = e->src; | |
1479 | ||
1480 | /* It is possible to have a non-simple jump here. Consider a target | |
1481 | where some forms of unconditional jumps clobber a register. This | |
1482 | happens on the fr30 for example. | |
1483 | ||
1484 | We know this block has a single successor, so we can just emit | |
1485 | the queued insns before the jump. */ | |
4b4bf941 | 1486 | if (JUMP_P (BB_END (bb))) |
96e82e0a | 1487 | before = BB_END (bb); |
3dec4024 JH |
1488 | else |
1489 | { | |
341c100f NS |
1490 | /* We'd better be fallthru, or we've lost track of |
1491 | what's what. */ | |
1492 | gcc_assert (e->flags & EDGE_FALLTHRU); | |
ca6c03ca | 1493 | |
a813c111 | 1494 | after = BB_END (bb); |
3dec4024 JH |
1495 | } |
1496 | } | |
1497 | /* Otherwise we must split the edge. */ | |
1498 | else | |
1499 | { | |
1500 | bb = split_edge (e); | |
a813c111 | 1501 | after = BB_END (bb); |
750054a2 | 1502 | |
750054a2 | 1503 | if (flag_reorder_blocks_and_partition |
9fb32434 | 1504 | && targetm.have_named_sections |
750054a2 | 1505 | && e->src != ENTRY_BLOCK_PTR |
076c7ab8 | 1506 | && BB_PARTITION (e->src) == BB_COLD_PARTITION |
6e0b03f5 PC |
1507 | && !(e->flags & EDGE_CROSSING) |
1508 | && JUMP_P (after) | |
1509 | && !any_condjump_p (after) | |
1510 | && (single_succ_edge (bb)->flags & EDGE_CROSSING)) | |
1511 | add_reg_note (after, REG_CROSSING_JUMP, NULL_RTX); | |
ca6c03ca JH |
1512 | } |
1513 | } | |
1514 | ||
ca6c03ca JH |
1515 | /* Now that we've found the spot, do the insertion. */ |
1516 | ||
1517 | if (before) | |
1518 | { | |
6fb5fa3c | 1519 | emit_insn_before_noloc (insns, before, bb); |
ca6c03ca JH |
1520 | last = prev_nonnote_insn (before); |
1521 | } | |
1522 | else | |
6fb5fa3c | 1523 | last = emit_insn_after_noloc (insns, after, bb); |
ca6c03ca JH |
1524 | |
1525 | if (returnjump_p (last)) | |
1526 | { | |
1527 | /* ??? Remove all outgoing edges from BB and add one for EXIT. | |
c22cacf3 MS |
1528 | This is not currently a problem because this only happens |
1529 | for the (single) epilogue, which already has a fallthru edge | |
1530 | to EXIT. */ | |
ca6c03ca | 1531 | |
c5cbcccf | 1532 | e = single_succ_edge (bb); |
341c100f | 1533 | gcc_assert (e->dest == EXIT_BLOCK_PTR |
c5cbcccf | 1534 | && single_succ_p (bb) && (e->flags & EDGE_FALLTHRU)); |
ca6c03ca | 1535 | |
5f0d2358 | 1536 | e->flags &= ~EDGE_FALLTHRU; |
ca6c03ca | 1537 | emit_barrier_after (last); |
0b17ab2f | 1538 | |
ca6c03ca JH |
1539 | if (before) |
1540 | delete_insn (before); | |
1541 | } | |
341c100f NS |
1542 | else |
1543 | gcc_assert (!JUMP_P (last)); | |
5f0d2358 | 1544 | |
12eff7b7 | 1545 | /* Mark the basic block for find_many_sub_basic_blocks. */ |
05549c96 SB |
1546 | if (current_ir_type () != IR_RTL_CFGLAYOUT) |
1547 | bb->aux = &bb->aux; | |
ca6c03ca JH |
1548 | } |
1549 | ||
1550 | /* Update the CFG for all queued instructions. */ | |
1551 | ||
1552 | void | |
d329e058 | 1553 | commit_edge_insertions (void) |
ca6c03ca | 1554 | { |
ca6c03ca | 1555 | basic_block bb; |
9dca2ad5 | 1556 | sbitmap blocks; |
9809a362 | 1557 | bool changed = false; |
ca6c03ca JH |
1558 | |
1559 | #ifdef ENABLE_CHECKING | |
1560 | verify_flow_info (); | |
1561 | #endif | |
1562 | ||
e0082a72 | 1563 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
ca6c03ca | 1564 | { |
628f6a4e BE |
1565 | edge e; |
1566 | edge_iterator ei; | |
ca6c03ca | 1567 | |
628f6a4e BE |
1568 | FOR_EACH_EDGE (e, ei, bb->succs) |
1569 | if (e->insns.r) | |
1570 | { | |
1571 | changed = true; | |
2ac66157 | 1572 | commit_one_edge_insertion (e); |
628f6a4e | 1573 | } |
3dec4024 | 1574 | } |
9dca2ad5 | 1575 | |
9809a362 JH |
1576 | if (!changed) |
1577 | return; | |
1578 | ||
05549c96 SB |
1579 | /* In the old rtl CFG API, it was OK to insert control flow on an |
1580 | edge, apparently? In cfglayout mode, this will *not* work, and | |
1581 | the caller is responsible for making sure that control flow is | |
1582 | valid at all times. */ | |
1583 | if (current_ir_type () == IR_RTL_CFGLAYOUT) | |
1584 | return; | |
1585 | ||
9809a362 JH |
1586 | blocks = sbitmap_alloc (last_basic_block); |
1587 | sbitmap_zero (blocks); | |
1588 | FOR_EACH_BB (bb) | |
1589 | if (bb->aux) | |
1590 | { | |
c22cacf3 | 1591 | SET_BIT (blocks, bb->index); |
9809a362 JH |
1592 | /* Check for forgotten bb->aux values before commit_edge_insertions |
1593 | call. */ | |
341c100f | 1594 | gcc_assert (bb->aux == &bb->aux); |
9809a362 JH |
1595 | bb->aux = NULL; |
1596 | } | |
1597 | find_many_sub_basic_blocks (blocks); | |
1598 | sbitmap_free (blocks); | |
ca6c03ca JH |
1599 | } |
1600 | \f | |
6fb5fa3c | 1601 | |
f470c378 ZD |
1602 | /* Print out RTL-specific basic block information (live information |
1603 | at start and end). */ | |
ca6c03ca | 1604 | |
10e9fecc | 1605 | static void |
726a989a | 1606 | rtl_dump_bb (basic_block bb, FILE *outf, int indent, int flags ATTRIBUTE_UNUSED) |
ca6c03ca JH |
1607 | { |
1608 | rtx insn; | |
1609 | rtx last; | |
f470c378 | 1610 | char *s_indent; |
ca6c03ca | 1611 | |
ae50c0cb | 1612 | s_indent = (char *) alloca ((size_t) indent + 1); |
400e39e3 | 1613 | memset (s_indent, ' ', (size_t) indent); |
f470c378 | 1614 | s_indent[indent] = '\0'; |
b8698a0f | 1615 | |
6fb5fa3c DB |
1616 | if (df) |
1617 | { | |
1618 | df_dump_top (bb, outf); | |
1619 | putc ('\n', outf); | |
1620 | } | |
ca6c03ca | 1621 | |
a813c111 | 1622 | for (insn = BB_HEAD (bb), last = NEXT_INSN (BB_END (bb)); insn != last; |
ca6c03ca JH |
1623 | insn = NEXT_INSN (insn)) |
1624 | print_rtl_single (outf, insn); | |
1625 | ||
6fb5fa3c DB |
1626 | if (df) |
1627 | { | |
1628 | df_dump_bottom (bb, outf); | |
1629 | putc ('\n', outf); | |
1630 | } | |
1631 | ||
ca6c03ca JH |
1632 | } |
1633 | \f | |
1634 | /* Like print_rtl, but also print out live information for the start of each | |
1635 | basic block. */ | |
1636 | ||
1637 | void | |
22ea9ec0 | 1638 | print_rtl_with_bb (FILE *outf, const_rtx rtx_first) |
ca6c03ca | 1639 | { |
22ea9ec0 | 1640 | const_rtx tmp_rtx; |
ca6c03ca JH |
1641 | if (rtx_first == 0) |
1642 | fprintf (outf, "(nil)\n"); | |
1643 | else | |
1644 | { | |
ca6c03ca JH |
1645 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
1646 | int max_uid = get_max_uid (); | |
5ed6ace5 MD |
1647 | basic_block *start = XCNEWVEC (basic_block, max_uid); |
1648 | basic_block *end = XCNEWVEC (basic_block, max_uid); | |
1649 | enum bb_state *in_bb_p = XCNEWVEC (enum bb_state, max_uid); | |
ca6c03ca | 1650 | |
e0082a72 ZD |
1651 | basic_block bb; |
1652 | ||
6fb5fa3c DB |
1653 | if (df) |
1654 | df_dump_start (outf); | |
1655 | ||
e0082a72 | 1656 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1657 | { |
ca6c03ca JH |
1658 | rtx x; |
1659 | ||
a813c111 SB |
1660 | start[INSN_UID (BB_HEAD (bb))] = bb; |
1661 | end[INSN_UID (BB_END (bb))] = bb; | |
1662 | for (x = BB_HEAD (bb); x != NULL_RTX; x = NEXT_INSN (x)) | |
ca6c03ca JH |
1663 | { |
1664 | enum bb_state state = IN_MULTIPLE_BB; | |
5f0d2358 | 1665 | |
ca6c03ca JH |
1666 | if (in_bb_p[INSN_UID (x)] == NOT_IN_BB) |
1667 | state = IN_ONE_BB; | |
1668 | in_bb_p[INSN_UID (x)] = state; | |
1669 | ||
a813c111 | 1670 | if (x == BB_END (bb)) |
ca6c03ca JH |
1671 | break; |
1672 | } | |
1673 | } | |
1674 | ||
1675 | for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) | |
1676 | { | |
1677 | int did_output; | |
ca6c03ca JH |
1678 | if ((bb = start[INSN_UID (tmp_rtx)]) != NULL) |
1679 | { | |
6fb5fa3c DB |
1680 | edge e; |
1681 | edge_iterator ei; | |
b8698a0f | 1682 | |
6fb5fa3c DB |
1683 | fprintf (outf, ";; Start of basic block ("); |
1684 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1685 | fprintf (outf, " %d", e->src->index); | |
1686 | fprintf (outf, ") -> %d\n", bb->index); | |
1687 | ||
1688 | if (df) | |
1689 | { | |
1690 | df_dump_top (bb, outf); | |
1691 | putc ('\n', outf); | |
1692 | } | |
e9ec5c6b SB |
1693 | FOR_EACH_EDGE (e, ei, bb->preds) |
1694 | { | |
1695 | fputs (";; Pred edge ", outf); | |
1696 | dump_edge_info (outf, e, 0); | |
1697 | fputc ('\n', outf); | |
1698 | } | |
ca6c03ca JH |
1699 | } |
1700 | ||
1701 | if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB | |
4b4bf941 JQ |
1702 | && !NOTE_P (tmp_rtx) |
1703 | && !BARRIER_P (tmp_rtx)) | |
ca6c03ca JH |
1704 | fprintf (outf, ";; Insn is not within a basic block\n"); |
1705 | else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB) | |
1706 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); | |
1707 | ||
1708 | did_output = print_rtl_single (outf, tmp_rtx); | |
1709 | ||
1710 | if ((bb = end[INSN_UID (tmp_rtx)]) != NULL) | |
1711 | { | |
6fb5fa3c DB |
1712 | edge e; |
1713 | edge_iterator ei; | |
1714 | ||
1715 | fprintf (outf, ";; End of basic block %d -> (", bb->index); | |
1716 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1717 | fprintf (outf, " %d", e->dest->index); | |
1718 | fprintf (outf, ")\n"); | |
1719 | ||
1720 | if (df) | |
1721 | { | |
1722 | df_dump_bottom (bb, outf); | |
1723 | putc ('\n', outf); | |
1724 | } | |
ca6c03ca | 1725 | putc ('\n', outf); |
e9ec5c6b SB |
1726 | FOR_EACH_EDGE (e, ei, bb->succs) |
1727 | { | |
1728 | fputs (";; Succ edge ", outf); | |
1729 | dump_edge_info (outf, e, 1); | |
1730 | fputc ('\n', outf); | |
1731 | } | |
ca6c03ca | 1732 | } |
ca6c03ca JH |
1733 | if (did_output) |
1734 | putc ('\n', outf); | |
1735 | } | |
1736 | ||
1737 | free (start); | |
1738 | free (end); | |
1739 | free (in_bb_p); | |
1740 | } | |
1741 | ||
cb91fab0 | 1742 | if (crtl->epilogue_delay_list != 0) |
ca6c03ca JH |
1743 | { |
1744 | fprintf (outf, "\n;; Insns in epilogue delay list:\n\n"); | |
cb91fab0 | 1745 | for (tmp_rtx = crtl->epilogue_delay_list; tmp_rtx != 0; |
ca6c03ca JH |
1746 | tmp_rtx = XEXP (tmp_rtx, 1)) |
1747 | print_rtl_single (outf, XEXP (tmp_rtx, 0)); | |
1748 | } | |
1749 | } | |
1750 | \f | |
b446e5a2 | 1751 | void |
d329e058 | 1752 | update_br_prob_note (basic_block bb) |
b446e5a2 JH |
1753 | { |
1754 | rtx note; | |
4b4bf941 | 1755 | if (!JUMP_P (BB_END (bb))) |
b446e5a2 | 1756 | return; |
a813c111 | 1757 | note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX); |
b446e5a2 JH |
1758 | if (!note || INTVAL (XEXP (note, 0)) == BRANCH_EDGE (bb)->probability) |
1759 | return; | |
1760 | XEXP (note, 0) = GEN_INT (BRANCH_EDGE (bb)->probability); | |
1761 | } | |
96370780 MK |
1762 | |
1763 | /* Get the last insn associated with block BB (that includes barriers and | |
1764 | tablejumps after BB). */ | |
1765 | rtx | |
1766 | get_last_bb_insn (basic_block bb) | |
1767 | { | |
1768 | rtx tmp; | |
1769 | rtx end = BB_END (bb); | |
1770 | ||
1771 | /* Include any jump table following the basic block. */ | |
1772 | if (tablejump_p (end, NULL, &tmp)) | |
1773 | end = tmp; | |
1774 | ||
1775 | /* Include any barriers that may follow the basic block. */ | |
1e211590 | 1776 | tmp = next_nonnote_insn_bb (end); |
96370780 MK |
1777 | while (tmp && BARRIER_P (tmp)) |
1778 | { | |
1779 | end = tmp; | |
1e211590 | 1780 | tmp = next_nonnote_insn_bb (end); |
96370780 MK |
1781 | } |
1782 | ||
1783 | return end; | |
1784 | } | |
b446e5a2 | 1785 | \f |
10e9fecc JH |
1786 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
1787 | cfglayout RTL. | |
ca6c03ca JH |
1788 | |
1789 | Currently it does following checks: | |
1790 | ||
ca6c03ca | 1791 | - overlapping of basic blocks |
9eab6785 | 1792 | - insns with wrong BLOCK_FOR_INSN pointers |
ca6c03ca | 1793 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) |
f63d1bf7 | 1794 | - tails of basic blocks (ensure that boundary is necessary) |
ca6c03ca JH |
1795 | - scans body of the basic block for JUMP_INSN, CODE_LABEL |
1796 | and NOTE_INSN_BASIC_BLOCK | |
750054a2 | 1797 | - verify that no fall_thru edge crosses hot/cold partition boundaries |
9eab6785 | 1798 | - verify that there are no pending RTL branch predictions |
ca6c03ca JH |
1799 | |
1800 | In future it can be extended check a lot of other stuff as well | |
1801 | (reachability of basic blocks, life information, etc. etc.). */ | |
f470c378 | 1802 | |
10e9fecc | 1803 | static int |
d329e058 | 1804 | rtl_verify_flow_info_1 (void) |
ca6c03ca | 1805 | { |
ca6c03ca | 1806 | rtx x; |
10e9fecc | 1807 | int err = 0; |
94eb5ddb | 1808 | basic_block bb; |
ca6c03ca | 1809 | |
9eab6785 | 1810 | /* Check the general integrity of the basic blocks. */ |
e0082a72 | 1811 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1812 | { |
9eab6785 | 1813 | rtx insn; |
5f0d2358 | 1814 | |
5e2d947c JH |
1815 | if (!(bb->flags & BB_RTL)) |
1816 | { | |
1817 | error ("BB_RTL flag not set for block %d", bb->index); | |
1818 | err = 1; | |
1819 | } | |
1820 | ||
9eab6785 | 1821 | FOR_BB_INSNS (bb, insn) |
8ce9fd5d | 1822 | if (BLOCK_FOR_INSN (insn) != bb) |
9eab6785 SB |
1823 | { |
1824 | error ("insn %d basic block pointer is %d, should be %d", | |
1825 | INSN_UID (insn), | |
1826 | BLOCK_FOR_INSN (insn) ? BLOCK_FOR_INSN (insn)->index : 0, | |
1827 | bb->index); | |
1828 | err = 1; | |
1829 | } | |
a7b87f73 ZD |
1830 | |
1831 | for (insn = bb->il.rtl->header; insn; insn = NEXT_INSN (insn)) | |
1832 | if (!BARRIER_P (insn) | |
1833 | && BLOCK_FOR_INSN (insn) != NULL) | |
1834 | { | |
1835 | error ("insn %d in header of bb %d has non-NULL basic block", | |
1836 | INSN_UID (insn), bb->index); | |
1837 | err = 1; | |
1838 | } | |
1839 | for (insn = bb->il.rtl->footer; insn; insn = NEXT_INSN (insn)) | |
1840 | if (!BARRIER_P (insn) | |
1841 | && BLOCK_FOR_INSN (insn) != NULL) | |
1842 | { | |
1843 | error ("insn %d in footer of bb %d has non-NULL basic block", | |
1844 | INSN_UID (insn), bb->index); | |
1845 | err = 1; | |
1846 | } | |
ca6c03ca JH |
1847 | } |
1848 | ||
1849 | /* Now check the basic blocks (boundaries etc.) */ | |
e0082a72 | 1850 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1851 | { |
3dec4024 | 1852 | int n_fallthru = 0, n_eh = 0, n_call = 0, n_abnormal = 0, n_branch = 0; |
3cf54412 | 1853 | edge e, fallthru = NULL; |
5a1a3e5e | 1854 | rtx note; |
628f6a4e | 1855 | edge_iterator ei; |
ca6c03ca | 1856 | |
2085a21f | 1857 | if (JUMP_P (BB_END (bb)) |
a813c111 | 1858 | && (note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX)) |
628f6a4e | 1859 | && EDGE_COUNT (bb->succs) >= 2 |
a813c111 | 1860 | && any_condjump_p (BB_END (bb))) |
5a1a3e5e | 1861 | { |
e53de54d JH |
1862 | if (INTVAL (XEXP (note, 0)) != BRANCH_EDGE (bb)->probability |
1863 | && profile_status != PROFILE_ABSENT) | |
5a1a3e5e | 1864 | { |
0108ae51 | 1865 | error ("verify_flow_info: REG_BR_PROB does not match cfg %wi %i", |
5a1a3e5e JH |
1866 | INTVAL (XEXP (note, 0)), BRANCH_EDGE (bb)->probability); |
1867 | err = 1; | |
1868 | } | |
1869 | } | |
628f6a4e | 1870 | FOR_EACH_EDGE (e, ei, bb->succs) |
ca6c03ca | 1871 | { |
ca6c03ca | 1872 | if (e->flags & EDGE_FALLTHRU) |
750054a2 CT |
1873 | { |
1874 | n_fallthru++, fallthru = e; | |
bd454efd | 1875 | if ((e->flags & EDGE_CROSSING) |
076c7ab8 | 1876 | || (BB_PARTITION (e->src) != BB_PARTITION (e->dest) |
9fb32434 CT |
1877 | && e->src != ENTRY_BLOCK_PTR |
1878 | && e->dest != EXIT_BLOCK_PTR)) | |
c22cacf3 | 1879 | { |
ab532386 | 1880 | error ("fallthru edge crosses section boundary (bb %i)", |
750054a2 CT |
1881 | e->src->index); |
1882 | err = 1; | |
1883 | } | |
1884 | } | |
3dec4024 | 1885 | |
65f43cdf ZD |
1886 | if ((e->flags & ~(EDGE_DFS_BACK |
1887 | | EDGE_CAN_FALLTHRU | |
1888 | | EDGE_IRREDUCIBLE_LOOP | |
9beb1c84 CT |
1889 | | EDGE_LOOP_EXIT |
1890 | | EDGE_CROSSING)) == 0) | |
3dec4024 JH |
1891 | n_branch++; |
1892 | ||
1893 | if (e->flags & EDGE_ABNORMAL_CALL) | |
1894 | n_call++; | |
1895 | ||
1896 | if (e->flags & EDGE_EH) | |
1897 | n_eh++; | |
1898 | else if (e->flags & EDGE_ABNORMAL) | |
1899 | n_abnormal++; | |
ca6c03ca | 1900 | } |
5f0d2358 | 1901 | |
1d65f45c | 1902 | if (n_eh && !find_reg_note (BB_END (bb), REG_EH_REGION, NULL_RTX)) |
3dec4024 | 1903 | { |
ab532386 | 1904 | error ("missing REG_EH_REGION note in the end of bb %i", bb->index); |
3dec4024 JH |
1905 | err = 1; |
1906 | } | |
1d65f45c RH |
1907 | if (n_eh > 1) |
1908 | { | |
1909 | error ("too many eh edges %i", bb->index); | |
1910 | err = 1; | |
1911 | } | |
3dec4024 | 1912 | if (n_branch |
4b4bf941 | 1913 | && (!JUMP_P (BB_END (bb)) |
a813c111 SB |
1914 | || (n_branch > 1 && (any_uncondjump_p (BB_END (bb)) |
1915 | || any_condjump_p (BB_END (bb)))))) | |
3dec4024 | 1916 | { |
ab532386 | 1917 | error ("too many outgoing branch edges from bb %i", bb->index); |
3dec4024 JH |
1918 | err = 1; |
1919 | } | |
a813c111 | 1920 | if (n_fallthru && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 1921 | { |
ab532386 | 1922 | error ("fallthru edge after unconditional jump %i", bb->index); |
3dec4024 JH |
1923 | err = 1; |
1924 | } | |
a813c111 | 1925 | if (n_branch != 1 && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 1926 | { |
1d65f45c RH |
1927 | error ("wrong number of branch edges after unconditional jump %i", |
1928 | bb->index); | |
3dec4024 JH |
1929 | err = 1; |
1930 | } | |
a813c111 | 1931 | if (n_branch != 1 && any_condjump_p (BB_END (bb)) |
c11fd0b2 | 1932 | && JUMP_LABEL (BB_END (bb)) != BB_HEAD (fallthru->dest)) |
3dec4024 | 1933 | { |
c11fd0b2 RG |
1934 | error ("wrong amount of branch edges after conditional jump %i", |
1935 | bb->index); | |
3dec4024 JH |
1936 | err = 1; |
1937 | } | |
4b4bf941 | 1938 | if (n_call && !CALL_P (BB_END (bb))) |
3dec4024 | 1939 | { |
ab532386 | 1940 | error ("call edges for non-call insn in bb %i", bb->index); |
3dec4024 JH |
1941 | err = 1; |
1942 | } | |
1943 | if (n_abnormal | |
4b4bf941 JQ |
1944 | && (!CALL_P (BB_END (bb)) && n_call != n_abnormal) |
1945 | && (!JUMP_P (BB_END (bb)) | |
a813c111 SB |
1946 | || any_condjump_p (BB_END (bb)) |
1947 | || any_uncondjump_p (BB_END (bb)))) | |
3dec4024 | 1948 | { |
ab532386 | 1949 | error ("abnormal edges for no purpose in bb %i", bb->index); |
3dec4024 JH |
1950 | err = 1; |
1951 | } | |
f87c27b4 | 1952 | |
a813c111 | 1953 | for (x = BB_HEAD (bb); x != NEXT_INSN (BB_END (bb)); x = NEXT_INSN (x)) |
0ca541aa | 1954 | /* We may have a barrier inside a basic block before dead code |
9524880c HPN |
1955 | elimination. There is no BLOCK_FOR_INSN field in a barrier. */ |
1956 | if (!BARRIER_P (x) && BLOCK_FOR_INSN (x) != bb) | |
5f0d2358 RK |
1957 | { |
1958 | debug_rtx (x); | |
1959 | if (! BLOCK_FOR_INSN (x)) | |
1960 | error | |
1961 | ("insn %d inside basic block %d but block_for_insn is NULL", | |
0b17ab2f | 1962 | INSN_UID (x), bb->index); |
5f0d2358 RK |
1963 | else |
1964 | error | |
1965 | ("insn %d inside basic block %d but block_for_insn is %i", | |
0b17ab2f | 1966 | INSN_UID (x), bb->index, BLOCK_FOR_INSN (x)->index); |
5f0d2358 RK |
1967 | |
1968 | err = 1; | |
1969 | } | |
ca6c03ca JH |
1970 | |
1971 | /* OK pointers are correct. Now check the header of basic | |
c22cacf3 | 1972 | block. It ought to contain optional CODE_LABEL followed |
ca6c03ca | 1973 | by NOTE_BASIC_BLOCK. */ |
a813c111 | 1974 | x = BB_HEAD (bb); |
4b4bf941 | 1975 | if (LABEL_P (x)) |
ca6c03ca | 1976 | { |
a813c111 | 1977 | if (BB_END (bb) == x) |
ca6c03ca JH |
1978 | { |
1979 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 1980 | bb->index); |
ca6c03ca JH |
1981 | err = 1; |
1982 | } | |
5f0d2358 | 1983 | |
ca6c03ca JH |
1984 | x = NEXT_INSN (x); |
1985 | } | |
5f0d2358 | 1986 | |
ca6c03ca JH |
1987 | if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb) |
1988 | { | |
1989 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 1990 | bb->index); |
ca6c03ca JH |
1991 | err = 1; |
1992 | } | |
1993 | ||
a813c111 | 1994 | if (BB_END (bb) == x) |
49243025 | 1995 | /* Do checks for empty blocks here. */ |
5f0d2358 | 1996 | ; |
ca6c03ca | 1997 | else |
5f0d2358 RK |
1998 | for (x = NEXT_INSN (x); x; x = NEXT_INSN (x)) |
1999 | { | |
2000 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2001 | { | |
2002 | error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d", | |
0b17ab2f | 2003 | INSN_UID (x), bb->index); |
5f0d2358 RK |
2004 | err = 1; |
2005 | } | |
2006 | ||
a813c111 | 2007 | if (x == BB_END (bb)) |
5f0d2358 | 2008 | break; |
ca6c03ca | 2009 | |
83fd323c | 2010 | if (control_flow_insn_p (x)) |
5f0d2358 | 2011 | { |
0b17ab2f | 2012 | error ("in basic block %d:", bb->index); |
5f0d2358 RK |
2013 | fatal_insn ("flow control insn inside a basic block", x); |
2014 | } | |
2015 | } | |
ca6c03ca JH |
2016 | } |
2017 | ||
10e9fecc | 2018 | /* Clean up. */ |
10e9fecc JH |
2019 | return err; |
2020 | } | |
5f0d2358 | 2021 | |
10e9fecc JH |
2022 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
2023 | cfglayout RTL. | |
5f0d2358 | 2024 | |
10e9fecc JH |
2025 | Currently it does following checks: |
2026 | - all checks of rtl_verify_flow_info_1 | |
9eab6785 | 2027 | - test head/end pointers |
10e9fecc JH |
2028 | - check that all insns are in the basic blocks |
2029 | (except the switch handling code, barriers and notes) | |
2030 | - check that all returns are followed by barriers | |
2031 | - check that all fallthru edge points to the adjacent blocks. */ | |
9eab6785 | 2032 | |
10e9fecc | 2033 | static int |
d329e058 | 2034 | rtl_verify_flow_info (void) |
10e9fecc JH |
2035 | { |
2036 | basic_block bb; | |
2037 | int err = rtl_verify_flow_info_1 (); | |
2038 | rtx x; | |
9eab6785 SB |
2039 | rtx last_head = get_last_insn (); |
2040 | basic_block *bb_info; | |
10e9fecc JH |
2041 | int num_bb_notes; |
2042 | const rtx rtx_first = get_insns (); | |
2043 | basic_block last_bb_seen = ENTRY_BLOCK_PTR, curr_bb = NULL; | |
9eab6785 SB |
2044 | const int max_uid = get_max_uid (); |
2045 | ||
2046 | bb_info = XCNEWVEC (basic_block, max_uid); | |
ca6c03ca | 2047 | |
10e9fecc JH |
2048 | FOR_EACH_BB_REVERSE (bb) |
2049 | { | |
2050 | edge e; | |
628f6a4e | 2051 | edge_iterator ei; |
9eab6785 SB |
2052 | rtx head = BB_HEAD (bb); |
2053 | rtx end = BB_END (bb); | |
628f6a4e | 2054 | |
9eab6785 | 2055 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) |
a7b87f73 ZD |
2056 | { |
2057 | /* Verify the end of the basic block is in the INSN chain. */ | |
2058 | if (x == end) | |
2059 | break; | |
2060 | ||
2061 | /* And that the code outside of basic blocks has NULL bb field. */ | |
2062 | if (!BARRIER_P (x) | |
2063 | && BLOCK_FOR_INSN (x) != NULL) | |
2064 | { | |
2065 | error ("insn %d outside of basic blocks has non-NULL bb field", | |
2066 | INSN_UID (x)); | |
2067 | err = 1; | |
2068 | } | |
2069 | } | |
9eab6785 SB |
2070 | |
2071 | if (!x) | |
2072 | { | |
2073 | error ("end insn %d for block %d not found in the insn stream", | |
2074 | INSN_UID (end), bb->index); | |
2075 | err = 1; | |
2076 | } | |
2077 | ||
2078 | /* Work backwards from the end to the head of the basic block | |
2079 | to verify the head is in the RTL chain. */ | |
2080 | for (; x != NULL_RTX; x = PREV_INSN (x)) | |
a00d11f0 | 2081 | { |
9eab6785 SB |
2082 | /* While walking over the insn chain, verify insns appear |
2083 | in only one basic block. */ | |
2084 | if (bb_info[INSN_UID (x)] != NULL) | |
2085 | { | |
2086 | error ("insn %d is in multiple basic blocks (%d and %d)", | |
2087 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); | |
2088 | err = 1; | |
2089 | } | |
2090 | ||
2091 | bb_info[INSN_UID (x)] = bb; | |
2092 | ||
2093 | if (x == head) | |
2094 | break; | |
2095 | } | |
2096 | if (!x) | |
2097 | { | |
2098 | error ("head insn %d for block %d not found in the insn stream", | |
2099 | INSN_UID (head), bb->index); | |
a00d11f0 JH |
2100 | err = 1; |
2101 | } | |
2102 | ||
a7b87f73 | 2103 | last_head = PREV_INSN (x); |
9eab6785 | 2104 | |
628f6a4e | 2105 | FOR_EACH_EDGE (e, ei, bb->succs) |
10e9fecc JH |
2106 | if (e->flags & EDGE_FALLTHRU) |
2107 | break; | |
2108 | if (!e) | |
2109 | { | |
2110 | rtx insn; | |
2111 | ||
2112 | /* Ensure existence of barrier in BB with no fallthru edges. */ | |
468059bc DD |
2113 | for (insn = NEXT_INSN (BB_END (bb)); ; insn = NEXT_INSN (insn)) |
2114 | { | |
2115 | if (!insn || NOTE_INSN_BASIC_BLOCK_P (insn)) | |
10e9fecc JH |
2116 | { |
2117 | error ("missing barrier after block %i", bb->index); | |
2118 | err = 1; | |
2119 | break; | |
2120 | } | |
468059bc DD |
2121 | if (BARRIER_P (insn)) |
2122 | break; | |
2123 | } | |
10e9fecc JH |
2124 | } |
2125 | else if (e->src != ENTRY_BLOCK_PTR | |
2126 | && e->dest != EXIT_BLOCK_PTR) | |
c22cacf3 | 2127 | { |
10e9fecc JH |
2128 | rtx insn; |
2129 | ||
2130 | if (e->src->next_bb != e->dest) | |
2131 | { | |
2132 | error | |
2133 | ("verify_flow_info: Incorrect blocks for fallthru %i->%i", | |
2134 | e->src->index, e->dest->index); | |
2135 | err = 1; | |
2136 | } | |
2137 | else | |
a813c111 | 2138 | for (insn = NEXT_INSN (BB_END (e->src)); insn != BB_HEAD (e->dest); |
10e9fecc | 2139 | insn = NEXT_INSN (insn)) |
6be85b25 | 2140 | if (BARRIER_P (insn) || INSN_P (insn)) |
10e9fecc JH |
2141 | { |
2142 | error ("verify_flow_info: Incorrect fallthru %i->%i", | |
2143 | e->src->index, e->dest->index); | |
2144 | fatal_insn ("wrong insn in the fallthru edge", insn); | |
2145 | err = 1; | |
2146 | } | |
c22cacf3 | 2147 | } |
10e9fecc | 2148 | } |
ca6c03ca | 2149 | |
a7b87f73 ZD |
2150 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) |
2151 | { | |
2152 | /* Check that the code before the first basic block has NULL | |
2153 | bb field. */ | |
2154 | if (!BARRIER_P (x) | |
2155 | && BLOCK_FOR_INSN (x) != NULL) | |
2156 | { | |
2157 | error ("insn %d outside of basic blocks has non-NULL bb field", | |
2158 | INSN_UID (x)); | |
2159 | err = 1; | |
2160 | } | |
2161 | } | |
9eab6785 SB |
2162 | free (bb_info); |
2163 | ||
ca6c03ca | 2164 | num_bb_notes = 0; |
e0082a72 ZD |
2165 | last_bb_seen = ENTRY_BLOCK_PTR; |
2166 | ||
5f0d2358 | 2167 | for (x = rtx_first; x; x = NEXT_INSN (x)) |
ca6c03ca JH |
2168 | { |
2169 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2170 | { | |
bf77398c | 2171 | bb = NOTE_BASIC_BLOCK (x); |
5f0d2358 | 2172 | |
ca6c03ca | 2173 | num_bb_notes++; |
e0082a72 | 2174 | if (bb != last_bb_seen->next_bb) |
10e9fecc | 2175 | internal_error ("basic blocks not laid down consecutively"); |
ca6c03ca | 2176 | |
10e9fecc | 2177 | curr_bb = last_bb_seen = bb; |
ca6c03ca JH |
2178 | } |
2179 | ||
10e9fecc | 2180 | if (!curr_bb) |
ca6c03ca JH |
2181 | { |
2182 | switch (GET_CODE (x)) | |
2183 | { | |
2184 | case BARRIER: | |
2185 | case NOTE: | |
2186 | break; | |
2187 | ||
2188 | case CODE_LABEL: | |
666c27b9 | 2189 | /* An addr_vec is placed outside any basic block. */ |
ca6c03ca | 2190 | if (NEXT_INSN (x) |
481683e1 | 2191 | && JUMP_TABLE_DATA_P (NEXT_INSN (x))) |
5f0d2358 | 2192 | x = NEXT_INSN (x); |
ca6c03ca JH |
2193 | |
2194 | /* But in any case, non-deletable labels can appear anywhere. */ | |
2195 | break; | |
2196 | ||
2197 | default: | |
1f978f5f | 2198 | fatal_insn ("insn outside basic block", x); |
ca6c03ca JH |
2199 | } |
2200 | } | |
2201 | ||
26cae194 | 2202 | if (JUMP_P (x) |
ca6c03ca | 2203 | && returnjump_p (x) && ! condjump_p (x) |
15eb3a2e | 2204 | && ! (next_nonnote_insn (x) && BARRIER_P (next_nonnote_insn (x)))) |
1f978f5f | 2205 | fatal_insn ("return not followed by barrier", x); |
a813c111 | 2206 | if (curr_bb && x == BB_END (curr_bb)) |
10e9fecc | 2207 | curr_bb = NULL; |
ca6c03ca JH |
2208 | } |
2209 | ||
24bd1a0b | 2210 | if (num_bb_notes != n_basic_blocks - NUM_FIXED_BLOCKS) |
ca6c03ca | 2211 | internal_error |
0b17ab2f RH |
2212 | ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)", |
2213 | num_bb_notes, n_basic_blocks); | |
ca6c03ca | 2214 | |
10e9fecc | 2215 | return err; |
ca6c03ca JH |
2216 | } |
2217 | \f | |
eaec9b3d | 2218 | /* Assume that the preceding pass has possibly eliminated jump instructions |
ca6c03ca JH |
2219 | or converted the unconditional jumps. Eliminate the edges from CFG. |
2220 | Return true if any edges are eliminated. */ | |
2221 | ||
2222 | bool | |
d329e058 | 2223 | purge_dead_edges (basic_block bb) |
ca6c03ca | 2224 | { |
628f6a4e | 2225 | edge e; |
a813c111 | 2226 | rtx insn = BB_END (bb), note; |
ca6c03ca | 2227 | bool purged = false; |
628f6a4e BE |
2228 | bool found; |
2229 | edge_iterator ei; | |
ca6c03ca | 2230 | |
b5b8b0ac AO |
2231 | if (DEBUG_INSN_P (insn) && insn != BB_HEAD (bb)) |
2232 | do | |
2233 | insn = PREV_INSN (insn); | |
2234 | while ((DEBUG_INSN_P (insn) || NOTE_P (insn)) && insn != BB_HEAD (bb)); | |
2235 | ||
70da1d03 | 2236 | /* If this instruction cannot trap, remove REG_EH_REGION notes. */ |
4b4bf941 | 2237 | if (NONJUMP_INSN_P (insn) |
70da1d03 JH |
2238 | && (note = find_reg_note (insn, REG_EH_REGION, NULL))) |
2239 | { | |
2240 | rtx eqnote; | |
2241 | ||
2242 | if (! may_trap_p (PATTERN (insn)) | |
2243 | || ((eqnote = find_reg_equal_equiv_note (insn)) | |
2244 | && ! may_trap_p (XEXP (eqnote, 0)))) | |
2245 | remove_note (insn, note); | |
2246 | } | |
2247 | ||
546c093e | 2248 | /* Cleanup abnormal edges caused by exceptions or non-local gotos. */ |
628f6a4e | 2249 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
546c093e | 2250 | { |
1d65f45c RH |
2251 | bool remove = false; |
2252 | ||
e5f9a909 JW |
2253 | /* There are three types of edges we need to handle correctly here: EH |
2254 | edges, abnormal call EH edges, and abnormal call non-EH edges. The | |
2255 | latter can appear when nonlocal gotos are used. */ | |
1d65f45c | 2256 | if (e->flags & EDGE_ABNORMAL_CALL) |
546c093e | 2257 | { |
1d65f45c RH |
2258 | if (!CALL_P (insn)) |
2259 | remove = true; | |
2260 | else if (can_nonlocal_goto (insn)) | |
2261 | ; | |
2262 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) | |
2263 | ; | |
2264 | else | |
2265 | remove = true; | |
546c093e | 2266 | } |
1d65f45c RH |
2267 | else if (e->flags & EDGE_EH) |
2268 | remove = !can_throw_internal (insn); | |
2269 | ||
2270 | if (remove) | |
546c093e | 2271 | { |
1d65f45c RH |
2272 | remove_edge (e); |
2273 | df_set_bb_dirty (bb); | |
2274 | purged = true; | |
546c093e RH |
2275 | } |
2276 | else | |
1d65f45c | 2277 | ei_next (&ei); |
546c093e | 2278 | } |
5f0d2358 | 2279 | |
4b4bf941 | 2280 | if (JUMP_P (insn)) |
ca6c03ca JH |
2281 | { |
2282 | rtx note; | |
2283 | edge b,f; | |
628f6a4e | 2284 | edge_iterator ei; |
5f0d2358 | 2285 | |
ca6c03ca JH |
2286 | /* We do care only about conditional jumps and simplejumps. */ |
2287 | if (!any_condjump_p (insn) | |
2288 | && !returnjump_p (insn) | |
2289 | && !simplejump_p (insn)) | |
c51d95ec | 2290 | return purged; |
5f0d2358 | 2291 | |
5a1a3e5e JH |
2292 | /* Branch probability/prediction notes are defined only for |
2293 | condjumps. We've possibly turned condjump into simplejump. */ | |
2294 | if (simplejump_p (insn)) | |
2295 | { | |
2296 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2297 | if (note) | |
2298 | remove_note (insn, note); | |
2299 | while ((note = find_reg_note (insn, REG_BR_PRED, NULL))) | |
2300 | remove_note (insn, note); | |
2301 | } | |
2302 | ||
628f6a4e | 2303 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
ca6c03ca | 2304 | { |
7fcd7218 JH |
2305 | /* Avoid abnormal flags to leak from computed jumps turned |
2306 | into simplejumps. */ | |
f87c27b4 | 2307 | |
0e1638d4 | 2308 | e->flags &= ~EDGE_ABNORMAL; |
7fcd7218 | 2309 | |
5a566bed MM |
2310 | /* See if this edge is one we should keep. */ |
2311 | if ((e->flags & EDGE_FALLTHRU) && any_condjump_p (insn)) | |
2312 | /* A conditional jump can fall through into the next | |
2313 | block, so we should keep the edge. */ | |
628f6a4e BE |
2314 | { |
2315 | ei_next (&ei); | |
2316 | continue; | |
2317 | } | |
5f0d2358 | 2318 | else if (e->dest != EXIT_BLOCK_PTR |
a813c111 | 2319 | && BB_HEAD (e->dest) == JUMP_LABEL (insn)) |
5a566bed MM |
2320 | /* If the destination block is the target of the jump, |
2321 | keep the edge. */ | |
628f6a4e BE |
2322 | { |
2323 | ei_next (&ei); | |
2324 | continue; | |
2325 | } | |
5a566bed MM |
2326 | else if (e->dest == EXIT_BLOCK_PTR && returnjump_p (insn)) |
2327 | /* If the destination block is the exit block, and this | |
2328 | instruction is a return, then keep the edge. */ | |
628f6a4e BE |
2329 | { |
2330 | ei_next (&ei); | |
2331 | continue; | |
2332 | } | |
5a566bed MM |
2333 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) |
2334 | /* Keep the edges that correspond to exceptions thrown by | |
0b75beaa EB |
2335 | this instruction and rematerialize the EDGE_ABNORMAL |
2336 | flag we just cleared above. */ | |
2337 | { | |
2338 | e->flags |= EDGE_ABNORMAL; | |
628f6a4e | 2339 | ei_next (&ei); |
0b75beaa EB |
2340 | continue; |
2341 | } | |
5f0d2358 | 2342 | |
5a566bed | 2343 | /* We do not need this edge. */ |
6fb5fa3c | 2344 | df_set_bb_dirty (bb); |
ca6c03ca JH |
2345 | purged = true; |
2346 | remove_edge (e); | |
2347 | } | |
5f0d2358 | 2348 | |
628f6a4e | 2349 | if (EDGE_COUNT (bb->succs) == 0 || !purged) |
c51d95ec | 2350 | return purged; |
5f0d2358 | 2351 | |
c263766c RH |
2352 | if (dump_file) |
2353 | fprintf (dump_file, "Purged edges from bb %i\n", bb->index); | |
5f0d2358 | 2354 | |
ca6c03ca JH |
2355 | if (!optimize) |
2356 | return purged; | |
2357 | ||
2358 | /* Redistribute probabilities. */ | |
c5cbcccf | 2359 | if (single_succ_p (bb)) |
ca6c03ca | 2360 | { |
c5cbcccf ZD |
2361 | single_succ_edge (bb)->probability = REG_BR_PROB_BASE; |
2362 | single_succ_edge (bb)->count = bb->count; | |
f87c27b4 | 2363 | } |
ca6c03ca JH |
2364 | else |
2365 | { | |
2366 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2367 | if (!note) | |
2368 | return purged; | |
5f0d2358 | 2369 | |
ca6c03ca JH |
2370 | b = BRANCH_EDGE (bb); |
2371 | f = FALLTHRU_EDGE (bb); | |
2372 | b->probability = INTVAL (XEXP (note, 0)); | |
2373 | f->probability = REG_BR_PROB_BASE - b->probability; | |
2374 | b->count = bb->count * b->probability / REG_BR_PROB_BASE; | |
2375 | f->count = bb->count * f->probability / REG_BR_PROB_BASE; | |
2376 | } | |
5f0d2358 | 2377 | |
ca6c03ca JH |
2378 | return purged; |
2379 | } | |
4b4bf941 | 2380 | else if (CALL_P (insn) && SIBLING_CALL_P (insn)) |
1722c2c8 RH |
2381 | { |
2382 | /* First, there should not be any EH or ABCALL edges resulting | |
2383 | from non-local gotos and the like. If there were, we shouldn't | |
2384 | have created the sibcall in the first place. Second, there | |
2385 | should of course never have been a fallthru edge. */ | |
c5cbcccf ZD |
2386 | gcc_assert (single_succ_p (bb)); |
2387 | gcc_assert (single_succ_edge (bb)->flags | |
2388 | == (EDGE_SIBCALL | EDGE_ABNORMAL)); | |
1722c2c8 RH |
2389 | |
2390 | return 0; | |
2391 | } | |
ca6c03ca | 2392 | |
ca6c03ca JH |
2393 | /* If we don't see a jump insn, we don't know exactly why the block would |
2394 | have been broken at this point. Look for a simple, non-fallthru edge, | |
2395 | as these are only created by conditional branches. If we find such an | |
2396 | edge we know that there used to be a jump here and can then safely | |
2397 | remove all non-fallthru edges. */ | |
628f6a4e BE |
2398 | found = false; |
2399 | FOR_EACH_EDGE (e, ei, bb->succs) | |
2400 | if (! (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU))) | |
2401 | { | |
2402 | found = true; | |
2403 | break; | |
2404 | } | |
5f0d2358 | 2405 | |
628f6a4e | 2406 | if (!found) |
ca6c03ca | 2407 | return purged; |
5f0d2358 | 2408 | |
2afa8dce DB |
2409 | /* Remove all but the fake and fallthru edges. The fake edge may be |
2410 | the only successor for this block in the case of noreturn | |
2411 | calls. */ | |
628f6a4e | 2412 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
ca6c03ca | 2413 | { |
2afa8dce | 2414 | if (!(e->flags & (EDGE_FALLTHRU | EDGE_FAKE))) |
c51d95ec | 2415 | { |
6fb5fa3c | 2416 | df_set_bb_dirty (bb); |
c51d95ec JH |
2417 | remove_edge (e); |
2418 | purged = true; | |
2419 | } | |
628f6a4e BE |
2420 | else |
2421 | ei_next (&ei); | |
ca6c03ca | 2422 | } |
5f0d2358 | 2423 | |
c5cbcccf | 2424 | gcc_assert (single_succ_p (bb)); |
5f0d2358 | 2425 | |
c5cbcccf ZD |
2426 | single_succ_edge (bb)->probability = REG_BR_PROB_BASE; |
2427 | single_succ_edge (bb)->count = bb->count; | |
ca6c03ca | 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 | |
25cd19de | 2439 | purge_all_dead_edges (void) |
ca6c03ca | 2440 | { |
e0082a72 | 2441 | int purged = false; |
e0082a72 | 2442 | basic_block bb; |
473fb060 | 2443 | |
e0082a72 | 2444 | FOR_EACH_BB (bb) |
473fb060 | 2445 | { |
e0082a72 | 2446 | bool purged_here = purge_dead_edges (bb); |
5f0d2358 | 2447 | |
473fb060 | 2448 | purged |= purged_here; |
473fb060 | 2449 | } |
5f0d2358 | 2450 | |
ca6c03ca JH |
2451 | return purged; |
2452 | } | |
9ee634e3 JH |
2453 | |
2454 | /* Same as split_block but update cfg_layout structures. */ | |
f470c378 ZD |
2455 | |
2456 | static basic_block | |
d329e058 | 2457 | cfg_layout_split_block (basic_block bb, void *insnp) |
9ee634e3 | 2458 | { |
ae50c0cb | 2459 | rtx insn = (rtx) insnp; |
f470c378 | 2460 | basic_block new_bb = rtl_split_block (bb, insn); |
9ee634e3 | 2461 | |
370369e1 JH |
2462 | new_bb->il.rtl->footer = bb->il.rtl->footer; |
2463 | bb->il.rtl->footer = NULL; | |
9ee634e3 | 2464 | |
f470c378 | 2465 | return new_bb; |
9ee634e3 JH |
2466 | } |
2467 | ||
9ee634e3 | 2468 | /* Redirect Edge to DEST. */ |
6de9cd9a | 2469 | static edge |
d329e058 | 2470 | cfg_layout_redirect_edge_and_branch (edge e, basic_block dest) |
9ee634e3 JH |
2471 | { |
2472 | basic_block src = e->src; | |
6de9cd9a | 2473 | edge ret; |
9ee634e3 | 2474 | |
bc35512f | 2475 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
6de9cd9a | 2476 | return NULL; |
bc35512f | 2477 | |
3348b696 | 2478 | if (e->dest == dest) |
6de9cd9a | 2479 | return e; |
bc35512f | 2480 | |
3348b696 | 2481 | if (e->src != ENTRY_BLOCK_PTR |
6de9cd9a | 2482 | && (ret = try_redirect_by_replacing_jump (e, dest, true))) |
f345f21a | 2483 | { |
6fb5fa3c | 2484 | df_set_bb_dirty (src); |
6de9cd9a | 2485 | return ret; |
f345f21a | 2486 | } |
bc35512f JH |
2487 | |
2488 | if (e->src == ENTRY_BLOCK_PTR | |
2489 | && (e->flags & EDGE_FALLTHRU) && !(e->flags & EDGE_COMPLEX)) | |
2490 | { | |
c263766c RH |
2491 | if (dump_file) |
2492 | fprintf (dump_file, "Redirecting entry edge from bb %i to %i\n", | |
bc35512f JH |
2493 | e->src->index, dest->index); |
2494 | ||
6fb5fa3c | 2495 | df_set_bb_dirty (e->src); |
bc35512f | 2496 | redirect_edge_succ (e, dest); |
6de9cd9a | 2497 | return e; |
bc35512f JH |
2498 | } |
2499 | ||
9ee634e3 JH |
2500 | /* Redirect_edge_and_branch may decide to turn branch into fallthru edge |
2501 | in the case the basic block appears to be in sequence. Avoid this | |
2502 | transformation. */ | |
2503 | ||
9ee634e3 JH |
2504 | if (e->flags & EDGE_FALLTHRU) |
2505 | { | |
2506 | /* Redirect any branch edges unified with the fallthru one. */ | |
4b4bf941 | 2507 | if (JUMP_P (BB_END (src)) |
432f982f JH |
2508 | && label_is_jump_target_p (BB_HEAD (e->dest), |
2509 | BB_END (src))) | |
9ee634e3 | 2510 | { |
341c100f | 2511 | edge redirected; |
c22cacf3 | 2512 | |
c263766c RH |
2513 | if (dump_file) |
2514 | fprintf (dump_file, "Fallthru edge unified with branch " | |
432f982f JH |
2515 | "%i->%i redirected to %i\n", |
2516 | e->src->index, e->dest->index, dest->index); | |
2517 | e->flags &= ~EDGE_FALLTHRU; | |
341c100f NS |
2518 | redirected = redirect_branch_edge (e, dest); |
2519 | gcc_assert (redirected); | |
432f982f | 2520 | e->flags |= EDGE_FALLTHRU; |
6fb5fa3c | 2521 | df_set_bb_dirty (e->src); |
6de9cd9a | 2522 | return e; |
9ee634e3 JH |
2523 | } |
2524 | /* In case we are redirecting fallthru edge to the branch edge | |
c22cacf3 | 2525 | of conditional jump, remove it. */ |
628f6a4e | 2526 | if (EDGE_COUNT (src->succs) == 2) |
9ee634e3 | 2527 | { |
03101c6f KH |
2528 | /* Find the edge that is different from E. */ |
2529 | edge s = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e); | |
628f6a4e | 2530 | |
9ee634e3 | 2531 | if (s->dest == dest |
a813c111 SB |
2532 | && any_condjump_p (BB_END (src)) |
2533 | && onlyjump_p (BB_END (src))) | |
2534 | delete_insn (BB_END (src)); | |
9ee634e3 | 2535 | } |
6de9cd9a | 2536 | ret = redirect_edge_succ_nodup (e, dest); |
c263766c RH |
2537 | if (dump_file) |
2538 | fprintf (dump_file, "Fallthru edge %i->%i redirected to %i\n", | |
bc35512f | 2539 | e->src->index, e->dest->index, dest->index); |
9ee634e3 JH |
2540 | } |
2541 | else | |
bc35512f | 2542 | ret = redirect_branch_edge (e, dest); |
9ee634e3 JH |
2543 | |
2544 | /* We don't want simplejumps in the insn stream during cfglayout. */ | |
341c100f | 2545 | gcc_assert (!simplejump_p (BB_END (src))); |
9ee634e3 | 2546 | |
6fb5fa3c | 2547 | df_set_bb_dirty (src); |
9ee634e3 JH |
2548 | return ret; |
2549 | } | |
2550 | ||
2551 | /* Simple wrapper as we always can redirect fallthru edges. */ | |
2552 | static basic_block | |
d329e058 | 2553 | cfg_layout_redirect_edge_and_branch_force (edge e, basic_block dest) |
9ee634e3 | 2554 | { |
341c100f NS |
2555 | edge redirected = cfg_layout_redirect_edge_and_branch (e, dest); |
2556 | ||
2557 | gcc_assert (redirected); | |
9ee634e3 JH |
2558 | return NULL; |
2559 | } | |
2560 | ||
f470c378 ZD |
2561 | /* Same as delete_basic_block but update cfg_layout structures. */ |
2562 | ||
9ee634e3 | 2563 | static void |
d329e058 | 2564 | cfg_layout_delete_block (basic_block bb) |
9ee634e3 | 2565 | { |
a813c111 | 2566 | rtx insn, next, prev = PREV_INSN (BB_HEAD (bb)), *to, remaints; |
9ee634e3 | 2567 | |
370369e1 | 2568 | if (bb->il.rtl->header) |
9ee634e3 | 2569 | { |
a813c111 | 2570 | next = BB_HEAD (bb); |
9ee634e3 | 2571 | if (prev) |
370369e1 | 2572 | NEXT_INSN (prev) = bb->il.rtl->header; |
9ee634e3 | 2573 | else |
370369e1 JH |
2574 | set_first_insn (bb->il.rtl->header); |
2575 | PREV_INSN (bb->il.rtl->header) = prev; | |
2576 | insn = bb->il.rtl->header; | |
9ee634e3 JH |
2577 | while (NEXT_INSN (insn)) |
2578 | insn = NEXT_INSN (insn); | |
2579 | NEXT_INSN (insn) = next; | |
2580 | PREV_INSN (next) = insn; | |
2581 | } | |
a813c111 | 2582 | next = NEXT_INSN (BB_END (bb)); |
370369e1 | 2583 | if (bb->il.rtl->footer) |
9ee634e3 | 2584 | { |
370369e1 | 2585 | insn = bb->il.rtl->footer; |
bc35512f JH |
2586 | while (insn) |
2587 | { | |
4b4bf941 | 2588 | if (BARRIER_P (insn)) |
bc35512f JH |
2589 | { |
2590 | if (PREV_INSN (insn)) | |
2591 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
2592 | else | |
370369e1 | 2593 | bb->il.rtl->footer = NEXT_INSN (insn); |
bc35512f JH |
2594 | if (NEXT_INSN (insn)) |
2595 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
2596 | } | |
4b4bf941 | 2597 | if (LABEL_P (insn)) |
bc35512f JH |
2598 | break; |
2599 | insn = NEXT_INSN (insn); | |
2600 | } | |
370369e1 | 2601 | if (bb->il.rtl->footer) |
bc35512f | 2602 | { |
a813c111 | 2603 | insn = BB_END (bb); |
370369e1 JH |
2604 | NEXT_INSN (insn) = bb->il.rtl->footer; |
2605 | PREV_INSN (bb->il.rtl->footer) = insn; | |
bc35512f JH |
2606 | while (NEXT_INSN (insn)) |
2607 | insn = NEXT_INSN (insn); | |
2608 | NEXT_INSN (insn) = next; | |
2609 | if (next) | |
2610 | PREV_INSN (next) = insn; | |
2611 | else | |
2612 | set_last_insn (insn); | |
2613 | } | |
9ee634e3 JH |
2614 | } |
2615 | if (bb->next_bb != EXIT_BLOCK_PTR) | |
370369e1 | 2616 | to = &bb->next_bb->il.rtl->header; |
9ee634e3 JH |
2617 | else |
2618 | to = &cfg_layout_function_footer; | |
997de8ed | 2619 | |
9ee634e3 JH |
2620 | rtl_delete_block (bb); |
2621 | ||
2622 | if (prev) | |
2623 | prev = NEXT_INSN (prev); | |
d329e058 | 2624 | else |
9ee634e3 JH |
2625 | prev = get_insns (); |
2626 | if (next) | |
2627 | next = PREV_INSN (next); | |
d329e058 | 2628 | else |
9ee634e3 JH |
2629 | next = get_last_insn (); |
2630 | ||
2631 | if (next && NEXT_INSN (next) != prev) | |
2632 | { | |
2633 | remaints = unlink_insn_chain (prev, next); | |
2634 | insn = remaints; | |
2635 | while (NEXT_INSN (insn)) | |
2636 | insn = NEXT_INSN (insn); | |
2637 | NEXT_INSN (insn) = *to; | |
2638 | if (*to) | |
2639 | PREV_INSN (*to) = insn; | |
2640 | *to = remaints; | |
2641 | } | |
2642 | } | |
2643 | ||
beb235f8 | 2644 | /* Return true when blocks A and B can be safely merged. */ |
b48d0358 | 2645 | |
bc35512f | 2646 | static bool |
b48d0358 | 2647 | cfg_layout_can_merge_blocks_p (basic_block a, basic_block b) |
bc35512f | 2648 | { |
750054a2 CT |
2649 | /* If we are partitioning hot/cold basic blocks, we don't want to |
2650 | mess up unconditional or indirect jumps that cross between hot | |
076c7ab8 ZW |
2651 | and cold sections. |
2652 | ||
8e8d5162 | 2653 | Basic block partitioning may result in some jumps that appear to |
c22cacf3 MS |
2654 | be optimizable (or blocks that appear to be mergeable), but which really |
2655 | must be left untouched (they are required to make it safely across | |
2656 | partition boundaries). See the comments at the top of | |
8e8d5162 CT |
2657 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
2658 | ||
87c8b4be | 2659 | if (BB_PARTITION (a) != BB_PARTITION (b)) |
076c7ab8 | 2660 | return false; |
750054a2 | 2661 | |
bc35512f | 2662 | /* There must be exactly one edge in between the blocks. */ |
c5cbcccf ZD |
2663 | return (single_succ_p (a) |
2664 | && single_succ (a) == b | |
2665 | && single_pred_p (b) == 1 | |
628f6a4e | 2666 | && a != b |
bc35512f | 2667 | /* Must be simple edge. */ |
c5cbcccf | 2668 | && !(single_succ_edge (a)->flags & EDGE_COMPLEX) |
bc35512f | 2669 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR |
49ea3702 SB |
2670 | /* If the jump insn has side effects, we can't kill the edge. |
2671 | When not optimizing, try_redirect_by_replacing_jump will | |
2672 | not allow us to redirect an edge by replacing a table jump. */ | |
4b4bf941 | 2673 | && (!JUMP_P (BB_END (a)) |
49ea3702 | 2674 | || ((!optimize || reload_completed) |
a813c111 | 2675 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f JH |
2676 | } |
2677 | ||
41806d92 NS |
2678 | /* Merge block A and B. The blocks must be mergeable. */ |
2679 | ||
bc35512f JH |
2680 | static void |
2681 | cfg_layout_merge_blocks (basic_block a, basic_block b) | |
2682 | { | |
2683 | #ifdef ENABLE_CHECKING | |
341c100f | 2684 | gcc_assert (cfg_layout_can_merge_blocks_p (a, b)); |
bc35512f JH |
2685 | #endif |
2686 | ||
6fb5fa3c DB |
2687 | if (dump_file) |
2688 | fprintf (dump_file, "merging block %d into block %d\n", b->index, a->index); | |
2689 | ||
bc35512f | 2690 | /* If there was a CODE_LABEL beginning B, delete it. */ |
4b4bf941 | 2691 | if (LABEL_P (BB_HEAD (b))) |
2c97f8e4 | 2692 | { |
2c97f8e4 RH |
2693 | delete_insn (BB_HEAD (b)); |
2694 | } | |
bc35512f JH |
2695 | |
2696 | /* We should have fallthru edge in a, or we can do dummy redirection to get | |
2697 | it cleaned up. */ | |
4b4bf941 | 2698 | if (JUMP_P (BB_END (a))) |
628f6a4e | 2699 | try_redirect_by_replacing_jump (EDGE_SUCC (a, 0), b, true); |
341c100f | 2700 | gcc_assert (!JUMP_P (BB_END (a))); |
bc35512f | 2701 | |
7241571e JJ |
2702 | /* When not optimizing and the edge is the only place in RTL which holds |
2703 | some unique locus, emit a nop with that locus in between. */ | |
2704 | if (!optimize && EDGE_SUCC (a, 0)->goto_locus) | |
2705 | { | |
1692ae7e | 2706 | rtx insn = BB_END (a), end = PREV_INSN (BB_HEAD (a)); |
7241571e JJ |
2707 | int goto_locus = EDGE_SUCC (a, 0)->goto_locus; |
2708 | ||
1692ae7e JJ |
2709 | while (insn != end && (!INSN_P (insn) || INSN_LOCATOR (insn) == 0)) |
2710 | insn = PREV_INSN (insn); | |
2711 | if (insn != end && locator_eq (INSN_LOCATOR (insn), goto_locus)) | |
7241571e JJ |
2712 | goto_locus = 0; |
2713 | else | |
2714 | { | |
2715 | insn = BB_HEAD (b); | |
1692ae7e JJ |
2716 | end = NEXT_INSN (BB_END (b)); |
2717 | while (insn != end && !INSN_P (insn)) | |
2718 | insn = NEXT_INSN (insn); | |
2719 | if (insn != end && INSN_LOCATOR (insn) != 0 | |
2720 | && locator_eq (INSN_LOCATOR (insn), goto_locus)) | |
7241571e JJ |
2721 | goto_locus = 0; |
2722 | } | |
2723 | if (goto_locus) | |
2724 | { | |
2725 | BB_END (a) = emit_insn_after_noloc (gen_nop (), BB_END (a), a); | |
2726 | INSN_LOCATOR (BB_END (a)) = goto_locus; | |
2727 | } | |
2728 | } | |
2729 | ||
bc35512f | 2730 | /* Possible line number notes should appear in between. */ |
370369e1 | 2731 | if (b->il.rtl->header) |
bc35512f | 2732 | { |
a813c111 | 2733 | rtx first = BB_END (a), last; |
bc35512f | 2734 | |
6fb5fa3c | 2735 | last = emit_insn_after_noloc (b->il.rtl->header, BB_END (a), a); |
a7b87f73 | 2736 | delete_insn_chain (NEXT_INSN (first), last, false); |
370369e1 | 2737 | b->il.rtl->header = NULL; |
bc35512f JH |
2738 | } |
2739 | ||
2740 | /* In the case basic blocks are not adjacent, move them around. */ | |
a813c111 | 2741 | if (NEXT_INSN (BB_END (a)) != BB_HEAD (b)) |
bc35512f | 2742 | { |
a813c111 | 2743 | rtx first = unlink_insn_chain (BB_HEAD (b), BB_END (b)); |
bc35512f | 2744 | |
6fb5fa3c | 2745 | emit_insn_after_noloc (first, BB_END (a), a); |
bc35512f JH |
2746 | /* Skip possible DELETED_LABEL insn. */ |
2747 | if (!NOTE_INSN_BASIC_BLOCK_P (first)) | |
2748 | first = NEXT_INSN (first); | |
341c100f | 2749 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (first)); |
a813c111 | 2750 | BB_HEAD (b) = NULL; |
6c3d0e31 SP |
2751 | |
2752 | /* emit_insn_after_noloc doesn't call df_insn_change_bb. | |
2753 | We need to explicitly call. */ | |
2754 | update_bb_for_insn_chain (NEXT_INSN (first), | |
2755 | BB_END (b), | |
2756 | a); | |
2757 | ||
bc35512f JH |
2758 | delete_insn (first); |
2759 | } | |
2760 | /* Otherwise just re-associate the instructions. */ | |
2761 | else | |
2762 | { | |
2763 | rtx insn; | |
2764 | ||
6c3d0e31 | 2765 | update_bb_for_insn_chain (BB_HEAD (b), BB_END (b), a); |
6fb5fa3c | 2766 | |
a813c111 | 2767 | insn = BB_HEAD (b); |
bc35512f JH |
2768 | /* Skip possible DELETED_LABEL insn. */ |
2769 | if (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
2770 | insn = NEXT_INSN (insn); | |
341c100f | 2771 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn)); |
a813c111 SB |
2772 | BB_HEAD (b) = NULL; |
2773 | BB_END (a) = BB_END (b); | |
bc35512f JH |
2774 | delete_insn (insn); |
2775 | } | |
2776 | ||
6fb5fa3c DB |
2777 | df_bb_delete (b->index); |
2778 | ||
bc35512f | 2779 | /* Possible tablejumps and barriers should appear after the block. */ |
370369e1 | 2780 | if (b->il.rtl->footer) |
bc35512f | 2781 | { |
370369e1 JH |
2782 | if (!a->il.rtl->footer) |
2783 | a->il.rtl->footer = b->il.rtl->footer; | |
bc35512f JH |
2784 | else |
2785 | { | |
370369e1 | 2786 | rtx last = a->il.rtl->footer; |
bc35512f JH |
2787 | |
2788 | while (NEXT_INSN (last)) | |
2789 | last = NEXT_INSN (last); | |
370369e1 JH |
2790 | NEXT_INSN (last) = b->il.rtl->footer; |
2791 | PREV_INSN (b->il.rtl->footer) = last; | |
bc35512f | 2792 | } |
370369e1 | 2793 | b->il.rtl->footer = NULL; |
bc35512f JH |
2794 | } |
2795 | ||
c263766c RH |
2796 | if (dump_file) |
2797 | fprintf (dump_file, "Merged blocks %d and %d.\n", | |
bc35512f | 2798 | a->index, b->index); |
bc35512f JH |
2799 | } |
2800 | ||
2801 | /* Split edge E. */ | |
f470c378 | 2802 | |
bc35512f JH |
2803 | static basic_block |
2804 | cfg_layout_split_edge (edge e) | |
2805 | { | |
bc35512f JH |
2806 | basic_block new_bb = |
2807 | create_basic_block (e->src != ENTRY_BLOCK_PTR | |
a813c111 | 2808 | ? NEXT_INSN (BB_END (e->src)) : get_insns (), |
bc35512f JH |
2809 | NULL_RTX, e->src); |
2810 | ||
3e7eb734 JJ |
2811 | if (e->dest == EXIT_BLOCK_PTR) |
2812 | BB_COPY_PARTITION (new_bb, e->src); | |
2813 | else | |
2814 | BB_COPY_PARTITION (new_bb, e->dest); | |
a9b2ee88 | 2815 | make_edge (new_bb, e->dest, EDGE_FALLTHRU); |
bc35512f JH |
2816 | redirect_edge_and_branch_force (e, new_bb); |
2817 | ||
2818 | return new_bb; | |
2819 | } | |
2820 | ||
f470c378 ZD |
2821 | /* Do postprocessing after making a forwarder block joined by edge FALLTHRU. */ |
2822 | ||
2823 | static void | |
2824 | rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED) | |
2825 | { | |
2826 | } | |
2827 | ||
6de9cd9a DN |
2828 | /* Return 1 if BB ends with a call, possibly followed by some |
2829 | instructions that must stay with the call, 0 otherwise. */ | |
2830 | ||
2831 | static bool | |
b48d0358 | 2832 | rtl_block_ends_with_call_p (basic_block bb) |
6de9cd9a DN |
2833 | { |
2834 | rtx insn = BB_END (bb); | |
2835 | ||
4b4bf941 | 2836 | while (!CALL_P (insn) |
6de9cd9a | 2837 | && insn != BB_HEAD (bb) |
92ddef69 | 2838 | && (keep_with_call_p (insn) |
b5b8b0ac AO |
2839 | || NOTE_P (insn) |
2840 | || DEBUG_INSN_P (insn))) | |
6de9cd9a | 2841 | insn = PREV_INSN (insn); |
4b4bf941 | 2842 | return (CALL_P (insn)); |
6de9cd9a DN |
2843 | } |
2844 | ||
2845 | /* Return 1 if BB ends with a conditional branch, 0 otherwise. */ | |
2846 | ||
2847 | static bool | |
9678086d | 2848 | rtl_block_ends_with_condjump_p (const_basic_block bb) |
6de9cd9a DN |
2849 | { |
2850 | return any_condjump_p (BB_END (bb)); | |
2851 | } | |
2852 | ||
2853 | /* Return true if we need to add fake edge to exit. | |
2854 | Helper function for rtl_flow_call_edges_add. */ | |
2855 | ||
2856 | static bool | |
9678086d | 2857 | need_fake_edge_p (const_rtx insn) |
6de9cd9a DN |
2858 | { |
2859 | if (!INSN_P (insn)) | |
2860 | return false; | |
2861 | ||
4b4bf941 | 2862 | if ((CALL_P (insn) |
6de9cd9a DN |
2863 | && !SIBLING_CALL_P (insn) |
2864 | && !find_reg_note (insn, REG_NORETURN, NULL) | |
becfd6e5 | 2865 | && !(RTL_CONST_OR_PURE_CALL_P (insn)))) |
6de9cd9a DN |
2866 | return true; |
2867 | ||
2868 | return ((GET_CODE (PATTERN (insn)) == ASM_OPERANDS | |
2869 | && MEM_VOLATILE_P (PATTERN (insn))) | |
2870 | || (GET_CODE (PATTERN (insn)) == PARALLEL | |
2871 | && asm_noperands (insn) != -1 | |
2872 | && MEM_VOLATILE_P (XVECEXP (PATTERN (insn), 0, 0))) | |
2873 | || GET_CODE (PATTERN (insn)) == ASM_INPUT); | |
2874 | } | |
2875 | ||
2876 | /* Add fake edges to the function exit for any non constant and non noreturn | |
2877 | calls, volatile inline assembly in the bitmap of blocks specified by | |
2878 | BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks | |
2879 | that were split. | |
2880 | ||
2881 | The goal is to expose cases in which entering a basic block does not imply | |
2882 | that all subsequent instructions must be executed. */ | |
2883 | ||
2884 | static int | |
2885 | rtl_flow_call_edges_add (sbitmap blocks) | |
2886 | { | |
2887 | int i; | |
2888 | int blocks_split = 0; | |
2889 | int last_bb = last_basic_block; | |
2890 | bool check_last_block = false; | |
2891 | ||
24bd1a0b | 2892 | if (n_basic_blocks == NUM_FIXED_BLOCKS) |
6de9cd9a DN |
2893 | return 0; |
2894 | ||
2895 | if (! blocks) | |
2896 | check_last_block = true; | |
2897 | else | |
2898 | check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index); | |
2899 | ||
2900 | /* In the last basic block, before epilogue generation, there will be | |
2901 | a fallthru edge to EXIT. Special care is required if the last insn | |
2902 | of the last basic block is a call because make_edge folds duplicate | |
2903 | edges, which would result in the fallthru edge also being marked | |
2904 | fake, which would result in the fallthru edge being removed by | |
2905 | remove_fake_edges, which would result in an invalid CFG. | |
2906 | ||
2907 | Moreover, we can't elide the outgoing fake edge, since the block | |
2908 | profiler needs to take this into account in order to solve the minimal | |
2909 | spanning tree in the case that the call doesn't return. | |
2910 | ||
2911 | Handle this by adding a dummy instruction in a new last basic block. */ | |
2912 | if (check_last_block) | |
2913 | { | |
2914 | basic_block bb = EXIT_BLOCK_PTR->prev_bb; | |
2915 | rtx insn = BB_END (bb); | |
2916 | ||
2917 | /* Back up past insns that must be kept in the same block as a call. */ | |
2918 | while (insn != BB_HEAD (bb) | |
2919 | && keep_with_call_p (insn)) | |
2920 | insn = PREV_INSN (insn); | |
2921 | ||
2922 | if (need_fake_edge_p (insn)) | |
2923 | { | |
2924 | edge e; | |
2925 | ||
9ff3d2de JL |
2926 | e = find_edge (bb, EXIT_BLOCK_PTR); |
2927 | if (e) | |
2928 | { | |
c41c1387 | 2929 | insert_insn_on_edge (gen_use (const0_rtx), e); |
9ff3d2de JL |
2930 | commit_edge_insertions (); |
2931 | } | |
6de9cd9a DN |
2932 | } |
2933 | } | |
2934 | ||
2935 | /* Now add fake edges to the function exit for any non constant | |
2936 | calls since there is no way that we can determine if they will | |
2937 | return or not... */ | |
2938 | ||
24bd1a0b | 2939 | for (i = NUM_FIXED_BLOCKS; i < last_bb; i++) |
6de9cd9a DN |
2940 | { |
2941 | basic_block bb = BASIC_BLOCK (i); | |
2942 | rtx insn; | |
2943 | rtx prev_insn; | |
2944 | ||
2945 | if (!bb) | |
2946 | continue; | |
2947 | ||
2948 | if (blocks && !TEST_BIT (blocks, i)) | |
2949 | continue; | |
2950 | ||
2951 | for (insn = BB_END (bb); ; insn = prev_insn) | |
2952 | { | |
2953 | prev_insn = PREV_INSN (insn); | |
2954 | if (need_fake_edge_p (insn)) | |
2955 | { | |
2956 | edge e; | |
2957 | rtx split_at_insn = insn; | |
2958 | ||
2959 | /* Don't split the block between a call and an insn that should | |
c22cacf3 | 2960 | remain in the same block as the call. */ |
4b4bf941 | 2961 | if (CALL_P (insn)) |
6de9cd9a DN |
2962 | while (split_at_insn != BB_END (bb) |
2963 | && keep_with_call_p (NEXT_INSN (split_at_insn))) | |
2964 | split_at_insn = NEXT_INSN (split_at_insn); | |
2965 | ||
2966 | /* The handling above of the final block before the epilogue | |
c22cacf3 | 2967 | should be enough to verify that there is no edge to the exit |
6de9cd9a DN |
2968 | block in CFG already. Calling make_edge in such case would |
2969 | cause us to mark that edge as fake and remove it later. */ | |
2970 | ||
2971 | #ifdef ENABLE_CHECKING | |
2972 | if (split_at_insn == BB_END (bb)) | |
628f6a4e | 2973 | { |
9ff3d2de JL |
2974 | e = find_edge (bb, EXIT_BLOCK_PTR); |
2975 | gcc_assert (e == NULL); | |
628f6a4e | 2976 | } |
6de9cd9a DN |
2977 | #endif |
2978 | ||
2979 | /* Note that the following may create a new basic block | |
2980 | and renumber the existing basic blocks. */ | |
2981 | if (split_at_insn != BB_END (bb)) | |
2982 | { | |
2983 | e = split_block (bb, split_at_insn); | |
2984 | if (e) | |
2985 | blocks_split++; | |
2986 | } | |
2987 | ||
2988 | make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE); | |
2989 | } | |
2990 | ||
2991 | if (insn == BB_HEAD (bb)) | |
2992 | break; | |
2993 | } | |
2994 | } | |
2995 | ||
2996 | if (blocks_split) | |
2997 | verify_flow_info (); | |
2998 | ||
2999 | return blocks_split; | |
3000 | } | |
3001 | ||
1cb7dfc3 | 3002 | /* Add COMP_RTX as a condition at end of COND_BB. FIRST_HEAD is |
315682fb | 3003 | the conditional branch target, SECOND_HEAD should be the fall-thru |
1cb7dfc3 MH |
3004 | there is no need to handle this here the loop versioning code handles |
3005 | this. the reason for SECON_HEAD is that it is needed for condition | |
3006 | in trees, and this should be of the same type since it is a hook. */ | |
3007 | static void | |
3008 | rtl_lv_add_condition_to_bb (basic_block first_head , | |
c22cacf3 MS |
3009 | basic_block second_head ATTRIBUTE_UNUSED, |
3010 | basic_block cond_bb, void *comp_rtx) | |
1cb7dfc3 MH |
3011 | { |
3012 | rtx label, seq, jump; | |
3013 | rtx op0 = XEXP ((rtx)comp_rtx, 0); | |
3014 | rtx op1 = XEXP ((rtx)comp_rtx, 1); | |
3015 | enum rtx_code comp = GET_CODE ((rtx)comp_rtx); | |
3016 | enum machine_mode mode; | |
3017 | ||
3018 | ||
3019 | label = block_label (first_head); | |
3020 | mode = GET_MODE (op0); | |
3021 | if (mode == VOIDmode) | |
3022 | mode = GET_MODE (op1); | |
3023 | ||
3024 | start_sequence (); | |
3025 | op0 = force_operand (op0, NULL_RTX); | |
3026 | op1 = force_operand (op1, NULL_RTX); | |
3027 | do_compare_rtx_and_jump (op0, op1, comp, 0, | |
3028 | mode, NULL_RTX, NULL_RTX, label); | |
3029 | jump = get_last_insn (); | |
3030 | JUMP_LABEL (jump) = label; | |
3031 | LABEL_NUSES (label)++; | |
3032 | seq = get_insns (); | |
3033 | end_sequence (); | |
3034 | ||
3035 | /* Add the new cond , in the new head. */ | |
3036 | emit_insn_after(seq, BB_END(cond_bb)); | |
3037 | } | |
3038 | ||
3039 | ||
3040 | /* Given a block B with unconditional branch at its end, get the | |
3041 | store the return the branch edge and the fall-thru edge in | |
3042 | BRANCH_EDGE and FALLTHRU_EDGE respectively. */ | |
3043 | static void | |
3044 | rtl_extract_cond_bb_edges (basic_block b, edge *branch_edge, | |
3045 | edge *fallthru_edge) | |
3046 | { | |
3047 | edge e = EDGE_SUCC (b, 0); | |
3048 | ||
3049 | if (e->flags & EDGE_FALLTHRU) | |
3050 | { | |
3051 | *fallthru_edge = e; | |
3052 | *branch_edge = EDGE_SUCC (b, 1); | |
3053 | } | |
3054 | else | |
3055 | { | |
3056 | *branch_edge = e; | |
3057 | *fallthru_edge = EDGE_SUCC (b, 1); | |
3058 | } | |
3059 | } | |
3060 | ||
5e2d947c JH |
3061 | void |
3062 | init_rtl_bb_info (basic_block bb) | |
3063 | { | |
3064 | gcc_assert (!bb->il.rtl); | |
ae50c0cb | 3065 | bb->il.rtl = GGC_CNEW (struct rtl_bb_info); |
5e2d947c JH |
3066 | } |
3067 | ||
1cb7dfc3 | 3068 | |
8cd37d0b RL |
3069 | /* Add EXPR to the end of basic block BB. */ |
3070 | ||
3071 | rtx | |
3072 | insert_insn_end_bb_new (rtx pat, basic_block bb) | |
3073 | { | |
3074 | rtx insn = BB_END (bb); | |
3075 | rtx new_insn; | |
3076 | rtx pat_end = pat; | |
3077 | ||
3078 | while (NEXT_INSN (pat_end) != NULL_RTX) | |
3079 | pat_end = NEXT_INSN (pat_end); | |
3080 | ||
3081 | /* If the last insn is a jump, insert EXPR in front [taking care to | |
3082 | handle cc0, etc. properly]. Similarly we need to care trapping | |
3083 | instructions in presence of non-call exceptions. */ | |
3084 | ||
3085 | if (JUMP_P (insn) | |
3086 | || (NONJUMP_INSN_P (insn) | |
3087 | && (!single_succ_p (bb) | |
3088 | || single_succ_edge (bb)->flags & EDGE_ABNORMAL))) | |
3089 | { | |
3090 | #ifdef HAVE_cc0 | |
3091 | rtx note; | |
3092 | #endif | |
3093 | /* If this is a jump table, then we can't insert stuff here. Since | |
3094 | we know the previous real insn must be the tablejump, we insert | |
3095 | the new instruction just before the tablejump. */ | |
3096 | if (GET_CODE (PATTERN (insn)) == ADDR_VEC | |
3097 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC) | |
3098 | insn = prev_real_insn (insn); | |
3099 | ||
3100 | #ifdef HAVE_cc0 | |
3101 | /* FIXME: 'twould be nice to call prev_cc0_setter here but it aborts | |
3102 | if cc0 isn't set. */ | |
3103 | note = find_reg_note (insn, REG_CC_SETTER, NULL_RTX); | |
3104 | if (note) | |
3105 | insn = XEXP (note, 0); | |
3106 | else | |
3107 | { | |
3108 | rtx maybe_cc0_setter = prev_nonnote_insn (insn); | |
3109 | if (maybe_cc0_setter | |
3110 | && INSN_P (maybe_cc0_setter) | |
3111 | && sets_cc0_p (PATTERN (maybe_cc0_setter))) | |
3112 | insn = maybe_cc0_setter; | |
3113 | } | |
3114 | #endif | |
3115 | /* FIXME: What if something in cc0/jump uses value set in new | |
3116 | insn? */ | |
6fb5fa3c | 3117 | new_insn = emit_insn_before_noloc (pat, insn, bb); |
8cd37d0b RL |
3118 | } |
3119 | ||
3120 | /* Likewise if the last insn is a call, as will happen in the presence | |
3121 | of exception handling. */ | |
3122 | else if (CALL_P (insn) | |
3123 | && (!single_succ_p (bb) | |
3124 | || single_succ_edge (bb)->flags & EDGE_ABNORMAL)) | |
3125 | { | |
3126 | /* Keeping in mind SMALL_REGISTER_CLASSES and parameters in registers, | |
3127 | we search backward and place the instructions before the first | |
3128 | parameter is loaded. Do this for everyone for consistency and a | |
3129 | presumption that we'll get better code elsewhere as well. */ | |
3130 | ||
3131 | /* Since different machines initialize their parameter registers | |
3132 | in different orders, assume nothing. Collect the set of all | |
3133 | parameter registers. */ | |
3134 | insn = find_first_parameter_load (insn, BB_HEAD (bb)); | |
3135 | ||
3136 | /* If we found all the parameter loads, then we want to insert | |
3137 | before the first parameter load. | |
3138 | ||
3139 | If we did not find all the parameter loads, then we might have | |
3140 | stopped on the head of the block, which could be a CODE_LABEL. | |
3141 | If we inserted before the CODE_LABEL, then we would be putting | |
3142 | the insn in the wrong basic block. In that case, put the insn | |
3143 | after the CODE_LABEL. Also, respect NOTE_INSN_BASIC_BLOCK. */ | |
3144 | while (LABEL_P (insn) | |
3145 | || NOTE_INSN_BASIC_BLOCK_P (insn)) | |
3146 | insn = NEXT_INSN (insn); | |
3147 | ||
6fb5fa3c | 3148 | new_insn = emit_insn_before_noloc (pat, insn, bb); |
8cd37d0b RL |
3149 | } |
3150 | else | |
6fb5fa3c | 3151 | new_insn = emit_insn_after_noloc (pat, insn, bb); |
8cd37d0b RL |
3152 | |
3153 | return new_insn; | |
3154 | } | |
3155 | ||
14fa2cc0 ZD |
3156 | /* Returns true if it is possible to remove edge E by redirecting |
3157 | it to the destination of the other edge from E->src. */ | |
3158 | ||
3159 | static bool | |
9678086d | 3160 | rtl_can_remove_branch_p (const_edge e) |
14fa2cc0 | 3161 | { |
9678086d KG |
3162 | const_basic_block src = e->src; |
3163 | const_basic_block target = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest; | |
3164 | const_rtx insn = BB_END (src), set; | |
14fa2cc0 ZD |
3165 | |
3166 | /* The conditions are taken from try_redirect_by_replacing_jump. */ | |
3167 | if (target == EXIT_BLOCK_PTR) | |
3168 | return false; | |
3169 | ||
3170 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) | |
3171 | return false; | |
3172 | ||
3173 | if (find_reg_note (insn, REG_CROSSING_JUMP, NULL_RTX) | |
3174 | || BB_PARTITION (src) != BB_PARTITION (target)) | |
3175 | return false; | |
3176 | ||
3177 | if (!onlyjump_p (insn) | |
3178 | || tablejump_p (insn, NULL, NULL)) | |
3179 | return false; | |
3180 | ||
3181 | set = single_set (insn); | |
3182 | if (!set || side_effects_p (set)) | |
3183 | return false; | |
3184 | ||
3185 | return true; | |
3186 | } | |
3187 | ||
9ee634e3 JH |
3188 | /* Implementation of CFG manipulation for linearized RTL. */ |
3189 | struct cfg_hooks rtl_cfg_hooks = { | |
f470c378 | 3190 | "rtl", |
9ee634e3 | 3191 | rtl_verify_flow_info, |
10e9fecc | 3192 | rtl_dump_bb, |
bc35512f | 3193 | rtl_create_basic_block, |
9ee634e3 JH |
3194 | rtl_redirect_edge_and_branch, |
3195 | rtl_redirect_edge_and_branch_force, | |
14fa2cc0 | 3196 | rtl_can_remove_branch_p, |
9ee634e3 JH |
3197 | rtl_delete_block, |
3198 | rtl_split_block, | |
f470c378 | 3199 | rtl_move_block_after, |
bc35512f JH |
3200 | rtl_can_merge_blocks, /* can_merge_blocks_p */ |
3201 | rtl_merge_blocks, | |
6de9cd9a DN |
3202 | rtl_predict_edge, |
3203 | rtl_predicted_by_p, | |
3204 | NULL, /* can_duplicate_block_p */ | |
3205 | NULL, /* duplicate_block */ | |
f470c378 ZD |
3206 | rtl_split_edge, |
3207 | rtl_make_forwarder_block, | |
6de9cd9a DN |
3208 | rtl_tidy_fallthru_edge, |
3209 | rtl_block_ends_with_call_p, | |
3210 | rtl_block_ends_with_condjump_p, | |
d9d4706f KH |
3211 | rtl_flow_call_edges_add, |
3212 | NULL, /* execute_on_growing_pred */ | |
1cb7dfc3 MH |
3213 | NULL, /* execute_on_shrinking_pred */ |
3214 | NULL, /* duplicate loop for trees */ | |
3215 | NULL, /* lv_add_condition_to_bb */ | |
3216 | NULL, /* lv_adjust_loop_header_phi*/ | |
3217 | NULL, /* extract_cond_bb_edges */ | |
c22cacf3 | 3218 | NULL /* flush_pending_stmts */ |
9ee634e3 JH |
3219 | }; |
3220 | ||
3221 | /* Implementation of CFG manipulation for cfg layout RTL, where | |
3222 | basic block connected via fallthru edges does not have to be adjacent. | |
3223 | This representation will hopefully become the default one in future | |
3224 | version of the compiler. */ | |
6de9cd9a DN |
3225 | |
3226 | /* We do not want to declare these functions in a header file, since they | |
3227 | should only be used through the cfghooks interface, and we do not want to | |
3228 | move them here since it would require also moving quite a lot of related | |
6fb5fa3c | 3229 | code. They are in cfglayout.c. */ |
9678086d | 3230 | extern bool cfg_layout_can_duplicate_bb_p (const_basic_block); |
6de9cd9a DN |
3231 | extern basic_block cfg_layout_duplicate_bb (basic_block); |
3232 | ||
9ee634e3 | 3233 | struct cfg_hooks cfg_layout_rtl_cfg_hooks = { |
f470c378 | 3234 | "cfglayout mode", |
bc35512f | 3235 | rtl_verify_flow_info_1, |
10e9fecc | 3236 | rtl_dump_bb, |
bc35512f | 3237 | cfg_layout_create_basic_block, |
9ee634e3 JH |
3238 | cfg_layout_redirect_edge_and_branch, |
3239 | cfg_layout_redirect_edge_and_branch_force, | |
14fa2cc0 | 3240 | rtl_can_remove_branch_p, |
9ee634e3 JH |
3241 | cfg_layout_delete_block, |
3242 | cfg_layout_split_block, | |
f470c378 | 3243 | rtl_move_block_after, |
bc35512f JH |
3244 | cfg_layout_can_merge_blocks_p, |
3245 | cfg_layout_merge_blocks, | |
6de9cd9a DN |
3246 | rtl_predict_edge, |
3247 | rtl_predicted_by_p, | |
3248 | cfg_layout_can_duplicate_bb_p, | |
3249 | cfg_layout_duplicate_bb, | |
f470c378 ZD |
3250 | cfg_layout_split_edge, |
3251 | rtl_make_forwarder_block, | |
6de9cd9a DN |
3252 | NULL, |
3253 | rtl_block_ends_with_call_p, | |
3254 | rtl_block_ends_with_condjump_p, | |
d9d4706f KH |
3255 | rtl_flow_call_edges_add, |
3256 | NULL, /* execute_on_growing_pred */ | |
1cb7dfc3 MH |
3257 | NULL, /* execute_on_shrinking_pred */ |
3258 | duplicate_loop_to_header_edge, /* duplicate loop for trees */ | |
3259 | rtl_lv_add_condition_to_bb, /* lv_add_condition_to_bb */ | |
3260 | NULL, /* lv_adjust_loop_header_phi*/ | |
3261 | rtl_extract_cond_bb_edges, /* extract_cond_bb_edges */ | |
c22cacf3 | 3262 | NULL /* flush_pending_stmts */ |
9ee634e3 | 3263 | }; |