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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, | |
677f3fa8 | 3 | 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 |
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 | |
ba5e9aca EB |
33 | - CFG fixing after coarse manipulation |
34 | fixup_abnormal_edges | |
bc35512f JH |
35 | |
36 | Functions not supposed for generic use: | |
5f0d2358 | 37 | - Infrastructure to determine quickly basic block for insn |
ca6c03ca | 38 | compute_bb_for_insn, update_bb_for_insn, set_block_for_insn, |
5f0d2358 | 39 | - Edge redirection with updating and optimizing of insn chain |
bc35512f | 40 | block_label, tidy_fallthru_edge, force_nonfallthru */ |
ca6c03ca JH |
41 | \f |
42 | #include "config.h" | |
43 | #include "system.h" | |
4977bab6 ZW |
44 | #include "coretypes.h" |
45 | #include "tm.h" | |
ca6c03ca | 46 | #include "tree.h" |
ca6c03ca JH |
47 | #include "hard-reg-set.h" |
48 | #include "basic-block.h" | |
49 | #include "regs.h" | |
50 | #include "flags.h" | |
51 | #include "output.h" | |
52 | #include "function.h" | |
53 | #include "except.h" | |
0cbd9993 | 54 | #include "rtl-error.h" |
ca6c03ca JH |
55 | #include "tm_p.h" |
56 | #include "obstack.h" | |
2a34bece | 57 | #include "insn-attr.h" |
0a2ed1f1 | 58 | #include "insn-config.h" |
9ee634e3 | 59 | #include "cfglayout.h" |
ff25ef99 | 60 | #include "expr.h" |
9fb32434 | 61 | #include "target.h" |
677f3fa8 | 62 | #include "common/common-target.h" |
1cb7dfc3 | 63 | #include "cfgloop.h" |
5e2d947c | 64 | #include "ggc.h" |
ef330312 | 65 | #include "tree-pass.h" |
6fb5fa3c | 66 | #include "df.h" |
ca6c03ca | 67 | |
9678086d KG |
68 | static int can_delete_note_p (const_rtx); |
69 | static int can_delete_label_p (const_rtx); | |
d329e058 | 70 | static basic_block rtl_split_edge (edge); |
f470c378 | 71 | static bool rtl_move_block_after (basic_block, basic_block); |
d329e058 | 72 | static int rtl_verify_flow_info (void); |
f470c378 | 73 | static basic_block cfg_layout_split_block (basic_block, void *); |
6de9cd9a | 74 | static edge cfg_layout_redirect_edge_and_branch (edge, basic_block); |
d329e058 AJ |
75 | static basic_block cfg_layout_redirect_edge_and_branch_force (edge, basic_block); |
76 | static void cfg_layout_delete_block (basic_block); | |
77 | static void rtl_delete_block (basic_block); | |
78 | static basic_block rtl_redirect_edge_and_branch_force (edge, basic_block); | |
6de9cd9a | 79 | static edge rtl_redirect_edge_and_branch (edge, basic_block); |
f470c378 | 80 | static basic_block rtl_split_block (basic_block, void *); |
726a989a | 81 | static void rtl_dump_bb (basic_block, FILE *, int, int); |
d329e058 | 82 | static int rtl_verify_flow_info_1 (void); |
f470c378 | 83 | static void rtl_make_forwarder_block (edge); |
ca6c03ca JH |
84 | \f |
85 | /* Return true if NOTE is not one of the ones that must be kept paired, | |
5f0d2358 | 86 | so that we may simply delete it. */ |
ca6c03ca JH |
87 | |
88 | static int | |
9678086d | 89 | can_delete_note_p (const_rtx note) |
ca6c03ca | 90 | { |
cd9c1ca8 RH |
91 | switch (NOTE_KIND (note)) |
92 | { | |
93 | case NOTE_INSN_DELETED: | |
94 | case NOTE_INSN_BASIC_BLOCK: | |
95 | case NOTE_INSN_EPILOGUE_BEG: | |
96 | return true; | |
97 | ||
98 | default: | |
99 | return false; | |
100 | } | |
ca6c03ca JH |
101 | } |
102 | ||
103 | /* True if a given label can be deleted. */ | |
104 | ||
105 | static int | |
9678086d | 106 | can_delete_label_p (const_rtx label) |
ca6c03ca | 107 | { |
5f0d2358 RK |
108 | return (!LABEL_PRESERVE_P (label) |
109 | /* User declared labels must be preserved. */ | |
110 | && LABEL_NAME (label) == 0 | |
610d2478 | 111 | && !in_expr_list_p (forced_labels, label)); |
ca6c03ca JH |
112 | } |
113 | ||
114 | /* Delete INSN by patching it out. Return the next insn. */ | |
115 | ||
116 | rtx | |
d329e058 | 117 | delete_insn (rtx insn) |
ca6c03ca JH |
118 | { |
119 | rtx next = NEXT_INSN (insn); | |
120 | rtx note; | |
121 | bool really_delete = true; | |
122 | ||
4b4bf941 | 123 | if (LABEL_P (insn)) |
ca6c03ca JH |
124 | { |
125 | /* Some labels can't be directly removed from the INSN chain, as they | |
c22cacf3 MS |
126 | might be references via variables, constant pool etc. |
127 | Convert them to the special NOTE_INSN_DELETED_LABEL note. */ | |
ca6c03ca JH |
128 | if (! can_delete_label_p (insn)) |
129 | { | |
130 | const char *name = LABEL_NAME (insn); | |
131 | ||
132 | really_delete = false; | |
133 | PUT_CODE (insn, NOTE); | |
a38e7aa5 | 134 | NOTE_KIND (insn) = NOTE_INSN_DELETED_LABEL; |
6773e15f | 135 | NOTE_DELETED_LABEL_NAME (insn) = name; |
ca6c03ca | 136 | } |
5f0d2358 | 137 | |
ca6c03ca JH |
138 | remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels); |
139 | } | |
140 | ||
141 | if (really_delete) | |
142 | { | |
cda94cbb | 143 | /* If this insn has already been deleted, something is very wrong. */ |
341c100f | 144 | gcc_assert (!INSN_DELETED_P (insn)); |
ca6c03ca JH |
145 | remove_insn (insn); |
146 | INSN_DELETED_P (insn) = 1; | |
147 | } | |
148 | ||
149 | /* If deleting a jump, decrement the use count of the label. Deleting | |
150 | the label itself should happen in the normal course of block merging. */ | |
cf7c4aa6 | 151 | if (JUMP_P (insn)) |
9295a326 | 152 | { |
cf7c4aa6 HPN |
153 | if (JUMP_LABEL (insn) |
154 | && LABEL_P (JUMP_LABEL (insn))) | |
155 | LABEL_NUSES (JUMP_LABEL (insn))--; | |
156 | ||
157 | /* If there are more targets, remove them too. */ | |
158 | while ((note | |
159 | = find_reg_note (insn, REG_LABEL_TARGET, NULL_RTX)) != NULL_RTX | |
4b4bf941 | 160 | && LABEL_P (XEXP (note, 0))) |
9295a326 JZ |
161 | { |
162 | LABEL_NUSES (XEXP (note, 0))--; | |
163 | remove_note (insn, note); | |
164 | } | |
165 | } | |
ca6c03ca | 166 | |
cf7c4aa6 HPN |
167 | /* Also if deleting any insn that references a label as an operand. */ |
168 | while ((note = find_reg_note (insn, REG_LABEL_OPERAND, NULL_RTX)) != NULL_RTX | |
169 | && LABEL_P (XEXP (note, 0))) | |
170 | { | |
171 | LABEL_NUSES (XEXP (note, 0))--; | |
172 | remove_note (insn, note); | |
173 | } | |
174 | ||
481683e1 | 175 | if (JUMP_TABLE_DATA_P (insn)) |
ca6c03ca JH |
176 | { |
177 | rtx pat = PATTERN (insn); | |
178 | int diff_vec_p = GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC; | |
179 | int len = XVECLEN (pat, diff_vec_p); | |
180 | int i; | |
181 | ||
182 | for (i = 0; i < len; i++) | |
a124fcda RH |
183 | { |
184 | rtx label = XEXP (XVECEXP (pat, diff_vec_p, i), 0); | |
185 | ||
186 | /* When deleting code in bulk (e.g. removing many unreachable | |
187 | blocks) we can delete a label that's a target of the vector | |
188 | before deleting the vector itself. */ | |
4b4bf941 | 189 | if (!NOTE_P (label)) |
a124fcda RH |
190 | LABEL_NUSES (label)--; |
191 | } | |
ca6c03ca JH |
192 | } |
193 | ||
194 | return next; | |
195 | } | |
196 | ||
3dec4024 | 197 | /* Like delete_insn but also purge dead edges from BB. */ |
9ed7b221 | 198 | |
3dec4024 | 199 | rtx |
d329e058 | 200 | delete_insn_and_edges (rtx insn) |
3dec4024 JH |
201 | { |
202 | rtx x; | |
203 | bool purge = false; | |
204 | ||
ba4f7968 | 205 | if (INSN_P (insn) |
3dec4024 | 206 | && BLOCK_FOR_INSN (insn) |
a813c111 | 207 | && BB_END (BLOCK_FOR_INSN (insn)) == insn) |
3dec4024 JH |
208 | purge = true; |
209 | x = delete_insn (insn); | |
210 | if (purge) | |
211 | purge_dead_edges (BLOCK_FOR_INSN (insn)); | |
212 | return x; | |
213 | } | |
214 | ||
ca6c03ca | 215 | /* Unlink a chain of insns between START and FINISH, leaving notes |
a7b87f73 ZD |
216 | that must be paired. If CLEAR_BB is true, we set bb field for |
217 | insns that cannot be removed to NULL. */ | |
ca6c03ca JH |
218 | |
219 | void | |
a7b87f73 | 220 | delete_insn_chain (rtx start, rtx finish, bool clear_bb) |
ca6c03ca | 221 | { |
ca6c03ca JH |
222 | rtx next; |
223 | ||
5f0d2358 RK |
224 | /* Unchain the insns one by one. It would be quicker to delete all of these |
225 | with a single unchaining, rather than one at a time, but we need to keep | |
226 | the NOTE's. */ | |
ca6c03ca JH |
227 | while (1) |
228 | { | |
229 | next = NEXT_INSN (start); | |
4b4bf941 | 230 | if (NOTE_P (start) && !can_delete_note_p (start)) |
ca6c03ca JH |
231 | ; |
232 | else | |
233 | next = delete_insn (start); | |
234 | ||
a7b87f73 ZD |
235 | if (clear_bb && !INSN_DELETED_P (start)) |
236 | set_block_for_insn (start, NULL); | |
237 | ||
ca6c03ca JH |
238 | if (start == finish) |
239 | break; | |
240 | start = next; | |
241 | } | |
242 | } | |
243 | \f | |
5f0d2358 RK |
244 | /* Create a new basic block consisting of the instructions between HEAD and END |
245 | inclusive. This function is designed to allow fast BB construction - reuses | |
246 | the note and basic block struct in BB_NOTE, if any and do not grow | |
247 | BASIC_BLOCK chain and should be used directly only by CFG construction code. | |
248 | END can be NULL in to create new empty basic block before HEAD. Both END | |
918ed612 ZD |
249 | and HEAD can be NULL to create basic block at the end of INSN chain. |
250 | AFTER is the basic block we should be put after. */ | |
ca6c03ca JH |
251 | |
252 | basic_block | |
d329e058 | 253 | create_basic_block_structure (rtx head, rtx end, rtx bb_note, basic_block after) |
ca6c03ca JH |
254 | { |
255 | basic_block bb; | |
256 | ||
257 | if (bb_note | |
ca6c03ca JH |
258 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL |
259 | && bb->aux == NULL) | |
260 | { | |
261 | /* If we found an existing note, thread it back onto the chain. */ | |
262 | ||
263 | rtx after; | |
264 | ||
4b4bf941 | 265 | if (LABEL_P (head)) |
ca6c03ca JH |
266 | after = head; |
267 | else | |
268 | { | |
269 | after = PREV_INSN (head); | |
270 | head = bb_note; | |
271 | } | |
272 | ||
273 | if (after != bb_note && NEXT_INSN (after) != bb_note) | |
ba4f7968 | 274 | reorder_insns_nobb (bb_note, bb_note, after); |
ca6c03ca JH |
275 | } |
276 | else | |
277 | { | |
278 | /* Otherwise we must create a note and a basic block structure. */ | |
279 | ||
280 | bb = alloc_block (); | |
281 | ||
5e2d947c | 282 | init_rtl_bb_info (bb); |
ca6c03ca | 283 | if (!head && !end) |
5f0d2358 RK |
284 | head = end = bb_note |
285 | = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); | |
4b4bf941 | 286 | else if (LABEL_P (head) && end) |
ca6c03ca JH |
287 | { |
288 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); | |
289 | if (head == end) | |
290 | end = bb_note; | |
291 | } | |
292 | else | |
293 | { | |
294 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); | |
295 | head = bb_note; | |
296 | if (!end) | |
297 | end = head; | |
298 | } | |
5f0d2358 | 299 | |
ca6c03ca JH |
300 | NOTE_BASIC_BLOCK (bb_note) = bb; |
301 | } | |
302 | ||
303 | /* Always include the bb note in the block. */ | |
304 | if (NEXT_INSN (end) == bb_note) | |
305 | end = bb_note; | |
306 | ||
a813c111 SB |
307 | BB_HEAD (bb) = head; |
308 | BB_END (bb) = end; | |
852c6ec7 | 309 | bb->index = last_basic_block++; |
5e2d947c | 310 | bb->flags = BB_NEW | BB_RTL; |
918ed612 | 311 | link_block (bb, after); |
68f9b844 | 312 | SET_BASIC_BLOCK (bb->index, bb); |
6fb5fa3c | 313 | df_bb_refs_record (bb->index, false); |
ba4f7968 | 314 | update_bb_for_insn (bb); |
076c7ab8 | 315 | BB_SET_PARTITION (bb, BB_UNPARTITIONED); |
ca6c03ca JH |
316 | |
317 | /* Tag the block so that we know it has been used when considering | |
318 | other basic block notes. */ | |
319 | bb->aux = bb; | |
320 | ||
321 | return bb; | |
322 | } | |
323 | ||
5f0d2358 | 324 | /* Create new basic block consisting of instructions in between HEAD and END |
918ed612 | 325 | and place it to the BB chain after block AFTER. END can be NULL in to |
5f0d2358 RK |
326 | create new empty basic block before HEAD. Both END and HEAD can be NULL to |
327 | create basic block at the end of INSN chain. */ | |
ca6c03ca | 328 | |
bc35512f JH |
329 | static basic_block |
330 | rtl_create_basic_block (void *headp, void *endp, basic_block after) | |
ca6c03ca | 331 | { |
ae50c0cb | 332 | rtx head = (rtx) headp, end = (rtx) endp; |
ca6c03ca | 333 | basic_block bb; |
0b17ab2f | 334 | |
7eca0767 | 335 | /* Grow the basic block array if needed. */ |
68f9b844 | 336 | if ((size_t) last_basic_block >= VEC_length (basic_block, basic_block_info)) |
7eca0767 JH |
337 | { |
338 | size_t new_size = last_basic_block + (last_basic_block + 3) / 4; | |
a590ac65 | 339 | VEC_safe_grow_cleared (basic_block, gc, basic_block_info, new_size); |
7eca0767 | 340 | } |
0b17ab2f | 341 | |
bf77398c | 342 | n_basic_blocks++; |
ca6c03ca | 343 | |
852c6ec7 | 344 | bb = create_basic_block_structure (head, end, NULL, after); |
ca6c03ca JH |
345 | bb->aux = NULL; |
346 | return bb; | |
347 | } | |
bc35512f JH |
348 | |
349 | static basic_block | |
350 | cfg_layout_create_basic_block (void *head, void *end, basic_block after) | |
351 | { | |
352 | basic_block newbb = rtl_create_basic_block (head, end, after); | |
353 | ||
bc35512f JH |
354 | return newbb; |
355 | } | |
ca6c03ca JH |
356 | \f |
357 | /* Delete the insns in a (non-live) block. We physically delete every | |
358 | non-deleted-note insn, and update the flow graph appropriately. | |
359 | ||
360 | Return nonzero if we deleted an exception handler. */ | |
361 | ||
362 | /* ??? Preserving all such notes strikes me as wrong. It would be nice | |
363 | to post-process the stream to remove empty blocks, loops, ranges, etc. */ | |
364 | ||
f0fda11c | 365 | static void |
d329e058 | 366 | rtl_delete_block (basic_block b) |
ca6c03ca | 367 | { |
96370780 | 368 | rtx insn, end; |
ca6c03ca JH |
369 | |
370 | /* If the head of this block is a CODE_LABEL, then it might be the | |
f39e46ba SB |
371 | label for an exception handler which can't be reached. We need |
372 | to remove the label from the exception_handler_label list. */ | |
a813c111 | 373 | insn = BB_HEAD (b); |
ca6c03ca | 374 | |
96370780 | 375 | end = get_last_bb_insn (b); |
ca6c03ca JH |
376 | |
377 | /* Selectively delete the entire chain. */ | |
a813c111 | 378 | BB_HEAD (b) = NULL; |
a7b87f73 ZD |
379 | delete_insn_chain (insn, end, true); |
380 | ||
6fb5fa3c DB |
381 | |
382 | if (dump_file) | |
383 | fprintf (dump_file, "deleting block %d\n", b->index); | |
384 | df_bb_delete (b->index); | |
ca6c03ca JH |
385 | } |
386 | \f | |
852c6ec7 | 387 | /* Records the basic block struct in BLOCK_FOR_INSN for every insn. */ |
ca6c03ca JH |
388 | |
389 | void | |
d329e058 | 390 | compute_bb_for_insn (void) |
ca6c03ca | 391 | { |
e0082a72 | 392 | basic_block bb; |
ca6c03ca | 393 | |
e0082a72 | 394 | FOR_EACH_BB (bb) |
ca6c03ca | 395 | { |
a813c111 | 396 | rtx end = BB_END (bb); |
5f0d2358 | 397 | rtx insn; |
ca6c03ca | 398 | |
a813c111 | 399 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
ca6c03ca | 400 | { |
ba4f7968 | 401 | BLOCK_FOR_INSN (insn) = bb; |
ca6c03ca JH |
402 | if (insn == end) |
403 | break; | |
ca6c03ca JH |
404 | } |
405 | } | |
406 | } | |
407 | ||
408 | /* Release the basic_block_for_insn array. */ | |
409 | ||
c2924966 | 410 | unsigned int |
d329e058 | 411 | free_bb_for_insn (void) |
ca6c03ca | 412 | { |
ba4f7968 JH |
413 | rtx insn; |
414 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) | |
4b4bf941 | 415 | if (!BARRIER_P (insn)) |
ba4f7968 | 416 | BLOCK_FOR_INSN (insn) = NULL; |
c2924966 | 417 | return 0; |
ca6c03ca JH |
418 | } |
419 | ||
2a34bece EB |
420 | static unsigned int |
421 | rest_of_pass_free_cfg (void) | |
422 | { | |
423 | #ifdef DELAY_SLOTS | |
424 | /* The resource.c machinery uses DF but the CFG isn't guaranteed to be | |
425 | valid at that point so it would be too late to call df_analyze. */ | |
426 | if (optimize > 0 && flag_delayed_branch) | |
ad78b8a6 EB |
427 | { |
428 | df_note_add_problem (); | |
429 | df_analyze (); | |
430 | } | |
2a34bece EB |
431 | #endif |
432 | ||
433 | free_bb_for_insn (); | |
434 | return 0; | |
435 | } | |
436 | ||
8ddbbcae | 437 | struct rtl_opt_pass pass_free_cfg = |
ef330312 | 438 | { |
8ddbbcae JH |
439 | { |
440 | RTL_PASS, | |
e0a42b0f | 441 | "*free_cfg", /* name */ |
ef330312 | 442 | NULL, /* gate */ |
2a34bece | 443 | rest_of_pass_free_cfg, /* execute */ |
ef330312 PB |
444 | NULL, /* sub */ |
445 | NULL, /* next */ | |
446 | 0, /* static_pass_number */ | |
7072a650 | 447 | TV_NONE, /* tv_id */ |
ef330312 PB |
448 | 0, /* properties_required */ |
449 | 0, /* properties_provided */ | |
450 | PROP_cfg, /* properties_destroyed */ | |
451 | 0, /* todo_flags_start */ | |
452 | 0, /* todo_flags_finish */ | |
8ddbbcae | 453 | } |
ef330312 PB |
454 | }; |
455 | ||
91278841 AP |
456 | /* Return RTX to emit after when we want to emit code on the entry of function. */ |
457 | rtx | |
458 | entry_of_function (void) | |
459 | { | |
c22cacf3 | 460 | return (n_basic_blocks > NUM_FIXED_BLOCKS ? |
24bd1a0b | 461 | BB_HEAD (ENTRY_BLOCK_PTR->next_bb) : get_insns ()); |
91278841 AP |
462 | } |
463 | ||
11b904a1 BS |
464 | /* Emit INSN at the entry point of the function, ensuring that it is only |
465 | executed once per function. */ | |
466 | void | |
467 | emit_insn_at_entry (rtx insn) | |
468 | { | |
469 | edge_iterator ei = ei_start (ENTRY_BLOCK_PTR->succs); | |
470 | edge e = ei_safe_edge (ei); | |
5419bc7f | 471 | gcc_assert (e->flags & EDGE_FALLTHRU); |
11b904a1 BS |
472 | |
473 | insert_insn_on_edge (insn, e); | |
474 | commit_edge_insertions (); | |
475 | } | |
476 | ||
6c3d0e31 | 477 | /* Update BLOCK_FOR_INSN of insns between BEGIN and END |
b8698a0f | 478 | (or BARRIER if found) and notify df of the bb change. |
6c3d0e31 SP |
479 | The insn chain range is inclusive |
480 | (i.e. both BEGIN and END will be updated. */ | |
ca6c03ca | 481 | |
6c3d0e31 SP |
482 | static void |
483 | update_bb_for_insn_chain (rtx begin, rtx end, basic_block bb) | |
ca6c03ca JH |
484 | { |
485 | rtx insn; | |
486 | ||
6c3d0e31 SP |
487 | end = NEXT_INSN (end); |
488 | for (insn = begin; insn != end; insn = NEXT_INSN (insn)) | |
63642d5a AO |
489 | if (!BARRIER_P (insn)) |
490 | df_insn_change_bb (insn, bb); | |
ca6c03ca | 491 | } |
6c3d0e31 SP |
492 | |
493 | /* Update BLOCK_FOR_INSN of insns in BB to BB, | |
494 | and notify df of the change. */ | |
495 | ||
496 | void | |
497 | update_bb_for_insn (basic_block bb) | |
498 | { | |
499 | update_bb_for_insn_chain (BB_HEAD (bb), BB_END (bb), bb); | |
500 | } | |
501 | ||
ca6c03ca | 502 | \f |
6fb5fa3c DB |
503 | /* Return the INSN immediately following the NOTE_INSN_BASIC_BLOCK |
504 | note associated with the BLOCK. */ | |
505 | ||
506 | static rtx | |
507 | first_insn_after_basic_block_note (basic_block block) | |
508 | { | |
509 | rtx insn; | |
510 | ||
511 | /* Get the first instruction in the block. */ | |
512 | insn = BB_HEAD (block); | |
513 | ||
514 | if (insn == NULL_RTX) | |
515 | return NULL_RTX; | |
516 | if (LABEL_P (insn)) | |
517 | insn = NEXT_INSN (insn); | |
518 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn)); | |
519 | ||
520 | return NEXT_INSN (insn); | |
521 | } | |
522 | ||
f470c378 ZD |
523 | /* Creates a new basic block just after basic block B by splitting |
524 | everything after specified instruction I. */ | |
ca6c03ca | 525 | |
f470c378 | 526 | static basic_block |
d329e058 | 527 | rtl_split_block (basic_block bb, void *insnp) |
ca6c03ca JH |
528 | { |
529 | basic_block new_bb; | |
ae50c0cb | 530 | rtx insn = (rtx) insnp; |
f470c378 | 531 | edge e; |
628f6a4e | 532 | edge_iterator ei; |
ca6c03ca | 533 | |
f470c378 ZD |
534 | if (!insn) |
535 | { | |
536 | insn = first_insn_after_basic_block_note (bb); | |
537 | ||
538 | if (insn) | |
b5b8b0ac AO |
539 | { |
540 | rtx next = insn; | |
541 | ||
542 | insn = PREV_INSN (insn); | |
543 | ||
544 | /* If the block contains only debug insns, insn would have | |
545 | been NULL in a non-debug compilation, and then we'd end | |
546 | up emitting a DELETED note. For -fcompare-debug | |
547 | stability, emit the note too. */ | |
548 | if (insn != BB_END (bb) | |
549 | && DEBUG_INSN_P (next) | |
550 | && DEBUG_INSN_P (BB_END (bb))) | |
551 | { | |
552 | while (next != BB_END (bb) && DEBUG_INSN_P (next)) | |
553 | next = NEXT_INSN (next); | |
554 | ||
555 | if (next == BB_END (bb)) | |
556 | emit_note_after (NOTE_INSN_DELETED, next); | |
557 | } | |
558 | } | |
f470c378 ZD |
559 | else |
560 | insn = get_last_insn (); | |
561 | } | |
562 | ||
563 | /* We probably should check type of the insn so that we do not create | |
564 | inconsistent cfg. It is checked in verify_flow_info anyway, so do not | |
565 | bother. */ | |
566 | if (insn == BB_END (bb)) | |
567 | emit_note_after (NOTE_INSN_DELETED, insn); | |
ca6c03ca JH |
568 | |
569 | /* Create the new basic block. */ | |
a813c111 | 570 | new_bb = create_basic_block (NEXT_INSN (insn), BB_END (bb), bb); |
076c7ab8 | 571 | BB_COPY_PARTITION (new_bb, bb); |
a813c111 | 572 | BB_END (bb) = insn; |
ca6c03ca JH |
573 | |
574 | /* Redirect the outgoing edges. */ | |
628f6a4e BE |
575 | new_bb->succs = bb->succs; |
576 | bb->succs = NULL; | |
577 | FOR_EACH_EDGE (e, ei, new_bb->succs) | |
ca6c03ca JH |
578 | e->src = new_bb; |
579 | ||
6fb5fa3c DB |
580 | /* The new block starts off being dirty. */ |
581 | df_set_bb_dirty (bb); | |
f470c378 | 582 | return new_bb; |
bc35512f JH |
583 | } |
584 | ||
ca6c03ca | 585 | /* Blocks A and B are to be merged into a single block A. The insns |
bc35512f | 586 | are already contiguous. */ |
ca6c03ca | 587 | |
bc35512f JH |
588 | static void |
589 | rtl_merge_blocks (basic_block a, basic_block b) | |
ca6c03ca | 590 | { |
a813c111 | 591 | rtx b_head = BB_HEAD (b), b_end = BB_END (b), a_end = BB_END (a); |
ca6c03ca | 592 | rtx del_first = NULL_RTX, del_last = NULL_RTX; |
b5b8b0ac | 593 | rtx b_debug_start = b_end, b_debug_end = b_end; |
50a36e42 | 594 | bool forwarder_p = (b->flags & BB_FORWARDER_BLOCK) != 0; |
ca6c03ca JH |
595 | int b_empty = 0; |
596 | ||
6fb5fa3c | 597 | if (dump_file) |
50a36e42 EB |
598 | fprintf (dump_file, "Merging block %d into block %d...\n", b->index, |
599 | a->index); | |
6fb5fa3c | 600 | |
b5b8b0ac AO |
601 | while (DEBUG_INSN_P (b_end)) |
602 | b_end = PREV_INSN (b_debug_start = b_end); | |
603 | ||
ca6c03ca | 604 | /* If there was a CODE_LABEL beginning B, delete it. */ |
4b4bf941 | 605 | if (LABEL_P (b_head)) |
ca6c03ca JH |
606 | { |
607 | /* Detect basic blocks with nothing but a label. This can happen | |
608 | in particular at the end of a function. */ | |
609 | if (b_head == b_end) | |
610 | b_empty = 1; | |
5f0d2358 | 611 | |
ca6c03ca JH |
612 | del_first = del_last = b_head; |
613 | b_head = NEXT_INSN (b_head); | |
614 | } | |
615 | ||
5f0d2358 RK |
616 | /* Delete the basic block note and handle blocks containing just that |
617 | note. */ | |
ca6c03ca JH |
618 | if (NOTE_INSN_BASIC_BLOCK_P (b_head)) |
619 | { | |
620 | if (b_head == b_end) | |
621 | b_empty = 1; | |
622 | if (! del_last) | |
623 | del_first = b_head; | |
5f0d2358 | 624 | |
ca6c03ca JH |
625 | del_last = b_head; |
626 | b_head = NEXT_INSN (b_head); | |
627 | } | |
628 | ||
629 | /* If there was a jump out of A, delete it. */ | |
4b4bf941 | 630 | if (JUMP_P (a_end)) |
ca6c03ca JH |
631 | { |
632 | rtx prev; | |
633 | ||
634 | for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev)) | |
4b4bf941 | 635 | if (!NOTE_P (prev) |
a38e7aa5 | 636 | || NOTE_INSN_BASIC_BLOCK_P (prev) |
a813c111 | 637 | || prev == BB_HEAD (a)) |
ca6c03ca JH |
638 | break; |
639 | ||
640 | del_first = a_end; | |
641 | ||
642 | #ifdef HAVE_cc0 | |
643 | /* If this was a conditional jump, we need to also delete | |
644 | the insn that set cc0. */ | |
645 | if (only_sets_cc0_p (prev)) | |
646 | { | |
647 | rtx tmp = prev; | |
5f0d2358 | 648 | |
ca6c03ca JH |
649 | prev = prev_nonnote_insn (prev); |
650 | if (!prev) | |
a813c111 | 651 | prev = BB_HEAD (a); |
ca6c03ca JH |
652 | del_first = tmp; |
653 | } | |
654 | #endif | |
655 | ||
656 | a_end = PREV_INSN (del_first); | |
657 | } | |
4b4bf941 | 658 | else if (BARRIER_P (NEXT_INSN (a_end))) |
ca6c03ca JH |
659 | del_first = NEXT_INSN (a_end); |
660 | ||
ca6c03ca JH |
661 | /* Delete everything marked above as well as crap that might be |
662 | hanging out between the two blocks. */ | |
f470c378 | 663 | BB_HEAD (b) = NULL; |
a7b87f73 | 664 | delete_insn_chain (del_first, del_last, true); |
ca6c03ca JH |
665 | |
666 | /* Reassociate the insns of B with A. */ | |
667 | if (!b_empty) | |
668 | { | |
b5b8b0ac | 669 | update_bb_for_insn_chain (a_end, b_debug_end, a); |
5f0d2358 | 670 | |
b5b8b0ac AO |
671 | a_end = b_debug_end; |
672 | } | |
673 | else if (b_end != b_debug_end) | |
674 | { | |
675 | /* Move any deleted labels and other notes between the end of A | |
676 | and the debug insns that make up B after the debug insns, | |
677 | bringing the debug insns into A while keeping the notes after | |
678 | the end of A. */ | |
679 | if (NEXT_INSN (a_end) != b_debug_start) | |
680 | reorder_insns_nobb (NEXT_INSN (a_end), PREV_INSN (b_debug_start), | |
681 | b_debug_end); | |
682 | update_bb_for_insn_chain (b_debug_start, b_debug_end, a); | |
683 | a_end = b_debug_end; | |
ca6c03ca | 684 | } |
5f0d2358 | 685 | |
6fb5fa3c | 686 | df_bb_delete (b->index); |
a813c111 | 687 | BB_END (a) = a_end; |
50a36e42 EB |
688 | |
689 | /* If B was a forwarder block, propagate the locus on the edge. */ | |
690 | if (forwarder_p && !EDGE_SUCC (b, 0)->goto_locus) | |
691 | EDGE_SUCC (b, 0)->goto_locus = EDGE_SUCC (a, 0)->goto_locus; | |
692 | ||
693 | if (dump_file) | |
694 | fprintf (dump_file, "Merged blocks %d and %d.\n", a->index, b->index); | |
ca6c03ca | 695 | } |
bc35512f | 696 | |
6fb5fa3c | 697 | |
bc35512f | 698 | /* Return true when block A and B can be merged. */ |
9678086d | 699 | |
b48d0358 DN |
700 | static bool |
701 | rtl_can_merge_blocks (basic_block a, basic_block b) | |
bc35512f | 702 | { |
750054a2 CT |
703 | /* If we are partitioning hot/cold basic blocks, we don't want to |
704 | mess up unconditional or indirect jumps that cross between hot | |
076c7ab8 ZW |
705 | and cold sections. |
706 | ||
8e8d5162 | 707 | Basic block partitioning may result in some jumps that appear to |
c22cacf3 MS |
708 | be optimizable (or blocks that appear to be mergeable), but which really |
709 | must be left untouched (they are required to make it safely across | |
710 | partition boundaries). See the comments at the top of | |
8e8d5162 | 711 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
076c7ab8 | 712 | |
87c8b4be | 713 | if (BB_PARTITION (a) != BB_PARTITION (b)) |
076c7ab8 | 714 | return false; |
750054a2 | 715 | |
bc35512f | 716 | /* There must be exactly one edge in between the blocks. */ |
c5cbcccf ZD |
717 | return (single_succ_p (a) |
718 | && single_succ (a) == b | |
719 | && single_pred_p (b) | |
628f6a4e | 720 | && a != b |
bc35512f | 721 | /* Must be simple edge. */ |
c5cbcccf | 722 | && !(single_succ_edge (a)->flags & EDGE_COMPLEX) |
bc35512f JH |
723 | && a->next_bb == b |
724 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR | |
725 | /* If the jump insn has side effects, | |
726 | we can't kill the edge. */ | |
4b4bf941 | 727 | && (!JUMP_P (BB_END (a)) |
e24e7211 | 728 | || (reload_completed |
a813c111 | 729 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f | 730 | } |
ca6c03ca | 731 | \f |
5f0d2358 RK |
732 | /* Return the label in the head of basic block BLOCK. Create one if it doesn't |
733 | exist. */ | |
ca6c03ca JH |
734 | |
735 | rtx | |
d329e058 | 736 | block_label (basic_block block) |
ca6c03ca JH |
737 | { |
738 | if (block == EXIT_BLOCK_PTR) | |
739 | return NULL_RTX; | |
5f0d2358 | 740 | |
4b4bf941 | 741 | if (!LABEL_P (BB_HEAD (block))) |
ca6c03ca | 742 | { |
a813c111 | 743 | BB_HEAD (block) = emit_label_before (gen_label_rtx (), BB_HEAD (block)); |
ca6c03ca | 744 | } |
5f0d2358 | 745 | |
a813c111 | 746 | return BB_HEAD (block); |
ca6c03ca JH |
747 | } |
748 | ||
749 | /* Attempt to perform edge redirection by replacing possibly complex jump | |
5f0d2358 RK |
750 | instruction by unconditional jump or removing jump completely. This can |
751 | apply only if all edges now point to the same block. The parameters and | |
752 | return values are equivalent to redirect_edge_and_branch. */ | |
ca6c03ca | 753 | |
6de9cd9a | 754 | edge |
bc35512f | 755 | try_redirect_by_replacing_jump (edge e, basic_block target, bool in_cfglayout) |
ca6c03ca JH |
756 | { |
757 | basic_block src = e->src; | |
a813c111 | 758 | rtx insn = BB_END (src), kill_from; |
e1233a7d | 759 | rtx set; |
ca6c03ca | 760 | int fallthru = 0; |
750054a2 CT |
761 | |
762 | /* If we are partitioning hot/cold basic blocks, we don't want to | |
763 | mess up unconditional or indirect jumps that cross between hot | |
8e8d5162 CT |
764 | and cold sections. |
765 | ||
766 | Basic block partitioning may result in some jumps that appear to | |
c22cacf3 MS |
767 | be optimizable (or blocks that appear to be mergeable), but which really |
768 | must be left untouched (they are required to make it safely across | |
769 | partition boundaries). See the comments at the top of | |
8e8d5162 | 770 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
c22cacf3 | 771 | |
87c8b4be CT |
772 | if (find_reg_note (insn, REG_CROSSING_JUMP, NULL_RTX) |
773 | || BB_PARTITION (src) != BB_PARTITION (target)) | |
9cf84a3c | 774 | return NULL; |
750054a2 | 775 | |
6a66a8a7 KH |
776 | /* We can replace or remove a complex jump only when we have exactly |
777 | two edges. Also, if we have exactly one outgoing edge, we can | |
778 | redirect that. */ | |
779 | if (EDGE_COUNT (src->succs) >= 3 | |
780 | /* Verify that all targets will be TARGET. Specifically, the | |
781 | edge that is not E must also go to TARGET. */ | |
782 | || (EDGE_COUNT (src->succs) == 2 | |
783 | && EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)) | |
784 | return NULL; | |
5f0d2358 | 785 | |
6a66a8a7 | 786 | if (!onlyjump_p (insn)) |
6de9cd9a | 787 | return NULL; |
3348b696 | 788 | if ((!optimize || reload_completed) && tablejump_p (insn, NULL, NULL)) |
6de9cd9a | 789 | return NULL; |
ca6c03ca JH |
790 | |
791 | /* Avoid removing branch with side effects. */ | |
792 | set = single_set (insn); | |
793 | if (!set || side_effects_p (set)) | |
6de9cd9a | 794 | return NULL; |
ca6c03ca JH |
795 | |
796 | /* In case we zap a conditional jump, we'll need to kill | |
797 | the cc0 setter too. */ | |
798 | kill_from = insn; | |
799 | #ifdef HAVE_cc0 | |
9caea4a7 RS |
800 | if (reg_mentioned_p (cc0_rtx, PATTERN (insn)) |
801 | && only_sets_cc0_p (PREV_INSN (insn))) | |
ca6c03ca JH |
802 | kill_from = PREV_INSN (insn); |
803 | #endif | |
804 | ||
805 | /* See if we can create the fallthru edge. */ | |
bc35512f | 806 | if (in_cfglayout || can_fallthru (src, target)) |
ca6c03ca | 807 | { |
c263766c RH |
808 | if (dump_file) |
809 | fprintf (dump_file, "Removing jump %i.\n", INSN_UID (insn)); | |
ca6c03ca JH |
810 | fallthru = 1; |
811 | ||
eaec9b3d | 812 | /* Selectively unlink whole insn chain. */ |
bc35512f JH |
813 | if (in_cfglayout) |
814 | { | |
370369e1 | 815 | rtx insn = src->il.rtl->footer; |
bc35512f | 816 | |
a7b87f73 | 817 | delete_insn_chain (kill_from, BB_END (src), false); |
bc35512f JH |
818 | |
819 | /* Remove barriers but keep jumptables. */ | |
820 | while (insn) | |
821 | { | |
4b4bf941 | 822 | if (BARRIER_P (insn)) |
bc35512f JH |
823 | { |
824 | if (PREV_INSN (insn)) | |
825 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
826 | else | |
370369e1 | 827 | src->il.rtl->footer = NEXT_INSN (insn); |
bc35512f JH |
828 | if (NEXT_INSN (insn)) |
829 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
830 | } | |
4b4bf941 | 831 | if (LABEL_P (insn)) |
bc35512f JH |
832 | break; |
833 | insn = NEXT_INSN (insn); | |
834 | } | |
835 | } | |
836 | else | |
a7b87f73 ZD |
837 | delete_insn_chain (kill_from, PREV_INSN (BB_HEAD (target)), |
838 | false); | |
ca6c03ca | 839 | } |
5f0d2358 | 840 | |
ca6c03ca JH |
841 | /* If this already is simplejump, redirect it. */ |
842 | else if (simplejump_p (insn)) | |
843 | { | |
844 | if (e->dest == target) | |
6de9cd9a | 845 | return NULL; |
c263766c RH |
846 | if (dump_file) |
847 | fprintf (dump_file, "Redirecting jump %i from %i to %i.\n", | |
0b17ab2f | 848 | INSN_UID (insn), e->dest->index, target->index); |
6ee3c8e4 JJ |
849 | if (!redirect_jump (insn, block_label (target), 0)) |
850 | { | |
341c100f NS |
851 | gcc_assert (target == EXIT_BLOCK_PTR); |
852 | return NULL; | |
6ee3c8e4 | 853 | } |
ca6c03ca | 854 | } |
5f0d2358 | 855 | |
6ee3c8e4 JJ |
856 | /* Cannot do anything for target exit block. */ |
857 | else if (target == EXIT_BLOCK_PTR) | |
6de9cd9a | 858 | return NULL; |
6ee3c8e4 | 859 | |
ca6c03ca JH |
860 | /* Or replace possibly complicated jump insn by simple jump insn. */ |
861 | else | |
862 | { | |
863 | rtx target_label = block_label (target); | |
eb5b8ad4 | 864 | rtx barrier, label, table; |
ca6c03ca | 865 | |
a7102479 | 866 | emit_jump_insn_after_noloc (gen_jump (target_label), insn); |
a813c111 | 867 | JUMP_LABEL (BB_END (src)) = target_label; |
ca6c03ca | 868 | LABEL_NUSES (target_label)++; |
c263766c RH |
869 | if (dump_file) |
870 | fprintf (dump_file, "Replacing insn %i by jump %i\n", | |
a813c111 | 871 | INSN_UID (insn), INSN_UID (BB_END (src))); |
ca6c03ca | 872 | |
4da2eb6b | 873 | |
ba4807a0 LB |
874 | delete_insn_chain (kill_from, insn, false); |
875 | ||
4da2eb6b RH |
876 | /* Recognize a tablejump that we are converting to a |
877 | simple jump and remove its associated CODE_LABEL | |
878 | and ADDR_VEC or ADDR_DIFF_VEC. */ | |
ba4807a0 LB |
879 | if (tablejump_p (insn, &label, &table)) |
880 | delete_insn_chain (label, table, false); | |
eb5b8ad4 | 881 | |
a813c111 | 882 | barrier = next_nonnote_insn (BB_END (src)); |
4b4bf941 | 883 | if (!barrier || !BARRIER_P (barrier)) |
a813c111 | 884 | emit_barrier_after (BB_END (src)); |
5d693491 JZ |
885 | else |
886 | { | |
a813c111 | 887 | if (barrier != NEXT_INSN (BB_END (src))) |
5d693491 JZ |
888 | { |
889 | /* Move the jump before barrier so that the notes | |
890 | which originally were or were created before jump table are | |
891 | inside the basic block. */ | |
a813c111 | 892 | rtx new_insn = BB_END (src); |
5d693491 | 893 | |
6c3d0e31 SP |
894 | update_bb_for_insn_chain (NEXT_INSN (BB_END (src)), |
895 | PREV_INSN (barrier), src); | |
5d693491 JZ |
896 | |
897 | NEXT_INSN (PREV_INSN (new_insn)) = NEXT_INSN (new_insn); | |
898 | PREV_INSN (NEXT_INSN (new_insn)) = PREV_INSN (new_insn); | |
899 | ||
900 | NEXT_INSN (new_insn) = barrier; | |
901 | NEXT_INSN (PREV_INSN (barrier)) = new_insn; | |
902 | ||
903 | PREV_INSN (new_insn) = PREV_INSN (barrier); | |
904 | PREV_INSN (barrier) = new_insn; | |
905 | } | |
906 | } | |
ca6c03ca JH |
907 | } |
908 | ||
909 | /* Keep only one edge out and set proper flags. */ | |
c5cbcccf | 910 | if (!single_succ_p (src)) |
628f6a4e | 911 | remove_edge (e); |
c5cbcccf | 912 | gcc_assert (single_succ_p (src)); |
628f6a4e | 913 | |
c5cbcccf | 914 | e = single_succ_edge (src); |
ca6c03ca JH |
915 | if (fallthru) |
916 | e->flags = EDGE_FALLTHRU; | |
917 | else | |
918 | e->flags = 0; | |
5f0d2358 | 919 | |
ca6c03ca JH |
920 | e->probability = REG_BR_PROB_BASE; |
921 | e->count = src->count; | |
922 | ||
ca6c03ca JH |
923 | if (e->dest != target) |
924 | redirect_edge_succ (e, target); | |
6de9cd9a | 925 | return e; |
ca6c03ca JH |
926 | } |
927 | ||
4e3825db MM |
928 | /* Subroutine of redirect_branch_edge that tries to patch the jump |
929 | instruction INSN so that it reaches block NEW. Do this | |
930 | only when it originally reached block OLD. Return true if this | |
931 | worked or the original target wasn't OLD, return false if redirection | |
932 | doesn't work. */ | |
933 | ||
934 | static bool | |
935 | patch_jump_insn (rtx insn, rtx old_label, basic_block new_bb) | |
ca6c03ca JH |
936 | { |
937 | rtx tmp; | |
ca6c03ca | 938 | /* Recognize a tablejump and adjust all matching cases. */ |
e1233a7d | 939 | if (tablejump_p (insn, NULL, &tmp)) |
ca6c03ca JH |
940 | { |
941 | rtvec vec; | |
942 | int j; | |
4e3825db | 943 | rtx new_label = block_label (new_bb); |
ca6c03ca | 944 | |
4e3825db MM |
945 | if (new_bb == EXIT_BLOCK_PTR) |
946 | return false; | |
ca6c03ca JH |
947 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) |
948 | vec = XVEC (PATTERN (tmp), 0); | |
949 | else | |
950 | vec = XVEC (PATTERN (tmp), 1); | |
951 | ||
952 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
953 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
954 | { | |
955 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (Pmode, new_label); | |
956 | --LABEL_NUSES (old_label); | |
957 | ++LABEL_NUSES (new_label); | |
958 | } | |
959 | ||
f9da5064 | 960 | /* Handle casesi dispatch insns. */ |
ca6c03ca JH |
961 | if ((tmp = single_set (insn)) != NULL |
962 | && SET_DEST (tmp) == pc_rtx | |
963 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
964 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF | |
965 | && XEXP (XEXP (SET_SRC (tmp), 2), 0) == old_label) | |
966 | { | |
4c33cb26 | 967 | XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (Pmode, |
ca6c03ca JH |
968 | new_label); |
969 | --LABEL_NUSES (old_label); | |
970 | ++LABEL_NUSES (new_label); | |
971 | } | |
972 | } | |
1c384bf1 RH |
973 | else if ((tmp = extract_asm_operands (PATTERN (insn))) != NULL) |
974 | { | |
975 | int i, n = ASM_OPERANDS_LABEL_LENGTH (tmp); | |
976 | rtx new_label, note; | |
977 | ||
978 | if (new_bb == EXIT_BLOCK_PTR) | |
979 | return false; | |
980 | new_label = block_label (new_bb); | |
981 | ||
982 | for (i = 0; i < n; ++i) | |
983 | { | |
984 | rtx old_ref = ASM_OPERANDS_LABEL (tmp, i); | |
985 | gcc_assert (GET_CODE (old_ref) == LABEL_REF); | |
986 | if (XEXP (old_ref, 0) == old_label) | |
987 | { | |
988 | ASM_OPERANDS_LABEL (tmp, i) | |
989 | = gen_rtx_LABEL_REF (Pmode, new_label); | |
990 | --LABEL_NUSES (old_label); | |
991 | ++LABEL_NUSES (new_label); | |
992 | } | |
993 | } | |
994 | ||
995 | if (JUMP_LABEL (insn) == old_label) | |
996 | { | |
997 | JUMP_LABEL (insn) = new_label; | |
998 | note = find_reg_note (insn, REG_LABEL_TARGET, new_label); | |
999 | if (note) | |
1000 | remove_note (insn, note); | |
1001 | } | |
1002 | else | |
1003 | { | |
1004 | note = find_reg_note (insn, REG_LABEL_TARGET, old_label); | |
1005 | if (note) | |
1006 | remove_note (insn, note); | |
1007 | if (JUMP_LABEL (insn) != new_label | |
1008 | && !find_reg_note (insn, REG_LABEL_TARGET, new_label)) | |
1009 | add_reg_note (insn, REG_LABEL_TARGET, new_label); | |
1010 | } | |
3b5fda81 JJ |
1011 | while ((note = find_reg_note (insn, REG_LABEL_OPERAND, old_label)) |
1012 | != NULL_RTX) | |
1013 | XEXP (note, 0) = new_label; | |
1c384bf1 | 1014 | } |
ca6c03ca JH |
1015 | else |
1016 | { | |
1017 | /* ?? We may play the games with moving the named labels from | |
1018 | one basic block to the other in case only one computed_jump is | |
1019 | available. */ | |
5f0d2358 RK |
1020 | if (computed_jump_p (insn) |
1021 | /* A return instruction can't be redirected. */ | |
1022 | || returnjump_p (insn)) | |
4e3825db | 1023 | return false; |
6ee3c8e4 | 1024 | |
4e3825db | 1025 | if (!currently_expanding_to_rtl || JUMP_LABEL (insn) == old_label) |
6ee3c8e4 | 1026 | { |
4e3825db MM |
1027 | /* If the insn doesn't go where we think, we're confused. */ |
1028 | gcc_assert (JUMP_LABEL (insn) == old_label); | |
1029 | ||
1030 | /* If the substitution doesn't succeed, die. This can happen | |
1031 | if the back end emitted unrecognizable instructions or if | |
1032 | target is exit block on some arches. */ | |
1033 | if (!redirect_jump (insn, block_label (new_bb), 0)) | |
1034 | { | |
1035 | gcc_assert (new_bb == EXIT_BLOCK_PTR); | |
1036 | return false; | |
1037 | } | |
6ee3c8e4 | 1038 | } |
ca6c03ca | 1039 | } |
4e3825db MM |
1040 | return true; |
1041 | } | |
1042 | ||
1043 | ||
1044 | /* Redirect edge representing branch of (un)conditional jump or tablejump, | |
1045 | NULL on failure */ | |
1046 | static edge | |
1047 | redirect_branch_edge (edge e, basic_block target) | |
1048 | { | |
1049 | rtx old_label = BB_HEAD (e->dest); | |
1050 | basic_block src = e->src; | |
1051 | rtx insn = BB_END (src); | |
1052 | ||
1053 | /* We can only redirect non-fallthru edges of jump insn. */ | |
1054 | if (e->flags & EDGE_FALLTHRU) | |
1055 | return NULL; | |
1056 | else if (!JUMP_P (insn) && !currently_expanding_to_rtl) | |
1057 | return NULL; | |
1058 | ||
1059 | if (!currently_expanding_to_rtl) | |
1060 | { | |
1061 | if (!patch_jump_insn (insn, old_label, target)) | |
1062 | return NULL; | |
1063 | } | |
1064 | else | |
1065 | /* When expanding this BB might actually contain multiple | |
1066 | jumps (i.e. not yet split by find_many_sub_basic_blocks). | |
1067 | Redirect all of those that match our label. */ | |
0f346928 | 1068 | FOR_BB_INSNS (src, insn) |
4e3825db MM |
1069 | if (JUMP_P (insn) && !patch_jump_insn (insn, old_label, target)) |
1070 | return NULL; | |
ca6c03ca | 1071 | |
c263766c RH |
1072 | if (dump_file) |
1073 | fprintf (dump_file, "Edge %i->%i redirected to %i\n", | |
0b17ab2f | 1074 | e->src->index, e->dest->index, target->index); |
5f0d2358 | 1075 | |
ca6c03ca | 1076 | if (e->dest != target) |
6de9cd9a | 1077 | e = redirect_edge_succ_nodup (e, target); |
6fb5fa3c | 1078 | |
6de9cd9a | 1079 | return e; |
bc35512f JH |
1080 | } |
1081 | ||
1082 | /* Attempt to change code to redirect edge E to TARGET. Don't do that on | |
1083 | expense of adding new instructions or reordering basic blocks. | |
1084 | ||
1085 | Function can be also called with edge destination equivalent to the TARGET. | |
1086 | Then it should try the simplifications and do nothing if none is possible. | |
1087 | ||
6de9cd9a DN |
1088 | Return edge representing the branch if transformation succeeded. Return NULL |
1089 | on failure. | |
1090 | We still return NULL in case E already destinated TARGET and we didn't | |
1091 | managed to simplify instruction stream. */ | |
bc35512f | 1092 | |
6de9cd9a | 1093 | static edge |
5671bf27 | 1094 | rtl_redirect_edge_and_branch (edge e, basic_block target) |
bc35512f | 1095 | { |
6de9cd9a | 1096 | edge ret; |
f345f21a JH |
1097 | basic_block src = e->src; |
1098 | ||
bc35512f | 1099 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
6de9cd9a | 1100 | return NULL; |
bc35512f | 1101 | |
3348b696 | 1102 | if (e->dest == target) |
6de9cd9a | 1103 | return e; |
3348b696 | 1104 | |
6de9cd9a | 1105 | if ((ret = try_redirect_by_replacing_jump (e, target, false)) != NULL) |
f345f21a | 1106 | { |
6fb5fa3c | 1107 | df_set_bb_dirty (src); |
6de9cd9a | 1108 | return ret; |
f345f21a | 1109 | } |
bc35512f | 1110 | |
6de9cd9a DN |
1111 | ret = redirect_branch_edge (e, target); |
1112 | if (!ret) | |
1113 | return NULL; | |
5f0d2358 | 1114 | |
6fb5fa3c | 1115 | df_set_bb_dirty (src); |
6de9cd9a | 1116 | return ret; |
ca6c03ca JH |
1117 | } |
1118 | ||
4fe9b91c | 1119 | /* Like force_nonfallthru below, but additionally performs redirection |
26898771 BS |
1120 | Used by redirect_edge_and_branch_force. JUMP_LABEL is used only |
1121 | when redirecting to the EXIT_BLOCK, it is either ret_rtx or | |
1122 | simple_return_rtx, indicating which kind of returnjump to create. | |
1123 | It should be NULL otherwise. */ | |
ca6c03ca | 1124 | |
dc0ff1c8 | 1125 | basic_block |
26898771 | 1126 | force_nonfallthru_and_redirect (edge e, basic_block target, rtx jump_label) |
ca6c03ca | 1127 | { |
a3716585 | 1128 | basic_block jump_block, new_bb = NULL, src = e->src; |
ca6c03ca JH |
1129 | rtx note; |
1130 | edge new_edge; | |
a3716585 | 1131 | int abnormal_edge_flags = 0; |
7241571e | 1132 | int loc; |
ca6c03ca | 1133 | |
cb9a1d9b JH |
1134 | /* In the case the last instruction is conditional jump to the next |
1135 | instruction, first redirect the jump itself and then continue | |
b20b352b | 1136 | by creating a basic block afterwards to redirect fallthru edge. */ |
cb9a1d9b | 1137 | if (e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR |
a813c111 | 1138 | && any_condjump_p (BB_END (e->src)) |
a813c111 | 1139 | && JUMP_LABEL (BB_END (e->src)) == BB_HEAD (e->dest)) |
cb9a1d9b JH |
1140 | { |
1141 | rtx note; | |
58e6ae30 | 1142 | edge b = unchecked_make_edge (e->src, target, 0); |
341c100f | 1143 | bool redirected; |
cb9a1d9b | 1144 | |
341c100f NS |
1145 | redirected = redirect_jump (BB_END (e->src), block_label (target), 0); |
1146 | gcc_assert (redirected); | |
c22cacf3 | 1147 | |
a813c111 | 1148 | note = find_reg_note (BB_END (e->src), REG_BR_PROB, NULL_RTX); |
cb9a1d9b JH |
1149 | if (note) |
1150 | { | |
1151 | int prob = INTVAL (XEXP (note, 0)); | |
1152 | ||
1153 | b->probability = prob; | |
1154 | b->count = e->count * prob / REG_BR_PROB_BASE; | |
1155 | e->probability -= e->probability; | |
1156 | e->count -= b->count; | |
1157 | if (e->probability < 0) | |
1158 | e->probability = 0; | |
1159 | if (e->count < 0) | |
1160 | e->count = 0; | |
1161 | } | |
1162 | } | |
1163 | ||
ca6c03ca | 1164 | if (e->flags & EDGE_ABNORMAL) |
a3716585 JH |
1165 | { |
1166 | /* Irritating special case - fallthru edge to the same block as abnormal | |
1167 | edge. | |
1168 | We can't redirect abnormal edge, but we still can split the fallthru | |
d329e058 | 1169 | one and create separate abnormal edge to original destination. |
a3716585 | 1170 | This allows bb-reorder to make such edge non-fallthru. */ |
341c100f | 1171 | gcc_assert (e->dest == target); |
a3716585 JH |
1172 | abnormal_edge_flags = e->flags & ~(EDGE_FALLTHRU | EDGE_CAN_FALLTHRU); |
1173 | e->flags &= EDGE_FALLTHRU | EDGE_CAN_FALLTHRU; | |
1174 | } | |
341c100f | 1175 | else |
24c545ff | 1176 | { |
341c100f NS |
1177 | gcc_assert (e->flags & EDGE_FALLTHRU); |
1178 | if (e->src == ENTRY_BLOCK_PTR) | |
1179 | { | |
1180 | /* We can't redirect the entry block. Create an empty block | |
628f6a4e BE |
1181 | at the start of the function which we use to add the new |
1182 | jump. */ | |
1183 | edge tmp; | |
1184 | edge_iterator ei; | |
1185 | bool found = false; | |
c22cacf3 | 1186 | |
628f6a4e | 1187 | basic_block bb = create_basic_block (BB_HEAD (e->dest), NULL, ENTRY_BLOCK_PTR); |
c22cacf3 | 1188 | |
341c100f NS |
1189 | /* Change the existing edge's source to be the new block, and add |
1190 | a new edge from the entry block to the new block. */ | |
1191 | e->src = bb; | |
628f6a4e BE |
1192 | for (ei = ei_start (ENTRY_BLOCK_PTR->succs); (tmp = ei_safe_edge (ei)); ) |
1193 | { | |
1194 | if (tmp == e) | |
1195 | { | |
865851d0 | 1196 | VEC_unordered_remove (edge, ENTRY_BLOCK_PTR->succs, ei.index); |
628f6a4e BE |
1197 | found = true; |
1198 | break; | |
1199 | } | |
1200 | else | |
1201 | ei_next (&ei); | |
1202 | } | |
c22cacf3 | 1203 | |
628f6a4e | 1204 | gcc_assert (found); |
c22cacf3 | 1205 | |
d4e6fecb | 1206 | VEC_safe_push (edge, gc, bb->succs, e); |
341c100f NS |
1207 | make_single_succ_edge (ENTRY_BLOCK_PTR, bb, EDGE_FALLTHRU); |
1208 | } | |
24c545ff BS |
1209 | } |
1210 | ||
628f6a4e | 1211 | if (EDGE_COUNT (e->src->succs) >= 2 || abnormal_edge_flags) |
ca6c03ca JH |
1212 | { |
1213 | /* Create the new structures. */ | |
31a78298 | 1214 | |
79019985 RH |
1215 | /* If the old block ended with a tablejump, skip its table |
1216 | by searching forward from there. Otherwise start searching | |
1217 | forward from the last instruction of the old block. */ | |
a813c111 SB |
1218 | if (!tablejump_p (BB_END (e->src), NULL, ¬e)) |
1219 | note = BB_END (e->src); | |
31a78298 RH |
1220 | note = NEXT_INSN (note); |
1221 | ||
31a78298 | 1222 | jump_block = create_basic_block (note, NULL, e->src); |
ca6c03ca JH |
1223 | jump_block->count = e->count; |
1224 | jump_block->frequency = EDGE_FREQUENCY (e); | |
1225 | jump_block->loop_depth = target->loop_depth; | |
1226 | ||
750054a2 CT |
1227 | /* Make sure new block ends up in correct hot/cold section. */ |
1228 | ||
076c7ab8 | 1229 | BB_COPY_PARTITION (jump_block, e->src); |
9fb32434 | 1230 | if (flag_reorder_blocks_and_partition |
677f3fa8 | 1231 | && targetm_common.have_named_sections |
87c8b4be CT |
1232 | && JUMP_P (BB_END (jump_block)) |
1233 | && !any_condjump_p (BB_END (jump_block)) | |
1234 | && (EDGE_SUCC (jump_block, 0)->flags & EDGE_CROSSING)) | |
65c5f2a6 | 1235 | add_reg_note (BB_END (jump_block), REG_CROSSING_JUMP, NULL_RTX); |
c22cacf3 | 1236 | |
ca6c03ca JH |
1237 | /* Wire edge in. */ |
1238 | new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU); | |
1239 | new_edge->probability = e->probability; | |
1240 | new_edge->count = e->count; | |
1241 | ||
1242 | /* Redirect old edge. */ | |
1243 | redirect_edge_pred (e, jump_block); | |
1244 | e->probability = REG_BR_PROB_BASE; | |
1245 | ||
1246 | new_bb = jump_block; | |
1247 | } | |
1248 | else | |
1249 | jump_block = e->src; | |
5f0d2358 | 1250 | |
7241571e JJ |
1251 | if (e->goto_locus && e->goto_block == NULL) |
1252 | loc = e->goto_locus; | |
1253 | else | |
1254 | loc = 0; | |
ca6c03ca JH |
1255 | e->flags &= ~EDGE_FALLTHRU; |
1256 | if (target == EXIT_BLOCK_PTR) | |
1257 | { | |
26898771 BS |
1258 | if (jump_label == ret_rtx) |
1259 | { | |
cf22ce3c | 1260 | #ifdef HAVE_return |
26898771 | 1261 | emit_jump_insn_after_setloc (gen_return (), BB_END (jump_block), loc); |
cf22ce3c | 1262 | #else |
26898771 | 1263 | gcc_unreachable (); |
cf22ce3c | 1264 | #endif |
26898771 BS |
1265 | } |
1266 | else | |
1267 | { | |
1268 | gcc_assert (jump_label == simple_return_rtx); | |
1269 | #ifdef HAVE_simple_return | |
1270 | emit_jump_insn_after_setloc (gen_simple_return (), | |
1271 | BB_END (jump_block), loc); | |
1272 | #else | |
1273 | gcc_unreachable (); | |
1274 | #endif | |
1275 | } | |
387748de | 1276 | set_return_jump_label (BB_END (jump_block)); |
ca6c03ca JH |
1277 | } |
1278 | else | |
1279 | { | |
1280 | rtx label = block_label (target); | |
7241571e | 1281 | emit_jump_insn_after_setloc (gen_jump (label), BB_END (jump_block), loc); |
a813c111 | 1282 | JUMP_LABEL (BB_END (jump_block)) = label; |
ca6c03ca JH |
1283 | LABEL_NUSES (label)++; |
1284 | } | |
5f0d2358 | 1285 | |
a813c111 | 1286 | emit_barrier_after (BB_END (jump_block)); |
ca6c03ca JH |
1287 | redirect_edge_succ_nodup (e, target); |
1288 | ||
a3716585 JH |
1289 | if (abnormal_edge_flags) |
1290 | make_edge (src, target, abnormal_edge_flags); | |
1291 | ||
b8698a0f | 1292 | df_mark_solutions_dirty (); |
ca6c03ca JH |
1293 | return new_bb; |
1294 | } | |
1295 | ||
1296 | /* Edge E is assumed to be fallthru edge. Emit needed jump instruction | |
1297 | (and possibly create new basic block) to make edge non-fallthru. | |
1298 | Return newly created BB or NULL if none. */ | |
5f0d2358 | 1299 | |
cf103ca4 EB |
1300 | static basic_block |
1301 | rtl_force_nonfallthru (edge e) | |
ca6c03ca | 1302 | { |
26898771 | 1303 | return force_nonfallthru_and_redirect (e, e->dest, NULL_RTX); |
ca6c03ca JH |
1304 | } |
1305 | ||
1306 | /* Redirect edge even at the expense of creating new jump insn or | |
1307 | basic block. Return new basic block if created, NULL otherwise. | |
41806d92 | 1308 | Conversion must be possible. */ |
ca6c03ca | 1309 | |
9ee634e3 | 1310 | static basic_block |
d329e058 | 1311 | rtl_redirect_edge_and_branch_force (edge e, basic_block target) |
ca6c03ca | 1312 | { |
5f0d2358 RK |
1313 | if (redirect_edge_and_branch (e, target) |
1314 | || e->dest == target) | |
ca6c03ca JH |
1315 | return NULL; |
1316 | ||
1317 | /* In case the edge redirection failed, try to force it to be non-fallthru | |
1318 | and redirect newly created simplejump. */ | |
6fb5fa3c | 1319 | df_set_bb_dirty (e->src); |
26898771 | 1320 | return force_nonfallthru_and_redirect (e, target, NULL_RTX); |
ca6c03ca JH |
1321 | } |
1322 | ||
1323 | /* The given edge should potentially be a fallthru edge. If that is in | |
1324 | fact true, delete the jump and barriers that are in the way. */ | |
1325 | ||
f470c378 ZD |
1326 | static void |
1327 | rtl_tidy_fallthru_edge (edge e) | |
ca6c03ca JH |
1328 | { |
1329 | rtx q; | |
f470c378 ZD |
1330 | basic_block b = e->src, c = b->next_bb; |
1331 | ||
ca6c03ca JH |
1332 | /* ??? In a late-running flow pass, other folks may have deleted basic |
1333 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
0fa2e4df | 1334 | and the target label. They ought to be chastised and fixed. |
ca6c03ca JH |
1335 | |
1336 | We can also wind up with a sequence of undeletable labels between | |
1337 | one block and the next. | |
1338 | ||
1339 | So search through a sequence of barriers, labels, and notes for | |
1340 | the head of block C and assert that we really do fall through. */ | |
1341 | ||
a813c111 | 1342 | for (q = NEXT_INSN (BB_END (b)); q != BB_HEAD (c); q = NEXT_INSN (q)) |
9c0a0632 RH |
1343 | if (INSN_P (q)) |
1344 | return; | |
ca6c03ca JH |
1345 | |
1346 | /* Remove what will soon cease being the jump insn from the source block. | |
1347 | If block B consisted only of this single jump, turn it into a deleted | |
1348 | note. */ | |
a813c111 | 1349 | q = BB_END (b); |
4b4bf941 | 1350 | if (JUMP_P (q) |
ca6c03ca JH |
1351 | && onlyjump_p (q) |
1352 | && (any_uncondjump_p (q) | |
c5cbcccf | 1353 | || single_succ_p (b))) |
ca6c03ca JH |
1354 | { |
1355 | #ifdef HAVE_cc0 | |
1356 | /* If this was a conditional jump, we need to also delete | |
1357 | the insn that set cc0. */ | |
1358 | if (any_condjump_p (q) && only_sets_cc0_p (PREV_INSN (q))) | |
1359 | q = PREV_INSN (q); | |
1360 | #endif | |
1361 | ||
1362 | q = PREV_INSN (q); | |
ca6c03ca JH |
1363 | } |
1364 | ||
1365 | /* Selectively unlink the sequence. */ | |
a813c111 | 1366 | if (q != PREV_INSN (BB_HEAD (c))) |
a7b87f73 | 1367 | delete_insn_chain (NEXT_INSN (q), PREV_INSN (BB_HEAD (c)), false); |
ca6c03ca JH |
1368 | |
1369 | e->flags |= EDGE_FALLTHRU; | |
1370 | } | |
ca6c03ca | 1371 | \f |
f470c378 ZD |
1372 | /* Should move basic block BB after basic block AFTER. NIY. */ |
1373 | ||
1374 | static bool | |
1375 | rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED, | |
1376 | basic_block after ATTRIBUTE_UNUSED) | |
1377 | { | |
1378 | return false; | |
1379 | } | |
1380 | ||
ca6c03ca | 1381 | /* Split a (typically critical) edge. Return the new block. |
41806d92 | 1382 | The edge must not be abnormal. |
ca6c03ca JH |
1383 | |
1384 | ??? The code generally expects to be called on critical edges. | |
1385 | The case of a block ending in an unconditional jump to a | |
1386 | block with multiple predecessors is not handled optimally. */ | |
1387 | ||
8ce33230 | 1388 | static basic_block |
d329e058 | 1389 | rtl_split_edge (edge edge_in) |
ca6c03ca JH |
1390 | { |
1391 | basic_block bb; | |
ca6c03ca JH |
1392 | rtx before; |
1393 | ||
1394 | /* Abnormal edges cannot be split. */ | |
341c100f | 1395 | gcc_assert (!(edge_in->flags & EDGE_ABNORMAL)); |
ca6c03ca JH |
1396 | |
1397 | /* We are going to place the new block in front of edge destination. | |
eaec9b3d | 1398 | Avoid existence of fallthru predecessors. */ |
ca6c03ca JH |
1399 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) |
1400 | { | |
0fd4b31d | 1401 | edge e = find_fallthru_edge (edge_in->dest->preds); |
ca6c03ca JH |
1402 | |
1403 | if (e) | |
1404 | force_nonfallthru (e); | |
1405 | } | |
1406 | ||
96e82e0a ZD |
1407 | /* Create the basic block note. */ |
1408 | if (edge_in->dest != EXIT_BLOCK_PTR) | |
a813c111 | 1409 | before = BB_HEAD (edge_in->dest); |
ca6c03ca JH |
1410 | else |
1411 | before = NULL_RTX; | |
1412 | ||
623a66fa R |
1413 | /* If this is a fall through edge to the exit block, the blocks might be |
1414 | not adjacent, and the right place is the after the source. */ | |
1415 | if (edge_in->flags & EDGE_FALLTHRU && edge_in->dest == EXIT_BLOCK_PTR) | |
1416 | { | |
1417 | before = NEXT_INSN (BB_END (edge_in->src)); | |
623a66fa | 1418 | bb = create_basic_block (before, NULL, edge_in->src); |
076c7ab8 | 1419 | BB_COPY_PARTITION (bb, edge_in->src); |
623a66fa R |
1420 | } |
1421 | else | |
9fb32434 CT |
1422 | { |
1423 | bb = create_basic_block (before, NULL, edge_in->dest->prev_bb); | |
076c7ab8 ZW |
1424 | /* ??? Why not edge_in->dest->prev_bb here? */ |
1425 | BB_COPY_PARTITION (bb, edge_in->dest); | |
9fb32434 | 1426 | } |
ca6c03ca | 1427 | |
4977bab6 | 1428 | make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU); |
ca6c03ca | 1429 | |
4d6922ee | 1430 | /* For non-fallthru edges, we must adjust the predecessor's |
ca6c03ca JH |
1431 | jump instruction to target our new block. */ |
1432 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1433 | { | |
341c100f NS |
1434 | edge redirected = redirect_edge_and_branch (edge_in, bb); |
1435 | gcc_assert (redirected); | |
ca6c03ca JH |
1436 | } |
1437 | else | |
3b5fda81 JJ |
1438 | { |
1439 | if (edge_in->src != ENTRY_BLOCK_PTR) | |
1440 | { | |
1441 | /* For asm goto even splitting of fallthru edge might | |
1442 | need insn patching, as other labels might point to the | |
1443 | old label. */ | |
1444 | rtx last = BB_END (edge_in->src); | |
1445 | if (last | |
1446 | && JUMP_P (last) | |
1447 | && edge_in->dest != EXIT_BLOCK_PTR | |
1448 | && extract_asm_operands (PATTERN (last)) != NULL_RTX | |
1449 | && patch_jump_insn (last, before, bb)) | |
1450 | df_set_bb_dirty (edge_in->src); | |
1451 | } | |
1452 | redirect_edge_succ (edge_in, bb); | |
1453 | } | |
ca6c03ca JH |
1454 | |
1455 | return bb; | |
1456 | } | |
1457 | ||
1458 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1459 | The new instructions and basic blocks (if any) will not appear in the | |
1460 | CFG until commit_edge_insertions is called. */ | |
1461 | ||
1462 | void | |
d329e058 | 1463 | insert_insn_on_edge (rtx pattern, edge e) |
ca6c03ca JH |
1464 | { |
1465 | /* We cannot insert instructions on an abnormal critical edge. | |
1466 | It will be easier to find the culprit if we die now. */ | |
341c100f | 1467 | gcc_assert (!((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e))); |
ca6c03ca | 1468 | |
6de9cd9a | 1469 | if (e->insns.r == NULL_RTX) |
ca6c03ca JH |
1470 | start_sequence (); |
1471 | else | |
6de9cd9a | 1472 | push_to_sequence (e->insns.r); |
ca6c03ca JH |
1473 | |
1474 | emit_insn (pattern); | |
1475 | ||
6de9cd9a | 1476 | e->insns.r = get_insns (); |
ca6c03ca JH |
1477 | end_sequence (); |
1478 | } | |
1479 | ||
1480 | /* Update the CFG for the instructions queued on edge E. */ | |
1481 | ||
4e3825db | 1482 | void |
2ac66157 | 1483 | commit_one_edge_insertion (edge e) |
ca6c03ca JH |
1484 | { |
1485 | rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last; | |
898c90c0 | 1486 | basic_block bb; |
ca6c03ca JH |
1487 | |
1488 | /* Pull the insns off the edge now since the edge might go away. */ | |
6de9cd9a DN |
1489 | insns = e->insns.r; |
1490 | e->insns.r = NULL_RTX; | |
ca6c03ca | 1491 | |
898c90c0 EB |
1492 | /* Figure out where to put these insns. If the destination has |
1493 | one predecessor, insert there. Except for the exit block. */ | |
1494 | if (single_pred_p (e->dest) && e->dest != EXIT_BLOCK_PTR) | |
ca6c03ca | 1495 | { |
898c90c0 EB |
1496 | bb = e->dest; |
1497 | ||
1498 | /* Get the location correct wrt a code label, and "nice" wrt | |
1499 | a basic block note, and before everything else. */ | |
1500 | tmp = BB_HEAD (bb); | |
1501 | if (LABEL_P (tmp)) | |
1502 | tmp = NEXT_INSN (tmp); | |
1503 | if (NOTE_INSN_BASIC_BLOCK_P (tmp)) | |
1504 | tmp = NEXT_INSN (tmp); | |
1505 | if (tmp == BB_HEAD (bb)) | |
1506 | before = tmp; | |
1507 | else if (tmp) | |
1508 | after = PREV_INSN (tmp); | |
1509 | else | |
1510 | after = get_last_insn (); | |
1511 | } | |
3dec4024 | 1512 | |
898c90c0 EB |
1513 | /* If the source has one successor and the edge is not abnormal, |
1514 | insert there. Except for the entry block. */ | |
1515 | else if ((e->flags & EDGE_ABNORMAL) == 0 | |
1516 | && single_succ_p (e->src) | |
1517 | && e->src != ENTRY_BLOCK_PTR) | |
1518 | { | |
1519 | bb = e->src; | |
3dec4024 | 1520 | |
898c90c0 EB |
1521 | /* It is possible to have a non-simple jump here. Consider a target |
1522 | where some forms of unconditional jumps clobber a register. This | |
1523 | happens on the fr30 for example. | |
ca6c03ca | 1524 | |
898c90c0 EB |
1525 | We know this block has a single successor, so we can just emit |
1526 | the queued insns before the jump. */ | |
1527 | if (JUMP_P (BB_END (bb))) | |
1528 | before = BB_END (bb); | |
3dec4024 JH |
1529 | else |
1530 | { | |
898c90c0 EB |
1531 | /* We'd better be fallthru, or we've lost track of what's what. */ |
1532 | gcc_assert (e->flags & EDGE_FALLTHRU); | |
750054a2 | 1533 | |
898c90c0 | 1534 | after = BB_END (bb); |
ca6c03ca JH |
1535 | } |
1536 | } | |
1537 | ||
898c90c0 EB |
1538 | /* Otherwise we must split the edge. */ |
1539 | else | |
1540 | { | |
1541 | bb = split_edge (e); | |
1542 | after = BB_END (bb); | |
ca6c03ca | 1543 | |
898c90c0 | 1544 | if (flag_reorder_blocks_and_partition |
677f3fa8 | 1545 | && targetm_common.have_named_sections |
898c90c0 EB |
1546 | && e->src != ENTRY_BLOCK_PTR |
1547 | && BB_PARTITION (e->src) == BB_COLD_PARTITION | |
1548 | && !(e->flags & EDGE_CROSSING) | |
1549 | && JUMP_P (after) | |
1550 | && !any_condjump_p (after) | |
1551 | && (single_succ_edge (bb)->flags & EDGE_CROSSING)) | |
1552 | add_reg_note (after, REG_CROSSING_JUMP, NULL_RTX); | |
1553 | } | |
1554 | ||
1555 | /* Now that we've found the spot, do the insertion. */ | |
ca6c03ca JH |
1556 | if (before) |
1557 | { | |
6fb5fa3c | 1558 | emit_insn_before_noloc (insns, before, bb); |
ca6c03ca JH |
1559 | last = prev_nonnote_insn (before); |
1560 | } | |
1561 | else | |
6fb5fa3c | 1562 | last = emit_insn_after_noloc (insns, after, bb); |
ca6c03ca JH |
1563 | |
1564 | if (returnjump_p (last)) | |
1565 | { | |
1566 | /* ??? Remove all outgoing edges from BB and add one for EXIT. | |
c22cacf3 MS |
1567 | This is not currently a problem because this only happens |
1568 | for the (single) epilogue, which already has a fallthru edge | |
1569 | to EXIT. */ | |
ca6c03ca | 1570 | |
c5cbcccf | 1571 | e = single_succ_edge (bb); |
341c100f | 1572 | gcc_assert (e->dest == EXIT_BLOCK_PTR |
c5cbcccf | 1573 | && single_succ_p (bb) && (e->flags & EDGE_FALLTHRU)); |
ca6c03ca | 1574 | |
5f0d2358 | 1575 | e->flags &= ~EDGE_FALLTHRU; |
ca6c03ca | 1576 | emit_barrier_after (last); |
0b17ab2f | 1577 | |
ca6c03ca JH |
1578 | if (before) |
1579 | delete_insn (before); | |
1580 | } | |
341c100f NS |
1581 | else |
1582 | gcc_assert (!JUMP_P (last)); | |
ca6c03ca JH |
1583 | } |
1584 | ||
1585 | /* Update the CFG for all queued instructions. */ | |
1586 | ||
1587 | void | |
d329e058 | 1588 | commit_edge_insertions (void) |
ca6c03ca | 1589 | { |
ca6c03ca JH |
1590 | basic_block bb; |
1591 | ||
1592 | #ifdef ENABLE_CHECKING | |
1593 | verify_flow_info (); | |
1594 | #endif | |
1595 | ||
e0082a72 | 1596 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
ca6c03ca | 1597 | { |
628f6a4e BE |
1598 | edge e; |
1599 | edge_iterator ei; | |
ca6c03ca | 1600 | |
628f6a4e BE |
1601 | FOR_EACH_EDGE (e, ei, bb->succs) |
1602 | if (e->insns.r) | |
cf103ca4 | 1603 | commit_one_edge_insertion (e); |
3dec4024 | 1604 | } |
ca6c03ca JH |
1605 | } |
1606 | \f | |
6fb5fa3c | 1607 | |
f470c378 ZD |
1608 | /* Print out RTL-specific basic block information (live information |
1609 | at start and end). */ | |
ca6c03ca | 1610 | |
10e9fecc | 1611 | static void |
726a989a | 1612 | rtl_dump_bb (basic_block bb, FILE *outf, int indent, int flags ATTRIBUTE_UNUSED) |
ca6c03ca JH |
1613 | { |
1614 | rtx insn; | |
1615 | rtx last; | |
f470c378 | 1616 | char *s_indent; |
ca6c03ca | 1617 | |
ae50c0cb | 1618 | s_indent = (char *) alloca ((size_t) indent + 1); |
400e39e3 | 1619 | memset (s_indent, ' ', (size_t) indent); |
f470c378 | 1620 | s_indent[indent] = '\0'; |
b8698a0f | 1621 | |
6fb5fa3c DB |
1622 | if (df) |
1623 | { | |
1624 | df_dump_top (bb, outf); | |
1625 | putc ('\n', outf); | |
1626 | } | |
ca6c03ca | 1627 | |
a813c111 | 1628 | for (insn = BB_HEAD (bb), last = NEXT_INSN (BB_END (bb)); insn != last; |
ca6c03ca JH |
1629 | insn = NEXT_INSN (insn)) |
1630 | print_rtl_single (outf, insn); | |
1631 | ||
6fb5fa3c DB |
1632 | if (df) |
1633 | { | |
1634 | df_dump_bottom (bb, outf); | |
1635 | putc ('\n', outf); | |
1636 | } | |
1637 | ||
ca6c03ca JH |
1638 | } |
1639 | \f | |
1640 | /* Like print_rtl, but also print out live information for the start of each | |
1641 | basic block. */ | |
1642 | ||
1643 | void | |
22ea9ec0 | 1644 | print_rtl_with_bb (FILE *outf, const_rtx rtx_first) |
ca6c03ca | 1645 | { |
22ea9ec0 | 1646 | const_rtx tmp_rtx; |
ca6c03ca JH |
1647 | if (rtx_first == 0) |
1648 | fprintf (outf, "(nil)\n"); | |
1649 | else | |
1650 | { | |
ca6c03ca JH |
1651 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
1652 | int max_uid = get_max_uid (); | |
5ed6ace5 MD |
1653 | basic_block *start = XCNEWVEC (basic_block, max_uid); |
1654 | basic_block *end = XCNEWVEC (basic_block, max_uid); | |
1655 | enum bb_state *in_bb_p = XCNEWVEC (enum bb_state, max_uid); | |
ca6c03ca | 1656 | |
e0082a72 ZD |
1657 | basic_block bb; |
1658 | ||
6fb5fa3c DB |
1659 | if (df) |
1660 | df_dump_start (outf); | |
1661 | ||
e0082a72 | 1662 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1663 | { |
ca6c03ca JH |
1664 | rtx x; |
1665 | ||
a813c111 SB |
1666 | start[INSN_UID (BB_HEAD (bb))] = bb; |
1667 | end[INSN_UID (BB_END (bb))] = bb; | |
1668 | for (x = BB_HEAD (bb); x != NULL_RTX; x = NEXT_INSN (x)) | |
ca6c03ca JH |
1669 | { |
1670 | enum bb_state state = IN_MULTIPLE_BB; | |
5f0d2358 | 1671 | |
ca6c03ca JH |
1672 | if (in_bb_p[INSN_UID (x)] == NOT_IN_BB) |
1673 | state = IN_ONE_BB; | |
1674 | in_bb_p[INSN_UID (x)] = state; | |
1675 | ||
a813c111 | 1676 | if (x == BB_END (bb)) |
ca6c03ca JH |
1677 | break; |
1678 | } | |
1679 | } | |
1680 | ||
1681 | for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) | |
1682 | { | |
1683 | int did_output; | |
6fb5fa3c | 1684 | |
510a442a RH |
1685 | bb = start[INSN_UID (tmp_rtx)]; |
1686 | if (bb != NULL) | |
1687 | dump_bb_info (bb, true, false, dump_flags, ";; ", outf); | |
ca6c03ca JH |
1688 | |
1689 | if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB | |
4b4bf941 JQ |
1690 | && !NOTE_P (tmp_rtx) |
1691 | && !BARRIER_P (tmp_rtx)) | |
ca6c03ca JH |
1692 | fprintf (outf, ";; Insn is not within a basic block\n"); |
1693 | else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB) | |
1694 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); | |
1695 | ||
1696 | did_output = print_rtl_single (outf, tmp_rtx); | |
1697 | ||
510a442a RH |
1698 | bb = end[INSN_UID (tmp_rtx)]; |
1699 | if (bb != NULL) | |
1700 | dump_bb_info (bb, false, true, dump_flags, ";; ", outf); | |
ca6c03ca JH |
1701 | if (did_output) |
1702 | putc ('\n', outf); | |
1703 | } | |
1704 | ||
1705 | free (start); | |
1706 | free (end); | |
1707 | free (in_bb_p); | |
1708 | } | |
1709 | ||
cb91fab0 | 1710 | if (crtl->epilogue_delay_list != 0) |
ca6c03ca JH |
1711 | { |
1712 | fprintf (outf, "\n;; Insns in epilogue delay list:\n\n"); | |
cb91fab0 | 1713 | for (tmp_rtx = crtl->epilogue_delay_list; tmp_rtx != 0; |
ca6c03ca JH |
1714 | tmp_rtx = XEXP (tmp_rtx, 1)) |
1715 | print_rtl_single (outf, XEXP (tmp_rtx, 0)); | |
1716 | } | |
1717 | } | |
1718 | \f | |
b446e5a2 | 1719 | void |
d329e058 | 1720 | update_br_prob_note (basic_block bb) |
b446e5a2 JH |
1721 | { |
1722 | rtx note; | |
4b4bf941 | 1723 | if (!JUMP_P (BB_END (bb))) |
b446e5a2 | 1724 | return; |
a813c111 | 1725 | note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX); |
b446e5a2 JH |
1726 | if (!note || INTVAL (XEXP (note, 0)) == BRANCH_EDGE (bb)->probability) |
1727 | return; | |
1728 | XEXP (note, 0) = GEN_INT (BRANCH_EDGE (bb)->probability); | |
1729 | } | |
96370780 MK |
1730 | |
1731 | /* Get the last insn associated with block BB (that includes barriers and | |
1732 | tablejumps after BB). */ | |
1733 | rtx | |
1734 | get_last_bb_insn (basic_block bb) | |
1735 | { | |
1736 | rtx tmp; | |
1737 | rtx end = BB_END (bb); | |
1738 | ||
1739 | /* Include any jump table following the basic block. */ | |
1740 | if (tablejump_p (end, NULL, &tmp)) | |
1741 | end = tmp; | |
1742 | ||
1743 | /* Include any barriers that may follow the basic block. */ | |
1e211590 | 1744 | tmp = next_nonnote_insn_bb (end); |
96370780 MK |
1745 | while (tmp && BARRIER_P (tmp)) |
1746 | { | |
1747 | end = tmp; | |
1e211590 | 1748 | tmp = next_nonnote_insn_bb (end); |
96370780 MK |
1749 | } |
1750 | ||
1751 | return end; | |
1752 | } | |
b446e5a2 | 1753 | \f |
10e9fecc JH |
1754 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
1755 | cfglayout RTL. | |
ca6c03ca JH |
1756 | |
1757 | Currently it does following checks: | |
1758 | ||
ca6c03ca | 1759 | - overlapping of basic blocks |
9eab6785 | 1760 | - insns with wrong BLOCK_FOR_INSN pointers |
ca6c03ca | 1761 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) |
f63d1bf7 | 1762 | - tails of basic blocks (ensure that boundary is necessary) |
ca6c03ca JH |
1763 | - scans body of the basic block for JUMP_INSN, CODE_LABEL |
1764 | and NOTE_INSN_BASIC_BLOCK | |
750054a2 | 1765 | - verify that no fall_thru edge crosses hot/cold partition boundaries |
9eab6785 | 1766 | - verify that there are no pending RTL branch predictions |
ca6c03ca JH |
1767 | |
1768 | In future it can be extended check a lot of other stuff as well | |
1769 | (reachability of basic blocks, life information, etc. etc.). */ | |
f470c378 | 1770 | |
10e9fecc | 1771 | static int |
d329e058 | 1772 | rtl_verify_flow_info_1 (void) |
ca6c03ca | 1773 | { |
ca6c03ca | 1774 | rtx x; |
10e9fecc | 1775 | int err = 0; |
94eb5ddb | 1776 | basic_block bb; |
ca6c03ca | 1777 | |
9eab6785 | 1778 | /* Check the general integrity of the basic blocks. */ |
e0082a72 | 1779 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1780 | { |
9eab6785 | 1781 | rtx insn; |
5f0d2358 | 1782 | |
5e2d947c JH |
1783 | if (!(bb->flags & BB_RTL)) |
1784 | { | |
1785 | error ("BB_RTL flag not set for block %d", bb->index); | |
1786 | err = 1; | |
1787 | } | |
1788 | ||
9eab6785 | 1789 | FOR_BB_INSNS (bb, insn) |
8ce9fd5d | 1790 | if (BLOCK_FOR_INSN (insn) != bb) |
9eab6785 SB |
1791 | { |
1792 | error ("insn %d basic block pointer is %d, should be %d", | |
1793 | INSN_UID (insn), | |
1794 | BLOCK_FOR_INSN (insn) ? BLOCK_FOR_INSN (insn)->index : 0, | |
1795 | bb->index); | |
1796 | err = 1; | |
1797 | } | |
a7b87f73 ZD |
1798 | |
1799 | for (insn = bb->il.rtl->header; insn; insn = NEXT_INSN (insn)) | |
1800 | if (!BARRIER_P (insn) | |
1801 | && BLOCK_FOR_INSN (insn) != NULL) | |
1802 | { | |
1803 | error ("insn %d in header of bb %d has non-NULL basic block", | |
1804 | INSN_UID (insn), bb->index); | |
1805 | err = 1; | |
1806 | } | |
1807 | for (insn = bb->il.rtl->footer; insn; insn = NEXT_INSN (insn)) | |
1808 | if (!BARRIER_P (insn) | |
1809 | && BLOCK_FOR_INSN (insn) != NULL) | |
1810 | { | |
1811 | error ("insn %d in footer of bb %d has non-NULL basic block", | |
1812 | INSN_UID (insn), bb->index); | |
1813 | err = 1; | |
1814 | } | |
ca6c03ca JH |
1815 | } |
1816 | ||
1817 | /* Now check the basic blocks (boundaries etc.) */ | |
e0082a72 | 1818 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1819 | { |
3dec4024 | 1820 | int n_fallthru = 0, n_eh = 0, n_call = 0, n_abnormal = 0, n_branch = 0; |
3cf54412 | 1821 | edge e, fallthru = NULL; |
5a1a3e5e | 1822 | rtx note; |
628f6a4e | 1823 | edge_iterator ei; |
ca6c03ca | 1824 | |
2085a21f | 1825 | if (JUMP_P (BB_END (bb)) |
a813c111 | 1826 | && (note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX)) |
628f6a4e | 1827 | && EDGE_COUNT (bb->succs) >= 2 |
a813c111 | 1828 | && any_condjump_p (BB_END (bb))) |
5a1a3e5e | 1829 | { |
e53de54d JH |
1830 | if (INTVAL (XEXP (note, 0)) != BRANCH_EDGE (bb)->probability |
1831 | && profile_status != PROFILE_ABSENT) | |
5a1a3e5e | 1832 | { |
0108ae51 | 1833 | error ("verify_flow_info: REG_BR_PROB does not match cfg %wi %i", |
5a1a3e5e JH |
1834 | INTVAL (XEXP (note, 0)), BRANCH_EDGE (bb)->probability); |
1835 | err = 1; | |
1836 | } | |
1837 | } | |
628f6a4e | 1838 | FOR_EACH_EDGE (e, ei, bb->succs) |
ca6c03ca | 1839 | { |
0be7e7a6 RH |
1840 | bool is_crossing; |
1841 | ||
ca6c03ca | 1842 | if (e->flags & EDGE_FALLTHRU) |
0be7e7a6 RH |
1843 | n_fallthru++, fallthru = e; |
1844 | ||
1845 | is_crossing = (BB_PARTITION (e->src) != BB_PARTITION (e->dest) | |
1846 | && e->src != ENTRY_BLOCK_PTR | |
1847 | && e->dest != EXIT_BLOCK_PTR); | |
1848 | if (e->flags & EDGE_CROSSING) | |
750054a2 | 1849 | { |
0be7e7a6 RH |
1850 | if (!is_crossing) |
1851 | { | |
1852 | error ("EDGE_CROSSING incorrectly set across same section"); | |
1853 | err = 1; | |
1854 | } | |
1855 | if (e->flags & EDGE_FALLTHRU) | |
1856 | { | |
ab532386 | 1857 | error ("fallthru edge crosses section boundary (bb %i)", |
750054a2 CT |
1858 | e->src->index); |
1859 | err = 1; | |
1860 | } | |
0be7e7a6 RH |
1861 | if (e->flags & EDGE_EH) |
1862 | { | |
1863 | error ("EH edge crosses section boundary (bb %i)", | |
1864 | e->src->index); | |
1865 | err = 1; | |
1866 | } | |
1867 | } | |
1868 | else if (is_crossing) | |
1869 | { | |
1870 | error ("EDGE_CROSSING missing across section boundary"); | |
1871 | err = 1; | |
750054a2 | 1872 | } |
3dec4024 | 1873 | |
65f43cdf ZD |
1874 | if ((e->flags & ~(EDGE_DFS_BACK |
1875 | | EDGE_CAN_FALLTHRU | |
1876 | | EDGE_IRREDUCIBLE_LOOP | |
9beb1c84 CT |
1877 | | EDGE_LOOP_EXIT |
1878 | | EDGE_CROSSING)) == 0) | |
3dec4024 JH |
1879 | n_branch++; |
1880 | ||
1881 | if (e->flags & EDGE_ABNORMAL_CALL) | |
1882 | n_call++; | |
1883 | ||
1884 | if (e->flags & EDGE_EH) | |
1885 | n_eh++; | |
1886 | else if (e->flags & EDGE_ABNORMAL) | |
1887 | n_abnormal++; | |
ca6c03ca | 1888 | } |
5f0d2358 | 1889 | |
1d65f45c | 1890 | if (n_eh && !find_reg_note (BB_END (bb), REG_EH_REGION, NULL_RTX)) |
3dec4024 | 1891 | { |
ab532386 | 1892 | error ("missing REG_EH_REGION note in the end of bb %i", bb->index); |
3dec4024 JH |
1893 | err = 1; |
1894 | } | |
1d65f45c RH |
1895 | if (n_eh > 1) |
1896 | { | |
1897 | error ("too many eh edges %i", bb->index); | |
1898 | err = 1; | |
1899 | } | |
3dec4024 | 1900 | if (n_branch |
4b4bf941 | 1901 | && (!JUMP_P (BB_END (bb)) |
a813c111 SB |
1902 | || (n_branch > 1 && (any_uncondjump_p (BB_END (bb)) |
1903 | || any_condjump_p (BB_END (bb)))))) | |
3dec4024 | 1904 | { |
ab532386 | 1905 | error ("too many outgoing branch edges from bb %i", bb->index); |
3dec4024 JH |
1906 | err = 1; |
1907 | } | |
a813c111 | 1908 | if (n_fallthru && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 1909 | { |
ab532386 | 1910 | error ("fallthru edge after unconditional jump %i", bb->index); |
3dec4024 JH |
1911 | err = 1; |
1912 | } | |
a813c111 | 1913 | if (n_branch != 1 && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 1914 | { |
1d65f45c RH |
1915 | error ("wrong number of branch edges after unconditional jump %i", |
1916 | bb->index); | |
3dec4024 JH |
1917 | err = 1; |
1918 | } | |
a813c111 | 1919 | if (n_branch != 1 && any_condjump_p (BB_END (bb)) |
c11fd0b2 | 1920 | && JUMP_LABEL (BB_END (bb)) != BB_HEAD (fallthru->dest)) |
3dec4024 | 1921 | { |
c11fd0b2 RG |
1922 | error ("wrong amount of branch edges after conditional jump %i", |
1923 | bb->index); | |
3dec4024 JH |
1924 | err = 1; |
1925 | } | |
4b4bf941 | 1926 | if (n_call && !CALL_P (BB_END (bb))) |
3dec4024 | 1927 | { |
ab532386 | 1928 | error ("call edges for non-call insn in bb %i", bb->index); |
3dec4024 JH |
1929 | err = 1; |
1930 | } | |
1931 | if (n_abnormal | |
4b4bf941 JQ |
1932 | && (!CALL_P (BB_END (bb)) && n_call != n_abnormal) |
1933 | && (!JUMP_P (BB_END (bb)) | |
a813c111 SB |
1934 | || any_condjump_p (BB_END (bb)) |
1935 | || any_uncondjump_p (BB_END (bb)))) | |
3dec4024 | 1936 | { |
ab532386 | 1937 | error ("abnormal edges for no purpose in bb %i", bb->index); |
3dec4024 JH |
1938 | err = 1; |
1939 | } | |
f87c27b4 | 1940 | |
a813c111 | 1941 | for (x = BB_HEAD (bb); x != NEXT_INSN (BB_END (bb)); x = NEXT_INSN (x)) |
0ca541aa | 1942 | /* We may have a barrier inside a basic block before dead code |
9524880c HPN |
1943 | elimination. There is no BLOCK_FOR_INSN field in a barrier. */ |
1944 | if (!BARRIER_P (x) && BLOCK_FOR_INSN (x) != bb) | |
5f0d2358 RK |
1945 | { |
1946 | debug_rtx (x); | |
1947 | if (! BLOCK_FOR_INSN (x)) | |
1948 | error | |
1949 | ("insn %d inside basic block %d but block_for_insn is NULL", | |
0b17ab2f | 1950 | INSN_UID (x), bb->index); |
5f0d2358 RK |
1951 | else |
1952 | error | |
1953 | ("insn %d inside basic block %d but block_for_insn is %i", | |
0b17ab2f | 1954 | INSN_UID (x), bb->index, BLOCK_FOR_INSN (x)->index); |
5f0d2358 RK |
1955 | |
1956 | err = 1; | |
1957 | } | |
ca6c03ca JH |
1958 | |
1959 | /* OK pointers are correct. Now check the header of basic | |
c22cacf3 | 1960 | block. It ought to contain optional CODE_LABEL followed |
ca6c03ca | 1961 | by NOTE_BASIC_BLOCK. */ |
a813c111 | 1962 | x = BB_HEAD (bb); |
4b4bf941 | 1963 | if (LABEL_P (x)) |
ca6c03ca | 1964 | { |
a813c111 | 1965 | if (BB_END (bb) == x) |
ca6c03ca JH |
1966 | { |
1967 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 1968 | bb->index); |
ca6c03ca JH |
1969 | err = 1; |
1970 | } | |
5f0d2358 | 1971 | |
ca6c03ca JH |
1972 | x = NEXT_INSN (x); |
1973 | } | |
5f0d2358 | 1974 | |
ca6c03ca JH |
1975 | if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb) |
1976 | { | |
1977 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 1978 | bb->index); |
ca6c03ca JH |
1979 | err = 1; |
1980 | } | |
1981 | ||
a813c111 | 1982 | if (BB_END (bb) == x) |
49243025 | 1983 | /* Do checks for empty blocks here. */ |
5f0d2358 | 1984 | ; |
ca6c03ca | 1985 | else |
5f0d2358 RK |
1986 | for (x = NEXT_INSN (x); x; x = NEXT_INSN (x)) |
1987 | { | |
1988 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
1989 | { | |
1990 | error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d", | |
0b17ab2f | 1991 | INSN_UID (x), bb->index); |
5f0d2358 RK |
1992 | err = 1; |
1993 | } | |
1994 | ||
a813c111 | 1995 | if (x == BB_END (bb)) |
5f0d2358 | 1996 | break; |
ca6c03ca | 1997 | |
83fd323c | 1998 | if (control_flow_insn_p (x)) |
5f0d2358 | 1999 | { |
0b17ab2f | 2000 | error ("in basic block %d:", bb->index); |
5f0d2358 RK |
2001 | fatal_insn ("flow control insn inside a basic block", x); |
2002 | } | |
2003 | } | |
ca6c03ca JH |
2004 | } |
2005 | ||
10e9fecc | 2006 | /* Clean up. */ |
10e9fecc JH |
2007 | return err; |
2008 | } | |
5f0d2358 | 2009 | |
10e9fecc JH |
2010 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
2011 | cfglayout RTL. | |
5f0d2358 | 2012 | |
10e9fecc JH |
2013 | Currently it does following checks: |
2014 | - all checks of rtl_verify_flow_info_1 | |
9eab6785 | 2015 | - test head/end pointers |
10e9fecc JH |
2016 | - check that all insns are in the basic blocks |
2017 | (except the switch handling code, barriers and notes) | |
2018 | - check that all returns are followed by barriers | |
2019 | - check that all fallthru edge points to the adjacent blocks. */ | |
9eab6785 | 2020 | |
10e9fecc | 2021 | static int |
d329e058 | 2022 | rtl_verify_flow_info (void) |
10e9fecc JH |
2023 | { |
2024 | basic_block bb; | |
2025 | int err = rtl_verify_flow_info_1 (); | |
2026 | rtx x; | |
9eab6785 SB |
2027 | rtx last_head = get_last_insn (); |
2028 | basic_block *bb_info; | |
10e9fecc JH |
2029 | int num_bb_notes; |
2030 | const rtx rtx_first = get_insns (); | |
2031 | basic_block last_bb_seen = ENTRY_BLOCK_PTR, curr_bb = NULL; | |
9eab6785 SB |
2032 | const int max_uid = get_max_uid (); |
2033 | ||
2034 | bb_info = XCNEWVEC (basic_block, max_uid); | |
ca6c03ca | 2035 | |
10e9fecc JH |
2036 | FOR_EACH_BB_REVERSE (bb) |
2037 | { | |
2038 | edge e; | |
9eab6785 SB |
2039 | rtx head = BB_HEAD (bb); |
2040 | rtx end = BB_END (bb); | |
628f6a4e | 2041 | |
9eab6785 | 2042 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) |
a7b87f73 ZD |
2043 | { |
2044 | /* Verify the end of the basic block is in the INSN chain. */ | |
2045 | if (x == end) | |
2046 | break; | |
2047 | ||
2048 | /* And that the code outside of basic blocks has NULL bb field. */ | |
2049 | if (!BARRIER_P (x) | |
2050 | && BLOCK_FOR_INSN (x) != NULL) | |
2051 | { | |
2052 | error ("insn %d outside of basic blocks has non-NULL bb field", | |
2053 | INSN_UID (x)); | |
2054 | err = 1; | |
2055 | } | |
2056 | } | |
9eab6785 SB |
2057 | |
2058 | if (!x) | |
2059 | { | |
2060 | error ("end insn %d for block %d not found in the insn stream", | |
2061 | INSN_UID (end), bb->index); | |
2062 | err = 1; | |
2063 | } | |
2064 | ||
2065 | /* Work backwards from the end to the head of the basic block | |
2066 | to verify the head is in the RTL chain. */ | |
2067 | for (; x != NULL_RTX; x = PREV_INSN (x)) | |
a00d11f0 | 2068 | { |
9eab6785 SB |
2069 | /* While walking over the insn chain, verify insns appear |
2070 | in only one basic block. */ | |
2071 | if (bb_info[INSN_UID (x)] != NULL) | |
2072 | { | |
2073 | error ("insn %d is in multiple basic blocks (%d and %d)", | |
2074 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); | |
2075 | err = 1; | |
2076 | } | |
2077 | ||
2078 | bb_info[INSN_UID (x)] = bb; | |
2079 | ||
2080 | if (x == head) | |
2081 | break; | |
2082 | } | |
2083 | if (!x) | |
2084 | { | |
2085 | error ("head insn %d for block %d not found in the insn stream", | |
2086 | INSN_UID (head), bb->index); | |
a00d11f0 JH |
2087 | err = 1; |
2088 | } | |
2089 | ||
a7b87f73 | 2090 | last_head = PREV_INSN (x); |
9eab6785 | 2091 | |
0fd4b31d | 2092 | e = find_fallthru_edge (bb->succs); |
10e9fecc JH |
2093 | if (!e) |
2094 | { | |
2095 | rtx insn; | |
2096 | ||
2097 | /* Ensure existence of barrier in BB with no fallthru edges. */ | |
468059bc DD |
2098 | for (insn = NEXT_INSN (BB_END (bb)); ; insn = NEXT_INSN (insn)) |
2099 | { | |
2100 | if (!insn || NOTE_INSN_BASIC_BLOCK_P (insn)) | |
10e9fecc JH |
2101 | { |
2102 | error ("missing barrier after block %i", bb->index); | |
2103 | err = 1; | |
2104 | break; | |
2105 | } | |
468059bc DD |
2106 | if (BARRIER_P (insn)) |
2107 | break; | |
2108 | } | |
10e9fecc JH |
2109 | } |
2110 | else if (e->src != ENTRY_BLOCK_PTR | |
2111 | && e->dest != EXIT_BLOCK_PTR) | |
c22cacf3 | 2112 | { |
10e9fecc JH |
2113 | rtx insn; |
2114 | ||
2115 | if (e->src->next_bb != e->dest) | |
2116 | { | |
2117 | error | |
2118 | ("verify_flow_info: Incorrect blocks for fallthru %i->%i", | |
2119 | e->src->index, e->dest->index); | |
2120 | err = 1; | |
2121 | } | |
2122 | else | |
a813c111 | 2123 | for (insn = NEXT_INSN (BB_END (e->src)); insn != BB_HEAD (e->dest); |
10e9fecc | 2124 | insn = NEXT_INSN (insn)) |
6be85b25 | 2125 | if (BARRIER_P (insn) || INSN_P (insn)) |
10e9fecc JH |
2126 | { |
2127 | error ("verify_flow_info: Incorrect fallthru %i->%i", | |
2128 | e->src->index, e->dest->index); | |
2129 | fatal_insn ("wrong insn in the fallthru edge", insn); | |
2130 | err = 1; | |
2131 | } | |
c22cacf3 | 2132 | } |
10e9fecc | 2133 | } |
ca6c03ca | 2134 | |
a7b87f73 ZD |
2135 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) |
2136 | { | |
2137 | /* Check that the code before the first basic block has NULL | |
2138 | bb field. */ | |
2139 | if (!BARRIER_P (x) | |
2140 | && BLOCK_FOR_INSN (x) != NULL) | |
2141 | { | |
2142 | error ("insn %d outside of basic blocks has non-NULL bb field", | |
2143 | INSN_UID (x)); | |
2144 | err = 1; | |
2145 | } | |
2146 | } | |
9eab6785 SB |
2147 | free (bb_info); |
2148 | ||
ca6c03ca | 2149 | num_bb_notes = 0; |
e0082a72 ZD |
2150 | last_bb_seen = ENTRY_BLOCK_PTR; |
2151 | ||
5f0d2358 | 2152 | for (x = rtx_first; x; x = NEXT_INSN (x)) |
ca6c03ca JH |
2153 | { |
2154 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2155 | { | |
bf77398c | 2156 | bb = NOTE_BASIC_BLOCK (x); |
5f0d2358 | 2157 | |
ca6c03ca | 2158 | num_bb_notes++; |
e0082a72 | 2159 | if (bb != last_bb_seen->next_bb) |
10e9fecc | 2160 | internal_error ("basic blocks not laid down consecutively"); |
ca6c03ca | 2161 | |
10e9fecc | 2162 | curr_bb = last_bb_seen = bb; |
ca6c03ca JH |
2163 | } |
2164 | ||
10e9fecc | 2165 | if (!curr_bb) |
ca6c03ca JH |
2166 | { |
2167 | switch (GET_CODE (x)) | |
2168 | { | |
2169 | case BARRIER: | |
2170 | case NOTE: | |
2171 | break; | |
2172 | ||
2173 | case CODE_LABEL: | |
666c27b9 | 2174 | /* An addr_vec is placed outside any basic block. */ |
ca6c03ca | 2175 | if (NEXT_INSN (x) |
481683e1 | 2176 | && JUMP_TABLE_DATA_P (NEXT_INSN (x))) |
5f0d2358 | 2177 | x = NEXT_INSN (x); |
ca6c03ca JH |
2178 | |
2179 | /* But in any case, non-deletable labels can appear anywhere. */ | |
2180 | break; | |
2181 | ||
2182 | default: | |
1f978f5f | 2183 | fatal_insn ("insn outside basic block", x); |
ca6c03ca JH |
2184 | } |
2185 | } | |
2186 | ||
26cae194 | 2187 | if (JUMP_P (x) |
ca6c03ca | 2188 | && returnjump_p (x) && ! condjump_p (x) |
15eb3a2e | 2189 | && ! (next_nonnote_insn (x) && BARRIER_P (next_nonnote_insn (x)))) |
1f978f5f | 2190 | fatal_insn ("return not followed by barrier", x); |
a813c111 | 2191 | if (curr_bb && x == BB_END (curr_bb)) |
10e9fecc | 2192 | curr_bb = NULL; |
ca6c03ca JH |
2193 | } |
2194 | ||
24bd1a0b | 2195 | if (num_bb_notes != n_basic_blocks - NUM_FIXED_BLOCKS) |
ca6c03ca | 2196 | internal_error |
0b17ab2f RH |
2197 | ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)", |
2198 | num_bb_notes, n_basic_blocks); | |
ca6c03ca | 2199 | |
10e9fecc | 2200 | return err; |
ca6c03ca JH |
2201 | } |
2202 | \f | |
eaec9b3d | 2203 | /* Assume that the preceding pass has possibly eliminated jump instructions |
ca6c03ca JH |
2204 | or converted the unconditional jumps. Eliminate the edges from CFG. |
2205 | Return true if any edges are eliminated. */ | |
2206 | ||
2207 | bool | |
d329e058 | 2208 | purge_dead_edges (basic_block bb) |
ca6c03ca | 2209 | { |
628f6a4e | 2210 | edge e; |
a813c111 | 2211 | rtx insn = BB_END (bb), note; |
ca6c03ca | 2212 | bool purged = false; |
628f6a4e BE |
2213 | bool found; |
2214 | edge_iterator ei; | |
ca6c03ca | 2215 | |
b5b8b0ac AO |
2216 | if (DEBUG_INSN_P (insn) && insn != BB_HEAD (bb)) |
2217 | do | |
2218 | insn = PREV_INSN (insn); | |
2219 | while ((DEBUG_INSN_P (insn) || NOTE_P (insn)) && insn != BB_HEAD (bb)); | |
2220 | ||
70da1d03 | 2221 | /* If this instruction cannot trap, remove REG_EH_REGION notes. */ |
4b4bf941 | 2222 | if (NONJUMP_INSN_P (insn) |
70da1d03 JH |
2223 | && (note = find_reg_note (insn, REG_EH_REGION, NULL))) |
2224 | { | |
2225 | rtx eqnote; | |
2226 | ||
2227 | if (! may_trap_p (PATTERN (insn)) | |
2228 | || ((eqnote = find_reg_equal_equiv_note (insn)) | |
2229 | && ! may_trap_p (XEXP (eqnote, 0)))) | |
2230 | remove_note (insn, note); | |
2231 | } | |
2232 | ||
546c093e | 2233 | /* Cleanup abnormal edges caused by exceptions or non-local gotos. */ |
628f6a4e | 2234 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
546c093e | 2235 | { |
1d65f45c RH |
2236 | bool remove = false; |
2237 | ||
e5f9a909 JW |
2238 | /* There are three types of edges we need to handle correctly here: EH |
2239 | edges, abnormal call EH edges, and abnormal call non-EH edges. The | |
2240 | latter can appear when nonlocal gotos are used. */ | |
1d65f45c | 2241 | if (e->flags & EDGE_ABNORMAL_CALL) |
546c093e | 2242 | { |
1d65f45c RH |
2243 | if (!CALL_P (insn)) |
2244 | remove = true; | |
2245 | else if (can_nonlocal_goto (insn)) | |
2246 | ; | |
2247 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) | |
2248 | ; | |
0a35513e AH |
2249 | else if (flag_tm && find_reg_note (insn, REG_TM, NULL)) |
2250 | ; | |
1d65f45c RH |
2251 | else |
2252 | remove = true; | |
546c093e | 2253 | } |
1d65f45c RH |
2254 | else if (e->flags & EDGE_EH) |
2255 | remove = !can_throw_internal (insn); | |
2256 | ||
2257 | if (remove) | |
546c093e | 2258 | { |
1d65f45c RH |
2259 | remove_edge (e); |
2260 | df_set_bb_dirty (bb); | |
2261 | purged = true; | |
546c093e RH |
2262 | } |
2263 | else | |
1d65f45c | 2264 | ei_next (&ei); |
546c093e | 2265 | } |
5f0d2358 | 2266 | |
4b4bf941 | 2267 | if (JUMP_P (insn)) |
ca6c03ca JH |
2268 | { |
2269 | rtx note; | |
2270 | edge b,f; | |
628f6a4e | 2271 | edge_iterator ei; |
5f0d2358 | 2272 | |
ca6c03ca JH |
2273 | /* We do care only about conditional jumps and simplejumps. */ |
2274 | if (!any_condjump_p (insn) | |
2275 | && !returnjump_p (insn) | |
2276 | && !simplejump_p (insn)) | |
c51d95ec | 2277 | return purged; |
5f0d2358 | 2278 | |
5a1a3e5e JH |
2279 | /* Branch probability/prediction notes are defined only for |
2280 | condjumps. We've possibly turned condjump into simplejump. */ | |
2281 | if (simplejump_p (insn)) | |
2282 | { | |
2283 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2284 | if (note) | |
2285 | remove_note (insn, note); | |
2286 | while ((note = find_reg_note (insn, REG_BR_PRED, NULL))) | |
2287 | remove_note (insn, note); | |
2288 | } | |
2289 | ||
628f6a4e | 2290 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
ca6c03ca | 2291 | { |
7fcd7218 JH |
2292 | /* Avoid abnormal flags to leak from computed jumps turned |
2293 | into simplejumps. */ | |
f87c27b4 | 2294 | |
0e1638d4 | 2295 | e->flags &= ~EDGE_ABNORMAL; |
7fcd7218 | 2296 | |
5a566bed MM |
2297 | /* See if this edge is one we should keep. */ |
2298 | if ((e->flags & EDGE_FALLTHRU) && any_condjump_p (insn)) | |
2299 | /* A conditional jump can fall through into the next | |
2300 | block, so we should keep the edge. */ | |
628f6a4e BE |
2301 | { |
2302 | ei_next (&ei); | |
2303 | continue; | |
2304 | } | |
5f0d2358 | 2305 | else if (e->dest != EXIT_BLOCK_PTR |
a813c111 | 2306 | && BB_HEAD (e->dest) == JUMP_LABEL (insn)) |
5a566bed MM |
2307 | /* If the destination block is the target of the jump, |
2308 | keep the edge. */ | |
628f6a4e BE |
2309 | { |
2310 | ei_next (&ei); | |
2311 | continue; | |
2312 | } | |
5a566bed MM |
2313 | else if (e->dest == EXIT_BLOCK_PTR && returnjump_p (insn)) |
2314 | /* If the destination block is the exit block, and this | |
2315 | instruction is a return, then keep the edge. */ | |
628f6a4e BE |
2316 | { |
2317 | ei_next (&ei); | |
2318 | continue; | |
2319 | } | |
5a566bed MM |
2320 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) |
2321 | /* Keep the edges that correspond to exceptions thrown by | |
0b75beaa EB |
2322 | this instruction and rematerialize the EDGE_ABNORMAL |
2323 | flag we just cleared above. */ | |
2324 | { | |
2325 | e->flags |= EDGE_ABNORMAL; | |
628f6a4e | 2326 | ei_next (&ei); |
0b75beaa EB |
2327 | continue; |
2328 | } | |
5f0d2358 | 2329 | |
5a566bed | 2330 | /* We do not need this edge. */ |
6fb5fa3c | 2331 | df_set_bb_dirty (bb); |
ca6c03ca JH |
2332 | purged = true; |
2333 | remove_edge (e); | |
2334 | } | |
5f0d2358 | 2335 | |
628f6a4e | 2336 | if (EDGE_COUNT (bb->succs) == 0 || !purged) |
c51d95ec | 2337 | return purged; |
5f0d2358 | 2338 | |
c263766c RH |
2339 | if (dump_file) |
2340 | fprintf (dump_file, "Purged edges from bb %i\n", bb->index); | |
5f0d2358 | 2341 | |
ca6c03ca JH |
2342 | if (!optimize) |
2343 | return purged; | |
2344 | ||
2345 | /* Redistribute probabilities. */ | |
c5cbcccf | 2346 | if (single_succ_p (bb)) |
ca6c03ca | 2347 | { |
c5cbcccf ZD |
2348 | single_succ_edge (bb)->probability = REG_BR_PROB_BASE; |
2349 | single_succ_edge (bb)->count = bb->count; | |
f87c27b4 | 2350 | } |
ca6c03ca JH |
2351 | else |
2352 | { | |
2353 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2354 | if (!note) | |
2355 | return purged; | |
5f0d2358 | 2356 | |
ca6c03ca JH |
2357 | b = BRANCH_EDGE (bb); |
2358 | f = FALLTHRU_EDGE (bb); | |
2359 | b->probability = INTVAL (XEXP (note, 0)); | |
2360 | f->probability = REG_BR_PROB_BASE - b->probability; | |
2361 | b->count = bb->count * b->probability / REG_BR_PROB_BASE; | |
2362 | f->count = bb->count * f->probability / REG_BR_PROB_BASE; | |
2363 | } | |
5f0d2358 | 2364 | |
ca6c03ca JH |
2365 | return purged; |
2366 | } | |
4b4bf941 | 2367 | else if (CALL_P (insn) && SIBLING_CALL_P (insn)) |
1722c2c8 RH |
2368 | { |
2369 | /* First, there should not be any EH or ABCALL edges resulting | |
2370 | from non-local gotos and the like. If there were, we shouldn't | |
2371 | have created the sibcall in the first place. Second, there | |
2372 | should of course never have been a fallthru edge. */ | |
c5cbcccf ZD |
2373 | gcc_assert (single_succ_p (bb)); |
2374 | gcc_assert (single_succ_edge (bb)->flags | |
2375 | == (EDGE_SIBCALL | EDGE_ABNORMAL)); | |
1722c2c8 RH |
2376 | |
2377 | return 0; | |
2378 | } | |
ca6c03ca | 2379 | |
ca6c03ca JH |
2380 | /* If we don't see a jump insn, we don't know exactly why the block would |
2381 | have been broken at this point. Look for a simple, non-fallthru edge, | |
2382 | as these are only created by conditional branches. If we find such an | |
2383 | edge we know that there used to be a jump here and can then safely | |
2384 | remove all non-fallthru edges. */ | |
628f6a4e BE |
2385 | found = false; |
2386 | FOR_EACH_EDGE (e, ei, bb->succs) | |
2387 | if (! (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU))) | |
2388 | { | |
2389 | found = true; | |
2390 | break; | |
2391 | } | |
5f0d2358 | 2392 | |
628f6a4e | 2393 | if (!found) |
ca6c03ca | 2394 | return purged; |
5f0d2358 | 2395 | |
2afa8dce DB |
2396 | /* Remove all but the fake and fallthru edges. The fake edge may be |
2397 | the only successor for this block in the case of noreturn | |
2398 | calls. */ | |
628f6a4e | 2399 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
ca6c03ca | 2400 | { |
2afa8dce | 2401 | if (!(e->flags & (EDGE_FALLTHRU | EDGE_FAKE))) |
c51d95ec | 2402 | { |
6fb5fa3c | 2403 | df_set_bb_dirty (bb); |
c51d95ec JH |
2404 | remove_edge (e); |
2405 | purged = true; | |
2406 | } | |
628f6a4e BE |
2407 | else |
2408 | ei_next (&ei); | |
ca6c03ca | 2409 | } |
5f0d2358 | 2410 | |
c5cbcccf | 2411 | gcc_assert (single_succ_p (bb)); |
5f0d2358 | 2412 | |
c5cbcccf ZD |
2413 | single_succ_edge (bb)->probability = REG_BR_PROB_BASE; |
2414 | single_succ_edge (bb)->count = bb->count; | |
ca6c03ca | 2415 | |
c263766c RH |
2416 | if (dump_file) |
2417 | fprintf (dump_file, "Purged non-fallthru edges from bb %i\n", | |
0b17ab2f | 2418 | bb->index); |
ca6c03ca JH |
2419 | return purged; |
2420 | } | |
2421 | ||
5f0d2358 RK |
2422 | /* Search all basic blocks for potentially dead edges and purge them. Return |
2423 | true if some edge has been eliminated. */ | |
ca6c03ca JH |
2424 | |
2425 | bool | |
25cd19de | 2426 | purge_all_dead_edges (void) |
ca6c03ca | 2427 | { |
e0082a72 | 2428 | int purged = false; |
e0082a72 | 2429 | basic_block bb; |
473fb060 | 2430 | |
e0082a72 | 2431 | FOR_EACH_BB (bb) |
473fb060 | 2432 | { |
e0082a72 | 2433 | bool purged_here = purge_dead_edges (bb); |
5f0d2358 | 2434 | |
473fb060 | 2435 | purged |= purged_here; |
473fb060 | 2436 | } |
5f0d2358 | 2437 | |
ca6c03ca JH |
2438 | return purged; |
2439 | } | |
9ee634e3 | 2440 | |
ba5e9aca EB |
2441 | /* This is used by a few passes that emit some instructions after abnormal |
2442 | calls, moving the basic block's end, while they in fact do want to emit | |
2443 | them on the fallthru edge. Look for abnormal call edges, find backward | |
2444 | the call in the block and insert the instructions on the edge instead. | |
2445 | ||
2446 | Similarly, handle instructions throwing exceptions internally. | |
2447 | ||
2448 | Return true when instructions have been found and inserted on edges. */ | |
2449 | ||
2450 | bool | |
2451 | fixup_abnormal_edges (void) | |
2452 | { | |
2453 | bool inserted = false; | |
2454 | basic_block bb; | |
2455 | ||
2456 | FOR_EACH_BB (bb) | |
2457 | { | |
2458 | edge e; | |
2459 | edge_iterator ei; | |
2460 | ||
2461 | /* Look for cases we are interested in - calls or instructions causing | |
2462 | exceptions. */ | |
2463 | FOR_EACH_EDGE (e, ei, bb->succs) | |
2464 | if ((e->flags & EDGE_ABNORMAL_CALL) | |
2465 | || ((e->flags & (EDGE_ABNORMAL | EDGE_EH)) | |
2466 | == (EDGE_ABNORMAL | EDGE_EH))) | |
2467 | break; | |
2468 | ||
2469 | if (e && !CALL_P (BB_END (bb)) && !can_throw_internal (BB_END (bb))) | |
2470 | { | |
2471 | rtx insn; | |
2472 | ||
2473 | /* Get past the new insns generated. Allow notes, as the insns | |
2474 | may be already deleted. */ | |
2475 | insn = BB_END (bb); | |
2476 | while ((NONJUMP_INSN_P (insn) || NOTE_P (insn)) | |
2477 | && !can_throw_internal (insn) | |
2478 | && insn != BB_HEAD (bb)) | |
2479 | insn = PREV_INSN (insn); | |
2480 | ||
2481 | if (CALL_P (insn) || can_throw_internal (insn)) | |
2482 | { | |
2483 | rtx stop, next; | |
2484 | ||
2485 | e = find_fallthru_edge (bb->succs); | |
2486 | ||
2487 | stop = NEXT_INSN (BB_END (bb)); | |
2488 | BB_END (bb) = insn; | |
2489 | ||
2490 | for (insn = NEXT_INSN (insn); insn != stop; insn = next) | |
2491 | { | |
2492 | next = NEXT_INSN (insn); | |
2493 | if (INSN_P (insn)) | |
2494 | { | |
2495 | delete_insn (insn); | |
2496 | ||
2497 | /* Sometimes there's still the return value USE. | |
2498 | If it's placed after a trapping call (i.e. that | |
2499 | call is the last insn anyway), we have no fallthru | |
2500 | edge. Simply delete this use and don't try to insert | |
2501 | on the non-existent edge. */ | |
2502 | if (GET_CODE (PATTERN (insn)) != USE) | |
2503 | { | |
2504 | /* We're not deleting it, we're moving it. */ | |
2505 | INSN_DELETED_P (insn) = 0; | |
2506 | PREV_INSN (insn) = NULL_RTX; | |
2507 | NEXT_INSN (insn) = NULL_RTX; | |
2508 | ||
2509 | insert_insn_on_edge (insn, e); | |
2510 | inserted = true; | |
2511 | } | |
2512 | } | |
2513 | else if (!BARRIER_P (insn)) | |
2514 | set_block_for_insn (insn, NULL); | |
2515 | } | |
2516 | } | |
2517 | ||
2518 | /* It may be that we don't find any trapping insn. In this | |
2519 | case we discovered quite late that the insn that had been | |
2520 | marked as can_throw_internal in fact couldn't trap at all. | |
2521 | So we should in fact delete the EH edges out of the block. */ | |
2522 | else | |
2523 | purge_dead_edges (bb); | |
2524 | } | |
2525 | } | |
2526 | ||
2527 | return inserted; | |
2528 | } | |
2529 | ||
9ee634e3 | 2530 | /* Same as split_block but update cfg_layout structures. */ |
f470c378 ZD |
2531 | |
2532 | static basic_block | |
d329e058 | 2533 | cfg_layout_split_block (basic_block bb, void *insnp) |
9ee634e3 | 2534 | { |
ae50c0cb | 2535 | rtx insn = (rtx) insnp; |
f470c378 | 2536 | basic_block new_bb = rtl_split_block (bb, insn); |
9ee634e3 | 2537 | |
370369e1 JH |
2538 | new_bb->il.rtl->footer = bb->il.rtl->footer; |
2539 | bb->il.rtl->footer = NULL; | |
9ee634e3 | 2540 | |
f470c378 | 2541 | return new_bb; |
9ee634e3 JH |
2542 | } |
2543 | ||
9ee634e3 | 2544 | /* Redirect Edge to DEST. */ |
6de9cd9a | 2545 | static edge |
d329e058 | 2546 | cfg_layout_redirect_edge_and_branch (edge e, basic_block dest) |
9ee634e3 JH |
2547 | { |
2548 | basic_block src = e->src; | |
6de9cd9a | 2549 | edge ret; |
9ee634e3 | 2550 | |
bc35512f | 2551 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
6de9cd9a | 2552 | return NULL; |
bc35512f | 2553 | |
3348b696 | 2554 | if (e->dest == dest) |
6de9cd9a | 2555 | return e; |
bc35512f | 2556 | |
3348b696 | 2557 | if (e->src != ENTRY_BLOCK_PTR |
6de9cd9a | 2558 | && (ret = try_redirect_by_replacing_jump (e, dest, true))) |
f345f21a | 2559 | { |
6fb5fa3c | 2560 | df_set_bb_dirty (src); |
6de9cd9a | 2561 | return ret; |
f345f21a | 2562 | } |
bc35512f JH |
2563 | |
2564 | if (e->src == ENTRY_BLOCK_PTR | |
2565 | && (e->flags & EDGE_FALLTHRU) && !(e->flags & EDGE_COMPLEX)) | |
2566 | { | |
c263766c RH |
2567 | if (dump_file) |
2568 | fprintf (dump_file, "Redirecting entry edge from bb %i to %i\n", | |
bc35512f JH |
2569 | e->src->index, dest->index); |
2570 | ||
6fb5fa3c | 2571 | df_set_bb_dirty (e->src); |
bc35512f | 2572 | redirect_edge_succ (e, dest); |
6de9cd9a | 2573 | return e; |
bc35512f JH |
2574 | } |
2575 | ||
9ee634e3 JH |
2576 | /* Redirect_edge_and_branch may decide to turn branch into fallthru edge |
2577 | in the case the basic block appears to be in sequence. Avoid this | |
2578 | transformation. */ | |
2579 | ||
9ee634e3 JH |
2580 | if (e->flags & EDGE_FALLTHRU) |
2581 | { | |
2582 | /* Redirect any branch edges unified with the fallthru one. */ | |
4b4bf941 | 2583 | if (JUMP_P (BB_END (src)) |
432f982f JH |
2584 | && label_is_jump_target_p (BB_HEAD (e->dest), |
2585 | BB_END (src))) | |
9ee634e3 | 2586 | { |
341c100f | 2587 | edge redirected; |
c22cacf3 | 2588 | |
c263766c RH |
2589 | if (dump_file) |
2590 | fprintf (dump_file, "Fallthru edge unified with branch " | |
432f982f JH |
2591 | "%i->%i redirected to %i\n", |
2592 | e->src->index, e->dest->index, dest->index); | |
2593 | e->flags &= ~EDGE_FALLTHRU; | |
341c100f NS |
2594 | redirected = redirect_branch_edge (e, dest); |
2595 | gcc_assert (redirected); | |
0c617be4 JL |
2596 | redirected->flags |= EDGE_FALLTHRU; |
2597 | df_set_bb_dirty (redirected->src); | |
2598 | return redirected; | |
9ee634e3 JH |
2599 | } |
2600 | /* In case we are redirecting fallthru edge to the branch edge | |
c22cacf3 | 2601 | of conditional jump, remove it. */ |
628f6a4e | 2602 | if (EDGE_COUNT (src->succs) == 2) |
9ee634e3 | 2603 | { |
03101c6f KH |
2604 | /* Find the edge that is different from E. */ |
2605 | edge s = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e); | |
628f6a4e | 2606 | |
9ee634e3 | 2607 | if (s->dest == dest |
a813c111 SB |
2608 | && any_condjump_p (BB_END (src)) |
2609 | && onlyjump_p (BB_END (src))) | |
2610 | delete_insn (BB_END (src)); | |
9ee634e3 | 2611 | } |
c263766c | 2612 | if (dump_file) |
dc764d10 | 2613 | fprintf (dump_file, "Redirecting fallthru edge %i->%i to %i\n", |
bc35512f | 2614 | e->src->index, e->dest->index, dest->index); |
0c617be4 | 2615 | ret = redirect_edge_succ_nodup (e, dest); |
9ee634e3 JH |
2616 | } |
2617 | else | |
bc35512f | 2618 | ret = redirect_branch_edge (e, dest); |
9ee634e3 JH |
2619 | |
2620 | /* We don't want simplejumps in the insn stream during cfglayout. */ | |
341c100f | 2621 | gcc_assert (!simplejump_p (BB_END (src))); |
9ee634e3 | 2622 | |
6fb5fa3c | 2623 | df_set_bb_dirty (src); |
9ee634e3 JH |
2624 | return ret; |
2625 | } | |
2626 | ||
2627 | /* Simple wrapper as we always can redirect fallthru edges. */ | |
2628 | static basic_block | |
d329e058 | 2629 | cfg_layout_redirect_edge_and_branch_force (edge e, basic_block dest) |
9ee634e3 | 2630 | { |
341c100f NS |
2631 | edge redirected = cfg_layout_redirect_edge_and_branch (e, dest); |
2632 | ||
2633 | gcc_assert (redirected); | |
9ee634e3 JH |
2634 | return NULL; |
2635 | } | |
2636 | ||
f470c378 ZD |
2637 | /* Same as delete_basic_block but update cfg_layout structures. */ |
2638 | ||
9ee634e3 | 2639 | static void |
d329e058 | 2640 | cfg_layout_delete_block (basic_block bb) |
9ee634e3 | 2641 | { |
a813c111 | 2642 | rtx insn, next, prev = PREV_INSN (BB_HEAD (bb)), *to, remaints; |
9ee634e3 | 2643 | |
370369e1 | 2644 | if (bb->il.rtl->header) |
9ee634e3 | 2645 | { |
a813c111 | 2646 | next = BB_HEAD (bb); |
9ee634e3 | 2647 | if (prev) |
370369e1 | 2648 | NEXT_INSN (prev) = bb->il.rtl->header; |
9ee634e3 | 2649 | else |
370369e1 JH |
2650 | set_first_insn (bb->il.rtl->header); |
2651 | PREV_INSN (bb->il.rtl->header) = prev; | |
2652 | insn = bb->il.rtl->header; | |
9ee634e3 JH |
2653 | while (NEXT_INSN (insn)) |
2654 | insn = NEXT_INSN (insn); | |
2655 | NEXT_INSN (insn) = next; | |
2656 | PREV_INSN (next) = insn; | |
2657 | } | |
a813c111 | 2658 | next = NEXT_INSN (BB_END (bb)); |
370369e1 | 2659 | if (bb->il.rtl->footer) |
9ee634e3 | 2660 | { |
370369e1 | 2661 | insn = bb->il.rtl->footer; |
bc35512f JH |
2662 | while (insn) |
2663 | { | |
4b4bf941 | 2664 | if (BARRIER_P (insn)) |
bc35512f JH |
2665 | { |
2666 | if (PREV_INSN (insn)) | |
2667 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
2668 | else | |
370369e1 | 2669 | bb->il.rtl->footer = NEXT_INSN (insn); |
bc35512f JH |
2670 | if (NEXT_INSN (insn)) |
2671 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
2672 | } | |
4b4bf941 | 2673 | if (LABEL_P (insn)) |
bc35512f JH |
2674 | break; |
2675 | insn = NEXT_INSN (insn); | |
2676 | } | |
370369e1 | 2677 | if (bb->il.rtl->footer) |
bc35512f | 2678 | { |
a813c111 | 2679 | insn = BB_END (bb); |
370369e1 JH |
2680 | NEXT_INSN (insn) = bb->il.rtl->footer; |
2681 | PREV_INSN (bb->il.rtl->footer) = insn; | |
bc35512f JH |
2682 | while (NEXT_INSN (insn)) |
2683 | insn = NEXT_INSN (insn); | |
2684 | NEXT_INSN (insn) = next; | |
2685 | if (next) | |
2686 | PREV_INSN (next) = insn; | |
2687 | else | |
2688 | set_last_insn (insn); | |
2689 | } | |
9ee634e3 JH |
2690 | } |
2691 | if (bb->next_bb != EXIT_BLOCK_PTR) | |
370369e1 | 2692 | to = &bb->next_bb->il.rtl->header; |
9ee634e3 JH |
2693 | else |
2694 | to = &cfg_layout_function_footer; | |
997de8ed | 2695 | |
9ee634e3 JH |
2696 | rtl_delete_block (bb); |
2697 | ||
2698 | if (prev) | |
2699 | prev = NEXT_INSN (prev); | |
d329e058 | 2700 | else |
9ee634e3 JH |
2701 | prev = get_insns (); |
2702 | if (next) | |
2703 | next = PREV_INSN (next); | |
d329e058 | 2704 | else |
9ee634e3 JH |
2705 | next = get_last_insn (); |
2706 | ||
2707 | if (next && NEXT_INSN (next) != prev) | |
2708 | { | |
2709 | remaints = unlink_insn_chain (prev, next); | |
2710 | insn = remaints; | |
2711 | while (NEXT_INSN (insn)) | |
2712 | insn = NEXT_INSN (insn); | |
2713 | NEXT_INSN (insn) = *to; | |
2714 | if (*to) | |
2715 | PREV_INSN (*to) = insn; | |
2716 | *to = remaints; | |
2717 | } | |
2718 | } | |
2719 | ||
beb235f8 | 2720 | /* Return true when blocks A and B can be safely merged. */ |
b48d0358 | 2721 | |
bc35512f | 2722 | static bool |
b48d0358 | 2723 | cfg_layout_can_merge_blocks_p (basic_block a, basic_block b) |
bc35512f | 2724 | { |
750054a2 CT |
2725 | /* If we are partitioning hot/cold basic blocks, we don't want to |
2726 | mess up unconditional or indirect jumps that cross between hot | |
076c7ab8 ZW |
2727 | and cold sections. |
2728 | ||
8e8d5162 | 2729 | Basic block partitioning may result in some jumps that appear to |
c22cacf3 MS |
2730 | be optimizable (or blocks that appear to be mergeable), but which really |
2731 | must be left untouched (they are required to make it safely across | |
2732 | partition boundaries). See the comments at the top of | |
8e8d5162 CT |
2733 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
2734 | ||
87c8b4be | 2735 | if (BB_PARTITION (a) != BB_PARTITION (b)) |
076c7ab8 | 2736 | return false; |
750054a2 | 2737 | |
bc35512f | 2738 | /* There must be exactly one edge in between the blocks. */ |
c5cbcccf ZD |
2739 | return (single_succ_p (a) |
2740 | && single_succ (a) == b | |
2741 | && single_pred_p (b) == 1 | |
628f6a4e | 2742 | && a != b |
bc35512f | 2743 | /* Must be simple edge. */ |
c5cbcccf | 2744 | && !(single_succ_edge (a)->flags & EDGE_COMPLEX) |
bc35512f | 2745 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR |
49ea3702 SB |
2746 | /* If the jump insn has side effects, we can't kill the edge. |
2747 | When not optimizing, try_redirect_by_replacing_jump will | |
2748 | not allow us to redirect an edge by replacing a table jump. */ | |
4b4bf941 | 2749 | && (!JUMP_P (BB_END (a)) |
49ea3702 | 2750 | || ((!optimize || reload_completed) |
a813c111 | 2751 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f JH |
2752 | } |
2753 | ||
41806d92 NS |
2754 | /* Merge block A and B. The blocks must be mergeable. */ |
2755 | ||
bc35512f JH |
2756 | static void |
2757 | cfg_layout_merge_blocks (basic_block a, basic_block b) | |
2758 | { | |
50a36e42 EB |
2759 | bool forwarder_p = (b->flags & BB_FORWARDER_BLOCK) != 0; |
2760 | ||
77a74ed7 | 2761 | gcc_checking_assert (cfg_layout_can_merge_blocks_p (a, b)); |
bc35512f | 2762 | |
6fb5fa3c | 2763 | if (dump_file) |
50a36e42 EB |
2764 | fprintf (dump_file, "Merging block %d into block %d...\n", b->index, |
2765 | a->index); | |
6fb5fa3c | 2766 | |
bc35512f | 2767 | /* If there was a CODE_LABEL beginning B, delete it. */ |
4b4bf941 | 2768 | if (LABEL_P (BB_HEAD (b))) |
2c97f8e4 | 2769 | { |
2c97f8e4 RH |
2770 | delete_insn (BB_HEAD (b)); |
2771 | } | |
bc35512f JH |
2772 | |
2773 | /* We should have fallthru edge in a, or we can do dummy redirection to get | |
2774 | it cleaned up. */ | |
4b4bf941 | 2775 | if (JUMP_P (BB_END (a))) |
628f6a4e | 2776 | try_redirect_by_replacing_jump (EDGE_SUCC (a, 0), b, true); |
341c100f | 2777 | gcc_assert (!JUMP_P (BB_END (a))); |
bc35512f | 2778 | |
7241571e JJ |
2779 | /* When not optimizing and the edge is the only place in RTL which holds |
2780 | some unique locus, emit a nop with that locus in between. */ | |
2781 | if (!optimize && EDGE_SUCC (a, 0)->goto_locus) | |
2782 | { | |
1692ae7e | 2783 | rtx insn = BB_END (a), end = PREV_INSN (BB_HEAD (a)); |
7241571e JJ |
2784 | int goto_locus = EDGE_SUCC (a, 0)->goto_locus; |
2785 | ||
1692ae7e JJ |
2786 | while (insn != end && (!INSN_P (insn) || INSN_LOCATOR (insn) == 0)) |
2787 | insn = PREV_INSN (insn); | |
2788 | if (insn != end && locator_eq (INSN_LOCATOR (insn), goto_locus)) | |
7241571e JJ |
2789 | goto_locus = 0; |
2790 | else | |
2791 | { | |
2792 | insn = BB_HEAD (b); | |
1692ae7e JJ |
2793 | end = NEXT_INSN (BB_END (b)); |
2794 | while (insn != end && !INSN_P (insn)) | |
2795 | insn = NEXT_INSN (insn); | |
2796 | if (insn != end && INSN_LOCATOR (insn) != 0 | |
2797 | && locator_eq (INSN_LOCATOR (insn), goto_locus)) | |
7241571e JJ |
2798 | goto_locus = 0; |
2799 | } | |
2800 | if (goto_locus) | |
2801 | { | |
2802 | BB_END (a) = emit_insn_after_noloc (gen_nop (), BB_END (a), a); | |
2803 | INSN_LOCATOR (BB_END (a)) = goto_locus; | |
2804 | } | |
2805 | } | |
2806 | ||
bc35512f | 2807 | /* Possible line number notes should appear in between. */ |
370369e1 | 2808 | if (b->il.rtl->header) |
bc35512f | 2809 | { |
a813c111 | 2810 | rtx first = BB_END (a), last; |
bc35512f | 2811 | |
6fb5fa3c | 2812 | last = emit_insn_after_noloc (b->il.rtl->header, BB_END (a), a); |
a7b87f73 | 2813 | delete_insn_chain (NEXT_INSN (first), last, false); |
370369e1 | 2814 | b->il.rtl->header = NULL; |
bc35512f JH |
2815 | } |
2816 | ||
2817 | /* In the case basic blocks are not adjacent, move them around. */ | |
a813c111 | 2818 | if (NEXT_INSN (BB_END (a)) != BB_HEAD (b)) |
bc35512f | 2819 | { |
a813c111 | 2820 | rtx first = unlink_insn_chain (BB_HEAD (b), BB_END (b)); |
bc35512f | 2821 | |
6fb5fa3c | 2822 | emit_insn_after_noloc (first, BB_END (a), a); |
bc35512f JH |
2823 | /* Skip possible DELETED_LABEL insn. */ |
2824 | if (!NOTE_INSN_BASIC_BLOCK_P (first)) | |
2825 | first = NEXT_INSN (first); | |
341c100f | 2826 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (first)); |
a813c111 | 2827 | BB_HEAD (b) = NULL; |
6c3d0e31 SP |
2828 | |
2829 | /* emit_insn_after_noloc doesn't call df_insn_change_bb. | |
2830 | We need to explicitly call. */ | |
2831 | update_bb_for_insn_chain (NEXT_INSN (first), | |
2832 | BB_END (b), | |
2833 | a); | |
2834 | ||
bc35512f JH |
2835 | delete_insn (first); |
2836 | } | |
2837 | /* Otherwise just re-associate the instructions. */ | |
2838 | else | |
2839 | { | |
2840 | rtx insn; | |
2841 | ||
6c3d0e31 | 2842 | update_bb_for_insn_chain (BB_HEAD (b), BB_END (b), a); |
6fb5fa3c | 2843 | |
a813c111 | 2844 | insn = BB_HEAD (b); |
bc35512f JH |
2845 | /* Skip possible DELETED_LABEL insn. */ |
2846 | if (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
2847 | insn = NEXT_INSN (insn); | |
341c100f | 2848 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn)); |
a813c111 SB |
2849 | BB_HEAD (b) = NULL; |
2850 | BB_END (a) = BB_END (b); | |
bc35512f JH |
2851 | delete_insn (insn); |
2852 | } | |
2853 | ||
6fb5fa3c DB |
2854 | df_bb_delete (b->index); |
2855 | ||
bc35512f | 2856 | /* Possible tablejumps and barriers should appear after the block. */ |
370369e1 | 2857 | if (b->il.rtl->footer) |
bc35512f | 2858 | { |
370369e1 JH |
2859 | if (!a->il.rtl->footer) |
2860 | a->il.rtl->footer = b->il.rtl->footer; | |
bc35512f JH |
2861 | else |
2862 | { | |
370369e1 | 2863 | rtx last = a->il.rtl->footer; |
bc35512f JH |
2864 | |
2865 | while (NEXT_INSN (last)) | |
2866 | last = NEXT_INSN (last); | |
370369e1 JH |
2867 | NEXT_INSN (last) = b->il.rtl->footer; |
2868 | PREV_INSN (b->il.rtl->footer) = last; | |
bc35512f | 2869 | } |
370369e1 | 2870 | b->il.rtl->footer = NULL; |
bc35512f JH |
2871 | } |
2872 | ||
50a36e42 EB |
2873 | /* If B was a forwarder block, propagate the locus on the edge. */ |
2874 | if (forwarder_p && !EDGE_SUCC (b, 0)->goto_locus) | |
2875 | EDGE_SUCC (b, 0)->goto_locus = EDGE_SUCC (a, 0)->goto_locus; | |
2876 | ||
c263766c | 2877 | if (dump_file) |
50a36e42 | 2878 | fprintf (dump_file, "Merged blocks %d and %d.\n", a->index, b->index); |
bc35512f JH |
2879 | } |
2880 | ||
2881 | /* Split edge E. */ | |
f470c378 | 2882 | |
bc35512f JH |
2883 | static basic_block |
2884 | cfg_layout_split_edge (edge e) | |
2885 | { | |
bc35512f JH |
2886 | basic_block new_bb = |
2887 | create_basic_block (e->src != ENTRY_BLOCK_PTR | |
a813c111 | 2888 | ? NEXT_INSN (BB_END (e->src)) : get_insns (), |
bc35512f JH |
2889 | NULL_RTX, e->src); |
2890 | ||
3e7eb734 JJ |
2891 | if (e->dest == EXIT_BLOCK_PTR) |
2892 | BB_COPY_PARTITION (new_bb, e->src); | |
2893 | else | |
2894 | BB_COPY_PARTITION (new_bb, e->dest); | |
a9b2ee88 | 2895 | make_edge (new_bb, e->dest, EDGE_FALLTHRU); |
bc35512f JH |
2896 | redirect_edge_and_branch_force (e, new_bb); |
2897 | ||
2898 | return new_bb; | |
2899 | } | |
2900 | ||
f470c378 ZD |
2901 | /* Do postprocessing after making a forwarder block joined by edge FALLTHRU. */ |
2902 | ||
2903 | static void | |
2904 | rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED) | |
2905 | { | |
2906 | } | |
2907 | ||
6de9cd9a DN |
2908 | /* Return 1 if BB ends with a call, possibly followed by some |
2909 | instructions that must stay with the call, 0 otherwise. */ | |
2910 | ||
2911 | static bool | |
b48d0358 | 2912 | rtl_block_ends_with_call_p (basic_block bb) |
6de9cd9a DN |
2913 | { |
2914 | rtx insn = BB_END (bb); | |
2915 | ||
4b4bf941 | 2916 | while (!CALL_P (insn) |
6de9cd9a | 2917 | && insn != BB_HEAD (bb) |
92ddef69 | 2918 | && (keep_with_call_p (insn) |
b5b8b0ac AO |
2919 | || NOTE_P (insn) |
2920 | || DEBUG_INSN_P (insn))) | |
6de9cd9a | 2921 | insn = PREV_INSN (insn); |
4b4bf941 | 2922 | return (CALL_P (insn)); |
6de9cd9a DN |
2923 | } |
2924 | ||
2925 | /* Return 1 if BB ends with a conditional branch, 0 otherwise. */ | |
2926 | ||
2927 | static bool | |
9678086d | 2928 | rtl_block_ends_with_condjump_p (const_basic_block bb) |
6de9cd9a DN |
2929 | { |
2930 | return any_condjump_p (BB_END (bb)); | |
2931 | } | |
2932 | ||
2933 | /* Return true if we need to add fake edge to exit. | |
2934 | Helper function for rtl_flow_call_edges_add. */ | |
2935 | ||
2936 | static bool | |
9678086d | 2937 | need_fake_edge_p (const_rtx insn) |
6de9cd9a DN |
2938 | { |
2939 | if (!INSN_P (insn)) | |
2940 | return false; | |
2941 | ||
4b4bf941 | 2942 | if ((CALL_P (insn) |
6de9cd9a DN |
2943 | && !SIBLING_CALL_P (insn) |
2944 | && !find_reg_note (insn, REG_NORETURN, NULL) | |
becfd6e5 | 2945 | && !(RTL_CONST_OR_PURE_CALL_P (insn)))) |
6de9cd9a DN |
2946 | return true; |
2947 | ||
2948 | return ((GET_CODE (PATTERN (insn)) == ASM_OPERANDS | |
2949 | && MEM_VOLATILE_P (PATTERN (insn))) | |
2950 | || (GET_CODE (PATTERN (insn)) == PARALLEL | |
2951 | && asm_noperands (insn) != -1 | |
2952 | && MEM_VOLATILE_P (XVECEXP (PATTERN (insn), 0, 0))) | |
2953 | || GET_CODE (PATTERN (insn)) == ASM_INPUT); | |
2954 | } | |
2955 | ||
2956 | /* Add fake edges to the function exit for any non constant and non noreturn | |
2957 | calls, volatile inline assembly in the bitmap of blocks specified by | |
2958 | BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks | |
2959 | that were split. | |
2960 | ||
2961 | The goal is to expose cases in which entering a basic block does not imply | |
2962 | that all subsequent instructions must be executed. */ | |
2963 | ||
2964 | static int | |
2965 | rtl_flow_call_edges_add (sbitmap blocks) | |
2966 | { | |
2967 | int i; | |
2968 | int blocks_split = 0; | |
2969 | int last_bb = last_basic_block; | |
2970 | bool check_last_block = false; | |
2971 | ||
24bd1a0b | 2972 | if (n_basic_blocks == NUM_FIXED_BLOCKS) |
6de9cd9a DN |
2973 | return 0; |
2974 | ||
2975 | if (! blocks) | |
2976 | check_last_block = true; | |
2977 | else | |
2978 | check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index); | |
2979 | ||
2980 | /* In the last basic block, before epilogue generation, there will be | |
2981 | a fallthru edge to EXIT. Special care is required if the last insn | |
2982 | of the last basic block is a call because make_edge folds duplicate | |
2983 | edges, which would result in the fallthru edge also being marked | |
2984 | fake, which would result in the fallthru edge being removed by | |
2985 | remove_fake_edges, which would result in an invalid CFG. | |
2986 | ||
2987 | Moreover, we can't elide the outgoing fake edge, since the block | |
2988 | profiler needs to take this into account in order to solve the minimal | |
2989 | spanning tree in the case that the call doesn't return. | |
2990 | ||
2991 | Handle this by adding a dummy instruction in a new last basic block. */ | |
2992 | if (check_last_block) | |
2993 | { | |
2994 | basic_block bb = EXIT_BLOCK_PTR->prev_bb; | |
2995 | rtx insn = BB_END (bb); | |
2996 | ||
2997 | /* Back up past insns that must be kept in the same block as a call. */ | |
2998 | while (insn != BB_HEAD (bb) | |
2999 | && keep_with_call_p (insn)) | |
3000 | insn = PREV_INSN (insn); | |
3001 | ||
3002 | if (need_fake_edge_p (insn)) | |
3003 | { | |
3004 | edge e; | |
3005 | ||
9ff3d2de JL |
3006 | e = find_edge (bb, EXIT_BLOCK_PTR); |
3007 | if (e) | |
3008 | { | |
c41c1387 | 3009 | insert_insn_on_edge (gen_use (const0_rtx), e); |
9ff3d2de JL |
3010 | commit_edge_insertions (); |
3011 | } | |
6de9cd9a DN |
3012 | } |
3013 | } | |
3014 | ||
3015 | /* Now add fake edges to the function exit for any non constant | |
3016 | calls since there is no way that we can determine if they will | |
3017 | return or not... */ | |
3018 | ||
24bd1a0b | 3019 | for (i = NUM_FIXED_BLOCKS; i < last_bb; i++) |
6de9cd9a DN |
3020 | { |
3021 | basic_block bb = BASIC_BLOCK (i); | |
3022 | rtx insn; | |
3023 | rtx prev_insn; | |
3024 | ||
3025 | if (!bb) | |
3026 | continue; | |
3027 | ||
3028 | if (blocks && !TEST_BIT (blocks, i)) | |
3029 | continue; | |
3030 | ||
3031 | for (insn = BB_END (bb); ; insn = prev_insn) | |
3032 | { | |
3033 | prev_insn = PREV_INSN (insn); | |
3034 | if (need_fake_edge_p (insn)) | |
3035 | { | |
3036 | edge e; | |
3037 | rtx split_at_insn = insn; | |
3038 | ||
3039 | /* Don't split the block between a call and an insn that should | |
c22cacf3 | 3040 | remain in the same block as the call. */ |
4b4bf941 | 3041 | if (CALL_P (insn)) |
6de9cd9a DN |
3042 | while (split_at_insn != BB_END (bb) |
3043 | && keep_with_call_p (NEXT_INSN (split_at_insn))) | |
3044 | split_at_insn = NEXT_INSN (split_at_insn); | |
3045 | ||
3046 | /* The handling above of the final block before the epilogue | |
c22cacf3 | 3047 | should be enough to verify that there is no edge to the exit |
6de9cd9a DN |
3048 | block in CFG already. Calling make_edge in such case would |
3049 | cause us to mark that edge as fake and remove it later. */ | |
3050 | ||
3051 | #ifdef ENABLE_CHECKING | |
3052 | if (split_at_insn == BB_END (bb)) | |
628f6a4e | 3053 | { |
9ff3d2de JL |
3054 | e = find_edge (bb, EXIT_BLOCK_PTR); |
3055 | gcc_assert (e == NULL); | |
628f6a4e | 3056 | } |
6de9cd9a DN |
3057 | #endif |
3058 | ||
3059 | /* Note that the following may create a new basic block | |
3060 | and renumber the existing basic blocks. */ | |
3061 | if (split_at_insn != BB_END (bb)) | |
3062 | { | |
3063 | e = split_block (bb, split_at_insn); | |
3064 | if (e) | |
3065 | blocks_split++; | |
3066 | } | |
3067 | ||
3068 | make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE); | |
3069 | } | |
3070 | ||
3071 | if (insn == BB_HEAD (bb)) | |
3072 | break; | |
3073 | } | |
3074 | } | |
3075 | ||
3076 | if (blocks_split) | |
3077 | verify_flow_info (); | |
3078 | ||
3079 | return blocks_split; | |
3080 | } | |
3081 | ||
1cb7dfc3 | 3082 | /* Add COMP_RTX as a condition at end of COND_BB. FIRST_HEAD is |
315682fb | 3083 | the conditional branch target, SECOND_HEAD should be the fall-thru |
1cb7dfc3 MH |
3084 | there is no need to handle this here the loop versioning code handles |
3085 | this. the reason for SECON_HEAD is that it is needed for condition | |
3086 | in trees, and this should be of the same type since it is a hook. */ | |
3087 | static void | |
3088 | rtl_lv_add_condition_to_bb (basic_block first_head , | |
c22cacf3 MS |
3089 | basic_block second_head ATTRIBUTE_UNUSED, |
3090 | basic_block cond_bb, void *comp_rtx) | |
1cb7dfc3 MH |
3091 | { |
3092 | rtx label, seq, jump; | |
3093 | rtx op0 = XEXP ((rtx)comp_rtx, 0); | |
3094 | rtx op1 = XEXP ((rtx)comp_rtx, 1); | |
3095 | enum rtx_code comp = GET_CODE ((rtx)comp_rtx); | |
3096 | enum machine_mode mode; | |
3097 | ||
3098 | ||
3099 | label = block_label (first_head); | |
3100 | mode = GET_MODE (op0); | |
3101 | if (mode == VOIDmode) | |
3102 | mode = GET_MODE (op1); | |
3103 | ||
3104 | start_sequence (); | |
3105 | op0 = force_operand (op0, NULL_RTX); | |
3106 | op1 = force_operand (op1, NULL_RTX); | |
3107 | do_compare_rtx_and_jump (op0, op1, comp, 0, | |
40e90eac | 3108 | mode, NULL_RTX, NULL_RTX, label, -1); |
1cb7dfc3 MH |
3109 | jump = get_last_insn (); |
3110 | JUMP_LABEL (jump) = label; | |
3111 | LABEL_NUSES (label)++; | |
3112 | seq = get_insns (); | |
3113 | end_sequence (); | |
3114 | ||
3115 | /* Add the new cond , in the new head. */ | |
3116 | emit_insn_after(seq, BB_END(cond_bb)); | |
3117 | } | |
3118 | ||
3119 | ||
3120 | /* Given a block B with unconditional branch at its end, get the | |
3121 | store the return the branch edge and the fall-thru edge in | |
3122 | BRANCH_EDGE and FALLTHRU_EDGE respectively. */ | |
3123 | static void | |
3124 | rtl_extract_cond_bb_edges (basic_block b, edge *branch_edge, | |
3125 | edge *fallthru_edge) | |
3126 | { | |
3127 | edge e = EDGE_SUCC (b, 0); | |
3128 | ||
3129 | if (e->flags & EDGE_FALLTHRU) | |
3130 | { | |
3131 | *fallthru_edge = e; | |
3132 | *branch_edge = EDGE_SUCC (b, 1); | |
3133 | } | |
3134 | else | |
3135 | { | |
3136 | *branch_edge = e; | |
3137 | *fallthru_edge = EDGE_SUCC (b, 1); | |
3138 | } | |
3139 | } | |
3140 | ||
5e2d947c JH |
3141 | void |
3142 | init_rtl_bb_info (basic_block bb) | |
3143 | { | |
3144 | gcc_assert (!bb->il.rtl); | |
a9429e29 | 3145 | bb->il.rtl = ggc_alloc_cleared_rtl_bb_info (); |
5e2d947c JH |
3146 | } |
3147 | ||
14fa2cc0 ZD |
3148 | /* Returns true if it is possible to remove edge E by redirecting |
3149 | it to the destination of the other edge from E->src. */ | |
3150 | ||
3151 | static bool | |
9678086d | 3152 | rtl_can_remove_branch_p (const_edge e) |
14fa2cc0 | 3153 | { |
9678086d KG |
3154 | const_basic_block src = e->src; |
3155 | const_basic_block target = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest; | |
3156 | const_rtx insn = BB_END (src), set; | |
14fa2cc0 ZD |
3157 | |
3158 | /* The conditions are taken from try_redirect_by_replacing_jump. */ | |
3159 | if (target == EXIT_BLOCK_PTR) | |
3160 | return false; | |
3161 | ||
3162 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) | |
3163 | return false; | |
3164 | ||
3165 | if (find_reg_note (insn, REG_CROSSING_JUMP, NULL_RTX) | |
3166 | || BB_PARTITION (src) != BB_PARTITION (target)) | |
3167 | return false; | |
3168 | ||
3169 | if (!onlyjump_p (insn) | |
3170 | || tablejump_p (insn, NULL, NULL)) | |
3171 | return false; | |
3172 | ||
3173 | set = single_set (insn); | |
3174 | if (!set || side_effects_p (set)) | |
3175 | return false; | |
3176 | ||
3177 | return true; | |
3178 | } | |
3179 | ||
9ee634e3 JH |
3180 | /* Implementation of CFG manipulation for linearized RTL. */ |
3181 | struct cfg_hooks rtl_cfg_hooks = { | |
f470c378 | 3182 | "rtl", |
9ee634e3 | 3183 | rtl_verify_flow_info, |
10e9fecc | 3184 | rtl_dump_bb, |
bc35512f | 3185 | rtl_create_basic_block, |
9ee634e3 JH |
3186 | rtl_redirect_edge_and_branch, |
3187 | rtl_redirect_edge_and_branch_force, | |
14fa2cc0 | 3188 | rtl_can_remove_branch_p, |
9ee634e3 JH |
3189 | rtl_delete_block, |
3190 | rtl_split_block, | |
f470c378 | 3191 | rtl_move_block_after, |
bc35512f JH |
3192 | rtl_can_merge_blocks, /* can_merge_blocks_p */ |
3193 | rtl_merge_blocks, | |
6de9cd9a DN |
3194 | rtl_predict_edge, |
3195 | rtl_predicted_by_p, | |
3196 | NULL, /* can_duplicate_block_p */ | |
3197 | NULL, /* duplicate_block */ | |
f470c378 ZD |
3198 | rtl_split_edge, |
3199 | rtl_make_forwarder_block, | |
6de9cd9a | 3200 | rtl_tidy_fallthru_edge, |
cf103ca4 | 3201 | rtl_force_nonfallthru, |
6de9cd9a DN |
3202 | rtl_block_ends_with_call_p, |
3203 | rtl_block_ends_with_condjump_p, | |
d9d4706f KH |
3204 | rtl_flow_call_edges_add, |
3205 | NULL, /* execute_on_growing_pred */ | |
1cb7dfc3 MH |
3206 | NULL, /* execute_on_shrinking_pred */ |
3207 | NULL, /* duplicate loop for trees */ | |
3208 | NULL, /* lv_add_condition_to_bb */ | |
3209 | NULL, /* lv_adjust_loop_header_phi*/ | |
3210 | NULL, /* extract_cond_bb_edges */ | |
c22cacf3 | 3211 | NULL /* flush_pending_stmts */ |
9ee634e3 JH |
3212 | }; |
3213 | ||
3214 | /* Implementation of CFG manipulation for cfg layout RTL, where | |
3215 | basic block connected via fallthru edges does not have to be adjacent. | |
3216 | This representation will hopefully become the default one in future | |
3217 | version of the compiler. */ | |
6de9cd9a DN |
3218 | |
3219 | /* We do not want to declare these functions in a header file, since they | |
3220 | should only be used through the cfghooks interface, and we do not want to | |
3221 | move them here since it would require also moving quite a lot of related | |
6fb5fa3c | 3222 | code. They are in cfglayout.c. */ |
9678086d | 3223 | extern bool cfg_layout_can_duplicate_bb_p (const_basic_block); |
6de9cd9a DN |
3224 | extern basic_block cfg_layout_duplicate_bb (basic_block); |
3225 | ||
9ee634e3 | 3226 | struct cfg_hooks cfg_layout_rtl_cfg_hooks = { |
f470c378 | 3227 | "cfglayout mode", |
bc35512f | 3228 | rtl_verify_flow_info_1, |
10e9fecc | 3229 | rtl_dump_bb, |
bc35512f | 3230 | cfg_layout_create_basic_block, |
9ee634e3 JH |
3231 | cfg_layout_redirect_edge_and_branch, |
3232 | cfg_layout_redirect_edge_and_branch_force, | |
14fa2cc0 | 3233 | rtl_can_remove_branch_p, |
9ee634e3 JH |
3234 | cfg_layout_delete_block, |
3235 | cfg_layout_split_block, | |
f470c378 | 3236 | rtl_move_block_after, |
bc35512f JH |
3237 | cfg_layout_can_merge_blocks_p, |
3238 | cfg_layout_merge_blocks, | |
6de9cd9a DN |
3239 | rtl_predict_edge, |
3240 | rtl_predicted_by_p, | |
3241 | cfg_layout_can_duplicate_bb_p, | |
3242 | cfg_layout_duplicate_bb, | |
f470c378 ZD |
3243 | cfg_layout_split_edge, |
3244 | rtl_make_forwarder_block, | |
cf103ca4 EB |
3245 | NULL, /* tidy_fallthru_edge */ |
3246 | rtl_force_nonfallthru, | |
6de9cd9a DN |
3247 | rtl_block_ends_with_call_p, |
3248 | rtl_block_ends_with_condjump_p, | |
d9d4706f KH |
3249 | rtl_flow_call_edges_add, |
3250 | NULL, /* execute_on_growing_pred */ | |
1cb7dfc3 MH |
3251 | NULL, /* execute_on_shrinking_pred */ |
3252 | duplicate_loop_to_header_edge, /* duplicate loop for trees */ | |
3253 | rtl_lv_add_condition_to_bb, /* lv_add_condition_to_bb */ | |
3254 | NULL, /* lv_adjust_loop_header_phi*/ | |
3255 | rtl_extract_cond_bb_edges, /* extract_cond_bb_edges */ | |
c22cacf3 | 3256 | NULL /* flush_pending_stmts */ |
9ee634e3 | 3257 | }; |