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ca6c03ca JH |
1 | /* Control flow graph manipulation code for GNU compiler. |
2 | Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, | |
7072a650 | 3 | 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 |
6fb5fa3c | 4 | Free Software Foundation, Inc. |
ca6c03ca JH |
5 | |
6 | This file is part of GCC. | |
7 | ||
8 | GCC is free software; you can redistribute it and/or modify it under | |
9 | the terms of the GNU General Public License as published by the Free | |
9dcd6f09 | 10 | Software Foundation; either version 3, or (at your option) any later |
ca6c03ca JH |
11 | version. |
12 | ||
13 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
14 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
19 | along with GCC; see the file COPYING3. If not see |
20 | <http://www.gnu.org/licenses/>. */ | |
ca6c03ca | 21 | |
5f0d2358 RK |
22 | /* This file contains low level functions to manipulate the CFG and analyze it |
23 | that are aware of the RTL intermediate language. | |
ca6c03ca JH |
24 | |
25 | Available functionality: | |
bc35512f | 26 | - Basic CFG/RTL manipulation API documented in cfghooks.h |
5f0d2358 | 27 | - CFG-aware instruction chain manipulation |
ca6c03ca | 28 | delete_insn, delete_insn_chain |
bc35512f JH |
29 | - Edge splitting and committing to edges |
30 | insert_insn_on_edge, commit_edge_insertions | |
31 | - CFG updating after insn simplification | |
32 | purge_dead_edges, purge_all_dead_edges | |
33 | ||
34 | Functions not supposed for generic use: | |
5f0d2358 | 35 | - Infrastructure to determine quickly basic block for insn |
ca6c03ca | 36 | compute_bb_for_insn, update_bb_for_insn, set_block_for_insn, |
5f0d2358 | 37 | - Edge redirection with updating and optimizing of insn chain |
bc35512f | 38 | block_label, tidy_fallthru_edge, force_nonfallthru */ |
ca6c03ca JH |
39 | \f |
40 | #include "config.h" | |
41 | #include "system.h" | |
4977bab6 ZW |
42 | #include "coretypes.h" |
43 | #include "tm.h" | |
ca6c03ca JH |
44 | #include "tree.h" |
45 | #include "rtl.h" | |
46 | #include "hard-reg-set.h" | |
47 | #include "basic-block.h" | |
48 | #include "regs.h" | |
49 | #include "flags.h" | |
50 | #include "output.h" | |
51 | #include "function.h" | |
52 | #include "except.h" | |
53 | #include "toplev.h" | |
54 | #include "tm_p.h" | |
55 | #include "obstack.h" | |
0a2ed1f1 | 56 | #include "insn-config.h" |
9ee634e3 | 57 | #include "cfglayout.h" |
ff25ef99 | 58 | #include "expr.h" |
9fb32434 | 59 | #include "target.h" |
1cb7dfc3 | 60 | #include "cfgloop.h" |
5e2d947c | 61 | #include "ggc.h" |
ef330312 | 62 | #include "tree-pass.h" |
6fb5fa3c | 63 | #include "df.h" |
ca6c03ca | 64 | |
9678086d KG |
65 | static int can_delete_note_p (const_rtx); |
66 | static int can_delete_label_p (const_rtx); | |
d329e058 | 67 | static basic_block rtl_split_edge (edge); |
f470c378 | 68 | static bool rtl_move_block_after (basic_block, basic_block); |
d329e058 | 69 | static int rtl_verify_flow_info (void); |
f470c378 | 70 | static basic_block cfg_layout_split_block (basic_block, void *); |
6de9cd9a | 71 | static edge cfg_layout_redirect_edge_and_branch (edge, basic_block); |
d329e058 AJ |
72 | static basic_block cfg_layout_redirect_edge_and_branch_force (edge, basic_block); |
73 | static void cfg_layout_delete_block (basic_block); | |
74 | static void rtl_delete_block (basic_block); | |
75 | static basic_block rtl_redirect_edge_and_branch_force (edge, basic_block); | |
6de9cd9a | 76 | static edge rtl_redirect_edge_and_branch (edge, basic_block); |
f470c378 | 77 | static basic_block rtl_split_block (basic_block, void *); |
726a989a | 78 | static void rtl_dump_bb (basic_block, FILE *, int, int); |
d329e058 | 79 | static int rtl_verify_flow_info_1 (void); |
f470c378 | 80 | static void rtl_make_forwarder_block (edge); |
ca6c03ca JH |
81 | \f |
82 | /* Return true if NOTE is not one of the ones that must be kept paired, | |
5f0d2358 | 83 | so that we may simply delete it. */ |
ca6c03ca JH |
84 | |
85 | static int | |
9678086d | 86 | can_delete_note_p (const_rtx note) |
ca6c03ca | 87 | { |
a38e7aa5 JH |
88 | return (NOTE_KIND (note) == NOTE_INSN_DELETED |
89 | || NOTE_KIND (note) == NOTE_INSN_BASIC_BLOCK); | |
ca6c03ca JH |
90 | } |
91 | ||
92 | /* True if a given label can be deleted. */ | |
93 | ||
94 | static int | |
9678086d | 95 | can_delete_label_p (const_rtx label) |
ca6c03ca | 96 | { |
5f0d2358 RK |
97 | return (!LABEL_PRESERVE_P (label) |
98 | /* User declared labels must be preserved. */ | |
99 | && LABEL_NAME (label) == 0 | |
610d2478 | 100 | && !in_expr_list_p (forced_labels, label)); |
ca6c03ca JH |
101 | } |
102 | ||
103 | /* Delete INSN by patching it out. Return the next insn. */ | |
104 | ||
105 | rtx | |
d329e058 | 106 | delete_insn (rtx insn) |
ca6c03ca JH |
107 | { |
108 | rtx next = NEXT_INSN (insn); | |
109 | rtx note; | |
110 | bool really_delete = true; | |
111 | ||
4b4bf941 | 112 | if (LABEL_P (insn)) |
ca6c03ca JH |
113 | { |
114 | /* Some labels can't be directly removed from the INSN chain, as they | |
c22cacf3 MS |
115 | might be references via variables, constant pool etc. |
116 | Convert them to the special NOTE_INSN_DELETED_LABEL note. */ | |
ca6c03ca JH |
117 | if (! can_delete_label_p (insn)) |
118 | { | |
119 | const char *name = LABEL_NAME (insn); | |
120 | ||
121 | really_delete = false; | |
122 | PUT_CODE (insn, NOTE); | |
a38e7aa5 | 123 | NOTE_KIND (insn) = NOTE_INSN_DELETED_LABEL; |
6773e15f | 124 | NOTE_DELETED_LABEL_NAME (insn) = name; |
ca6c03ca | 125 | } |
5f0d2358 | 126 | |
ca6c03ca JH |
127 | remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels); |
128 | } | |
129 | ||
130 | if (really_delete) | |
131 | { | |
cda94cbb | 132 | /* If this insn has already been deleted, something is very wrong. */ |
341c100f | 133 | gcc_assert (!INSN_DELETED_P (insn)); |
ca6c03ca JH |
134 | remove_insn (insn); |
135 | INSN_DELETED_P (insn) = 1; | |
136 | } | |
137 | ||
138 | /* If deleting a jump, decrement the use count of the label. Deleting | |
139 | the label itself should happen in the normal course of block merging. */ | |
cf7c4aa6 | 140 | if (JUMP_P (insn)) |
9295a326 | 141 | { |
cf7c4aa6 HPN |
142 | if (JUMP_LABEL (insn) |
143 | && LABEL_P (JUMP_LABEL (insn))) | |
144 | LABEL_NUSES (JUMP_LABEL (insn))--; | |
145 | ||
146 | /* If there are more targets, remove them too. */ | |
147 | while ((note | |
148 | = find_reg_note (insn, REG_LABEL_TARGET, NULL_RTX)) != NULL_RTX | |
4b4bf941 | 149 | && LABEL_P (XEXP (note, 0))) |
9295a326 JZ |
150 | { |
151 | LABEL_NUSES (XEXP (note, 0))--; | |
152 | remove_note (insn, note); | |
153 | } | |
154 | } | |
ca6c03ca | 155 | |
cf7c4aa6 HPN |
156 | /* Also if deleting any insn that references a label as an operand. */ |
157 | while ((note = find_reg_note (insn, REG_LABEL_OPERAND, NULL_RTX)) != NULL_RTX | |
158 | && LABEL_P (XEXP (note, 0))) | |
159 | { | |
160 | LABEL_NUSES (XEXP (note, 0))--; | |
161 | remove_note (insn, note); | |
162 | } | |
163 | ||
4b4bf941 | 164 | if (JUMP_P (insn) |
ca6c03ca JH |
165 | && (GET_CODE (PATTERN (insn)) == ADDR_VEC |
166 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)) | |
167 | { | |
168 | rtx pat = PATTERN (insn); | |
169 | int diff_vec_p = GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC; | |
170 | int len = XVECLEN (pat, diff_vec_p); | |
171 | int i; | |
172 | ||
173 | for (i = 0; i < len; i++) | |
a124fcda RH |
174 | { |
175 | rtx label = XEXP (XVECEXP (pat, diff_vec_p, i), 0); | |
176 | ||
177 | /* When deleting code in bulk (e.g. removing many unreachable | |
178 | blocks) we can delete a label that's a target of the vector | |
179 | before deleting the vector itself. */ | |
4b4bf941 | 180 | if (!NOTE_P (label)) |
a124fcda RH |
181 | LABEL_NUSES (label)--; |
182 | } | |
ca6c03ca JH |
183 | } |
184 | ||
185 | return next; | |
186 | } | |
187 | ||
3dec4024 | 188 | /* Like delete_insn but also purge dead edges from BB. */ |
9ed7b221 | 189 | |
3dec4024 | 190 | rtx |
d329e058 | 191 | delete_insn_and_edges (rtx insn) |
3dec4024 JH |
192 | { |
193 | rtx x; | |
194 | bool purge = false; | |
195 | ||
ba4f7968 | 196 | if (INSN_P (insn) |
3dec4024 | 197 | && BLOCK_FOR_INSN (insn) |
a813c111 | 198 | && BB_END (BLOCK_FOR_INSN (insn)) == insn) |
3dec4024 JH |
199 | purge = true; |
200 | x = delete_insn (insn); | |
201 | if (purge) | |
202 | purge_dead_edges (BLOCK_FOR_INSN (insn)); | |
203 | return x; | |
204 | } | |
205 | ||
ca6c03ca | 206 | /* Unlink a chain of insns between START and FINISH, leaving notes |
a7b87f73 ZD |
207 | that must be paired. If CLEAR_BB is true, we set bb field for |
208 | insns that cannot be removed to NULL. */ | |
ca6c03ca JH |
209 | |
210 | void | |
a7b87f73 | 211 | delete_insn_chain (rtx start, rtx finish, bool clear_bb) |
ca6c03ca | 212 | { |
ca6c03ca JH |
213 | rtx next; |
214 | ||
5f0d2358 RK |
215 | /* Unchain the insns one by one. It would be quicker to delete all of these |
216 | with a single unchaining, rather than one at a time, but we need to keep | |
217 | the NOTE's. */ | |
ca6c03ca JH |
218 | while (1) |
219 | { | |
220 | next = NEXT_INSN (start); | |
4b4bf941 | 221 | if (NOTE_P (start) && !can_delete_note_p (start)) |
ca6c03ca JH |
222 | ; |
223 | else | |
224 | next = delete_insn (start); | |
225 | ||
a7b87f73 ZD |
226 | if (clear_bb && !INSN_DELETED_P (start)) |
227 | set_block_for_insn (start, NULL); | |
228 | ||
ca6c03ca JH |
229 | if (start == finish) |
230 | break; | |
231 | start = next; | |
232 | } | |
233 | } | |
234 | \f | |
5f0d2358 RK |
235 | /* Create a new basic block consisting of the instructions between HEAD and END |
236 | inclusive. This function is designed to allow fast BB construction - reuses | |
237 | the note and basic block struct in BB_NOTE, if any and do not grow | |
238 | BASIC_BLOCK chain and should be used directly only by CFG construction code. | |
239 | END can be NULL in to create new empty basic block before HEAD. Both END | |
918ed612 ZD |
240 | and HEAD can be NULL to create basic block at the end of INSN chain. |
241 | AFTER is the basic block we should be put after. */ | |
ca6c03ca JH |
242 | |
243 | basic_block | |
d329e058 | 244 | create_basic_block_structure (rtx head, rtx end, rtx bb_note, basic_block after) |
ca6c03ca JH |
245 | { |
246 | basic_block bb; | |
247 | ||
248 | if (bb_note | |
ca6c03ca JH |
249 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL |
250 | && bb->aux == NULL) | |
251 | { | |
252 | /* If we found an existing note, thread it back onto the chain. */ | |
253 | ||
254 | rtx after; | |
255 | ||
4b4bf941 | 256 | if (LABEL_P (head)) |
ca6c03ca JH |
257 | after = head; |
258 | else | |
259 | { | |
260 | after = PREV_INSN (head); | |
261 | head = bb_note; | |
262 | } | |
263 | ||
264 | if (after != bb_note && NEXT_INSN (after) != bb_note) | |
ba4f7968 | 265 | reorder_insns_nobb (bb_note, bb_note, after); |
ca6c03ca JH |
266 | } |
267 | else | |
268 | { | |
269 | /* Otherwise we must create a note and a basic block structure. */ | |
270 | ||
271 | bb = alloc_block (); | |
272 | ||
5e2d947c | 273 | init_rtl_bb_info (bb); |
ca6c03ca | 274 | if (!head && !end) |
5f0d2358 RK |
275 | head = end = bb_note |
276 | = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); | |
4b4bf941 | 277 | else if (LABEL_P (head) && end) |
ca6c03ca JH |
278 | { |
279 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); | |
280 | if (head == end) | |
281 | end = bb_note; | |
282 | } | |
283 | else | |
284 | { | |
285 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); | |
286 | head = bb_note; | |
287 | if (!end) | |
288 | end = head; | |
289 | } | |
5f0d2358 | 290 | |
ca6c03ca JH |
291 | NOTE_BASIC_BLOCK (bb_note) = bb; |
292 | } | |
293 | ||
294 | /* Always include the bb note in the block. */ | |
295 | if (NEXT_INSN (end) == bb_note) | |
296 | end = bb_note; | |
297 | ||
a813c111 SB |
298 | BB_HEAD (bb) = head; |
299 | BB_END (bb) = end; | |
852c6ec7 | 300 | bb->index = last_basic_block++; |
5e2d947c | 301 | bb->flags = BB_NEW | BB_RTL; |
918ed612 | 302 | link_block (bb, after); |
68f9b844 | 303 | SET_BASIC_BLOCK (bb->index, bb); |
6fb5fa3c | 304 | df_bb_refs_record (bb->index, false); |
ba4f7968 | 305 | update_bb_for_insn (bb); |
076c7ab8 | 306 | BB_SET_PARTITION (bb, BB_UNPARTITIONED); |
ca6c03ca JH |
307 | |
308 | /* Tag the block so that we know it has been used when considering | |
309 | other basic block notes. */ | |
310 | bb->aux = bb; | |
311 | ||
312 | return bb; | |
313 | } | |
314 | ||
5f0d2358 | 315 | /* Create new basic block consisting of instructions in between HEAD and END |
918ed612 | 316 | and place it to the BB chain after block AFTER. END can be NULL in to |
5f0d2358 RK |
317 | create new empty basic block before HEAD. Both END and HEAD can be NULL to |
318 | create basic block at the end of INSN chain. */ | |
ca6c03ca | 319 | |
bc35512f JH |
320 | static basic_block |
321 | rtl_create_basic_block (void *headp, void *endp, basic_block after) | |
ca6c03ca | 322 | { |
ae50c0cb | 323 | rtx head = (rtx) headp, end = (rtx) endp; |
ca6c03ca | 324 | basic_block bb; |
0b17ab2f | 325 | |
7eca0767 | 326 | /* Grow the basic block array if needed. */ |
68f9b844 | 327 | if ((size_t) last_basic_block >= VEC_length (basic_block, basic_block_info)) |
7eca0767 JH |
328 | { |
329 | size_t new_size = last_basic_block + (last_basic_block + 3) / 4; | |
a590ac65 | 330 | VEC_safe_grow_cleared (basic_block, gc, basic_block_info, new_size); |
7eca0767 | 331 | } |
0b17ab2f | 332 | |
bf77398c | 333 | n_basic_blocks++; |
ca6c03ca | 334 | |
852c6ec7 | 335 | bb = create_basic_block_structure (head, end, NULL, after); |
ca6c03ca JH |
336 | bb->aux = NULL; |
337 | return bb; | |
338 | } | |
bc35512f JH |
339 | |
340 | static basic_block | |
341 | cfg_layout_create_basic_block (void *head, void *end, basic_block after) | |
342 | { | |
343 | basic_block newbb = rtl_create_basic_block (head, end, after); | |
344 | ||
bc35512f JH |
345 | return newbb; |
346 | } | |
ca6c03ca JH |
347 | \f |
348 | /* Delete the insns in a (non-live) block. We physically delete every | |
349 | non-deleted-note insn, and update the flow graph appropriately. | |
350 | ||
351 | Return nonzero if we deleted an exception handler. */ | |
352 | ||
353 | /* ??? Preserving all such notes strikes me as wrong. It would be nice | |
354 | to post-process the stream to remove empty blocks, loops, ranges, etc. */ | |
355 | ||
f0fda11c | 356 | static void |
d329e058 | 357 | rtl_delete_block (basic_block b) |
ca6c03ca | 358 | { |
96370780 | 359 | rtx insn, end; |
ca6c03ca JH |
360 | |
361 | /* If the head of this block is a CODE_LABEL, then it might be the | |
f39e46ba SB |
362 | label for an exception handler which can't be reached. We need |
363 | to remove the label from the exception_handler_label list. */ | |
a813c111 | 364 | insn = BB_HEAD (b); |
ca6c03ca | 365 | |
96370780 | 366 | end = get_last_bb_insn (b); |
ca6c03ca JH |
367 | |
368 | /* Selectively delete the entire chain. */ | |
a813c111 | 369 | BB_HEAD (b) = NULL; |
a7b87f73 ZD |
370 | delete_insn_chain (insn, end, true); |
371 | ||
6fb5fa3c DB |
372 | |
373 | if (dump_file) | |
374 | fprintf (dump_file, "deleting block %d\n", b->index); | |
375 | df_bb_delete (b->index); | |
ca6c03ca JH |
376 | } |
377 | \f | |
852c6ec7 | 378 | /* Records the basic block struct in BLOCK_FOR_INSN for every insn. */ |
ca6c03ca JH |
379 | |
380 | void | |
d329e058 | 381 | compute_bb_for_insn (void) |
ca6c03ca | 382 | { |
e0082a72 | 383 | basic_block bb; |
ca6c03ca | 384 | |
e0082a72 | 385 | FOR_EACH_BB (bb) |
ca6c03ca | 386 | { |
a813c111 | 387 | rtx end = BB_END (bb); |
5f0d2358 | 388 | rtx insn; |
ca6c03ca | 389 | |
a813c111 | 390 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
ca6c03ca | 391 | { |
ba4f7968 | 392 | BLOCK_FOR_INSN (insn) = bb; |
ca6c03ca JH |
393 | if (insn == end) |
394 | break; | |
ca6c03ca JH |
395 | } |
396 | } | |
397 | } | |
398 | ||
399 | /* Release the basic_block_for_insn array. */ | |
400 | ||
c2924966 | 401 | unsigned int |
d329e058 | 402 | free_bb_for_insn (void) |
ca6c03ca | 403 | { |
ba4f7968 JH |
404 | rtx insn; |
405 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) | |
4b4bf941 | 406 | if (!BARRIER_P (insn)) |
ba4f7968 | 407 | BLOCK_FOR_INSN (insn) = NULL; |
c2924966 | 408 | return 0; |
ca6c03ca JH |
409 | } |
410 | ||
8ddbbcae | 411 | struct rtl_opt_pass pass_free_cfg = |
ef330312 | 412 | { |
8ddbbcae JH |
413 | { |
414 | RTL_PASS, | |
ef330312 PB |
415 | NULL, /* name */ |
416 | NULL, /* gate */ | |
417 | free_bb_for_insn, /* execute */ | |
418 | NULL, /* sub */ | |
419 | NULL, /* next */ | |
420 | 0, /* static_pass_number */ | |
7072a650 | 421 | TV_NONE, /* tv_id */ |
ef330312 PB |
422 | 0, /* properties_required */ |
423 | 0, /* properties_provided */ | |
424 | PROP_cfg, /* properties_destroyed */ | |
425 | 0, /* todo_flags_start */ | |
426 | 0, /* todo_flags_finish */ | |
8ddbbcae | 427 | } |
ef330312 PB |
428 | }; |
429 | ||
91278841 AP |
430 | /* Return RTX to emit after when we want to emit code on the entry of function. */ |
431 | rtx | |
432 | entry_of_function (void) | |
433 | { | |
c22cacf3 | 434 | return (n_basic_blocks > NUM_FIXED_BLOCKS ? |
24bd1a0b | 435 | BB_HEAD (ENTRY_BLOCK_PTR->next_bb) : get_insns ()); |
91278841 AP |
436 | } |
437 | ||
11b904a1 BS |
438 | /* Emit INSN at the entry point of the function, ensuring that it is only |
439 | executed once per function. */ | |
440 | void | |
441 | emit_insn_at_entry (rtx insn) | |
442 | { | |
443 | edge_iterator ei = ei_start (ENTRY_BLOCK_PTR->succs); | |
444 | edge e = ei_safe_edge (ei); | |
5419bc7f | 445 | gcc_assert (e->flags & EDGE_FALLTHRU); |
11b904a1 BS |
446 | |
447 | insert_insn_on_edge (insn, e); | |
448 | commit_edge_insertions (); | |
449 | } | |
450 | ||
6c3d0e31 SP |
451 | /* Update BLOCK_FOR_INSN of insns between BEGIN and END |
452 | (or BARRIER if found) and notify df of the bb change. | |
453 | The insn chain range is inclusive | |
454 | (i.e. both BEGIN and END will be updated. */ | |
ca6c03ca | 455 | |
6c3d0e31 SP |
456 | static void |
457 | update_bb_for_insn_chain (rtx begin, rtx end, basic_block bb) | |
ca6c03ca JH |
458 | { |
459 | rtx insn; | |
460 | ||
6c3d0e31 SP |
461 | end = NEXT_INSN (end); |
462 | for (insn = begin; insn != end; insn = NEXT_INSN (insn)) | |
63642d5a AO |
463 | if (!BARRIER_P (insn)) |
464 | df_insn_change_bb (insn, bb); | |
ca6c03ca | 465 | } |
6c3d0e31 SP |
466 | |
467 | /* Update BLOCK_FOR_INSN of insns in BB to BB, | |
468 | and notify df of the change. */ | |
469 | ||
470 | void | |
471 | update_bb_for_insn (basic_block bb) | |
472 | { | |
473 | update_bb_for_insn_chain (BB_HEAD (bb), BB_END (bb), bb); | |
474 | } | |
475 | ||
ca6c03ca | 476 | \f |
6fb5fa3c DB |
477 | /* Return the INSN immediately following the NOTE_INSN_BASIC_BLOCK |
478 | note associated with the BLOCK. */ | |
479 | ||
480 | static rtx | |
481 | first_insn_after_basic_block_note (basic_block block) | |
482 | { | |
483 | rtx insn; | |
484 | ||
485 | /* Get the first instruction in the block. */ | |
486 | insn = BB_HEAD (block); | |
487 | ||
488 | if (insn == NULL_RTX) | |
489 | return NULL_RTX; | |
490 | if (LABEL_P (insn)) | |
491 | insn = NEXT_INSN (insn); | |
492 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn)); | |
493 | ||
494 | return NEXT_INSN (insn); | |
495 | } | |
496 | ||
f470c378 ZD |
497 | /* Creates a new basic block just after basic block B by splitting |
498 | everything after specified instruction I. */ | |
ca6c03ca | 499 | |
f470c378 | 500 | static basic_block |
d329e058 | 501 | rtl_split_block (basic_block bb, void *insnp) |
ca6c03ca JH |
502 | { |
503 | basic_block new_bb; | |
ae50c0cb | 504 | rtx insn = (rtx) insnp; |
f470c378 | 505 | edge e; |
628f6a4e | 506 | edge_iterator ei; |
ca6c03ca | 507 | |
f470c378 ZD |
508 | if (!insn) |
509 | { | |
510 | insn = first_insn_after_basic_block_note (bb); | |
511 | ||
512 | if (insn) | |
513 | insn = PREV_INSN (insn); | |
514 | else | |
515 | insn = get_last_insn (); | |
516 | } | |
517 | ||
518 | /* We probably should check type of the insn so that we do not create | |
519 | inconsistent cfg. It is checked in verify_flow_info anyway, so do not | |
520 | bother. */ | |
521 | if (insn == BB_END (bb)) | |
522 | emit_note_after (NOTE_INSN_DELETED, insn); | |
ca6c03ca JH |
523 | |
524 | /* Create the new basic block. */ | |
a813c111 | 525 | new_bb = create_basic_block (NEXT_INSN (insn), BB_END (bb), bb); |
076c7ab8 | 526 | BB_COPY_PARTITION (new_bb, bb); |
a813c111 | 527 | BB_END (bb) = insn; |
ca6c03ca JH |
528 | |
529 | /* Redirect the outgoing edges. */ | |
628f6a4e BE |
530 | new_bb->succs = bb->succs; |
531 | bb->succs = NULL; | |
532 | FOR_EACH_EDGE (e, ei, new_bb->succs) | |
ca6c03ca JH |
533 | e->src = new_bb; |
534 | ||
6fb5fa3c DB |
535 | /* The new block starts off being dirty. */ |
536 | df_set_bb_dirty (bb); | |
f470c378 | 537 | return new_bb; |
bc35512f JH |
538 | } |
539 | ||
ca6c03ca | 540 | /* Blocks A and B are to be merged into a single block A. The insns |
bc35512f | 541 | are already contiguous. */ |
ca6c03ca | 542 | |
bc35512f JH |
543 | static void |
544 | rtl_merge_blocks (basic_block a, basic_block b) | |
ca6c03ca | 545 | { |
a813c111 | 546 | rtx b_head = BB_HEAD (b), b_end = BB_END (b), a_end = BB_END (a); |
ca6c03ca JH |
547 | rtx del_first = NULL_RTX, del_last = NULL_RTX; |
548 | int b_empty = 0; | |
549 | ||
6fb5fa3c DB |
550 | if (dump_file) |
551 | fprintf (dump_file, "merging block %d into block %d\n", b->index, a->index); | |
552 | ||
ca6c03ca | 553 | /* If there was a CODE_LABEL beginning B, delete it. */ |
4b4bf941 | 554 | if (LABEL_P (b_head)) |
ca6c03ca JH |
555 | { |
556 | /* Detect basic blocks with nothing but a label. This can happen | |
557 | in particular at the end of a function. */ | |
558 | if (b_head == b_end) | |
559 | b_empty = 1; | |
5f0d2358 | 560 | |
ca6c03ca JH |
561 | del_first = del_last = b_head; |
562 | b_head = NEXT_INSN (b_head); | |
563 | } | |
564 | ||
5f0d2358 RK |
565 | /* Delete the basic block note and handle blocks containing just that |
566 | note. */ | |
ca6c03ca JH |
567 | if (NOTE_INSN_BASIC_BLOCK_P (b_head)) |
568 | { | |
569 | if (b_head == b_end) | |
570 | b_empty = 1; | |
571 | if (! del_last) | |
572 | del_first = b_head; | |
5f0d2358 | 573 | |
ca6c03ca JH |
574 | del_last = b_head; |
575 | b_head = NEXT_INSN (b_head); | |
576 | } | |
577 | ||
578 | /* If there was a jump out of A, delete it. */ | |
4b4bf941 | 579 | if (JUMP_P (a_end)) |
ca6c03ca JH |
580 | { |
581 | rtx prev; | |
582 | ||
583 | for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev)) | |
4b4bf941 | 584 | if (!NOTE_P (prev) |
a38e7aa5 | 585 | || NOTE_INSN_BASIC_BLOCK_P (prev) |
a813c111 | 586 | || prev == BB_HEAD (a)) |
ca6c03ca JH |
587 | break; |
588 | ||
589 | del_first = a_end; | |
590 | ||
591 | #ifdef HAVE_cc0 | |
592 | /* If this was a conditional jump, we need to also delete | |
593 | the insn that set cc0. */ | |
594 | if (only_sets_cc0_p (prev)) | |
595 | { | |
596 | rtx tmp = prev; | |
5f0d2358 | 597 | |
ca6c03ca JH |
598 | prev = prev_nonnote_insn (prev); |
599 | if (!prev) | |
a813c111 | 600 | prev = BB_HEAD (a); |
ca6c03ca JH |
601 | del_first = tmp; |
602 | } | |
603 | #endif | |
604 | ||
605 | a_end = PREV_INSN (del_first); | |
606 | } | |
4b4bf941 | 607 | else if (BARRIER_P (NEXT_INSN (a_end))) |
ca6c03ca JH |
608 | del_first = NEXT_INSN (a_end); |
609 | ||
ca6c03ca JH |
610 | /* Delete everything marked above as well as crap that might be |
611 | hanging out between the two blocks. */ | |
f470c378 | 612 | BB_HEAD (b) = NULL; |
a7b87f73 | 613 | delete_insn_chain (del_first, del_last, true); |
ca6c03ca JH |
614 | |
615 | /* Reassociate the insns of B with A. */ | |
616 | if (!b_empty) | |
617 | { | |
6c3d0e31 | 618 | update_bb_for_insn_chain (a_end, b_end, a); |
5f0d2358 | 619 | |
ca6c03ca JH |
620 | a_end = b_end; |
621 | } | |
5f0d2358 | 622 | |
6fb5fa3c | 623 | df_bb_delete (b->index); |
a813c111 | 624 | BB_END (a) = a_end; |
ca6c03ca | 625 | } |
bc35512f | 626 | |
6fb5fa3c | 627 | |
bc35512f | 628 | /* Return true when block A and B can be merged. */ |
9678086d | 629 | |
b48d0358 DN |
630 | static bool |
631 | rtl_can_merge_blocks (basic_block a, basic_block b) | |
bc35512f | 632 | { |
750054a2 CT |
633 | /* If we are partitioning hot/cold basic blocks, we don't want to |
634 | mess up unconditional or indirect jumps that cross between hot | |
076c7ab8 ZW |
635 | and cold sections. |
636 | ||
8e8d5162 | 637 | Basic block partitioning may result in some jumps that appear to |
c22cacf3 MS |
638 | be optimizable (or blocks that appear to be mergeable), but which really |
639 | must be left untouched (they are required to make it safely across | |
640 | partition boundaries). See the comments at the top of | |
8e8d5162 | 641 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
076c7ab8 | 642 | |
87c8b4be | 643 | if (BB_PARTITION (a) != BB_PARTITION (b)) |
076c7ab8 | 644 | return false; |
750054a2 | 645 | |
bc35512f | 646 | /* There must be exactly one edge in between the blocks. */ |
c5cbcccf ZD |
647 | return (single_succ_p (a) |
648 | && single_succ (a) == b | |
649 | && single_pred_p (b) | |
628f6a4e | 650 | && a != b |
bc35512f | 651 | /* Must be simple edge. */ |
c5cbcccf | 652 | && !(single_succ_edge (a)->flags & EDGE_COMPLEX) |
bc35512f JH |
653 | && a->next_bb == b |
654 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR | |
655 | /* If the jump insn has side effects, | |
656 | we can't kill the edge. */ | |
4b4bf941 | 657 | && (!JUMP_P (BB_END (a)) |
e24e7211 | 658 | || (reload_completed |
a813c111 | 659 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f | 660 | } |
ca6c03ca | 661 | \f |
5f0d2358 RK |
662 | /* Return the label in the head of basic block BLOCK. Create one if it doesn't |
663 | exist. */ | |
ca6c03ca JH |
664 | |
665 | rtx | |
d329e058 | 666 | block_label (basic_block block) |
ca6c03ca JH |
667 | { |
668 | if (block == EXIT_BLOCK_PTR) | |
669 | return NULL_RTX; | |
5f0d2358 | 670 | |
4b4bf941 | 671 | if (!LABEL_P (BB_HEAD (block))) |
ca6c03ca | 672 | { |
a813c111 | 673 | BB_HEAD (block) = emit_label_before (gen_label_rtx (), BB_HEAD (block)); |
ca6c03ca | 674 | } |
5f0d2358 | 675 | |
a813c111 | 676 | return BB_HEAD (block); |
ca6c03ca JH |
677 | } |
678 | ||
679 | /* Attempt to perform edge redirection by replacing possibly complex jump | |
5f0d2358 RK |
680 | instruction by unconditional jump or removing jump completely. This can |
681 | apply only if all edges now point to the same block. The parameters and | |
682 | return values are equivalent to redirect_edge_and_branch. */ | |
ca6c03ca | 683 | |
6de9cd9a | 684 | edge |
bc35512f | 685 | try_redirect_by_replacing_jump (edge e, basic_block target, bool in_cfglayout) |
ca6c03ca JH |
686 | { |
687 | basic_block src = e->src; | |
a813c111 | 688 | rtx insn = BB_END (src), kill_from; |
e1233a7d | 689 | rtx set; |
ca6c03ca | 690 | int fallthru = 0; |
750054a2 CT |
691 | |
692 | /* If we are partitioning hot/cold basic blocks, we don't want to | |
693 | mess up unconditional or indirect jumps that cross between hot | |
8e8d5162 CT |
694 | and cold sections. |
695 | ||
696 | Basic block partitioning may result in some jumps that appear to | |
c22cacf3 MS |
697 | be optimizable (or blocks that appear to be mergeable), but which really |
698 | must be left untouched (they are required to make it safely across | |
699 | partition boundaries). See the comments at the top of | |
8e8d5162 | 700 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
c22cacf3 | 701 | |
87c8b4be CT |
702 | if (find_reg_note (insn, REG_CROSSING_JUMP, NULL_RTX) |
703 | || BB_PARTITION (src) != BB_PARTITION (target)) | |
9cf84a3c | 704 | return NULL; |
750054a2 | 705 | |
6a66a8a7 KH |
706 | /* We can replace or remove a complex jump only when we have exactly |
707 | two edges. Also, if we have exactly one outgoing edge, we can | |
708 | redirect that. */ | |
709 | if (EDGE_COUNT (src->succs) >= 3 | |
710 | /* Verify that all targets will be TARGET. Specifically, the | |
711 | edge that is not E must also go to TARGET. */ | |
712 | || (EDGE_COUNT (src->succs) == 2 | |
713 | && EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)) | |
714 | return NULL; | |
5f0d2358 | 715 | |
6a66a8a7 | 716 | if (!onlyjump_p (insn)) |
6de9cd9a | 717 | return NULL; |
3348b696 | 718 | if ((!optimize || reload_completed) && tablejump_p (insn, NULL, NULL)) |
6de9cd9a | 719 | return NULL; |
ca6c03ca JH |
720 | |
721 | /* Avoid removing branch with side effects. */ | |
722 | set = single_set (insn); | |
723 | if (!set || side_effects_p (set)) | |
6de9cd9a | 724 | return NULL; |
ca6c03ca JH |
725 | |
726 | /* In case we zap a conditional jump, we'll need to kill | |
727 | the cc0 setter too. */ | |
728 | kill_from = insn; | |
729 | #ifdef HAVE_cc0 | |
9caea4a7 RS |
730 | if (reg_mentioned_p (cc0_rtx, PATTERN (insn)) |
731 | && only_sets_cc0_p (PREV_INSN (insn))) | |
ca6c03ca JH |
732 | kill_from = PREV_INSN (insn); |
733 | #endif | |
734 | ||
735 | /* See if we can create the fallthru edge. */ | |
bc35512f | 736 | if (in_cfglayout || can_fallthru (src, target)) |
ca6c03ca | 737 | { |
c263766c RH |
738 | if (dump_file) |
739 | fprintf (dump_file, "Removing jump %i.\n", INSN_UID (insn)); | |
ca6c03ca JH |
740 | fallthru = 1; |
741 | ||
eaec9b3d | 742 | /* Selectively unlink whole insn chain. */ |
bc35512f JH |
743 | if (in_cfglayout) |
744 | { | |
370369e1 | 745 | rtx insn = src->il.rtl->footer; |
bc35512f | 746 | |
a7b87f73 | 747 | delete_insn_chain (kill_from, BB_END (src), false); |
bc35512f JH |
748 | |
749 | /* Remove barriers but keep jumptables. */ | |
750 | while (insn) | |
751 | { | |
4b4bf941 | 752 | if (BARRIER_P (insn)) |
bc35512f JH |
753 | { |
754 | if (PREV_INSN (insn)) | |
755 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
756 | else | |
370369e1 | 757 | src->il.rtl->footer = NEXT_INSN (insn); |
bc35512f JH |
758 | if (NEXT_INSN (insn)) |
759 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
760 | } | |
4b4bf941 | 761 | if (LABEL_P (insn)) |
bc35512f JH |
762 | break; |
763 | insn = NEXT_INSN (insn); | |
764 | } | |
765 | } | |
766 | else | |
a7b87f73 ZD |
767 | delete_insn_chain (kill_from, PREV_INSN (BB_HEAD (target)), |
768 | false); | |
ca6c03ca | 769 | } |
5f0d2358 | 770 | |
ca6c03ca JH |
771 | /* If this already is simplejump, redirect it. */ |
772 | else if (simplejump_p (insn)) | |
773 | { | |
774 | if (e->dest == target) | |
6de9cd9a | 775 | return NULL; |
c263766c RH |
776 | if (dump_file) |
777 | fprintf (dump_file, "Redirecting jump %i from %i to %i.\n", | |
0b17ab2f | 778 | INSN_UID (insn), e->dest->index, target->index); |
6ee3c8e4 JJ |
779 | if (!redirect_jump (insn, block_label (target), 0)) |
780 | { | |
341c100f NS |
781 | gcc_assert (target == EXIT_BLOCK_PTR); |
782 | return NULL; | |
6ee3c8e4 | 783 | } |
ca6c03ca | 784 | } |
5f0d2358 | 785 | |
6ee3c8e4 JJ |
786 | /* Cannot do anything for target exit block. */ |
787 | else if (target == EXIT_BLOCK_PTR) | |
6de9cd9a | 788 | return NULL; |
6ee3c8e4 | 789 | |
ca6c03ca JH |
790 | /* Or replace possibly complicated jump insn by simple jump insn. */ |
791 | else | |
792 | { | |
793 | rtx target_label = block_label (target); | |
eb5b8ad4 | 794 | rtx barrier, label, table; |
ca6c03ca | 795 | |
a7102479 | 796 | emit_jump_insn_after_noloc (gen_jump (target_label), insn); |
a813c111 | 797 | JUMP_LABEL (BB_END (src)) = target_label; |
ca6c03ca | 798 | LABEL_NUSES (target_label)++; |
c263766c RH |
799 | if (dump_file) |
800 | fprintf (dump_file, "Replacing insn %i by jump %i\n", | |
a813c111 | 801 | INSN_UID (insn), INSN_UID (BB_END (src))); |
ca6c03ca | 802 | |
4da2eb6b | 803 | |
ba4807a0 LB |
804 | delete_insn_chain (kill_from, insn, false); |
805 | ||
4da2eb6b RH |
806 | /* Recognize a tablejump that we are converting to a |
807 | simple jump and remove its associated CODE_LABEL | |
808 | and ADDR_VEC or ADDR_DIFF_VEC. */ | |
ba4807a0 LB |
809 | if (tablejump_p (insn, &label, &table)) |
810 | delete_insn_chain (label, table, false); | |
eb5b8ad4 | 811 | |
a813c111 | 812 | barrier = next_nonnote_insn (BB_END (src)); |
4b4bf941 | 813 | if (!barrier || !BARRIER_P (barrier)) |
a813c111 | 814 | emit_barrier_after (BB_END (src)); |
5d693491 JZ |
815 | else |
816 | { | |
a813c111 | 817 | if (barrier != NEXT_INSN (BB_END (src))) |
5d693491 JZ |
818 | { |
819 | /* Move the jump before barrier so that the notes | |
820 | which originally were or were created before jump table are | |
821 | inside the basic block. */ | |
a813c111 | 822 | rtx new_insn = BB_END (src); |
5d693491 | 823 | |
6c3d0e31 SP |
824 | update_bb_for_insn_chain (NEXT_INSN (BB_END (src)), |
825 | PREV_INSN (barrier), src); | |
5d693491 JZ |
826 | |
827 | NEXT_INSN (PREV_INSN (new_insn)) = NEXT_INSN (new_insn); | |
828 | PREV_INSN (NEXT_INSN (new_insn)) = PREV_INSN (new_insn); | |
829 | ||
830 | NEXT_INSN (new_insn) = barrier; | |
831 | NEXT_INSN (PREV_INSN (barrier)) = new_insn; | |
832 | ||
833 | PREV_INSN (new_insn) = PREV_INSN (barrier); | |
834 | PREV_INSN (barrier) = new_insn; | |
835 | } | |
836 | } | |
ca6c03ca JH |
837 | } |
838 | ||
839 | /* Keep only one edge out and set proper flags. */ | |
c5cbcccf | 840 | if (!single_succ_p (src)) |
628f6a4e | 841 | remove_edge (e); |
c5cbcccf | 842 | gcc_assert (single_succ_p (src)); |
628f6a4e | 843 | |
c5cbcccf | 844 | e = single_succ_edge (src); |
ca6c03ca JH |
845 | if (fallthru) |
846 | e->flags = EDGE_FALLTHRU; | |
847 | else | |
848 | e->flags = 0; | |
5f0d2358 | 849 | |
ca6c03ca JH |
850 | e->probability = REG_BR_PROB_BASE; |
851 | e->count = src->count; | |
852 | ||
ca6c03ca JH |
853 | if (e->dest != target) |
854 | redirect_edge_succ (e, target); | |
6de9cd9a | 855 | return e; |
ca6c03ca JH |
856 | } |
857 | ||
4e3825db MM |
858 | /* Subroutine of redirect_branch_edge that tries to patch the jump |
859 | instruction INSN so that it reaches block NEW. Do this | |
860 | only when it originally reached block OLD. Return true if this | |
861 | worked or the original target wasn't OLD, return false if redirection | |
862 | doesn't work. */ | |
863 | ||
864 | static bool | |
865 | patch_jump_insn (rtx insn, rtx old_label, basic_block new_bb) | |
ca6c03ca JH |
866 | { |
867 | rtx tmp; | |
ca6c03ca | 868 | /* Recognize a tablejump and adjust all matching cases. */ |
e1233a7d | 869 | if (tablejump_p (insn, NULL, &tmp)) |
ca6c03ca JH |
870 | { |
871 | rtvec vec; | |
872 | int j; | |
4e3825db | 873 | rtx new_label = block_label (new_bb); |
ca6c03ca | 874 | |
4e3825db MM |
875 | if (new_bb == EXIT_BLOCK_PTR) |
876 | return false; | |
ca6c03ca JH |
877 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) |
878 | vec = XVEC (PATTERN (tmp), 0); | |
879 | else | |
880 | vec = XVEC (PATTERN (tmp), 1); | |
881 | ||
882 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
883 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
884 | { | |
885 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (Pmode, new_label); | |
886 | --LABEL_NUSES (old_label); | |
887 | ++LABEL_NUSES (new_label); | |
888 | } | |
889 | ||
f9da5064 | 890 | /* Handle casesi dispatch insns. */ |
ca6c03ca JH |
891 | if ((tmp = single_set (insn)) != NULL |
892 | && SET_DEST (tmp) == pc_rtx | |
893 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
894 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF | |
895 | && XEXP (XEXP (SET_SRC (tmp), 2), 0) == old_label) | |
896 | { | |
4c33cb26 | 897 | XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (Pmode, |
ca6c03ca JH |
898 | new_label); |
899 | --LABEL_NUSES (old_label); | |
900 | ++LABEL_NUSES (new_label); | |
901 | } | |
902 | } | |
903 | else | |
904 | { | |
905 | /* ?? We may play the games with moving the named labels from | |
906 | one basic block to the other in case only one computed_jump is | |
907 | available. */ | |
5f0d2358 RK |
908 | if (computed_jump_p (insn) |
909 | /* A return instruction can't be redirected. */ | |
910 | || returnjump_p (insn)) | |
4e3825db | 911 | return false; |
6ee3c8e4 | 912 | |
4e3825db | 913 | if (!currently_expanding_to_rtl || JUMP_LABEL (insn) == old_label) |
6ee3c8e4 | 914 | { |
4e3825db MM |
915 | /* If the insn doesn't go where we think, we're confused. */ |
916 | gcc_assert (JUMP_LABEL (insn) == old_label); | |
917 | ||
918 | /* If the substitution doesn't succeed, die. This can happen | |
919 | if the back end emitted unrecognizable instructions or if | |
920 | target is exit block on some arches. */ | |
921 | if (!redirect_jump (insn, block_label (new_bb), 0)) | |
922 | { | |
923 | gcc_assert (new_bb == EXIT_BLOCK_PTR); | |
924 | return false; | |
925 | } | |
6ee3c8e4 | 926 | } |
ca6c03ca | 927 | } |
4e3825db MM |
928 | return true; |
929 | } | |
930 | ||
931 | ||
932 | /* Redirect edge representing branch of (un)conditional jump or tablejump, | |
933 | NULL on failure */ | |
934 | static edge | |
935 | redirect_branch_edge (edge e, basic_block target) | |
936 | { | |
937 | rtx old_label = BB_HEAD (e->dest); | |
938 | basic_block src = e->src; | |
939 | rtx insn = BB_END (src); | |
940 | ||
941 | /* We can only redirect non-fallthru edges of jump insn. */ | |
942 | if (e->flags & EDGE_FALLTHRU) | |
943 | return NULL; | |
944 | else if (!JUMP_P (insn) && !currently_expanding_to_rtl) | |
945 | return NULL; | |
946 | ||
947 | if (!currently_expanding_to_rtl) | |
948 | { | |
949 | if (!patch_jump_insn (insn, old_label, target)) | |
950 | return NULL; | |
951 | } | |
952 | else | |
953 | /* When expanding this BB might actually contain multiple | |
954 | jumps (i.e. not yet split by find_many_sub_basic_blocks). | |
955 | Redirect all of those that match our label. */ | |
956 | for (insn = BB_HEAD (src); insn != NEXT_INSN (BB_END (src)); | |
957 | insn = NEXT_INSN (insn)) | |
958 | if (JUMP_P (insn) && !patch_jump_insn (insn, old_label, target)) | |
959 | return NULL; | |
ca6c03ca | 960 | |
c263766c RH |
961 | if (dump_file) |
962 | fprintf (dump_file, "Edge %i->%i redirected to %i\n", | |
0b17ab2f | 963 | e->src->index, e->dest->index, target->index); |
5f0d2358 | 964 | |
ca6c03ca | 965 | if (e->dest != target) |
6de9cd9a | 966 | e = redirect_edge_succ_nodup (e, target); |
6fb5fa3c | 967 | |
6de9cd9a | 968 | return e; |
bc35512f JH |
969 | } |
970 | ||
971 | /* Attempt to change code to redirect edge E to TARGET. Don't do that on | |
972 | expense of adding new instructions or reordering basic blocks. | |
973 | ||
974 | Function can be also called with edge destination equivalent to the TARGET. | |
975 | Then it should try the simplifications and do nothing if none is possible. | |
976 | ||
6de9cd9a DN |
977 | Return edge representing the branch if transformation succeeded. Return NULL |
978 | on failure. | |
979 | We still return NULL in case E already destinated TARGET and we didn't | |
980 | managed to simplify instruction stream. */ | |
bc35512f | 981 | |
6de9cd9a | 982 | static edge |
5671bf27 | 983 | rtl_redirect_edge_and_branch (edge e, basic_block target) |
bc35512f | 984 | { |
6de9cd9a | 985 | edge ret; |
f345f21a JH |
986 | basic_block src = e->src; |
987 | ||
bc35512f | 988 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
6de9cd9a | 989 | return NULL; |
bc35512f | 990 | |
3348b696 | 991 | if (e->dest == target) |
6de9cd9a | 992 | return e; |
3348b696 | 993 | |
6de9cd9a | 994 | if ((ret = try_redirect_by_replacing_jump (e, target, false)) != NULL) |
f345f21a | 995 | { |
6fb5fa3c | 996 | df_set_bb_dirty (src); |
6de9cd9a | 997 | return ret; |
f345f21a | 998 | } |
bc35512f | 999 | |
6de9cd9a DN |
1000 | ret = redirect_branch_edge (e, target); |
1001 | if (!ret) | |
1002 | return NULL; | |
5f0d2358 | 1003 | |
6fb5fa3c | 1004 | df_set_bb_dirty (src); |
6de9cd9a | 1005 | return ret; |
ca6c03ca JH |
1006 | } |
1007 | ||
4fe9b91c | 1008 | /* Like force_nonfallthru below, but additionally performs redirection |
ca6c03ca JH |
1009 | Used by redirect_edge_and_branch_force. */ |
1010 | ||
9167e1c0 | 1011 | static basic_block |
d329e058 | 1012 | force_nonfallthru_and_redirect (edge e, basic_block target) |
ca6c03ca | 1013 | { |
a3716585 | 1014 | basic_block jump_block, new_bb = NULL, src = e->src; |
ca6c03ca JH |
1015 | rtx note; |
1016 | edge new_edge; | |
a3716585 | 1017 | int abnormal_edge_flags = 0; |
7241571e | 1018 | int loc; |
ca6c03ca | 1019 | |
cb9a1d9b JH |
1020 | /* In the case the last instruction is conditional jump to the next |
1021 | instruction, first redirect the jump itself and then continue | |
b20b352b | 1022 | by creating a basic block afterwards to redirect fallthru edge. */ |
cb9a1d9b | 1023 | if (e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR |
a813c111 | 1024 | && any_condjump_p (BB_END (e->src)) |
a813c111 | 1025 | && JUMP_LABEL (BB_END (e->src)) == BB_HEAD (e->dest)) |
cb9a1d9b JH |
1026 | { |
1027 | rtx note; | |
58e6ae30 | 1028 | edge b = unchecked_make_edge (e->src, target, 0); |
341c100f | 1029 | bool redirected; |
cb9a1d9b | 1030 | |
341c100f NS |
1031 | redirected = redirect_jump (BB_END (e->src), block_label (target), 0); |
1032 | gcc_assert (redirected); | |
c22cacf3 | 1033 | |
a813c111 | 1034 | note = find_reg_note (BB_END (e->src), REG_BR_PROB, NULL_RTX); |
cb9a1d9b JH |
1035 | if (note) |
1036 | { | |
1037 | int prob = INTVAL (XEXP (note, 0)); | |
1038 | ||
1039 | b->probability = prob; | |
1040 | b->count = e->count * prob / REG_BR_PROB_BASE; | |
1041 | e->probability -= e->probability; | |
1042 | e->count -= b->count; | |
1043 | if (e->probability < 0) | |
1044 | e->probability = 0; | |
1045 | if (e->count < 0) | |
1046 | e->count = 0; | |
1047 | } | |
1048 | } | |
1049 | ||
ca6c03ca | 1050 | if (e->flags & EDGE_ABNORMAL) |
a3716585 JH |
1051 | { |
1052 | /* Irritating special case - fallthru edge to the same block as abnormal | |
1053 | edge. | |
1054 | We can't redirect abnormal edge, but we still can split the fallthru | |
d329e058 | 1055 | one and create separate abnormal edge to original destination. |
a3716585 | 1056 | This allows bb-reorder to make such edge non-fallthru. */ |
341c100f | 1057 | gcc_assert (e->dest == target); |
a3716585 JH |
1058 | abnormal_edge_flags = e->flags & ~(EDGE_FALLTHRU | EDGE_CAN_FALLTHRU); |
1059 | e->flags &= EDGE_FALLTHRU | EDGE_CAN_FALLTHRU; | |
1060 | } | |
341c100f | 1061 | else |
24c545ff | 1062 | { |
341c100f NS |
1063 | gcc_assert (e->flags & EDGE_FALLTHRU); |
1064 | if (e->src == ENTRY_BLOCK_PTR) | |
1065 | { | |
1066 | /* We can't redirect the entry block. Create an empty block | |
628f6a4e BE |
1067 | at the start of the function which we use to add the new |
1068 | jump. */ | |
1069 | edge tmp; | |
1070 | edge_iterator ei; | |
1071 | bool found = false; | |
c22cacf3 | 1072 | |
628f6a4e | 1073 | basic_block bb = create_basic_block (BB_HEAD (e->dest), NULL, ENTRY_BLOCK_PTR); |
c22cacf3 | 1074 | |
341c100f NS |
1075 | /* Change the existing edge's source to be the new block, and add |
1076 | a new edge from the entry block to the new block. */ | |
1077 | e->src = bb; | |
628f6a4e BE |
1078 | for (ei = ei_start (ENTRY_BLOCK_PTR->succs); (tmp = ei_safe_edge (ei)); ) |
1079 | { | |
1080 | if (tmp == e) | |
1081 | { | |
865851d0 | 1082 | VEC_unordered_remove (edge, ENTRY_BLOCK_PTR->succs, ei.index); |
628f6a4e BE |
1083 | found = true; |
1084 | break; | |
1085 | } | |
1086 | else | |
1087 | ei_next (&ei); | |
1088 | } | |
c22cacf3 | 1089 | |
628f6a4e | 1090 | gcc_assert (found); |
c22cacf3 | 1091 | |
d4e6fecb | 1092 | VEC_safe_push (edge, gc, bb->succs, e); |
341c100f NS |
1093 | make_single_succ_edge (ENTRY_BLOCK_PTR, bb, EDGE_FALLTHRU); |
1094 | } | |
24c545ff BS |
1095 | } |
1096 | ||
628f6a4e | 1097 | if (EDGE_COUNT (e->src->succs) >= 2 || abnormal_edge_flags) |
ca6c03ca JH |
1098 | { |
1099 | /* Create the new structures. */ | |
31a78298 | 1100 | |
79019985 RH |
1101 | /* If the old block ended with a tablejump, skip its table |
1102 | by searching forward from there. Otherwise start searching | |
1103 | forward from the last instruction of the old block. */ | |
a813c111 SB |
1104 | if (!tablejump_p (BB_END (e->src), NULL, ¬e)) |
1105 | note = BB_END (e->src); | |
31a78298 RH |
1106 | note = NEXT_INSN (note); |
1107 | ||
31a78298 | 1108 | jump_block = create_basic_block (note, NULL, e->src); |
ca6c03ca JH |
1109 | jump_block->count = e->count; |
1110 | jump_block->frequency = EDGE_FREQUENCY (e); | |
1111 | jump_block->loop_depth = target->loop_depth; | |
1112 | ||
750054a2 CT |
1113 | /* Make sure new block ends up in correct hot/cold section. */ |
1114 | ||
076c7ab8 | 1115 | BB_COPY_PARTITION (jump_block, e->src); |
9fb32434 | 1116 | if (flag_reorder_blocks_and_partition |
87c8b4be CT |
1117 | && targetm.have_named_sections |
1118 | && JUMP_P (BB_END (jump_block)) | |
1119 | && !any_condjump_p (BB_END (jump_block)) | |
1120 | && (EDGE_SUCC (jump_block, 0)->flags & EDGE_CROSSING)) | |
65c5f2a6 | 1121 | add_reg_note (BB_END (jump_block), REG_CROSSING_JUMP, NULL_RTX); |
c22cacf3 | 1122 | |
ca6c03ca JH |
1123 | /* Wire edge in. */ |
1124 | new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU); | |
1125 | new_edge->probability = e->probability; | |
1126 | new_edge->count = e->count; | |
1127 | ||
1128 | /* Redirect old edge. */ | |
1129 | redirect_edge_pred (e, jump_block); | |
1130 | e->probability = REG_BR_PROB_BASE; | |
1131 | ||
1132 | new_bb = jump_block; | |
1133 | } | |
1134 | else | |
1135 | jump_block = e->src; | |
5f0d2358 | 1136 | |
7241571e JJ |
1137 | if (e->goto_locus && e->goto_block == NULL) |
1138 | loc = e->goto_locus; | |
1139 | else | |
1140 | loc = 0; | |
ca6c03ca JH |
1141 | e->flags &= ~EDGE_FALLTHRU; |
1142 | if (target == EXIT_BLOCK_PTR) | |
1143 | { | |
cf22ce3c | 1144 | #ifdef HAVE_return |
7241571e | 1145 | emit_jump_insn_after_setloc (gen_return (), BB_END (jump_block), loc); |
cf22ce3c | 1146 | #else |
341c100f | 1147 | gcc_unreachable (); |
cf22ce3c | 1148 | #endif |
ca6c03ca JH |
1149 | } |
1150 | else | |
1151 | { | |
1152 | rtx label = block_label (target); | |
7241571e | 1153 | emit_jump_insn_after_setloc (gen_jump (label), BB_END (jump_block), loc); |
a813c111 | 1154 | JUMP_LABEL (BB_END (jump_block)) = label; |
ca6c03ca JH |
1155 | LABEL_NUSES (label)++; |
1156 | } | |
5f0d2358 | 1157 | |
a813c111 | 1158 | emit_barrier_after (BB_END (jump_block)); |
ca6c03ca JH |
1159 | redirect_edge_succ_nodup (e, target); |
1160 | ||
a3716585 JH |
1161 | if (abnormal_edge_flags) |
1162 | make_edge (src, target, abnormal_edge_flags); | |
1163 | ||
6fb5fa3c | 1164 | df_mark_solutions_dirty (); |
ca6c03ca JH |
1165 | return new_bb; |
1166 | } | |
1167 | ||
1168 | /* Edge E is assumed to be fallthru edge. Emit needed jump instruction | |
1169 | (and possibly create new basic block) to make edge non-fallthru. | |
1170 | Return newly created BB or NULL if none. */ | |
5f0d2358 | 1171 | |
ca6c03ca | 1172 | basic_block |
d329e058 | 1173 | force_nonfallthru (edge e) |
ca6c03ca JH |
1174 | { |
1175 | return force_nonfallthru_and_redirect (e, e->dest); | |
1176 | } | |
1177 | ||
1178 | /* Redirect edge even at the expense of creating new jump insn or | |
1179 | basic block. Return new basic block if created, NULL otherwise. | |
41806d92 | 1180 | Conversion must be possible. */ |
ca6c03ca | 1181 | |
9ee634e3 | 1182 | static basic_block |
d329e058 | 1183 | rtl_redirect_edge_and_branch_force (edge e, basic_block target) |
ca6c03ca | 1184 | { |
5f0d2358 RK |
1185 | if (redirect_edge_and_branch (e, target) |
1186 | || e->dest == target) | |
ca6c03ca JH |
1187 | return NULL; |
1188 | ||
1189 | /* In case the edge redirection failed, try to force it to be non-fallthru | |
1190 | and redirect newly created simplejump. */ | |
6fb5fa3c | 1191 | df_set_bb_dirty (e->src); |
5f0d2358 | 1192 | return force_nonfallthru_and_redirect (e, target); |
ca6c03ca JH |
1193 | } |
1194 | ||
1195 | /* The given edge should potentially be a fallthru edge. If that is in | |
1196 | fact true, delete the jump and barriers that are in the way. */ | |
1197 | ||
f470c378 ZD |
1198 | static void |
1199 | rtl_tidy_fallthru_edge (edge e) | |
ca6c03ca JH |
1200 | { |
1201 | rtx q; | |
f470c378 ZD |
1202 | basic_block b = e->src, c = b->next_bb; |
1203 | ||
ca6c03ca JH |
1204 | /* ??? In a late-running flow pass, other folks may have deleted basic |
1205 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
0fa2e4df | 1206 | and the target label. They ought to be chastised and fixed. |
ca6c03ca JH |
1207 | |
1208 | We can also wind up with a sequence of undeletable labels between | |
1209 | one block and the next. | |
1210 | ||
1211 | So search through a sequence of barriers, labels, and notes for | |
1212 | the head of block C and assert that we really do fall through. */ | |
1213 | ||
a813c111 | 1214 | for (q = NEXT_INSN (BB_END (b)); q != BB_HEAD (c); q = NEXT_INSN (q)) |
9c0a0632 RH |
1215 | if (INSN_P (q)) |
1216 | return; | |
ca6c03ca JH |
1217 | |
1218 | /* Remove what will soon cease being the jump insn from the source block. | |
1219 | If block B consisted only of this single jump, turn it into a deleted | |
1220 | note. */ | |
a813c111 | 1221 | q = BB_END (b); |
4b4bf941 | 1222 | if (JUMP_P (q) |
ca6c03ca JH |
1223 | && onlyjump_p (q) |
1224 | && (any_uncondjump_p (q) | |
c5cbcccf | 1225 | || single_succ_p (b))) |
ca6c03ca JH |
1226 | { |
1227 | #ifdef HAVE_cc0 | |
1228 | /* If this was a conditional jump, we need to also delete | |
1229 | the insn that set cc0. */ | |
1230 | if (any_condjump_p (q) && only_sets_cc0_p (PREV_INSN (q))) | |
1231 | q = PREV_INSN (q); | |
1232 | #endif | |
1233 | ||
1234 | q = PREV_INSN (q); | |
ca6c03ca JH |
1235 | } |
1236 | ||
1237 | /* Selectively unlink the sequence. */ | |
a813c111 | 1238 | if (q != PREV_INSN (BB_HEAD (c))) |
a7b87f73 | 1239 | delete_insn_chain (NEXT_INSN (q), PREV_INSN (BB_HEAD (c)), false); |
ca6c03ca JH |
1240 | |
1241 | e->flags |= EDGE_FALLTHRU; | |
1242 | } | |
ca6c03ca | 1243 | \f |
f470c378 ZD |
1244 | /* Should move basic block BB after basic block AFTER. NIY. */ |
1245 | ||
1246 | static bool | |
1247 | rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED, | |
1248 | basic_block after ATTRIBUTE_UNUSED) | |
1249 | { | |
1250 | return false; | |
1251 | } | |
1252 | ||
ca6c03ca | 1253 | /* Split a (typically critical) edge. Return the new block. |
41806d92 | 1254 | The edge must not be abnormal. |
ca6c03ca JH |
1255 | |
1256 | ??? The code generally expects to be called on critical edges. | |
1257 | The case of a block ending in an unconditional jump to a | |
1258 | block with multiple predecessors is not handled optimally. */ | |
1259 | ||
8ce33230 | 1260 | static basic_block |
d329e058 | 1261 | rtl_split_edge (edge edge_in) |
ca6c03ca JH |
1262 | { |
1263 | basic_block bb; | |
ca6c03ca JH |
1264 | rtx before; |
1265 | ||
1266 | /* Abnormal edges cannot be split. */ | |
341c100f | 1267 | gcc_assert (!(edge_in->flags & EDGE_ABNORMAL)); |
ca6c03ca JH |
1268 | |
1269 | /* We are going to place the new block in front of edge destination. | |
eaec9b3d | 1270 | Avoid existence of fallthru predecessors. */ |
ca6c03ca JH |
1271 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) |
1272 | { | |
1273 | edge e; | |
628f6a4e | 1274 | edge_iterator ei; |
5f0d2358 | 1275 | |
628f6a4e | 1276 | FOR_EACH_EDGE (e, ei, edge_in->dest->preds) |
ca6c03ca JH |
1277 | if (e->flags & EDGE_FALLTHRU) |
1278 | break; | |
1279 | ||
1280 | if (e) | |
1281 | force_nonfallthru (e); | |
1282 | } | |
1283 | ||
96e82e0a ZD |
1284 | /* Create the basic block note. */ |
1285 | if (edge_in->dest != EXIT_BLOCK_PTR) | |
a813c111 | 1286 | before = BB_HEAD (edge_in->dest); |
ca6c03ca JH |
1287 | else |
1288 | before = NULL_RTX; | |
1289 | ||
623a66fa R |
1290 | /* If this is a fall through edge to the exit block, the blocks might be |
1291 | not adjacent, and the right place is the after the source. */ | |
1292 | if (edge_in->flags & EDGE_FALLTHRU && edge_in->dest == EXIT_BLOCK_PTR) | |
1293 | { | |
1294 | before = NEXT_INSN (BB_END (edge_in->src)); | |
623a66fa | 1295 | bb = create_basic_block (before, NULL, edge_in->src); |
076c7ab8 | 1296 | BB_COPY_PARTITION (bb, edge_in->src); |
623a66fa R |
1297 | } |
1298 | else | |
9fb32434 CT |
1299 | { |
1300 | bb = create_basic_block (before, NULL, edge_in->dest->prev_bb); | |
076c7ab8 ZW |
1301 | /* ??? Why not edge_in->dest->prev_bb here? */ |
1302 | BB_COPY_PARTITION (bb, edge_in->dest); | |
9fb32434 | 1303 | } |
ca6c03ca | 1304 | |
4977bab6 | 1305 | make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU); |
ca6c03ca | 1306 | |
4d6922ee | 1307 | /* For non-fallthru edges, we must adjust the predecessor's |
ca6c03ca JH |
1308 | jump instruction to target our new block. */ |
1309 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1310 | { | |
341c100f NS |
1311 | edge redirected = redirect_edge_and_branch (edge_in, bb); |
1312 | gcc_assert (redirected); | |
ca6c03ca JH |
1313 | } |
1314 | else | |
1315 | redirect_edge_succ (edge_in, bb); | |
1316 | ||
1317 | return bb; | |
1318 | } | |
1319 | ||
1320 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1321 | The new instructions and basic blocks (if any) will not appear in the | |
1322 | CFG until commit_edge_insertions is called. */ | |
1323 | ||
1324 | void | |
d329e058 | 1325 | insert_insn_on_edge (rtx pattern, edge e) |
ca6c03ca JH |
1326 | { |
1327 | /* We cannot insert instructions on an abnormal critical edge. | |
1328 | It will be easier to find the culprit if we die now. */ | |
341c100f | 1329 | gcc_assert (!((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e))); |
ca6c03ca | 1330 | |
6de9cd9a | 1331 | if (e->insns.r == NULL_RTX) |
ca6c03ca JH |
1332 | start_sequence (); |
1333 | else | |
6de9cd9a | 1334 | push_to_sequence (e->insns.r); |
ca6c03ca JH |
1335 | |
1336 | emit_insn (pattern); | |
1337 | ||
6de9cd9a | 1338 | e->insns.r = get_insns (); |
ca6c03ca JH |
1339 | end_sequence (); |
1340 | } | |
1341 | ||
1342 | /* Update the CFG for the instructions queued on edge E. */ | |
1343 | ||
4e3825db | 1344 | void |
2ac66157 | 1345 | commit_one_edge_insertion (edge e) |
ca6c03ca JH |
1346 | { |
1347 | rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last; | |
eae4bc56 | 1348 | basic_block bb = NULL; |
ca6c03ca JH |
1349 | |
1350 | /* Pull the insns off the edge now since the edge might go away. */ | |
6de9cd9a DN |
1351 | insns = e->insns.r; |
1352 | e->insns.r = NULL_RTX; | |
ca6c03ca | 1353 | |
3dec4024 | 1354 | if (!before && !after) |
ca6c03ca | 1355 | { |
3dec4024 | 1356 | /* Figure out where to put these things. If the destination has |
c22cacf3 | 1357 | one predecessor, insert there. Except for the exit block. */ |
c5cbcccf | 1358 | if (single_pred_p (e->dest) && e->dest != EXIT_BLOCK_PTR) |
ca6c03ca | 1359 | { |
3dec4024 JH |
1360 | bb = e->dest; |
1361 | ||
1362 | /* Get the location correct wrt a code label, and "nice" wrt | |
1363 | a basic block note, and before everything else. */ | |
a813c111 | 1364 | tmp = BB_HEAD (bb); |
4b4bf941 | 1365 | if (LABEL_P (tmp)) |
3dec4024 JH |
1366 | tmp = NEXT_INSN (tmp); |
1367 | if (NOTE_INSN_BASIC_BLOCK_P (tmp)) | |
1368 | tmp = NEXT_INSN (tmp); | |
a813c111 | 1369 | if (tmp == BB_HEAD (bb)) |
3dec4024 JH |
1370 | before = tmp; |
1371 | else if (tmp) | |
1372 | after = PREV_INSN (tmp); | |
1373 | else | |
1374 | after = get_last_insn (); | |
1375 | } | |
1376 | ||
1377 | /* If the source has one successor and the edge is not abnormal, | |
c22cacf3 | 1378 | insert there. Except for the entry block. */ |
3dec4024 | 1379 | else if ((e->flags & EDGE_ABNORMAL) == 0 |
c5cbcccf | 1380 | && single_succ_p (e->src) |
3dec4024 JH |
1381 | && e->src != ENTRY_BLOCK_PTR) |
1382 | { | |
1383 | bb = e->src; | |
1384 | ||
1385 | /* It is possible to have a non-simple jump here. Consider a target | |
1386 | where some forms of unconditional jumps clobber a register. This | |
1387 | happens on the fr30 for example. | |
1388 | ||
1389 | We know this block has a single successor, so we can just emit | |
1390 | the queued insns before the jump. */ | |
4b4bf941 | 1391 | if (JUMP_P (BB_END (bb))) |
96e82e0a | 1392 | before = BB_END (bb); |
3dec4024 JH |
1393 | else |
1394 | { | |
341c100f NS |
1395 | /* We'd better be fallthru, or we've lost track of |
1396 | what's what. */ | |
1397 | gcc_assert (e->flags & EDGE_FALLTHRU); | |
ca6c03ca | 1398 | |
a813c111 | 1399 | after = BB_END (bb); |
3dec4024 JH |
1400 | } |
1401 | } | |
1402 | /* Otherwise we must split the edge. */ | |
1403 | else | |
1404 | { | |
1405 | bb = split_edge (e); | |
a813c111 | 1406 | after = BB_END (bb); |
750054a2 | 1407 | |
750054a2 | 1408 | if (flag_reorder_blocks_and_partition |
9fb32434 | 1409 | && targetm.have_named_sections |
750054a2 | 1410 | && e->src != ENTRY_BLOCK_PTR |
076c7ab8 | 1411 | && BB_PARTITION (e->src) == BB_COLD_PARTITION |
bd454efd | 1412 | && !(e->flags & EDGE_CROSSING)) |
750054a2 | 1413 | { |
87c8b4be | 1414 | rtx bb_note, cur_insn; |
750054a2 CT |
1415 | |
1416 | bb_note = NULL_RTX; | |
1417 | for (cur_insn = BB_HEAD (bb); cur_insn != NEXT_INSN (BB_END (bb)); | |
1418 | cur_insn = NEXT_INSN (cur_insn)) | |
a38e7aa5 | 1419 | if (NOTE_INSN_BASIC_BLOCK_P (cur_insn)) |
750054a2 CT |
1420 | { |
1421 | bb_note = cur_insn; | |
1422 | break; | |
1423 | } | |
1424 | ||
4b4bf941 | 1425 | if (JUMP_P (BB_END (bb)) |
750054a2 | 1426 | && !any_condjump_p (BB_END (bb)) |
c22cacf3 | 1427 | && (single_succ_edge (bb)->flags & EDGE_CROSSING)) |
65c5f2a6 | 1428 | add_reg_note (BB_END (bb), REG_CROSSING_JUMP, NULL_RTX); |
750054a2 | 1429 | } |
ca6c03ca JH |
1430 | } |
1431 | } | |
1432 | ||
ca6c03ca JH |
1433 | /* Now that we've found the spot, do the insertion. */ |
1434 | ||
1435 | if (before) | |
1436 | { | |
6fb5fa3c | 1437 | emit_insn_before_noloc (insns, before, bb); |
ca6c03ca JH |
1438 | last = prev_nonnote_insn (before); |
1439 | } | |
1440 | else | |
6fb5fa3c | 1441 | last = emit_insn_after_noloc (insns, after, bb); |
ca6c03ca JH |
1442 | |
1443 | if (returnjump_p (last)) | |
1444 | { | |
1445 | /* ??? Remove all outgoing edges from BB and add one for EXIT. | |
c22cacf3 MS |
1446 | This is not currently a problem because this only happens |
1447 | for the (single) epilogue, which already has a fallthru edge | |
1448 | to EXIT. */ | |
ca6c03ca | 1449 | |
c5cbcccf | 1450 | e = single_succ_edge (bb); |
341c100f | 1451 | gcc_assert (e->dest == EXIT_BLOCK_PTR |
c5cbcccf | 1452 | && single_succ_p (bb) && (e->flags & EDGE_FALLTHRU)); |
ca6c03ca | 1453 | |
5f0d2358 | 1454 | e->flags &= ~EDGE_FALLTHRU; |
ca6c03ca | 1455 | emit_barrier_after (last); |
0b17ab2f | 1456 | |
ca6c03ca JH |
1457 | if (before) |
1458 | delete_insn (before); | |
1459 | } | |
341c100f NS |
1460 | else |
1461 | gcc_assert (!JUMP_P (last)); | |
5f0d2358 | 1462 | |
12eff7b7 | 1463 | /* Mark the basic block for find_many_sub_basic_blocks. */ |
05549c96 SB |
1464 | if (current_ir_type () != IR_RTL_CFGLAYOUT) |
1465 | bb->aux = &bb->aux; | |
ca6c03ca JH |
1466 | } |
1467 | ||
1468 | /* Update the CFG for all queued instructions. */ | |
1469 | ||
1470 | void | |
d329e058 | 1471 | commit_edge_insertions (void) |
ca6c03ca | 1472 | { |
ca6c03ca | 1473 | basic_block bb; |
9dca2ad5 | 1474 | sbitmap blocks; |
9809a362 | 1475 | bool changed = false; |
ca6c03ca JH |
1476 | |
1477 | #ifdef ENABLE_CHECKING | |
1478 | verify_flow_info (); | |
1479 | #endif | |
1480 | ||
e0082a72 | 1481 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
ca6c03ca | 1482 | { |
628f6a4e BE |
1483 | edge e; |
1484 | edge_iterator ei; | |
ca6c03ca | 1485 | |
628f6a4e BE |
1486 | FOR_EACH_EDGE (e, ei, bb->succs) |
1487 | if (e->insns.r) | |
1488 | { | |
1489 | changed = true; | |
2ac66157 | 1490 | commit_one_edge_insertion (e); |
628f6a4e | 1491 | } |
3dec4024 | 1492 | } |
9dca2ad5 | 1493 | |
9809a362 JH |
1494 | if (!changed) |
1495 | return; | |
1496 | ||
05549c96 SB |
1497 | /* In the old rtl CFG API, it was OK to insert control flow on an |
1498 | edge, apparently? In cfglayout mode, this will *not* work, and | |
1499 | the caller is responsible for making sure that control flow is | |
1500 | valid at all times. */ | |
1501 | if (current_ir_type () == IR_RTL_CFGLAYOUT) | |
1502 | return; | |
1503 | ||
9809a362 JH |
1504 | blocks = sbitmap_alloc (last_basic_block); |
1505 | sbitmap_zero (blocks); | |
1506 | FOR_EACH_BB (bb) | |
1507 | if (bb->aux) | |
1508 | { | |
c22cacf3 | 1509 | SET_BIT (blocks, bb->index); |
9809a362 JH |
1510 | /* Check for forgotten bb->aux values before commit_edge_insertions |
1511 | call. */ | |
341c100f | 1512 | gcc_assert (bb->aux == &bb->aux); |
9809a362 JH |
1513 | bb->aux = NULL; |
1514 | } | |
1515 | find_many_sub_basic_blocks (blocks); | |
1516 | sbitmap_free (blocks); | |
ca6c03ca JH |
1517 | } |
1518 | \f | |
6fb5fa3c | 1519 | |
f470c378 ZD |
1520 | /* Print out RTL-specific basic block information (live information |
1521 | at start and end). */ | |
ca6c03ca | 1522 | |
10e9fecc | 1523 | static void |
726a989a | 1524 | rtl_dump_bb (basic_block bb, FILE *outf, int indent, int flags ATTRIBUTE_UNUSED) |
ca6c03ca JH |
1525 | { |
1526 | rtx insn; | |
1527 | rtx last; | |
f470c378 | 1528 | char *s_indent; |
ca6c03ca | 1529 | |
ae50c0cb | 1530 | s_indent = (char *) alloca ((size_t) indent + 1); |
400e39e3 | 1531 | memset (s_indent, ' ', (size_t) indent); |
f470c378 | 1532 | s_indent[indent] = '\0'; |
6fb5fa3c DB |
1533 | |
1534 | if (df) | |
1535 | { | |
1536 | df_dump_top (bb, outf); | |
1537 | putc ('\n', outf); | |
1538 | } | |
ca6c03ca | 1539 | |
a813c111 | 1540 | for (insn = BB_HEAD (bb), last = NEXT_INSN (BB_END (bb)); insn != last; |
ca6c03ca JH |
1541 | insn = NEXT_INSN (insn)) |
1542 | print_rtl_single (outf, insn); | |
1543 | ||
6fb5fa3c DB |
1544 | if (df) |
1545 | { | |
1546 | df_dump_bottom (bb, outf); | |
1547 | putc ('\n', outf); | |
1548 | } | |
1549 | ||
ca6c03ca JH |
1550 | } |
1551 | \f | |
1552 | /* Like print_rtl, but also print out live information for the start of each | |
1553 | basic block. */ | |
1554 | ||
1555 | void | |
22ea9ec0 | 1556 | print_rtl_with_bb (FILE *outf, const_rtx rtx_first) |
ca6c03ca | 1557 | { |
22ea9ec0 | 1558 | const_rtx tmp_rtx; |
ca6c03ca JH |
1559 | if (rtx_first == 0) |
1560 | fprintf (outf, "(nil)\n"); | |
1561 | else | |
1562 | { | |
ca6c03ca JH |
1563 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
1564 | int max_uid = get_max_uid (); | |
5ed6ace5 MD |
1565 | basic_block *start = XCNEWVEC (basic_block, max_uid); |
1566 | basic_block *end = XCNEWVEC (basic_block, max_uid); | |
1567 | enum bb_state *in_bb_p = XCNEWVEC (enum bb_state, max_uid); | |
ca6c03ca | 1568 | |
e0082a72 ZD |
1569 | basic_block bb; |
1570 | ||
6fb5fa3c DB |
1571 | if (df) |
1572 | df_dump_start (outf); | |
1573 | ||
e0082a72 | 1574 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1575 | { |
ca6c03ca JH |
1576 | rtx x; |
1577 | ||
a813c111 SB |
1578 | start[INSN_UID (BB_HEAD (bb))] = bb; |
1579 | end[INSN_UID (BB_END (bb))] = bb; | |
1580 | for (x = BB_HEAD (bb); x != NULL_RTX; x = NEXT_INSN (x)) | |
ca6c03ca JH |
1581 | { |
1582 | enum bb_state state = IN_MULTIPLE_BB; | |
5f0d2358 | 1583 | |
ca6c03ca JH |
1584 | if (in_bb_p[INSN_UID (x)] == NOT_IN_BB) |
1585 | state = IN_ONE_BB; | |
1586 | in_bb_p[INSN_UID (x)] = state; | |
1587 | ||
a813c111 | 1588 | if (x == BB_END (bb)) |
ca6c03ca JH |
1589 | break; |
1590 | } | |
1591 | } | |
1592 | ||
1593 | for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) | |
1594 | { | |
1595 | int did_output; | |
ca6c03ca JH |
1596 | if ((bb = start[INSN_UID (tmp_rtx)]) != NULL) |
1597 | { | |
6fb5fa3c DB |
1598 | edge e; |
1599 | edge_iterator ei; | |
1600 | ||
1601 | fprintf (outf, ";; Start of basic block ("); | |
1602 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1603 | fprintf (outf, " %d", e->src->index); | |
1604 | fprintf (outf, ") -> %d\n", bb->index); | |
1605 | ||
1606 | if (df) | |
1607 | { | |
1608 | df_dump_top (bb, outf); | |
1609 | putc ('\n', outf); | |
1610 | } | |
e9ec5c6b SB |
1611 | FOR_EACH_EDGE (e, ei, bb->preds) |
1612 | { | |
1613 | fputs (";; Pred edge ", outf); | |
1614 | dump_edge_info (outf, e, 0); | |
1615 | fputc ('\n', outf); | |
1616 | } | |
ca6c03ca JH |
1617 | } |
1618 | ||
1619 | if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB | |
4b4bf941 JQ |
1620 | && !NOTE_P (tmp_rtx) |
1621 | && !BARRIER_P (tmp_rtx)) | |
ca6c03ca JH |
1622 | fprintf (outf, ";; Insn is not within a basic block\n"); |
1623 | else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB) | |
1624 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); | |
1625 | ||
1626 | did_output = print_rtl_single (outf, tmp_rtx); | |
1627 | ||
1628 | if ((bb = end[INSN_UID (tmp_rtx)]) != NULL) | |
1629 | { | |
6fb5fa3c DB |
1630 | edge e; |
1631 | edge_iterator ei; | |
1632 | ||
1633 | fprintf (outf, ";; End of basic block %d -> (", bb->index); | |
1634 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1635 | fprintf (outf, " %d", e->dest->index); | |
1636 | fprintf (outf, ")\n"); | |
1637 | ||
1638 | if (df) | |
1639 | { | |
1640 | df_dump_bottom (bb, outf); | |
1641 | putc ('\n', outf); | |
1642 | } | |
ca6c03ca | 1643 | putc ('\n', outf); |
e9ec5c6b SB |
1644 | FOR_EACH_EDGE (e, ei, bb->succs) |
1645 | { | |
1646 | fputs (";; Succ edge ", outf); | |
1647 | dump_edge_info (outf, e, 1); | |
1648 | fputc ('\n', outf); | |
1649 | } | |
ca6c03ca | 1650 | } |
ca6c03ca JH |
1651 | if (did_output) |
1652 | putc ('\n', outf); | |
1653 | } | |
1654 | ||
1655 | free (start); | |
1656 | free (end); | |
1657 | free (in_bb_p); | |
1658 | } | |
1659 | ||
cb91fab0 | 1660 | if (crtl->epilogue_delay_list != 0) |
ca6c03ca JH |
1661 | { |
1662 | fprintf (outf, "\n;; Insns in epilogue delay list:\n\n"); | |
cb91fab0 | 1663 | for (tmp_rtx = crtl->epilogue_delay_list; tmp_rtx != 0; |
ca6c03ca JH |
1664 | tmp_rtx = XEXP (tmp_rtx, 1)) |
1665 | print_rtl_single (outf, XEXP (tmp_rtx, 0)); | |
1666 | } | |
1667 | } | |
1668 | \f | |
b446e5a2 | 1669 | void |
d329e058 | 1670 | update_br_prob_note (basic_block bb) |
b446e5a2 JH |
1671 | { |
1672 | rtx note; | |
4b4bf941 | 1673 | if (!JUMP_P (BB_END (bb))) |
b446e5a2 | 1674 | return; |
a813c111 | 1675 | note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX); |
b446e5a2 JH |
1676 | if (!note || INTVAL (XEXP (note, 0)) == BRANCH_EDGE (bb)->probability) |
1677 | return; | |
1678 | XEXP (note, 0) = GEN_INT (BRANCH_EDGE (bb)->probability); | |
1679 | } | |
96370780 MK |
1680 | |
1681 | /* Get the last insn associated with block BB (that includes barriers and | |
1682 | tablejumps after BB). */ | |
1683 | rtx | |
1684 | get_last_bb_insn (basic_block bb) | |
1685 | { | |
1686 | rtx tmp; | |
1687 | rtx end = BB_END (bb); | |
1688 | ||
1689 | /* Include any jump table following the basic block. */ | |
1690 | if (tablejump_p (end, NULL, &tmp)) | |
1691 | end = tmp; | |
1692 | ||
1693 | /* Include any barriers that may follow the basic block. */ | |
1694 | tmp = next_nonnote_insn (end); | |
1695 | while (tmp && BARRIER_P (tmp)) | |
1696 | { | |
1697 | end = tmp; | |
1698 | tmp = next_nonnote_insn (end); | |
1699 | } | |
1700 | ||
1701 | return end; | |
1702 | } | |
b446e5a2 | 1703 | \f |
10e9fecc JH |
1704 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
1705 | cfglayout RTL. | |
ca6c03ca JH |
1706 | |
1707 | Currently it does following checks: | |
1708 | ||
ca6c03ca | 1709 | - overlapping of basic blocks |
9eab6785 | 1710 | - insns with wrong BLOCK_FOR_INSN pointers |
ca6c03ca | 1711 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) |
f63d1bf7 | 1712 | - tails of basic blocks (ensure that boundary is necessary) |
ca6c03ca JH |
1713 | - scans body of the basic block for JUMP_INSN, CODE_LABEL |
1714 | and NOTE_INSN_BASIC_BLOCK | |
750054a2 | 1715 | - verify that no fall_thru edge crosses hot/cold partition boundaries |
9eab6785 | 1716 | - verify that there are no pending RTL branch predictions |
ca6c03ca JH |
1717 | |
1718 | In future it can be extended check a lot of other stuff as well | |
1719 | (reachability of basic blocks, life information, etc. etc.). */ | |
f470c378 | 1720 | |
10e9fecc | 1721 | static int |
d329e058 | 1722 | rtl_verify_flow_info_1 (void) |
ca6c03ca | 1723 | { |
ca6c03ca | 1724 | rtx x; |
10e9fecc | 1725 | int err = 0; |
94eb5ddb | 1726 | basic_block bb; |
ca6c03ca | 1727 | |
9eab6785 | 1728 | /* Check the general integrity of the basic blocks. */ |
e0082a72 | 1729 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1730 | { |
9eab6785 | 1731 | rtx insn; |
5f0d2358 | 1732 | |
5e2d947c JH |
1733 | if (!(bb->flags & BB_RTL)) |
1734 | { | |
1735 | error ("BB_RTL flag not set for block %d", bb->index); | |
1736 | err = 1; | |
1737 | } | |
1738 | ||
9eab6785 | 1739 | FOR_BB_INSNS (bb, insn) |
8ce9fd5d | 1740 | if (BLOCK_FOR_INSN (insn) != bb) |
9eab6785 SB |
1741 | { |
1742 | error ("insn %d basic block pointer is %d, should be %d", | |
1743 | INSN_UID (insn), | |
1744 | BLOCK_FOR_INSN (insn) ? BLOCK_FOR_INSN (insn)->index : 0, | |
1745 | bb->index); | |
1746 | err = 1; | |
1747 | } | |
a7b87f73 ZD |
1748 | |
1749 | for (insn = bb->il.rtl->header; insn; insn = NEXT_INSN (insn)) | |
1750 | if (!BARRIER_P (insn) | |
1751 | && BLOCK_FOR_INSN (insn) != NULL) | |
1752 | { | |
1753 | error ("insn %d in header of bb %d has non-NULL basic block", | |
1754 | INSN_UID (insn), bb->index); | |
1755 | err = 1; | |
1756 | } | |
1757 | for (insn = bb->il.rtl->footer; insn; insn = NEXT_INSN (insn)) | |
1758 | if (!BARRIER_P (insn) | |
1759 | && BLOCK_FOR_INSN (insn) != NULL) | |
1760 | { | |
1761 | error ("insn %d in footer of bb %d has non-NULL basic block", | |
1762 | INSN_UID (insn), bb->index); | |
1763 | err = 1; | |
1764 | } | |
ca6c03ca JH |
1765 | } |
1766 | ||
1767 | /* Now check the basic blocks (boundaries etc.) */ | |
e0082a72 | 1768 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1769 | { |
3dec4024 | 1770 | int n_fallthru = 0, n_eh = 0, n_call = 0, n_abnormal = 0, n_branch = 0; |
3cf54412 | 1771 | edge e, fallthru = NULL; |
5a1a3e5e | 1772 | rtx note; |
628f6a4e | 1773 | edge_iterator ei; |
ca6c03ca | 1774 | |
2085a21f | 1775 | if (JUMP_P (BB_END (bb)) |
a813c111 | 1776 | && (note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX)) |
628f6a4e | 1777 | && EDGE_COUNT (bb->succs) >= 2 |
a813c111 | 1778 | && any_condjump_p (BB_END (bb))) |
5a1a3e5e | 1779 | { |
e53de54d JH |
1780 | if (INTVAL (XEXP (note, 0)) != BRANCH_EDGE (bb)->probability |
1781 | && profile_status != PROFILE_ABSENT) | |
5a1a3e5e | 1782 | { |
0108ae51 | 1783 | error ("verify_flow_info: REG_BR_PROB does not match cfg %wi %i", |
5a1a3e5e JH |
1784 | INTVAL (XEXP (note, 0)), BRANCH_EDGE (bb)->probability); |
1785 | err = 1; | |
1786 | } | |
1787 | } | |
628f6a4e | 1788 | FOR_EACH_EDGE (e, ei, bb->succs) |
ca6c03ca | 1789 | { |
ca6c03ca | 1790 | if (e->flags & EDGE_FALLTHRU) |
750054a2 CT |
1791 | { |
1792 | n_fallthru++, fallthru = e; | |
bd454efd | 1793 | if ((e->flags & EDGE_CROSSING) |
076c7ab8 | 1794 | || (BB_PARTITION (e->src) != BB_PARTITION (e->dest) |
9fb32434 CT |
1795 | && e->src != ENTRY_BLOCK_PTR |
1796 | && e->dest != EXIT_BLOCK_PTR)) | |
c22cacf3 | 1797 | { |
ab532386 | 1798 | error ("fallthru edge crosses section boundary (bb %i)", |
750054a2 CT |
1799 | e->src->index); |
1800 | err = 1; | |
1801 | } | |
1802 | } | |
3dec4024 | 1803 | |
65f43cdf ZD |
1804 | if ((e->flags & ~(EDGE_DFS_BACK |
1805 | | EDGE_CAN_FALLTHRU | |
1806 | | EDGE_IRREDUCIBLE_LOOP | |
9beb1c84 CT |
1807 | | EDGE_LOOP_EXIT |
1808 | | EDGE_CROSSING)) == 0) | |
3dec4024 JH |
1809 | n_branch++; |
1810 | ||
1811 | if (e->flags & EDGE_ABNORMAL_CALL) | |
1812 | n_call++; | |
1813 | ||
1814 | if (e->flags & EDGE_EH) | |
1815 | n_eh++; | |
1816 | else if (e->flags & EDGE_ABNORMAL) | |
1817 | n_abnormal++; | |
ca6c03ca | 1818 | } |
5f0d2358 | 1819 | |
a813c111 SB |
1820 | if (n_eh && GET_CODE (PATTERN (BB_END (bb))) != RESX |
1821 | && !find_reg_note (BB_END (bb), REG_EH_REGION, NULL_RTX)) | |
3dec4024 | 1822 | { |
ab532386 | 1823 | error ("missing REG_EH_REGION note in the end of bb %i", bb->index); |
3dec4024 JH |
1824 | err = 1; |
1825 | } | |
1826 | if (n_branch | |
4b4bf941 | 1827 | && (!JUMP_P (BB_END (bb)) |
a813c111 SB |
1828 | || (n_branch > 1 && (any_uncondjump_p (BB_END (bb)) |
1829 | || any_condjump_p (BB_END (bb)))))) | |
3dec4024 | 1830 | { |
ab532386 | 1831 | error ("too many outgoing branch edges from bb %i", bb->index); |
3dec4024 JH |
1832 | err = 1; |
1833 | } | |
a813c111 | 1834 | if (n_fallthru && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 1835 | { |
ab532386 | 1836 | error ("fallthru edge after unconditional jump %i", bb->index); |
3dec4024 JH |
1837 | err = 1; |
1838 | } | |
a813c111 | 1839 | if (n_branch != 1 && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 1840 | { |
ab532386 | 1841 | error ("wrong amount of branch edges after unconditional jump %i", bb->index); |
3dec4024 JH |
1842 | err = 1; |
1843 | } | |
a813c111 | 1844 | if (n_branch != 1 && any_condjump_p (BB_END (bb)) |
c11fd0b2 | 1845 | && JUMP_LABEL (BB_END (bb)) != BB_HEAD (fallthru->dest)) |
3dec4024 | 1846 | { |
c11fd0b2 RG |
1847 | error ("wrong amount of branch edges after conditional jump %i", |
1848 | bb->index); | |
3dec4024 JH |
1849 | err = 1; |
1850 | } | |
4b4bf941 | 1851 | if (n_call && !CALL_P (BB_END (bb))) |
3dec4024 | 1852 | { |
ab532386 | 1853 | error ("call edges for non-call insn in bb %i", bb->index); |
3dec4024 JH |
1854 | err = 1; |
1855 | } | |
1856 | if (n_abnormal | |
4b4bf941 JQ |
1857 | && (!CALL_P (BB_END (bb)) && n_call != n_abnormal) |
1858 | && (!JUMP_P (BB_END (bb)) | |
a813c111 SB |
1859 | || any_condjump_p (BB_END (bb)) |
1860 | || any_uncondjump_p (BB_END (bb)))) | |
3dec4024 | 1861 | { |
ab532386 | 1862 | error ("abnormal edges for no purpose in bb %i", bb->index); |
3dec4024 JH |
1863 | err = 1; |
1864 | } | |
f87c27b4 | 1865 | |
a813c111 | 1866 | for (x = BB_HEAD (bb); x != NEXT_INSN (BB_END (bb)); x = NEXT_INSN (x)) |
0ca541aa | 1867 | /* We may have a barrier inside a basic block before dead code |
9524880c HPN |
1868 | elimination. There is no BLOCK_FOR_INSN field in a barrier. */ |
1869 | if (!BARRIER_P (x) && BLOCK_FOR_INSN (x) != bb) | |
5f0d2358 RK |
1870 | { |
1871 | debug_rtx (x); | |
1872 | if (! BLOCK_FOR_INSN (x)) | |
1873 | error | |
1874 | ("insn %d inside basic block %d but block_for_insn is NULL", | |
0b17ab2f | 1875 | INSN_UID (x), bb->index); |
5f0d2358 RK |
1876 | else |
1877 | error | |
1878 | ("insn %d inside basic block %d but block_for_insn is %i", | |
0b17ab2f | 1879 | INSN_UID (x), bb->index, BLOCK_FOR_INSN (x)->index); |
5f0d2358 RK |
1880 | |
1881 | err = 1; | |
1882 | } | |
ca6c03ca JH |
1883 | |
1884 | /* OK pointers are correct. Now check the header of basic | |
c22cacf3 | 1885 | block. It ought to contain optional CODE_LABEL followed |
ca6c03ca | 1886 | by NOTE_BASIC_BLOCK. */ |
a813c111 | 1887 | x = BB_HEAD (bb); |
4b4bf941 | 1888 | if (LABEL_P (x)) |
ca6c03ca | 1889 | { |
a813c111 | 1890 | if (BB_END (bb) == x) |
ca6c03ca JH |
1891 | { |
1892 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 1893 | bb->index); |
ca6c03ca JH |
1894 | err = 1; |
1895 | } | |
5f0d2358 | 1896 | |
ca6c03ca JH |
1897 | x = NEXT_INSN (x); |
1898 | } | |
5f0d2358 | 1899 | |
ca6c03ca JH |
1900 | if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb) |
1901 | { | |
1902 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 1903 | bb->index); |
ca6c03ca JH |
1904 | err = 1; |
1905 | } | |
1906 | ||
a813c111 | 1907 | if (BB_END (bb) == x) |
49243025 | 1908 | /* Do checks for empty blocks here. */ |
5f0d2358 | 1909 | ; |
ca6c03ca | 1910 | else |
5f0d2358 RK |
1911 | for (x = NEXT_INSN (x); x; x = NEXT_INSN (x)) |
1912 | { | |
1913 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
1914 | { | |
1915 | error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d", | |
0b17ab2f | 1916 | INSN_UID (x), bb->index); |
5f0d2358 RK |
1917 | err = 1; |
1918 | } | |
1919 | ||
a813c111 | 1920 | if (x == BB_END (bb)) |
5f0d2358 | 1921 | break; |
ca6c03ca | 1922 | |
83fd323c | 1923 | if (control_flow_insn_p (x)) |
5f0d2358 | 1924 | { |
0b17ab2f | 1925 | error ("in basic block %d:", bb->index); |
5f0d2358 RK |
1926 | fatal_insn ("flow control insn inside a basic block", x); |
1927 | } | |
1928 | } | |
ca6c03ca JH |
1929 | } |
1930 | ||
10e9fecc | 1931 | /* Clean up. */ |
10e9fecc JH |
1932 | return err; |
1933 | } | |
5f0d2358 | 1934 | |
10e9fecc JH |
1935 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
1936 | cfglayout RTL. | |
5f0d2358 | 1937 | |
10e9fecc JH |
1938 | Currently it does following checks: |
1939 | - all checks of rtl_verify_flow_info_1 | |
9eab6785 | 1940 | - test head/end pointers |
10e9fecc JH |
1941 | - check that all insns are in the basic blocks |
1942 | (except the switch handling code, barriers and notes) | |
1943 | - check that all returns are followed by barriers | |
1944 | - check that all fallthru edge points to the adjacent blocks. */ | |
9eab6785 | 1945 | |
10e9fecc | 1946 | static int |
d329e058 | 1947 | rtl_verify_flow_info (void) |
10e9fecc JH |
1948 | { |
1949 | basic_block bb; | |
1950 | int err = rtl_verify_flow_info_1 (); | |
1951 | rtx x; | |
9eab6785 SB |
1952 | rtx last_head = get_last_insn (); |
1953 | basic_block *bb_info; | |
10e9fecc JH |
1954 | int num_bb_notes; |
1955 | const rtx rtx_first = get_insns (); | |
1956 | basic_block last_bb_seen = ENTRY_BLOCK_PTR, curr_bb = NULL; | |
9eab6785 SB |
1957 | const int max_uid = get_max_uid (); |
1958 | ||
1959 | bb_info = XCNEWVEC (basic_block, max_uid); | |
ca6c03ca | 1960 | |
10e9fecc JH |
1961 | FOR_EACH_BB_REVERSE (bb) |
1962 | { | |
1963 | edge e; | |
628f6a4e | 1964 | edge_iterator ei; |
9eab6785 SB |
1965 | rtx head = BB_HEAD (bb); |
1966 | rtx end = BB_END (bb); | |
628f6a4e | 1967 | |
9eab6785 | 1968 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) |
a7b87f73 ZD |
1969 | { |
1970 | /* Verify the end of the basic block is in the INSN chain. */ | |
1971 | if (x == end) | |
1972 | break; | |
1973 | ||
1974 | /* And that the code outside of basic blocks has NULL bb field. */ | |
1975 | if (!BARRIER_P (x) | |
1976 | && BLOCK_FOR_INSN (x) != NULL) | |
1977 | { | |
1978 | error ("insn %d outside of basic blocks has non-NULL bb field", | |
1979 | INSN_UID (x)); | |
1980 | err = 1; | |
1981 | } | |
1982 | } | |
9eab6785 SB |
1983 | |
1984 | if (!x) | |
1985 | { | |
1986 | error ("end insn %d for block %d not found in the insn stream", | |
1987 | INSN_UID (end), bb->index); | |
1988 | err = 1; | |
1989 | } | |
1990 | ||
1991 | /* Work backwards from the end to the head of the basic block | |
1992 | to verify the head is in the RTL chain. */ | |
1993 | for (; x != NULL_RTX; x = PREV_INSN (x)) | |
a00d11f0 | 1994 | { |
9eab6785 SB |
1995 | /* While walking over the insn chain, verify insns appear |
1996 | in only one basic block. */ | |
1997 | if (bb_info[INSN_UID (x)] != NULL) | |
1998 | { | |
1999 | error ("insn %d is in multiple basic blocks (%d and %d)", | |
2000 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); | |
2001 | err = 1; | |
2002 | } | |
2003 | ||
2004 | bb_info[INSN_UID (x)] = bb; | |
2005 | ||
2006 | if (x == head) | |
2007 | break; | |
2008 | } | |
2009 | if (!x) | |
2010 | { | |
2011 | error ("head insn %d for block %d not found in the insn stream", | |
2012 | INSN_UID (head), bb->index); | |
a00d11f0 JH |
2013 | err = 1; |
2014 | } | |
2015 | ||
a7b87f73 | 2016 | last_head = PREV_INSN (x); |
9eab6785 | 2017 | |
628f6a4e | 2018 | FOR_EACH_EDGE (e, ei, bb->succs) |
10e9fecc JH |
2019 | if (e->flags & EDGE_FALLTHRU) |
2020 | break; | |
2021 | if (!e) | |
2022 | { | |
2023 | rtx insn; | |
2024 | ||
2025 | /* Ensure existence of barrier in BB with no fallthru edges. */ | |
4b4bf941 | 2026 | for (insn = BB_END (bb); !insn || !BARRIER_P (insn); |
10e9fecc JH |
2027 | insn = NEXT_INSN (insn)) |
2028 | if (!insn | |
a38e7aa5 | 2029 | || NOTE_INSN_BASIC_BLOCK_P (insn)) |
10e9fecc JH |
2030 | { |
2031 | error ("missing barrier after block %i", bb->index); | |
2032 | err = 1; | |
2033 | break; | |
2034 | } | |
2035 | } | |
2036 | else if (e->src != ENTRY_BLOCK_PTR | |
2037 | && e->dest != EXIT_BLOCK_PTR) | |
c22cacf3 | 2038 | { |
10e9fecc JH |
2039 | rtx insn; |
2040 | ||
2041 | if (e->src->next_bb != e->dest) | |
2042 | { | |
2043 | error | |
2044 | ("verify_flow_info: Incorrect blocks for fallthru %i->%i", | |
2045 | e->src->index, e->dest->index); | |
2046 | err = 1; | |
2047 | } | |
2048 | else | |
a813c111 | 2049 | for (insn = NEXT_INSN (BB_END (e->src)); insn != BB_HEAD (e->dest); |
10e9fecc | 2050 | insn = NEXT_INSN (insn)) |
6be85b25 | 2051 | if (BARRIER_P (insn) || INSN_P (insn)) |
10e9fecc JH |
2052 | { |
2053 | error ("verify_flow_info: Incorrect fallthru %i->%i", | |
2054 | e->src->index, e->dest->index); | |
2055 | fatal_insn ("wrong insn in the fallthru edge", insn); | |
2056 | err = 1; | |
2057 | } | |
c22cacf3 | 2058 | } |
10e9fecc | 2059 | } |
ca6c03ca | 2060 | |
a7b87f73 ZD |
2061 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) |
2062 | { | |
2063 | /* Check that the code before the first basic block has NULL | |
2064 | bb field. */ | |
2065 | if (!BARRIER_P (x) | |
2066 | && BLOCK_FOR_INSN (x) != NULL) | |
2067 | { | |
2068 | error ("insn %d outside of basic blocks has non-NULL bb field", | |
2069 | INSN_UID (x)); | |
2070 | err = 1; | |
2071 | } | |
2072 | } | |
9eab6785 SB |
2073 | free (bb_info); |
2074 | ||
ca6c03ca | 2075 | num_bb_notes = 0; |
e0082a72 ZD |
2076 | last_bb_seen = ENTRY_BLOCK_PTR; |
2077 | ||
5f0d2358 | 2078 | for (x = rtx_first; x; x = NEXT_INSN (x)) |
ca6c03ca JH |
2079 | { |
2080 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2081 | { | |
bf77398c | 2082 | bb = NOTE_BASIC_BLOCK (x); |
5f0d2358 | 2083 | |
ca6c03ca | 2084 | num_bb_notes++; |
e0082a72 | 2085 | if (bb != last_bb_seen->next_bb) |
10e9fecc | 2086 | internal_error ("basic blocks not laid down consecutively"); |
ca6c03ca | 2087 | |
10e9fecc | 2088 | curr_bb = last_bb_seen = bb; |
ca6c03ca JH |
2089 | } |
2090 | ||
10e9fecc | 2091 | if (!curr_bb) |
ca6c03ca JH |
2092 | { |
2093 | switch (GET_CODE (x)) | |
2094 | { | |
2095 | case BARRIER: | |
2096 | case NOTE: | |
2097 | break; | |
2098 | ||
2099 | case CODE_LABEL: | |
666c27b9 | 2100 | /* An addr_vec is placed outside any basic block. */ |
ca6c03ca | 2101 | if (NEXT_INSN (x) |
4b4bf941 | 2102 | && JUMP_P (NEXT_INSN (x)) |
ca6c03ca JH |
2103 | && (GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_DIFF_VEC |
2104 | || GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_VEC)) | |
5f0d2358 | 2105 | x = NEXT_INSN (x); |
ca6c03ca JH |
2106 | |
2107 | /* But in any case, non-deletable labels can appear anywhere. */ | |
2108 | break; | |
2109 | ||
2110 | default: | |
1f978f5f | 2111 | fatal_insn ("insn outside basic block", x); |
ca6c03ca JH |
2112 | } |
2113 | } | |
2114 | ||
26cae194 | 2115 | if (JUMP_P (x) |
ca6c03ca | 2116 | && returnjump_p (x) && ! condjump_p (x) |
15eb3a2e | 2117 | && ! (next_nonnote_insn (x) && BARRIER_P (next_nonnote_insn (x)))) |
1f978f5f | 2118 | fatal_insn ("return not followed by barrier", x); |
a813c111 | 2119 | if (curr_bb && x == BB_END (curr_bb)) |
10e9fecc | 2120 | curr_bb = NULL; |
ca6c03ca JH |
2121 | } |
2122 | ||
24bd1a0b | 2123 | if (num_bb_notes != n_basic_blocks - NUM_FIXED_BLOCKS) |
ca6c03ca | 2124 | internal_error |
0b17ab2f RH |
2125 | ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)", |
2126 | num_bb_notes, n_basic_blocks); | |
ca6c03ca | 2127 | |
10e9fecc | 2128 | return err; |
ca6c03ca JH |
2129 | } |
2130 | \f | |
eaec9b3d | 2131 | /* Assume that the preceding pass has possibly eliminated jump instructions |
ca6c03ca JH |
2132 | or converted the unconditional jumps. Eliminate the edges from CFG. |
2133 | Return true if any edges are eliminated. */ | |
2134 | ||
2135 | bool | |
d329e058 | 2136 | purge_dead_edges (basic_block bb) |
ca6c03ca | 2137 | { |
628f6a4e | 2138 | edge e; |
a813c111 | 2139 | rtx insn = BB_END (bb), note; |
ca6c03ca | 2140 | bool purged = false; |
628f6a4e BE |
2141 | bool found; |
2142 | edge_iterator ei; | |
ca6c03ca | 2143 | |
70da1d03 | 2144 | /* If this instruction cannot trap, remove REG_EH_REGION notes. */ |
4b4bf941 | 2145 | if (NONJUMP_INSN_P (insn) |
70da1d03 JH |
2146 | && (note = find_reg_note (insn, REG_EH_REGION, NULL))) |
2147 | { | |
2148 | rtx eqnote; | |
2149 | ||
2150 | if (! may_trap_p (PATTERN (insn)) | |
2151 | || ((eqnote = find_reg_equal_equiv_note (insn)) | |
2152 | && ! may_trap_p (XEXP (eqnote, 0)))) | |
2153 | remove_note (insn, note); | |
2154 | } | |
2155 | ||
546c093e | 2156 | /* Cleanup abnormal edges caused by exceptions or non-local gotos. */ |
628f6a4e | 2157 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
546c093e | 2158 | { |
e5f9a909 JW |
2159 | /* There are three types of edges we need to handle correctly here: EH |
2160 | edges, abnormal call EH edges, and abnormal call non-EH edges. The | |
2161 | latter can appear when nonlocal gotos are used. */ | |
2162 | if (e->flags & EDGE_EH) | |
546c093e | 2163 | { |
e5f9a909 JW |
2164 | if (can_throw_internal (BB_END (bb)) |
2165 | /* If this is a call edge, verify that this is a call insn. */ | |
2166 | && (! (e->flags & EDGE_ABNORMAL_CALL) | |
2167 | || CALL_P (BB_END (bb)))) | |
628f6a4e BE |
2168 | { |
2169 | ei_next (&ei); | |
2170 | continue; | |
2171 | } | |
546c093e | 2172 | } |
e5f9a909 | 2173 | else if (e->flags & EDGE_ABNORMAL_CALL) |
546c093e | 2174 | { |
e5f9a909 JW |
2175 | if (CALL_P (BB_END (bb)) |
2176 | && (! (note = find_reg_note (insn, REG_EH_REGION, NULL)) | |
2177 | || INTVAL (XEXP (note, 0)) >= 0)) | |
628f6a4e BE |
2178 | { |
2179 | ei_next (&ei); | |
2180 | continue; | |
2181 | } | |
546c093e RH |
2182 | } |
2183 | else | |
628f6a4e BE |
2184 | { |
2185 | ei_next (&ei); | |
2186 | continue; | |
2187 | } | |
546c093e RH |
2188 | |
2189 | remove_edge (e); | |
6fb5fa3c | 2190 | df_set_bb_dirty (bb); |
546c093e RH |
2191 | purged = true; |
2192 | } | |
5f0d2358 | 2193 | |
4b4bf941 | 2194 | if (JUMP_P (insn)) |
ca6c03ca JH |
2195 | { |
2196 | rtx note; | |
2197 | edge b,f; | |
628f6a4e | 2198 | edge_iterator ei; |
5f0d2358 | 2199 | |
ca6c03ca JH |
2200 | /* We do care only about conditional jumps and simplejumps. */ |
2201 | if (!any_condjump_p (insn) | |
2202 | && !returnjump_p (insn) | |
2203 | && !simplejump_p (insn)) | |
c51d95ec | 2204 | return purged; |
5f0d2358 | 2205 | |
5a1a3e5e JH |
2206 | /* Branch probability/prediction notes are defined only for |
2207 | condjumps. We've possibly turned condjump into simplejump. */ | |
2208 | if (simplejump_p (insn)) | |
2209 | { | |
2210 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2211 | if (note) | |
2212 | remove_note (insn, note); | |
2213 | while ((note = find_reg_note (insn, REG_BR_PRED, NULL))) | |
2214 | remove_note (insn, note); | |
2215 | } | |
2216 | ||
628f6a4e | 2217 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
ca6c03ca | 2218 | { |
7fcd7218 JH |
2219 | /* Avoid abnormal flags to leak from computed jumps turned |
2220 | into simplejumps. */ | |
f87c27b4 | 2221 | |
0e1638d4 | 2222 | e->flags &= ~EDGE_ABNORMAL; |
7fcd7218 | 2223 | |
5a566bed MM |
2224 | /* See if this edge is one we should keep. */ |
2225 | if ((e->flags & EDGE_FALLTHRU) && any_condjump_p (insn)) | |
2226 | /* A conditional jump can fall through into the next | |
2227 | block, so we should keep the edge. */ | |
628f6a4e BE |
2228 | { |
2229 | ei_next (&ei); | |
2230 | continue; | |
2231 | } | |
5f0d2358 | 2232 | else if (e->dest != EXIT_BLOCK_PTR |
a813c111 | 2233 | && BB_HEAD (e->dest) == JUMP_LABEL (insn)) |
5a566bed MM |
2234 | /* If the destination block is the target of the jump, |
2235 | keep the edge. */ | |
628f6a4e BE |
2236 | { |
2237 | ei_next (&ei); | |
2238 | continue; | |
2239 | } | |
5a566bed MM |
2240 | else if (e->dest == EXIT_BLOCK_PTR && returnjump_p (insn)) |
2241 | /* If the destination block is the exit block, and this | |
2242 | instruction is a return, then keep the edge. */ | |
628f6a4e BE |
2243 | { |
2244 | ei_next (&ei); | |
2245 | continue; | |
2246 | } | |
5a566bed MM |
2247 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) |
2248 | /* Keep the edges that correspond to exceptions thrown by | |
0b75beaa EB |
2249 | this instruction and rematerialize the EDGE_ABNORMAL |
2250 | flag we just cleared above. */ | |
2251 | { | |
2252 | e->flags |= EDGE_ABNORMAL; | |
628f6a4e | 2253 | ei_next (&ei); |
0b75beaa EB |
2254 | continue; |
2255 | } | |
5f0d2358 | 2256 | |
5a566bed | 2257 | /* We do not need this edge. */ |
6fb5fa3c | 2258 | df_set_bb_dirty (bb); |
ca6c03ca JH |
2259 | purged = true; |
2260 | remove_edge (e); | |
2261 | } | |
5f0d2358 | 2262 | |
628f6a4e | 2263 | if (EDGE_COUNT (bb->succs) == 0 || !purged) |
c51d95ec | 2264 | return purged; |
5f0d2358 | 2265 | |
c263766c RH |
2266 | if (dump_file) |
2267 | fprintf (dump_file, "Purged edges from bb %i\n", bb->index); | |
5f0d2358 | 2268 | |
ca6c03ca JH |
2269 | if (!optimize) |
2270 | return purged; | |
2271 | ||
2272 | /* Redistribute probabilities. */ | |
c5cbcccf | 2273 | if (single_succ_p (bb)) |
ca6c03ca | 2274 | { |
c5cbcccf ZD |
2275 | single_succ_edge (bb)->probability = REG_BR_PROB_BASE; |
2276 | single_succ_edge (bb)->count = bb->count; | |
f87c27b4 | 2277 | } |
ca6c03ca JH |
2278 | else |
2279 | { | |
2280 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2281 | if (!note) | |
2282 | return purged; | |
5f0d2358 | 2283 | |
ca6c03ca JH |
2284 | b = BRANCH_EDGE (bb); |
2285 | f = FALLTHRU_EDGE (bb); | |
2286 | b->probability = INTVAL (XEXP (note, 0)); | |
2287 | f->probability = REG_BR_PROB_BASE - b->probability; | |
2288 | b->count = bb->count * b->probability / REG_BR_PROB_BASE; | |
2289 | f->count = bb->count * f->probability / REG_BR_PROB_BASE; | |
2290 | } | |
5f0d2358 | 2291 | |
ca6c03ca JH |
2292 | return purged; |
2293 | } | |
4b4bf941 | 2294 | else if (CALL_P (insn) && SIBLING_CALL_P (insn)) |
1722c2c8 RH |
2295 | { |
2296 | /* First, there should not be any EH or ABCALL edges resulting | |
2297 | from non-local gotos and the like. If there were, we shouldn't | |
2298 | have created the sibcall in the first place. Second, there | |
2299 | should of course never have been a fallthru edge. */ | |
c5cbcccf ZD |
2300 | gcc_assert (single_succ_p (bb)); |
2301 | gcc_assert (single_succ_edge (bb)->flags | |
2302 | == (EDGE_SIBCALL | EDGE_ABNORMAL)); | |
1722c2c8 RH |
2303 | |
2304 | return 0; | |
2305 | } | |
ca6c03ca | 2306 | |
ca6c03ca JH |
2307 | /* If we don't see a jump insn, we don't know exactly why the block would |
2308 | have been broken at this point. Look for a simple, non-fallthru edge, | |
2309 | as these are only created by conditional branches. If we find such an | |
2310 | edge we know that there used to be a jump here and can then safely | |
2311 | remove all non-fallthru edges. */ | |
628f6a4e BE |
2312 | found = false; |
2313 | FOR_EACH_EDGE (e, ei, bb->succs) | |
2314 | if (! (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU))) | |
2315 | { | |
2316 | found = true; | |
2317 | break; | |
2318 | } | |
5f0d2358 | 2319 | |
628f6a4e | 2320 | if (!found) |
ca6c03ca | 2321 | return purged; |
5f0d2358 | 2322 | |
2afa8dce DB |
2323 | /* Remove all but the fake and fallthru edges. The fake edge may be |
2324 | the only successor for this block in the case of noreturn | |
2325 | calls. */ | |
628f6a4e | 2326 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
ca6c03ca | 2327 | { |
2afa8dce | 2328 | if (!(e->flags & (EDGE_FALLTHRU | EDGE_FAKE))) |
c51d95ec | 2329 | { |
6fb5fa3c | 2330 | df_set_bb_dirty (bb); |
c51d95ec JH |
2331 | remove_edge (e); |
2332 | purged = true; | |
2333 | } | |
628f6a4e BE |
2334 | else |
2335 | ei_next (&ei); | |
ca6c03ca | 2336 | } |
5f0d2358 | 2337 | |
c5cbcccf | 2338 | gcc_assert (single_succ_p (bb)); |
5f0d2358 | 2339 | |
c5cbcccf ZD |
2340 | single_succ_edge (bb)->probability = REG_BR_PROB_BASE; |
2341 | single_succ_edge (bb)->count = bb->count; | |
ca6c03ca | 2342 | |
c263766c RH |
2343 | if (dump_file) |
2344 | fprintf (dump_file, "Purged non-fallthru edges from bb %i\n", | |
0b17ab2f | 2345 | bb->index); |
ca6c03ca JH |
2346 | return purged; |
2347 | } | |
2348 | ||
5f0d2358 RK |
2349 | /* Search all basic blocks for potentially dead edges and purge them. Return |
2350 | true if some edge has been eliminated. */ | |
ca6c03ca JH |
2351 | |
2352 | bool | |
25cd19de | 2353 | purge_all_dead_edges (void) |
ca6c03ca | 2354 | { |
e0082a72 | 2355 | int purged = false; |
e0082a72 | 2356 | basic_block bb; |
473fb060 | 2357 | |
e0082a72 | 2358 | FOR_EACH_BB (bb) |
473fb060 | 2359 | { |
e0082a72 | 2360 | bool purged_here = purge_dead_edges (bb); |
5f0d2358 | 2361 | |
473fb060 | 2362 | purged |= purged_here; |
473fb060 | 2363 | } |
5f0d2358 | 2364 | |
ca6c03ca JH |
2365 | return purged; |
2366 | } | |
9ee634e3 JH |
2367 | |
2368 | /* Same as split_block but update cfg_layout structures. */ | |
f470c378 ZD |
2369 | |
2370 | static basic_block | |
d329e058 | 2371 | cfg_layout_split_block (basic_block bb, void *insnp) |
9ee634e3 | 2372 | { |
ae50c0cb | 2373 | rtx insn = (rtx) insnp; |
f470c378 | 2374 | basic_block new_bb = rtl_split_block (bb, insn); |
9ee634e3 | 2375 | |
370369e1 JH |
2376 | new_bb->il.rtl->footer = bb->il.rtl->footer; |
2377 | bb->il.rtl->footer = NULL; | |
9ee634e3 | 2378 | |
f470c378 | 2379 | return new_bb; |
9ee634e3 JH |
2380 | } |
2381 | ||
9ee634e3 | 2382 | /* Redirect Edge to DEST. */ |
6de9cd9a | 2383 | static edge |
d329e058 | 2384 | cfg_layout_redirect_edge_and_branch (edge e, basic_block dest) |
9ee634e3 JH |
2385 | { |
2386 | basic_block src = e->src; | |
6de9cd9a | 2387 | edge ret; |
9ee634e3 | 2388 | |
bc35512f | 2389 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
6de9cd9a | 2390 | return NULL; |
bc35512f | 2391 | |
3348b696 | 2392 | if (e->dest == dest) |
6de9cd9a | 2393 | return e; |
bc35512f | 2394 | |
3348b696 | 2395 | if (e->src != ENTRY_BLOCK_PTR |
6de9cd9a | 2396 | && (ret = try_redirect_by_replacing_jump (e, dest, true))) |
f345f21a | 2397 | { |
6fb5fa3c | 2398 | df_set_bb_dirty (src); |
6de9cd9a | 2399 | return ret; |
f345f21a | 2400 | } |
bc35512f JH |
2401 | |
2402 | if (e->src == ENTRY_BLOCK_PTR | |
2403 | && (e->flags & EDGE_FALLTHRU) && !(e->flags & EDGE_COMPLEX)) | |
2404 | { | |
c263766c RH |
2405 | if (dump_file) |
2406 | fprintf (dump_file, "Redirecting entry edge from bb %i to %i\n", | |
bc35512f JH |
2407 | e->src->index, dest->index); |
2408 | ||
6fb5fa3c | 2409 | df_set_bb_dirty (e->src); |
bc35512f | 2410 | redirect_edge_succ (e, dest); |
6de9cd9a | 2411 | return e; |
bc35512f JH |
2412 | } |
2413 | ||
9ee634e3 JH |
2414 | /* Redirect_edge_and_branch may decide to turn branch into fallthru edge |
2415 | in the case the basic block appears to be in sequence. Avoid this | |
2416 | transformation. */ | |
2417 | ||
9ee634e3 JH |
2418 | if (e->flags & EDGE_FALLTHRU) |
2419 | { | |
2420 | /* Redirect any branch edges unified with the fallthru one. */ | |
4b4bf941 | 2421 | if (JUMP_P (BB_END (src)) |
432f982f JH |
2422 | && label_is_jump_target_p (BB_HEAD (e->dest), |
2423 | BB_END (src))) | |
9ee634e3 | 2424 | { |
341c100f | 2425 | edge redirected; |
c22cacf3 | 2426 | |
c263766c RH |
2427 | if (dump_file) |
2428 | fprintf (dump_file, "Fallthru edge unified with branch " | |
432f982f JH |
2429 | "%i->%i redirected to %i\n", |
2430 | e->src->index, e->dest->index, dest->index); | |
2431 | e->flags &= ~EDGE_FALLTHRU; | |
341c100f NS |
2432 | redirected = redirect_branch_edge (e, dest); |
2433 | gcc_assert (redirected); | |
432f982f | 2434 | e->flags |= EDGE_FALLTHRU; |
6fb5fa3c | 2435 | df_set_bb_dirty (e->src); |
6de9cd9a | 2436 | return e; |
9ee634e3 JH |
2437 | } |
2438 | /* In case we are redirecting fallthru edge to the branch edge | |
c22cacf3 | 2439 | of conditional jump, remove it. */ |
628f6a4e | 2440 | if (EDGE_COUNT (src->succs) == 2) |
9ee634e3 | 2441 | { |
03101c6f KH |
2442 | /* Find the edge that is different from E. */ |
2443 | edge s = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e); | |
628f6a4e | 2444 | |
9ee634e3 | 2445 | if (s->dest == dest |
a813c111 SB |
2446 | && any_condjump_p (BB_END (src)) |
2447 | && onlyjump_p (BB_END (src))) | |
2448 | delete_insn (BB_END (src)); | |
9ee634e3 | 2449 | } |
6de9cd9a | 2450 | ret = redirect_edge_succ_nodup (e, dest); |
c263766c RH |
2451 | if (dump_file) |
2452 | fprintf (dump_file, "Fallthru edge %i->%i redirected to %i\n", | |
bc35512f | 2453 | e->src->index, e->dest->index, dest->index); |
9ee634e3 JH |
2454 | } |
2455 | else | |
bc35512f | 2456 | ret = redirect_branch_edge (e, dest); |
9ee634e3 JH |
2457 | |
2458 | /* We don't want simplejumps in the insn stream during cfglayout. */ | |
341c100f | 2459 | gcc_assert (!simplejump_p (BB_END (src))); |
9ee634e3 | 2460 | |
6fb5fa3c | 2461 | df_set_bb_dirty (src); |
9ee634e3 JH |
2462 | return ret; |
2463 | } | |
2464 | ||
2465 | /* Simple wrapper as we always can redirect fallthru edges. */ | |
2466 | static basic_block | |
d329e058 | 2467 | cfg_layout_redirect_edge_and_branch_force (edge e, basic_block dest) |
9ee634e3 | 2468 | { |
341c100f NS |
2469 | edge redirected = cfg_layout_redirect_edge_and_branch (e, dest); |
2470 | ||
2471 | gcc_assert (redirected); | |
9ee634e3 JH |
2472 | return NULL; |
2473 | } | |
2474 | ||
f470c378 ZD |
2475 | /* Same as delete_basic_block but update cfg_layout structures. */ |
2476 | ||
9ee634e3 | 2477 | static void |
d329e058 | 2478 | cfg_layout_delete_block (basic_block bb) |
9ee634e3 | 2479 | { |
a813c111 | 2480 | rtx insn, next, prev = PREV_INSN (BB_HEAD (bb)), *to, remaints; |
9ee634e3 | 2481 | |
370369e1 | 2482 | if (bb->il.rtl->header) |
9ee634e3 | 2483 | { |
a813c111 | 2484 | next = BB_HEAD (bb); |
9ee634e3 | 2485 | if (prev) |
370369e1 | 2486 | NEXT_INSN (prev) = bb->il.rtl->header; |
9ee634e3 | 2487 | else |
370369e1 JH |
2488 | set_first_insn (bb->il.rtl->header); |
2489 | PREV_INSN (bb->il.rtl->header) = prev; | |
2490 | insn = bb->il.rtl->header; | |
9ee634e3 JH |
2491 | while (NEXT_INSN (insn)) |
2492 | insn = NEXT_INSN (insn); | |
2493 | NEXT_INSN (insn) = next; | |
2494 | PREV_INSN (next) = insn; | |
2495 | } | |
a813c111 | 2496 | next = NEXT_INSN (BB_END (bb)); |
370369e1 | 2497 | if (bb->il.rtl->footer) |
9ee634e3 | 2498 | { |
370369e1 | 2499 | insn = bb->il.rtl->footer; |
bc35512f JH |
2500 | while (insn) |
2501 | { | |
4b4bf941 | 2502 | if (BARRIER_P (insn)) |
bc35512f JH |
2503 | { |
2504 | if (PREV_INSN (insn)) | |
2505 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
2506 | else | |
370369e1 | 2507 | bb->il.rtl->footer = NEXT_INSN (insn); |
bc35512f JH |
2508 | if (NEXT_INSN (insn)) |
2509 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
2510 | } | |
4b4bf941 | 2511 | if (LABEL_P (insn)) |
bc35512f JH |
2512 | break; |
2513 | insn = NEXT_INSN (insn); | |
2514 | } | |
370369e1 | 2515 | if (bb->il.rtl->footer) |
bc35512f | 2516 | { |
a813c111 | 2517 | insn = BB_END (bb); |
370369e1 JH |
2518 | NEXT_INSN (insn) = bb->il.rtl->footer; |
2519 | PREV_INSN (bb->il.rtl->footer) = insn; | |
bc35512f JH |
2520 | while (NEXT_INSN (insn)) |
2521 | insn = NEXT_INSN (insn); | |
2522 | NEXT_INSN (insn) = next; | |
2523 | if (next) | |
2524 | PREV_INSN (next) = insn; | |
2525 | else | |
2526 | set_last_insn (insn); | |
2527 | } | |
9ee634e3 JH |
2528 | } |
2529 | if (bb->next_bb != EXIT_BLOCK_PTR) | |
370369e1 | 2530 | to = &bb->next_bb->il.rtl->header; |
9ee634e3 JH |
2531 | else |
2532 | to = &cfg_layout_function_footer; | |
997de8ed | 2533 | |
9ee634e3 JH |
2534 | rtl_delete_block (bb); |
2535 | ||
2536 | if (prev) | |
2537 | prev = NEXT_INSN (prev); | |
d329e058 | 2538 | else |
9ee634e3 JH |
2539 | prev = get_insns (); |
2540 | if (next) | |
2541 | next = PREV_INSN (next); | |
d329e058 | 2542 | else |
9ee634e3 JH |
2543 | next = get_last_insn (); |
2544 | ||
2545 | if (next && NEXT_INSN (next) != prev) | |
2546 | { | |
2547 | remaints = unlink_insn_chain (prev, next); | |
2548 | insn = remaints; | |
2549 | while (NEXT_INSN (insn)) | |
2550 | insn = NEXT_INSN (insn); | |
2551 | NEXT_INSN (insn) = *to; | |
2552 | if (*to) | |
2553 | PREV_INSN (*to) = insn; | |
2554 | *to = remaints; | |
2555 | } | |
2556 | } | |
2557 | ||
beb235f8 | 2558 | /* Return true when blocks A and B can be safely merged. */ |
b48d0358 | 2559 | |
bc35512f | 2560 | static bool |
b48d0358 | 2561 | cfg_layout_can_merge_blocks_p (basic_block a, basic_block b) |
bc35512f | 2562 | { |
750054a2 CT |
2563 | /* If we are partitioning hot/cold basic blocks, we don't want to |
2564 | mess up unconditional or indirect jumps that cross between hot | |
076c7ab8 ZW |
2565 | and cold sections. |
2566 | ||
8e8d5162 | 2567 | Basic block partitioning may result in some jumps that appear to |
c22cacf3 MS |
2568 | be optimizable (or blocks that appear to be mergeable), but which really |
2569 | must be left untouched (they are required to make it safely across | |
2570 | partition boundaries). See the comments at the top of | |
8e8d5162 CT |
2571 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
2572 | ||
87c8b4be | 2573 | if (BB_PARTITION (a) != BB_PARTITION (b)) |
076c7ab8 | 2574 | return false; |
750054a2 | 2575 | |
bc35512f | 2576 | /* There must be exactly one edge in between the blocks. */ |
c5cbcccf ZD |
2577 | return (single_succ_p (a) |
2578 | && single_succ (a) == b | |
2579 | && single_pred_p (b) == 1 | |
628f6a4e | 2580 | && a != b |
bc35512f | 2581 | /* Must be simple edge. */ |
c5cbcccf | 2582 | && !(single_succ_edge (a)->flags & EDGE_COMPLEX) |
bc35512f | 2583 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR |
49ea3702 SB |
2584 | /* If the jump insn has side effects, we can't kill the edge. |
2585 | When not optimizing, try_redirect_by_replacing_jump will | |
2586 | not allow us to redirect an edge by replacing a table jump. */ | |
4b4bf941 | 2587 | && (!JUMP_P (BB_END (a)) |
49ea3702 | 2588 | || ((!optimize || reload_completed) |
a813c111 | 2589 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f JH |
2590 | } |
2591 | ||
41806d92 NS |
2592 | /* Merge block A and B. The blocks must be mergeable. */ |
2593 | ||
bc35512f JH |
2594 | static void |
2595 | cfg_layout_merge_blocks (basic_block a, basic_block b) | |
2596 | { | |
2597 | #ifdef ENABLE_CHECKING | |
341c100f | 2598 | gcc_assert (cfg_layout_can_merge_blocks_p (a, b)); |
bc35512f JH |
2599 | #endif |
2600 | ||
6fb5fa3c DB |
2601 | if (dump_file) |
2602 | fprintf (dump_file, "merging block %d into block %d\n", b->index, a->index); | |
2603 | ||
bc35512f | 2604 | /* If there was a CODE_LABEL beginning B, delete it. */ |
4b4bf941 | 2605 | if (LABEL_P (BB_HEAD (b))) |
2c97f8e4 | 2606 | { |
2c97f8e4 RH |
2607 | delete_insn (BB_HEAD (b)); |
2608 | } | |
bc35512f JH |
2609 | |
2610 | /* We should have fallthru edge in a, or we can do dummy redirection to get | |
2611 | it cleaned up. */ | |
4b4bf941 | 2612 | if (JUMP_P (BB_END (a))) |
628f6a4e | 2613 | try_redirect_by_replacing_jump (EDGE_SUCC (a, 0), b, true); |
341c100f | 2614 | gcc_assert (!JUMP_P (BB_END (a))); |
bc35512f | 2615 | |
7241571e JJ |
2616 | /* When not optimizing and the edge is the only place in RTL which holds |
2617 | some unique locus, emit a nop with that locus in between. */ | |
2618 | if (!optimize && EDGE_SUCC (a, 0)->goto_locus) | |
2619 | { | |
1692ae7e | 2620 | rtx insn = BB_END (a), end = PREV_INSN (BB_HEAD (a)); |
7241571e JJ |
2621 | int goto_locus = EDGE_SUCC (a, 0)->goto_locus; |
2622 | ||
1692ae7e JJ |
2623 | while (insn != end && (!INSN_P (insn) || INSN_LOCATOR (insn) == 0)) |
2624 | insn = PREV_INSN (insn); | |
2625 | if (insn != end && locator_eq (INSN_LOCATOR (insn), goto_locus)) | |
7241571e JJ |
2626 | goto_locus = 0; |
2627 | else | |
2628 | { | |
2629 | insn = BB_HEAD (b); | |
1692ae7e JJ |
2630 | end = NEXT_INSN (BB_END (b)); |
2631 | while (insn != end && !INSN_P (insn)) | |
2632 | insn = NEXT_INSN (insn); | |
2633 | if (insn != end && INSN_LOCATOR (insn) != 0 | |
2634 | && locator_eq (INSN_LOCATOR (insn), goto_locus)) | |
7241571e JJ |
2635 | goto_locus = 0; |
2636 | } | |
2637 | if (goto_locus) | |
2638 | { | |
2639 | BB_END (a) = emit_insn_after_noloc (gen_nop (), BB_END (a), a); | |
2640 | INSN_LOCATOR (BB_END (a)) = goto_locus; | |
2641 | } | |
2642 | } | |
2643 | ||
bc35512f | 2644 | /* Possible line number notes should appear in between. */ |
370369e1 | 2645 | if (b->il.rtl->header) |
bc35512f | 2646 | { |
a813c111 | 2647 | rtx first = BB_END (a), last; |
bc35512f | 2648 | |
6fb5fa3c | 2649 | last = emit_insn_after_noloc (b->il.rtl->header, BB_END (a), a); |
a7b87f73 | 2650 | delete_insn_chain (NEXT_INSN (first), last, false); |
370369e1 | 2651 | b->il.rtl->header = NULL; |
bc35512f JH |
2652 | } |
2653 | ||
2654 | /* In the case basic blocks are not adjacent, move them around. */ | |
a813c111 | 2655 | if (NEXT_INSN (BB_END (a)) != BB_HEAD (b)) |
bc35512f | 2656 | { |
a813c111 | 2657 | rtx first = unlink_insn_chain (BB_HEAD (b), BB_END (b)); |
bc35512f | 2658 | |
6fb5fa3c | 2659 | emit_insn_after_noloc (first, BB_END (a), a); |
bc35512f JH |
2660 | /* Skip possible DELETED_LABEL insn. */ |
2661 | if (!NOTE_INSN_BASIC_BLOCK_P (first)) | |
2662 | first = NEXT_INSN (first); | |
341c100f | 2663 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (first)); |
a813c111 | 2664 | BB_HEAD (b) = NULL; |
6c3d0e31 SP |
2665 | |
2666 | /* emit_insn_after_noloc doesn't call df_insn_change_bb. | |
2667 | We need to explicitly call. */ | |
2668 | update_bb_for_insn_chain (NEXT_INSN (first), | |
2669 | BB_END (b), | |
2670 | a); | |
2671 | ||
bc35512f JH |
2672 | delete_insn (first); |
2673 | } | |
2674 | /* Otherwise just re-associate the instructions. */ | |
2675 | else | |
2676 | { | |
2677 | rtx insn; | |
2678 | ||
6c3d0e31 | 2679 | update_bb_for_insn_chain (BB_HEAD (b), BB_END (b), a); |
6fb5fa3c | 2680 | |
a813c111 | 2681 | insn = BB_HEAD (b); |
bc35512f JH |
2682 | /* Skip possible DELETED_LABEL insn. */ |
2683 | if (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
2684 | insn = NEXT_INSN (insn); | |
341c100f | 2685 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn)); |
a813c111 SB |
2686 | BB_HEAD (b) = NULL; |
2687 | BB_END (a) = BB_END (b); | |
bc35512f JH |
2688 | delete_insn (insn); |
2689 | } | |
2690 | ||
6fb5fa3c DB |
2691 | df_bb_delete (b->index); |
2692 | ||
bc35512f | 2693 | /* Possible tablejumps and barriers should appear after the block. */ |
370369e1 | 2694 | if (b->il.rtl->footer) |
bc35512f | 2695 | { |
370369e1 JH |
2696 | if (!a->il.rtl->footer) |
2697 | a->il.rtl->footer = b->il.rtl->footer; | |
bc35512f JH |
2698 | else |
2699 | { | |
370369e1 | 2700 | rtx last = a->il.rtl->footer; |
bc35512f JH |
2701 | |
2702 | while (NEXT_INSN (last)) | |
2703 | last = NEXT_INSN (last); | |
370369e1 JH |
2704 | NEXT_INSN (last) = b->il.rtl->footer; |
2705 | PREV_INSN (b->il.rtl->footer) = last; | |
bc35512f | 2706 | } |
370369e1 | 2707 | b->il.rtl->footer = NULL; |
bc35512f JH |
2708 | } |
2709 | ||
c263766c RH |
2710 | if (dump_file) |
2711 | fprintf (dump_file, "Merged blocks %d and %d.\n", | |
bc35512f | 2712 | a->index, b->index); |
bc35512f JH |
2713 | } |
2714 | ||
2715 | /* Split edge E. */ | |
f470c378 | 2716 | |
bc35512f JH |
2717 | static basic_block |
2718 | cfg_layout_split_edge (edge e) | |
2719 | { | |
bc35512f JH |
2720 | basic_block new_bb = |
2721 | create_basic_block (e->src != ENTRY_BLOCK_PTR | |
a813c111 | 2722 | ? NEXT_INSN (BB_END (e->src)) : get_insns (), |
bc35512f JH |
2723 | NULL_RTX, e->src); |
2724 | ||
3e7eb734 JJ |
2725 | if (e->dest == EXIT_BLOCK_PTR) |
2726 | BB_COPY_PARTITION (new_bb, e->src); | |
2727 | else | |
2728 | BB_COPY_PARTITION (new_bb, e->dest); | |
a9b2ee88 | 2729 | make_edge (new_bb, e->dest, EDGE_FALLTHRU); |
bc35512f JH |
2730 | redirect_edge_and_branch_force (e, new_bb); |
2731 | ||
2732 | return new_bb; | |
2733 | } | |
2734 | ||
f470c378 ZD |
2735 | /* Do postprocessing after making a forwarder block joined by edge FALLTHRU. */ |
2736 | ||
2737 | static void | |
2738 | rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED) | |
2739 | { | |
2740 | } | |
2741 | ||
6de9cd9a DN |
2742 | /* Return 1 if BB ends with a call, possibly followed by some |
2743 | instructions that must stay with the call, 0 otherwise. */ | |
2744 | ||
2745 | static bool | |
b48d0358 | 2746 | rtl_block_ends_with_call_p (basic_block bb) |
6de9cd9a DN |
2747 | { |
2748 | rtx insn = BB_END (bb); | |
2749 | ||
4b4bf941 | 2750 | while (!CALL_P (insn) |
6de9cd9a | 2751 | && insn != BB_HEAD (bb) |
92ddef69 AO |
2752 | && (keep_with_call_p (insn) |
2753 | || NOTE_P (insn))) | |
6de9cd9a | 2754 | insn = PREV_INSN (insn); |
4b4bf941 | 2755 | return (CALL_P (insn)); |
6de9cd9a DN |
2756 | } |
2757 | ||
2758 | /* Return 1 if BB ends with a conditional branch, 0 otherwise. */ | |
2759 | ||
2760 | static bool | |
9678086d | 2761 | rtl_block_ends_with_condjump_p (const_basic_block bb) |
6de9cd9a DN |
2762 | { |
2763 | return any_condjump_p (BB_END (bb)); | |
2764 | } | |
2765 | ||
2766 | /* Return true if we need to add fake edge to exit. | |
2767 | Helper function for rtl_flow_call_edges_add. */ | |
2768 | ||
2769 | static bool | |
9678086d | 2770 | need_fake_edge_p (const_rtx insn) |
6de9cd9a DN |
2771 | { |
2772 | if (!INSN_P (insn)) | |
2773 | return false; | |
2774 | ||
4b4bf941 | 2775 | if ((CALL_P (insn) |
6de9cd9a DN |
2776 | && !SIBLING_CALL_P (insn) |
2777 | && !find_reg_note (insn, REG_NORETURN, NULL) | |
becfd6e5 | 2778 | && !(RTL_CONST_OR_PURE_CALL_P (insn)))) |
6de9cd9a DN |
2779 | return true; |
2780 | ||
2781 | return ((GET_CODE (PATTERN (insn)) == ASM_OPERANDS | |
2782 | && MEM_VOLATILE_P (PATTERN (insn))) | |
2783 | || (GET_CODE (PATTERN (insn)) == PARALLEL | |
2784 | && asm_noperands (insn) != -1 | |
2785 | && MEM_VOLATILE_P (XVECEXP (PATTERN (insn), 0, 0))) | |
2786 | || GET_CODE (PATTERN (insn)) == ASM_INPUT); | |
2787 | } | |
2788 | ||
2789 | /* Add fake edges to the function exit for any non constant and non noreturn | |
2790 | calls, volatile inline assembly in the bitmap of blocks specified by | |
2791 | BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks | |
2792 | that were split. | |
2793 | ||
2794 | The goal is to expose cases in which entering a basic block does not imply | |
2795 | that all subsequent instructions must be executed. */ | |
2796 | ||
2797 | static int | |
2798 | rtl_flow_call_edges_add (sbitmap blocks) | |
2799 | { | |
2800 | int i; | |
2801 | int blocks_split = 0; | |
2802 | int last_bb = last_basic_block; | |
2803 | bool check_last_block = false; | |
2804 | ||
24bd1a0b | 2805 | if (n_basic_blocks == NUM_FIXED_BLOCKS) |
6de9cd9a DN |
2806 | return 0; |
2807 | ||
2808 | if (! blocks) | |
2809 | check_last_block = true; | |
2810 | else | |
2811 | check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index); | |
2812 | ||
2813 | /* In the last basic block, before epilogue generation, there will be | |
2814 | a fallthru edge to EXIT. Special care is required if the last insn | |
2815 | of the last basic block is a call because make_edge folds duplicate | |
2816 | edges, which would result in the fallthru edge also being marked | |
2817 | fake, which would result in the fallthru edge being removed by | |
2818 | remove_fake_edges, which would result in an invalid CFG. | |
2819 | ||
2820 | Moreover, we can't elide the outgoing fake edge, since the block | |
2821 | profiler needs to take this into account in order to solve the minimal | |
2822 | spanning tree in the case that the call doesn't return. | |
2823 | ||
2824 | Handle this by adding a dummy instruction in a new last basic block. */ | |
2825 | if (check_last_block) | |
2826 | { | |
2827 | basic_block bb = EXIT_BLOCK_PTR->prev_bb; | |
2828 | rtx insn = BB_END (bb); | |
2829 | ||
2830 | /* Back up past insns that must be kept in the same block as a call. */ | |
2831 | while (insn != BB_HEAD (bb) | |
2832 | && keep_with_call_p (insn)) | |
2833 | insn = PREV_INSN (insn); | |
2834 | ||
2835 | if (need_fake_edge_p (insn)) | |
2836 | { | |
2837 | edge e; | |
2838 | ||
9ff3d2de JL |
2839 | e = find_edge (bb, EXIT_BLOCK_PTR); |
2840 | if (e) | |
2841 | { | |
c41c1387 | 2842 | insert_insn_on_edge (gen_use (const0_rtx), e); |
9ff3d2de JL |
2843 | commit_edge_insertions (); |
2844 | } | |
6de9cd9a DN |
2845 | } |
2846 | } | |
2847 | ||
2848 | /* Now add fake edges to the function exit for any non constant | |
2849 | calls since there is no way that we can determine if they will | |
2850 | return or not... */ | |
2851 | ||
24bd1a0b | 2852 | for (i = NUM_FIXED_BLOCKS; i < last_bb; i++) |
6de9cd9a DN |
2853 | { |
2854 | basic_block bb = BASIC_BLOCK (i); | |
2855 | rtx insn; | |
2856 | rtx prev_insn; | |
2857 | ||
2858 | if (!bb) | |
2859 | continue; | |
2860 | ||
2861 | if (blocks && !TEST_BIT (blocks, i)) | |
2862 | continue; | |
2863 | ||
2864 | for (insn = BB_END (bb); ; insn = prev_insn) | |
2865 | { | |
2866 | prev_insn = PREV_INSN (insn); | |
2867 | if (need_fake_edge_p (insn)) | |
2868 | { | |
2869 | edge e; | |
2870 | rtx split_at_insn = insn; | |
2871 | ||
2872 | /* Don't split the block between a call and an insn that should | |
c22cacf3 | 2873 | remain in the same block as the call. */ |
4b4bf941 | 2874 | if (CALL_P (insn)) |
6de9cd9a DN |
2875 | while (split_at_insn != BB_END (bb) |
2876 | && keep_with_call_p (NEXT_INSN (split_at_insn))) | |
2877 | split_at_insn = NEXT_INSN (split_at_insn); | |
2878 | ||
2879 | /* The handling above of the final block before the epilogue | |
c22cacf3 | 2880 | should be enough to verify that there is no edge to the exit |
6de9cd9a DN |
2881 | block in CFG already. Calling make_edge in such case would |
2882 | cause us to mark that edge as fake and remove it later. */ | |
2883 | ||
2884 | #ifdef ENABLE_CHECKING | |
2885 | if (split_at_insn == BB_END (bb)) | |
628f6a4e | 2886 | { |
9ff3d2de JL |
2887 | e = find_edge (bb, EXIT_BLOCK_PTR); |
2888 | gcc_assert (e == NULL); | |
628f6a4e | 2889 | } |
6de9cd9a DN |
2890 | #endif |
2891 | ||
2892 | /* Note that the following may create a new basic block | |
2893 | and renumber the existing basic blocks. */ | |
2894 | if (split_at_insn != BB_END (bb)) | |
2895 | { | |
2896 | e = split_block (bb, split_at_insn); | |
2897 | if (e) | |
2898 | blocks_split++; | |
2899 | } | |
2900 | ||
2901 | make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE); | |
2902 | } | |
2903 | ||
2904 | if (insn == BB_HEAD (bb)) | |
2905 | break; | |
2906 | } | |
2907 | } | |
2908 | ||
2909 | if (blocks_split) | |
2910 | verify_flow_info (); | |
2911 | ||
2912 | return blocks_split; | |
2913 | } | |
2914 | ||
1cb7dfc3 | 2915 | /* Add COMP_RTX as a condition at end of COND_BB. FIRST_HEAD is |
315682fb | 2916 | the conditional branch target, SECOND_HEAD should be the fall-thru |
1cb7dfc3 MH |
2917 | there is no need to handle this here the loop versioning code handles |
2918 | this. the reason for SECON_HEAD is that it is needed for condition | |
2919 | in trees, and this should be of the same type since it is a hook. */ | |
2920 | static void | |
2921 | rtl_lv_add_condition_to_bb (basic_block first_head , | |
c22cacf3 MS |
2922 | basic_block second_head ATTRIBUTE_UNUSED, |
2923 | basic_block cond_bb, void *comp_rtx) | |
1cb7dfc3 MH |
2924 | { |
2925 | rtx label, seq, jump; | |
2926 | rtx op0 = XEXP ((rtx)comp_rtx, 0); | |
2927 | rtx op1 = XEXP ((rtx)comp_rtx, 1); | |
2928 | enum rtx_code comp = GET_CODE ((rtx)comp_rtx); | |
2929 | enum machine_mode mode; | |
2930 | ||
2931 | ||
2932 | label = block_label (first_head); | |
2933 | mode = GET_MODE (op0); | |
2934 | if (mode == VOIDmode) | |
2935 | mode = GET_MODE (op1); | |
2936 | ||
2937 | start_sequence (); | |
2938 | op0 = force_operand (op0, NULL_RTX); | |
2939 | op1 = force_operand (op1, NULL_RTX); | |
2940 | do_compare_rtx_and_jump (op0, op1, comp, 0, | |
2941 | mode, NULL_RTX, NULL_RTX, label); | |
2942 | jump = get_last_insn (); | |
2943 | JUMP_LABEL (jump) = label; | |
2944 | LABEL_NUSES (label)++; | |
2945 | seq = get_insns (); | |
2946 | end_sequence (); | |
2947 | ||
2948 | /* Add the new cond , in the new head. */ | |
2949 | emit_insn_after(seq, BB_END(cond_bb)); | |
2950 | } | |
2951 | ||
2952 | ||
2953 | /* Given a block B with unconditional branch at its end, get the | |
2954 | store the return the branch edge and the fall-thru edge in | |
2955 | BRANCH_EDGE and FALLTHRU_EDGE respectively. */ | |
2956 | static void | |
2957 | rtl_extract_cond_bb_edges (basic_block b, edge *branch_edge, | |
2958 | edge *fallthru_edge) | |
2959 | { | |
2960 | edge e = EDGE_SUCC (b, 0); | |
2961 | ||
2962 | if (e->flags & EDGE_FALLTHRU) | |
2963 | { | |
2964 | *fallthru_edge = e; | |
2965 | *branch_edge = EDGE_SUCC (b, 1); | |
2966 | } | |
2967 | else | |
2968 | { | |
2969 | *branch_edge = e; | |
2970 | *fallthru_edge = EDGE_SUCC (b, 1); | |
2971 | } | |
2972 | } | |
2973 | ||
5e2d947c JH |
2974 | void |
2975 | init_rtl_bb_info (basic_block bb) | |
2976 | { | |
2977 | gcc_assert (!bb->il.rtl); | |
ae50c0cb | 2978 | bb->il.rtl = GGC_CNEW (struct rtl_bb_info); |
5e2d947c JH |
2979 | } |
2980 | ||
1cb7dfc3 | 2981 | |
8cd37d0b RL |
2982 | /* Add EXPR to the end of basic block BB. */ |
2983 | ||
2984 | rtx | |
2985 | insert_insn_end_bb_new (rtx pat, basic_block bb) | |
2986 | { | |
2987 | rtx insn = BB_END (bb); | |
2988 | rtx new_insn; | |
2989 | rtx pat_end = pat; | |
2990 | ||
2991 | while (NEXT_INSN (pat_end) != NULL_RTX) | |
2992 | pat_end = NEXT_INSN (pat_end); | |
2993 | ||
2994 | /* If the last insn is a jump, insert EXPR in front [taking care to | |
2995 | handle cc0, etc. properly]. Similarly we need to care trapping | |
2996 | instructions in presence of non-call exceptions. */ | |
2997 | ||
2998 | if (JUMP_P (insn) | |
2999 | || (NONJUMP_INSN_P (insn) | |
3000 | && (!single_succ_p (bb) | |
3001 | || single_succ_edge (bb)->flags & EDGE_ABNORMAL))) | |
3002 | { | |
3003 | #ifdef HAVE_cc0 | |
3004 | rtx note; | |
3005 | #endif | |
3006 | /* If this is a jump table, then we can't insert stuff here. Since | |
3007 | we know the previous real insn must be the tablejump, we insert | |
3008 | the new instruction just before the tablejump. */ | |
3009 | if (GET_CODE (PATTERN (insn)) == ADDR_VEC | |
3010 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC) | |
3011 | insn = prev_real_insn (insn); | |
3012 | ||
3013 | #ifdef HAVE_cc0 | |
3014 | /* FIXME: 'twould be nice to call prev_cc0_setter here but it aborts | |
3015 | if cc0 isn't set. */ | |
3016 | note = find_reg_note (insn, REG_CC_SETTER, NULL_RTX); | |
3017 | if (note) | |
3018 | insn = XEXP (note, 0); | |
3019 | else | |
3020 | { | |
3021 | rtx maybe_cc0_setter = prev_nonnote_insn (insn); | |
3022 | if (maybe_cc0_setter | |
3023 | && INSN_P (maybe_cc0_setter) | |
3024 | && sets_cc0_p (PATTERN (maybe_cc0_setter))) | |
3025 | insn = maybe_cc0_setter; | |
3026 | } | |
3027 | #endif | |
3028 | /* FIXME: What if something in cc0/jump uses value set in new | |
3029 | insn? */ | |
6fb5fa3c | 3030 | new_insn = emit_insn_before_noloc (pat, insn, bb); |
8cd37d0b RL |
3031 | } |
3032 | ||
3033 | /* Likewise if the last insn is a call, as will happen in the presence | |
3034 | of exception handling. */ | |
3035 | else if (CALL_P (insn) | |
3036 | && (!single_succ_p (bb) | |
3037 | || single_succ_edge (bb)->flags & EDGE_ABNORMAL)) | |
3038 | { | |
3039 | /* Keeping in mind SMALL_REGISTER_CLASSES and parameters in registers, | |
3040 | we search backward and place the instructions before the first | |
3041 | parameter is loaded. Do this for everyone for consistency and a | |
3042 | presumption that we'll get better code elsewhere as well. */ | |
3043 | ||
3044 | /* Since different machines initialize their parameter registers | |
3045 | in different orders, assume nothing. Collect the set of all | |
3046 | parameter registers. */ | |
3047 | insn = find_first_parameter_load (insn, BB_HEAD (bb)); | |
3048 | ||
3049 | /* If we found all the parameter loads, then we want to insert | |
3050 | before the first parameter load. | |
3051 | ||
3052 | If we did not find all the parameter loads, then we might have | |
3053 | stopped on the head of the block, which could be a CODE_LABEL. | |
3054 | If we inserted before the CODE_LABEL, then we would be putting | |
3055 | the insn in the wrong basic block. In that case, put the insn | |
3056 | after the CODE_LABEL. Also, respect NOTE_INSN_BASIC_BLOCK. */ | |
3057 | while (LABEL_P (insn) | |
3058 | || NOTE_INSN_BASIC_BLOCK_P (insn)) | |
3059 | insn = NEXT_INSN (insn); | |
3060 | ||
6fb5fa3c | 3061 | new_insn = emit_insn_before_noloc (pat, insn, bb); |
8cd37d0b RL |
3062 | } |
3063 | else | |
6fb5fa3c | 3064 | new_insn = emit_insn_after_noloc (pat, insn, bb); |
8cd37d0b RL |
3065 | |
3066 | return new_insn; | |
3067 | } | |
3068 | ||
14fa2cc0 ZD |
3069 | /* Returns true if it is possible to remove edge E by redirecting |
3070 | it to the destination of the other edge from E->src. */ | |
3071 | ||
3072 | static bool | |
9678086d | 3073 | rtl_can_remove_branch_p (const_edge e) |
14fa2cc0 | 3074 | { |
9678086d KG |
3075 | const_basic_block src = e->src; |
3076 | const_basic_block target = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest; | |
3077 | const_rtx insn = BB_END (src), set; | |
14fa2cc0 ZD |
3078 | |
3079 | /* The conditions are taken from try_redirect_by_replacing_jump. */ | |
3080 | if (target == EXIT_BLOCK_PTR) | |
3081 | return false; | |
3082 | ||
3083 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) | |
3084 | return false; | |
3085 | ||
3086 | if (find_reg_note (insn, REG_CROSSING_JUMP, NULL_RTX) | |
3087 | || BB_PARTITION (src) != BB_PARTITION (target)) | |
3088 | return false; | |
3089 | ||
3090 | if (!onlyjump_p (insn) | |
3091 | || tablejump_p (insn, NULL, NULL)) | |
3092 | return false; | |
3093 | ||
3094 | set = single_set (insn); | |
3095 | if (!set || side_effects_p (set)) | |
3096 | return false; | |
3097 | ||
3098 | return true; | |
3099 | } | |
3100 | ||
9ee634e3 JH |
3101 | /* Implementation of CFG manipulation for linearized RTL. */ |
3102 | struct cfg_hooks rtl_cfg_hooks = { | |
f470c378 | 3103 | "rtl", |
9ee634e3 | 3104 | rtl_verify_flow_info, |
10e9fecc | 3105 | rtl_dump_bb, |
bc35512f | 3106 | rtl_create_basic_block, |
9ee634e3 JH |
3107 | rtl_redirect_edge_and_branch, |
3108 | rtl_redirect_edge_and_branch_force, | |
14fa2cc0 | 3109 | rtl_can_remove_branch_p, |
9ee634e3 JH |
3110 | rtl_delete_block, |
3111 | rtl_split_block, | |
f470c378 | 3112 | rtl_move_block_after, |
bc35512f JH |
3113 | rtl_can_merge_blocks, /* can_merge_blocks_p */ |
3114 | rtl_merge_blocks, | |
6de9cd9a DN |
3115 | rtl_predict_edge, |
3116 | rtl_predicted_by_p, | |
3117 | NULL, /* can_duplicate_block_p */ | |
3118 | NULL, /* duplicate_block */ | |
f470c378 ZD |
3119 | rtl_split_edge, |
3120 | rtl_make_forwarder_block, | |
6de9cd9a DN |
3121 | rtl_tidy_fallthru_edge, |
3122 | rtl_block_ends_with_call_p, | |
3123 | rtl_block_ends_with_condjump_p, | |
d9d4706f KH |
3124 | rtl_flow_call_edges_add, |
3125 | NULL, /* execute_on_growing_pred */ | |
1cb7dfc3 MH |
3126 | NULL, /* execute_on_shrinking_pred */ |
3127 | NULL, /* duplicate loop for trees */ | |
3128 | NULL, /* lv_add_condition_to_bb */ | |
3129 | NULL, /* lv_adjust_loop_header_phi*/ | |
3130 | NULL, /* extract_cond_bb_edges */ | |
c22cacf3 | 3131 | NULL /* flush_pending_stmts */ |
9ee634e3 JH |
3132 | }; |
3133 | ||
3134 | /* Implementation of CFG manipulation for cfg layout RTL, where | |
3135 | basic block connected via fallthru edges does not have to be adjacent. | |
3136 | This representation will hopefully become the default one in future | |
3137 | version of the compiler. */ | |
6de9cd9a DN |
3138 | |
3139 | /* We do not want to declare these functions in a header file, since they | |
3140 | should only be used through the cfghooks interface, and we do not want to | |
3141 | move them here since it would require also moving quite a lot of related | |
6fb5fa3c | 3142 | code. They are in cfglayout.c. */ |
9678086d | 3143 | extern bool cfg_layout_can_duplicate_bb_p (const_basic_block); |
6de9cd9a DN |
3144 | extern basic_block cfg_layout_duplicate_bb (basic_block); |
3145 | ||
9ee634e3 | 3146 | struct cfg_hooks cfg_layout_rtl_cfg_hooks = { |
f470c378 | 3147 | "cfglayout mode", |
bc35512f | 3148 | rtl_verify_flow_info_1, |
10e9fecc | 3149 | rtl_dump_bb, |
bc35512f | 3150 | cfg_layout_create_basic_block, |
9ee634e3 JH |
3151 | cfg_layout_redirect_edge_and_branch, |
3152 | cfg_layout_redirect_edge_and_branch_force, | |
14fa2cc0 | 3153 | rtl_can_remove_branch_p, |
9ee634e3 JH |
3154 | cfg_layout_delete_block, |
3155 | cfg_layout_split_block, | |
f470c378 | 3156 | rtl_move_block_after, |
bc35512f JH |
3157 | cfg_layout_can_merge_blocks_p, |
3158 | cfg_layout_merge_blocks, | |
6de9cd9a DN |
3159 | rtl_predict_edge, |
3160 | rtl_predicted_by_p, | |
3161 | cfg_layout_can_duplicate_bb_p, | |
3162 | cfg_layout_duplicate_bb, | |
f470c378 ZD |
3163 | cfg_layout_split_edge, |
3164 | rtl_make_forwarder_block, | |
6de9cd9a DN |
3165 | NULL, |
3166 | rtl_block_ends_with_call_p, | |
3167 | rtl_block_ends_with_condjump_p, | |
d9d4706f KH |
3168 | rtl_flow_call_edges_add, |
3169 | NULL, /* execute_on_growing_pred */ | |
1cb7dfc3 MH |
3170 | NULL, /* execute_on_shrinking_pred */ |
3171 | duplicate_loop_to_header_edge, /* duplicate loop for trees */ | |
3172 | rtl_lv_add_condition_to_bb, /* lv_add_condition_to_bb */ | |
3173 | NULL, /* lv_adjust_loop_header_phi*/ | |
3174 | rtl_extract_cond_bb_edges, /* extract_cond_bb_edges */ | |
c22cacf3 | 3175 | NULL /* flush_pending_stmts */ |
9ee634e3 | 3176 | }; |