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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, | |
4ab80063 | 3 | 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. |
ca6c03ca JH |
4 | |
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it under | |
8 | the terms of the GNU General Public License as published by the Free | |
9 | Software Foundation; either version 2, or (at your option) any later | |
10 | version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING. If not, write to the Free | |
366ccddb KC |
19 | Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA |
20 | 02110-1301, USA. */ | |
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" |
ca6c03ca | 63 | |
d329e058 AJ |
64 | static int can_delete_note_p (rtx); |
65 | static int can_delete_label_p (rtx); | |
66 | static void commit_one_edge_insertion (edge, int); | |
d329e058 AJ |
67 | static rtx last_loop_beg_note (rtx); |
68 | static bool back_edge_of_syntactic_loop_p (basic_block, basic_block); | |
d329e058 | 69 | static basic_block rtl_split_edge (edge); |
f470c378 | 70 | static bool rtl_move_block_after (basic_block, basic_block); |
d329e058 | 71 | static int rtl_verify_flow_info (void); |
f470c378 | 72 | static basic_block cfg_layout_split_block (basic_block, void *); |
6de9cd9a | 73 | static edge cfg_layout_redirect_edge_and_branch (edge, basic_block); |
d329e058 AJ |
74 | static basic_block cfg_layout_redirect_edge_and_branch_force (edge, basic_block); |
75 | static void cfg_layout_delete_block (basic_block); | |
76 | static void rtl_delete_block (basic_block); | |
77 | static basic_block rtl_redirect_edge_and_branch_force (edge, basic_block); | |
6de9cd9a | 78 | static edge rtl_redirect_edge_and_branch (edge, basic_block); |
f470c378 ZD |
79 | static basic_block rtl_split_block (basic_block, void *); |
80 | static void rtl_dump_bb (basic_block, FILE *, int); | |
d329e058 | 81 | static int rtl_verify_flow_info_1 (void); |
ff25ef99 | 82 | static void mark_killed_regs (rtx, rtx, void *); |
f470c378 | 83 | static void rtl_make_forwarder_block (edge); |
ca6c03ca JH |
84 | \f |
85 | /* Return true if NOTE is not one of the ones that must be kept paired, | |
5f0d2358 | 86 | so that we may simply delete it. */ |
ca6c03ca JH |
87 | |
88 | static int | |
d329e058 | 89 | can_delete_note_p (rtx note) |
ca6c03ca JH |
90 | { |
91 | return (NOTE_LINE_NUMBER (note) == NOTE_INSN_DELETED | |
87c8b4be | 92 | || NOTE_LINE_NUMBER (note) == NOTE_INSN_BASIC_BLOCK); |
ca6c03ca JH |
93 | } |
94 | ||
95 | /* True if a given label can be deleted. */ | |
96 | ||
97 | static int | |
d329e058 | 98 | can_delete_label_p (rtx label) |
ca6c03ca | 99 | { |
5f0d2358 RK |
100 | return (!LABEL_PRESERVE_P (label) |
101 | /* User declared labels must be preserved. */ | |
102 | && LABEL_NAME (label) == 0 | |
610d2478 | 103 | && !in_expr_list_p (forced_labels, label)); |
ca6c03ca JH |
104 | } |
105 | ||
106 | /* Delete INSN by patching it out. Return the next insn. */ | |
107 | ||
108 | rtx | |
d329e058 | 109 | delete_insn (rtx insn) |
ca6c03ca JH |
110 | { |
111 | rtx next = NEXT_INSN (insn); | |
112 | rtx note; | |
113 | bool really_delete = true; | |
114 | ||
4b4bf941 | 115 | if (LABEL_P (insn)) |
ca6c03ca JH |
116 | { |
117 | /* Some labels can't be directly removed from the INSN chain, as they | |
f87c27b4 | 118 | might be references via variables, constant pool etc. |
ca6c03ca JH |
119 | Convert them to the special NOTE_INSN_DELETED_LABEL note. */ |
120 | if (! can_delete_label_p (insn)) | |
121 | { | |
122 | const char *name = LABEL_NAME (insn); | |
123 | ||
124 | really_delete = false; | |
125 | PUT_CODE (insn, NOTE); | |
126 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED_LABEL; | |
6773e15f | 127 | NOTE_DELETED_LABEL_NAME (insn) = name; |
ca6c03ca | 128 | } |
5f0d2358 | 129 | |
ca6c03ca JH |
130 | remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels); |
131 | } | |
132 | ||
133 | if (really_delete) | |
134 | { | |
cda94cbb | 135 | /* If this insn has already been deleted, something is very wrong. */ |
341c100f | 136 | gcc_assert (!INSN_DELETED_P (insn)); |
ca6c03ca JH |
137 | remove_insn (insn); |
138 | INSN_DELETED_P (insn) = 1; | |
139 | } | |
140 | ||
141 | /* If deleting a jump, decrement the use count of the label. Deleting | |
142 | the label itself should happen in the normal course of block merging. */ | |
4b4bf941 | 143 | if (JUMP_P (insn) |
ca6c03ca | 144 | && JUMP_LABEL (insn) |
4b4bf941 | 145 | && LABEL_P (JUMP_LABEL (insn))) |
ca6c03ca JH |
146 | LABEL_NUSES (JUMP_LABEL (insn))--; |
147 | ||
148 | /* Also if deleting an insn that references a label. */ | |
9295a326 JZ |
149 | else |
150 | { | |
151 | while ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)) != NULL_RTX | |
4b4bf941 | 152 | && LABEL_P (XEXP (note, 0))) |
9295a326 JZ |
153 | { |
154 | LABEL_NUSES (XEXP (note, 0))--; | |
155 | remove_note (insn, note); | |
156 | } | |
157 | } | |
ca6c03ca | 158 | |
4b4bf941 | 159 | if (JUMP_P (insn) |
ca6c03ca JH |
160 | && (GET_CODE (PATTERN (insn)) == ADDR_VEC |
161 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)) | |
162 | { | |
163 | rtx pat = PATTERN (insn); | |
164 | int diff_vec_p = GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC; | |
165 | int len = XVECLEN (pat, diff_vec_p); | |
166 | int i; | |
167 | ||
168 | for (i = 0; i < len; i++) | |
a124fcda RH |
169 | { |
170 | rtx label = XEXP (XVECEXP (pat, diff_vec_p, i), 0); | |
171 | ||
172 | /* When deleting code in bulk (e.g. removing many unreachable | |
173 | blocks) we can delete a label that's a target of the vector | |
174 | before deleting the vector itself. */ | |
4b4bf941 | 175 | if (!NOTE_P (label)) |
a124fcda RH |
176 | LABEL_NUSES (label)--; |
177 | } | |
ca6c03ca JH |
178 | } |
179 | ||
180 | return next; | |
181 | } | |
182 | ||
3dec4024 JH |
183 | /* Like delete_insn but also purge dead edges from BB. */ |
184 | rtx | |
d329e058 | 185 | delete_insn_and_edges (rtx insn) |
3dec4024 JH |
186 | { |
187 | rtx x; | |
188 | bool purge = false; | |
189 | ||
ba4f7968 | 190 | if (INSN_P (insn) |
3dec4024 | 191 | && BLOCK_FOR_INSN (insn) |
a813c111 | 192 | && BB_END (BLOCK_FOR_INSN (insn)) == insn) |
3dec4024 JH |
193 | purge = true; |
194 | x = delete_insn (insn); | |
195 | if (purge) | |
196 | purge_dead_edges (BLOCK_FOR_INSN (insn)); | |
197 | return x; | |
198 | } | |
199 | ||
ca6c03ca JH |
200 | /* Unlink a chain of insns between START and FINISH, leaving notes |
201 | that must be paired. */ | |
202 | ||
203 | void | |
d329e058 | 204 | delete_insn_chain (rtx start, rtx finish) |
ca6c03ca | 205 | { |
ca6c03ca JH |
206 | rtx next; |
207 | ||
5f0d2358 RK |
208 | /* Unchain the insns one by one. It would be quicker to delete all of these |
209 | with a single unchaining, rather than one at a time, but we need to keep | |
210 | the NOTE's. */ | |
ca6c03ca JH |
211 | while (1) |
212 | { | |
213 | next = NEXT_INSN (start); | |
4b4bf941 | 214 | if (NOTE_P (start) && !can_delete_note_p (start)) |
ca6c03ca JH |
215 | ; |
216 | else | |
217 | next = delete_insn (start); | |
218 | ||
219 | if (start == finish) | |
220 | break; | |
221 | start = next; | |
222 | } | |
223 | } | |
3dec4024 JH |
224 | |
225 | /* Like delete_insn but also purge dead edges from BB. */ | |
226 | void | |
d329e058 | 227 | delete_insn_chain_and_edges (rtx first, rtx last) |
3dec4024 JH |
228 | { |
229 | bool purge = false; | |
230 | ||
ba4f7968 | 231 | if (INSN_P (last) |
3dec4024 | 232 | && BLOCK_FOR_INSN (last) |
a813c111 | 233 | && BB_END (BLOCK_FOR_INSN (last)) == last) |
3dec4024 JH |
234 | purge = true; |
235 | delete_insn_chain (first, last); | |
236 | if (purge) | |
237 | purge_dead_edges (BLOCK_FOR_INSN (last)); | |
238 | } | |
ca6c03ca | 239 | \f |
5f0d2358 RK |
240 | /* Create a new basic block consisting of the instructions between HEAD and END |
241 | inclusive. This function is designed to allow fast BB construction - reuses | |
242 | the note and basic block struct in BB_NOTE, if any and do not grow | |
243 | BASIC_BLOCK chain and should be used directly only by CFG construction code. | |
244 | END can be NULL in to create new empty basic block before HEAD. Both END | |
918ed612 ZD |
245 | and HEAD can be NULL to create basic block at the end of INSN chain. |
246 | AFTER is the basic block we should be put after. */ | |
ca6c03ca JH |
247 | |
248 | basic_block | |
d329e058 | 249 | create_basic_block_structure (rtx head, rtx end, rtx bb_note, basic_block after) |
ca6c03ca JH |
250 | { |
251 | basic_block bb; | |
252 | ||
253 | if (bb_note | |
ca6c03ca JH |
254 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL |
255 | && bb->aux == NULL) | |
256 | { | |
257 | /* If we found an existing note, thread it back onto the chain. */ | |
258 | ||
259 | rtx after; | |
260 | ||
4b4bf941 | 261 | if (LABEL_P (head)) |
ca6c03ca JH |
262 | after = head; |
263 | else | |
264 | { | |
265 | after = PREV_INSN (head); | |
266 | head = bb_note; | |
267 | } | |
268 | ||
269 | if (after != bb_note && NEXT_INSN (after) != bb_note) | |
ba4f7968 | 270 | reorder_insns_nobb (bb_note, bb_note, after); |
ca6c03ca JH |
271 | } |
272 | else | |
273 | { | |
274 | /* Otherwise we must create a note and a basic block structure. */ | |
275 | ||
276 | bb = alloc_block (); | |
277 | ||
5e2d947c | 278 | init_rtl_bb_info (bb); |
ca6c03ca | 279 | if (!head && !end) |
5f0d2358 RK |
280 | head = end = bb_note |
281 | = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); | |
4b4bf941 | 282 | else if (LABEL_P (head) && end) |
ca6c03ca JH |
283 | { |
284 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); | |
285 | if (head == end) | |
286 | end = bb_note; | |
287 | } | |
288 | else | |
289 | { | |
290 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); | |
291 | head = bb_note; | |
292 | if (!end) | |
293 | end = head; | |
294 | } | |
5f0d2358 | 295 | |
ca6c03ca JH |
296 | NOTE_BASIC_BLOCK (bb_note) = bb; |
297 | } | |
298 | ||
299 | /* Always include the bb note in the block. */ | |
300 | if (NEXT_INSN (end) == bb_note) | |
301 | end = bb_note; | |
302 | ||
a813c111 SB |
303 | BB_HEAD (bb) = head; |
304 | BB_END (bb) = end; | |
852c6ec7 | 305 | bb->index = last_basic_block++; |
5e2d947c | 306 | bb->flags = BB_NEW | BB_RTL; |
918ed612 | 307 | link_block (bb, after); |
68f9b844 | 308 | SET_BASIC_BLOCK (bb->index, bb); |
ba4f7968 | 309 | update_bb_for_insn (bb); |
076c7ab8 | 310 | BB_SET_PARTITION (bb, BB_UNPARTITIONED); |
ca6c03ca JH |
311 | |
312 | /* Tag the block so that we know it has been used when considering | |
313 | other basic block notes. */ | |
314 | bb->aux = bb; | |
315 | ||
316 | return bb; | |
317 | } | |
318 | ||
5f0d2358 | 319 | /* Create new basic block consisting of instructions in between HEAD and END |
918ed612 | 320 | and place it to the BB chain after block AFTER. END can be NULL in to |
5f0d2358 RK |
321 | create new empty basic block before HEAD. Both END and HEAD can be NULL to |
322 | create basic block at the end of INSN chain. */ | |
ca6c03ca | 323 | |
bc35512f JH |
324 | static basic_block |
325 | rtl_create_basic_block (void *headp, void *endp, basic_block after) | |
ca6c03ca | 326 | { |
bc35512f | 327 | rtx head = headp, end = endp; |
ca6c03ca | 328 | basic_block bb; |
0b17ab2f | 329 | |
7eca0767 | 330 | /* Grow the basic block array if needed. */ |
68f9b844 | 331 | if ((size_t) last_basic_block >= VEC_length (basic_block, basic_block_info)) |
7eca0767 | 332 | { |
68f9b844 | 333 | size_t old_size = VEC_length (basic_block, basic_block_info); |
7eca0767 | 334 | size_t new_size = last_basic_block + (last_basic_block + 3) / 4; |
68f9b844 KH |
335 | basic_block *p; |
336 | VEC_safe_grow (basic_block, gc, basic_block_info, new_size); | |
337 | p = VEC_address (basic_block, basic_block_info); | |
338 | memset (&p[old_size], 0, sizeof (basic_block) * (new_size - old_size)); | |
7eca0767 | 339 | } |
0b17ab2f | 340 | |
bf77398c | 341 | n_basic_blocks++; |
ca6c03ca | 342 | |
852c6ec7 | 343 | bb = create_basic_block_structure (head, end, NULL, after); |
ca6c03ca JH |
344 | bb->aux = NULL; |
345 | return bb; | |
346 | } | |
bc35512f JH |
347 | |
348 | static basic_block | |
349 | cfg_layout_create_basic_block (void *head, void *end, basic_block after) | |
350 | { | |
351 | basic_block newbb = rtl_create_basic_block (head, end, after); | |
352 | ||
bc35512f JH |
353 | return newbb; |
354 | } | |
ca6c03ca JH |
355 | \f |
356 | /* Delete the insns in a (non-live) block. We physically delete every | |
357 | non-deleted-note insn, and update the flow graph appropriately. | |
358 | ||
359 | Return nonzero if we deleted an exception handler. */ | |
360 | ||
361 | /* ??? Preserving all such notes strikes me as wrong. It would be nice | |
362 | to post-process the stream to remove empty blocks, loops, ranges, etc. */ | |
363 | ||
f0fda11c | 364 | static void |
d329e058 | 365 | rtl_delete_block (basic_block b) |
ca6c03ca | 366 | { |
ca6c03ca JH |
367 | rtx insn, end, tmp; |
368 | ||
369 | /* If the head of this block is a CODE_LABEL, then it might be the | |
f39e46ba SB |
370 | label for an exception handler which can't be reached. We need |
371 | to remove the label from the exception_handler_label list. */ | |
a813c111 | 372 | insn = BB_HEAD (b); |
4b4bf941 | 373 | if (LABEL_P (insn)) |
ca6c03ca JH |
374 | maybe_remove_eh_handler (insn); |
375 | ||
376 | /* Include any jump table following the basic block. */ | |
a813c111 | 377 | end = BB_END (b); |
e1233a7d | 378 | if (tablejump_p (end, NULL, &tmp)) |
ca6c03ca JH |
379 | end = tmp; |
380 | ||
4ab80063 | 381 | /* Include any barriers that may follow the basic block. */ |
ca6c03ca | 382 | tmp = next_nonnote_insn (end); |
4ab80063 RS |
383 | while (tmp && BARRIER_P (tmp)) |
384 | { | |
385 | end = tmp; | |
386 | tmp = next_nonnote_insn (end); | |
387 | } | |
ca6c03ca JH |
388 | |
389 | /* Selectively delete the entire chain. */ | |
a813c111 | 390 | BB_HEAD (b) = NULL; |
ca6c03ca | 391 | delete_insn_chain (insn, end); |
ca6c03ca JH |
392 | } |
393 | \f | |
852c6ec7 | 394 | /* Records the basic block struct in BLOCK_FOR_INSN for every insn. */ |
ca6c03ca JH |
395 | |
396 | void | |
d329e058 | 397 | compute_bb_for_insn (void) |
ca6c03ca | 398 | { |
e0082a72 | 399 | basic_block bb; |
ca6c03ca | 400 | |
e0082a72 | 401 | FOR_EACH_BB (bb) |
ca6c03ca | 402 | { |
a813c111 | 403 | rtx end = BB_END (bb); |
5f0d2358 | 404 | rtx insn; |
ca6c03ca | 405 | |
a813c111 | 406 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
ca6c03ca | 407 | { |
ba4f7968 | 408 | BLOCK_FOR_INSN (insn) = bb; |
ca6c03ca JH |
409 | if (insn == end) |
410 | break; | |
ca6c03ca JH |
411 | } |
412 | } | |
413 | } | |
414 | ||
415 | /* Release the basic_block_for_insn array. */ | |
416 | ||
417 | void | |
d329e058 | 418 | free_bb_for_insn (void) |
ca6c03ca | 419 | { |
ba4f7968 JH |
420 | rtx insn; |
421 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) | |
4b4bf941 | 422 | if (!BARRIER_P (insn)) |
ba4f7968 | 423 | BLOCK_FOR_INSN (insn) = NULL; |
ca6c03ca JH |
424 | } |
425 | ||
ef330312 PB |
426 | struct tree_opt_pass pass_free_cfg = |
427 | { | |
428 | NULL, /* name */ | |
429 | NULL, /* gate */ | |
430 | free_bb_for_insn, /* execute */ | |
431 | NULL, /* sub */ | |
432 | NULL, /* next */ | |
433 | 0, /* static_pass_number */ | |
434 | 0, /* tv_id */ | |
435 | 0, /* properties_required */ | |
436 | 0, /* properties_provided */ | |
437 | PROP_cfg, /* properties_destroyed */ | |
438 | 0, /* todo_flags_start */ | |
439 | 0, /* todo_flags_finish */ | |
440 | 0 /* letter */ | |
441 | }; | |
442 | ||
91278841 AP |
443 | /* Return RTX to emit after when we want to emit code on the entry of function. */ |
444 | rtx | |
445 | entry_of_function (void) | |
446 | { | |
24bd1a0b DB |
447 | return (n_basic_blocks > NUM_FIXED_BLOCKS ? |
448 | BB_HEAD (ENTRY_BLOCK_PTR->next_bb) : get_insns ()); | |
91278841 AP |
449 | } |
450 | ||
ca6c03ca JH |
451 | /* Update insns block within BB. */ |
452 | ||
453 | void | |
d329e058 | 454 | update_bb_for_insn (basic_block bb) |
ca6c03ca JH |
455 | { |
456 | rtx insn; | |
457 | ||
a813c111 | 458 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
ca6c03ca | 459 | { |
4b4bf941 | 460 | if (!BARRIER_P (insn)) |
bcc53e2a | 461 | set_block_for_insn (insn, bb); |
a813c111 | 462 | if (insn == BB_END (bb)) |
ca6c03ca JH |
463 | break; |
464 | } | |
465 | } | |
ca6c03ca | 466 | \f |
f470c378 ZD |
467 | /* Creates a new basic block just after basic block B by splitting |
468 | everything after specified instruction I. */ | |
ca6c03ca | 469 | |
f470c378 | 470 | static basic_block |
d329e058 | 471 | rtl_split_block (basic_block bb, void *insnp) |
ca6c03ca JH |
472 | { |
473 | basic_block new_bb; | |
9ee634e3 | 474 | rtx insn = insnp; |
f470c378 | 475 | edge e; |
628f6a4e | 476 | edge_iterator ei; |
ca6c03ca | 477 | |
f470c378 ZD |
478 | if (!insn) |
479 | { | |
480 | insn = first_insn_after_basic_block_note (bb); | |
481 | ||
482 | if (insn) | |
483 | insn = PREV_INSN (insn); | |
484 | else | |
485 | insn = get_last_insn (); | |
486 | } | |
487 | ||
488 | /* We probably should check type of the insn so that we do not create | |
489 | inconsistent cfg. It is checked in verify_flow_info anyway, so do not | |
490 | bother. */ | |
491 | if (insn == BB_END (bb)) | |
492 | emit_note_after (NOTE_INSN_DELETED, insn); | |
ca6c03ca JH |
493 | |
494 | /* Create the new basic block. */ | |
a813c111 | 495 | new_bb = create_basic_block (NEXT_INSN (insn), BB_END (bb), bb); |
076c7ab8 | 496 | BB_COPY_PARTITION (new_bb, bb); |
a813c111 | 497 | BB_END (bb) = insn; |
ca6c03ca JH |
498 | |
499 | /* Redirect the outgoing edges. */ | |
628f6a4e BE |
500 | new_bb->succs = bb->succs; |
501 | bb->succs = NULL; | |
502 | FOR_EACH_EDGE (e, ei, new_bb->succs) | |
ca6c03ca JH |
503 | e->src = new_bb; |
504 | ||
5e2d947c | 505 | if (bb->il.rtl->global_live_at_start) |
ca6c03ca | 506 | { |
5e2d947c JH |
507 | new_bb->il.rtl->global_live_at_start = ALLOC_REG_SET (®_obstack); |
508 | new_bb->il.rtl->global_live_at_end = ALLOC_REG_SET (®_obstack); | |
509 | COPY_REG_SET (new_bb->il.rtl->global_live_at_end, bb->il.rtl->global_live_at_end); | |
ca6c03ca JH |
510 | |
511 | /* We now have to calculate which registers are live at the end | |
512 | of the split basic block and at the start of the new basic | |
513 | block. Start with those registers that are known to be live | |
514 | at the end of the original basic block and get | |
515 | propagate_block to determine which registers are live. */ | |
5e2d947c JH |
516 | COPY_REG_SET (new_bb->il.rtl->global_live_at_start, bb->il.rtl->global_live_at_end); |
517 | propagate_block (new_bb, new_bb->il.rtl->global_live_at_start, NULL, NULL, 0); | |
518 | COPY_REG_SET (bb->il.rtl->global_live_at_end, | |
519 | new_bb->il.rtl->global_live_at_start); | |
0a2ed1f1 JH |
520 | #ifdef HAVE_conditional_execution |
521 | /* In the presence of conditional execution we are not able to update | |
522 | liveness precisely. */ | |
523 | if (reload_completed) | |
524 | { | |
525 | bb->flags |= BB_DIRTY; | |
526 | new_bb->flags |= BB_DIRTY; | |
527 | } | |
528 | #endif | |
ca6c03ca JH |
529 | } |
530 | ||
f470c378 | 531 | return new_bb; |
bc35512f JH |
532 | } |
533 | ||
ca6c03ca | 534 | /* Blocks A and B are to be merged into a single block A. The insns |
bc35512f | 535 | are already contiguous. */ |
ca6c03ca | 536 | |
bc35512f JH |
537 | static void |
538 | rtl_merge_blocks (basic_block a, basic_block b) | |
ca6c03ca | 539 | { |
a813c111 | 540 | rtx b_head = BB_HEAD (b), b_end = BB_END (b), a_end = BB_END (a); |
ca6c03ca JH |
541 | rtx del_first = NULL_RTX, del_last = NULL_RTX; |
542 | int b_empty = 0; | |
543 | ||
544 | /* If there was a CODE_LABEL beginning B, delete it. */ | |
4b4bf941 | 545 | if (LABEL_P (b_head)) |
ca6c03ca | 546 | { |
2c97f8e4 RH |
547 | /* This might have been an EH label that no longer has incoming |
548 | EH edges. Update data structures to match. */ | |
549 | maybe_remove_eh_handler (b_head); | |
550 | ||
ca6c03ca JH |
551 | /* Detect basic blocks with nothing but a label. This can happen |
552 | in particular at the end of a function. */ | |
553 | if (b_head == b_end) | |
554 | b_empty = 1; | |
5f0d2358 | 555 | |
ca6c03ca JH |
556 | del_first = del_last = b_head; |
557 | b_head = NEXT_INSN (b_head); | |
558 | } | |
559 | ||
5f0d2358 RK |
560 | /* Delete the basic block note and handle blocks containing just that |
561 | note. */ | |
ca6c03ca JH |
562 | if (NOTE_INSN_BASIC_BLOCK_P (b_head)) |
563 | { | |
564 | if (b_head == b_end) | |
565 | b_empty = 1; | |
566 | if (! del_last) | |
567 | del_first = b_head; | |
5f0d2358 | 568 | |
ca6c03ca JH |
569 | del_last = b_head; |
570 | b_head = NEXT_INSN (b_head); | |
571 | } | |
572 | ||
573 | /* If there was a jump out of A, delete it. */ | |
4b4bf941 | 574 | if (JUMP_P (a_end)) |
ca6c03ca JH |
575 | { |
576 | rtx prev; | |
577 | ||
578 | for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev)) | |
4b4bf941 | 579 | if (!NOTE_P (prev) |
ca6c03ca | 580 | || NOTE_LINE_NUMBER (prev) == NOTE_INSN_BASIC_BLOCK |
a813c111 | 581 | || prev == BB_HEAD (a)) |
ca6c03ca JH |
582 | break; |
583 | ||
584 | del_first = a_end; | |
585 | ||
586 | #ifdef HAVE_cc0 | |
587 | /* If this was a conditional jump, we need to also delete | |
588 | the insn that set cc0. */ | |
589 | if (only_sets_cc0_p (prev)) | |
590 | { | |
591 | rtx tmp = prev; | |
5f0d2358 | 592 | |
ca6c03ca JH |
593 | prev = prev_nonnote_insn (prev); |
594 | if (!prev) | |
a813c111 | 595 | prev = BB_HEAD (a); |
ca6c03ca JH |
596 | del_first = tmp; |
597 | } | |
598 | #endif | |
599 | ||
600 | a_end = PREV_INSN (del_first); | |
601 | } | |
4b4bf941 | 602 | else if (BARRIER_P (NEXT_INSN (a_end))) |
ca6c03ca JH |
603 | del_first = NEXT_INSN (a_end); |
604 | ||
ca6c03ca JH |
605 | /* Delete everything marked above as well as crap that might be |
606 | hanging out between the two blocks. */ | |
f470c378 | 607 | BB_HEAD (b) = NULL; |
ca6c03ca JH |
608 | delete_insn_chain (del_first, del_last); |
609 | ||
610 | /* Reassociate the insns of B with A. */ | |
611 | if (!b_empty) | |
612 | { | |
ba4f7968 | 613 | rtx x; |
5f0d2358 | 614 | |
ba4f7968 JH |
615 | for (x = a_end; x != b_end; x = NEXT_INSN (x)) |
616 | set_block_for_insn (x, a); | |
5f0d2358 | 617 | |
ba4f7968 | 618 | set_block_for_insn (b_end, a); |
5f0d2358 | 619 | |
ca6c03ca JH |
620 | a_end = b_end; |
621 | } | |
5f0d2358 | 622 | |
a813c111 | 623 | BB_END (a) = a_end; |
5e2d947c | 624 | a->il.rtl->global_live_at_end = b->il.rtl->global_live_at_end; |
ca6c03ca | 625 | } |
bc35512f JH |
626 | |
627 | /* Return true when block A and B can be merged. */ | |
628 | static bool | |
629 | rtl_can_merge_blocks (basic_block a,basic_block b) | |
630 | { | |
750054a2 CT |
631 | /* If we are partitioning hot/cold basic blocks, we don't want to |
632 | mess up unconditional or indirect jumps that cross between hot | |
076c7ab8 ZW |
633 | and cold sections. |
634 | ||
8e8d5162 CT |
635 | Basic block partitioning may result in some jumps that appear to |
636 | be optimizable (or blocks that appear to be mergeable), but which really | |
637 | must be left untouched (they are required to make it safely across | |
638 | partition boundaries). See the comments at the top of | |
639 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ | |
076c7ab8 | 640 | |
87c8b4be | 641 | if (BB_PARTITION (a) != BB_PARTITION (b)) |
076c7ab8 | 642 | return false; |
750054a2 | 643 | |
bc35512f | 644 | /* There must be exactly one edge in between the blocks. */ |
c5cbcccf ZD |
645 | return (single_succ_p (a) |
646 | && single_succ (a) == b | |
647 | && single_pred_p (b) | |
628f6a4e | 648 | && a != b |
bc35512f | 649 | /* Must be simple edge. */ |
c5cbcccf | 650 | && !(single_succ_edge (a)->flags & EDGE_COMPLEX) |
bc35512f JH |
651 | && a->next_bb == b |
652 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR | |
653 | /* If the jump insn has side effects, | |
654 | we can't kill the edge. */ | |
4b4bf941 | 655 | && (!JUMP_P (BB_END (a)) |
e24e7211 | 656 | || (reload_completed |
a813c111 | 657 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f | 658 | } |
ca6c03ca | 659 | \f |
5f0d2358 RK |
660 | /* Return the label in the head of basic block BLOCK. Create one if it doesn't |
661 | exist. */ | |
ca6c03ca JH |
662 | |
663 | rtx | |
d329e058 | 664 | block_label (basic_block block) |
ca6c03ca JH |
665 | { |
666 | if (block == EXIT_BLOCK_PTR) | |
667 | return NULL_RTX; | |
5f0d2358 | 668 | |
4b4bf941 | 669 | if (!LABEL_P (BB_HEAD (block))) |
ca6c03ca | 670 | { |
a813c111 | 671 | BB_HEAD (block) = emit_label_before (gen_label_rtx (), BB_HEAD (block)); |
ca6c03ca | 672 | } |
5f0d2358 | 673 | |
a813c111 | 674 | return BB_HEAD (block); |
ca6c03ca JH |
675 | } |
676 | ||
677 | /* Attempt to perform edge redirection by replacing possibly complex jump | |
5f0d2358 RK |
678 | instruction by unconditional jump or removing jump completely. This can |
679 | apply only if all edges now point to the same block. The parameters and | |
680 | return values are equivalent to redirect_edge_and_branch. */ | |
ca6c03ca | 681 | |
6de9cd9a | 682 | edge |
bc35512f | 683 | try_redirect_by_replacing_jump (edge e, basic_block target, bool in_cfglayout) |
ca6c03ca JH |
684 | { |
685 | basic_block src = e->src; | |
a813c111 | 686 | rtx insn = BB_END (src), kill_from; |
e1233a7d | 687 | rtx set; |
ca6c03ca | 688 | int fallthru = 0; |
750054a2 CT |
689 | |
690 | /* If we are partitioning hot/cold basic blocks, we don't want to | |
691 | mess up unconditional or indirect jumps that cross between hot | |
8e8d5162 CT |
692 | and cold sections. |
693 | ||
694 | Basic block partitioning may result in some jumps that appear to | |
695 | be optimizable (or blocks that appear to be mergeable), but which really | |
696 | must be left untouched (they are required to make it safely across | |
697 | partition boundaries). See the comments at the top of | |
698 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ | |
750054a2 | 699 | |
87c8b4be CT |
700 | if (find_reg_note (insn, REG_CROSSING_JUMP, NULL_RTX) |
701 | || BB_PARTITION (src) != BB_PARTITION (target)) | |
9cf84a3c | 702 | return NULL; |
750054a2 | 703 | |
6a66a8a7 KH |
704 | /* We can replace or remove a complex jump only when we have exactly |
705 | two edges. Also, if we have exactly one outgoing edge, we can | |
706 | redirect that. */ | |
707 | if (EDGE_COUNT (src->succs) >= 3 | |
708 | /* Verify that all targets will be TARGET. Specifically, the | |
709 | edge that is not E must also go to TARGET. */ | |
710 | || (EDGE_COUNT (src->succs) == 2 | |
711 | && EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)) | |
712 | return NULL; | |
5f0d2358 | 713 | |
6a66a8a7 | 714 | if (!onlyjump_p (insn)) |
6de9cd9a | 715 | return NULL; |
3348b696 | 716 | if ((!optimize || reload_completed) && tablejump_p (insn, NULL, NULL)) |
6de9cd9a | 717 | return NULL; |
ca6c03ca JH |
718 | |
719 | /* Avoid removing branch with side effects. */ | |
720 | set = single_set (insn); | |
721 | if (!set || side_effects_p (set)) | |
6de9cd9a | 722 | return NULL; |
ca6c03ca JH |
723 | |
724 | /* In case we zap a conditional jump, we'll need to kill | |
725 | the cc0 setter too. */ | |
726 | kill_from = insn; | |
727 | #ifdef HAVE_cc0 | |
728 | if (reg_mentioned_p (cc0_rtx, PATTERN (insn))) | |
729 | kill_from = PREV_INSN (insn); | |
730 | #endif | |
731 | ||
732 | /* See if we can create the fallthru edge. */ | |
bc35512f | 733 | if (in_cfglayout || can_fallthru (src, target)) |
ca6c03ca | 734 | { |
c263766c RH |
735 | if (dump_file) |
736 | fprintf (dump_file, "Removing jump %i.\n", INSN_UID (insn)); | |
ca6c03ca JH |
737 | fallthru = 1; |
738 | ||
eaec9b3d | 739 | /* Selectively unlink whole insn chain. */ |
bc35512f JH |
740 | if (in_cfglayout) |
741 | { | |
370369e1 | 742 | rtx insn = src->il.rtl->footer; |
bc35512f | 743 | |
a813c111 | 744 | delete_insn_chain (kill_from, BB_END (src)); |
bc35512f JH |
745 | |
746 | /* Remove barriers but keep jumptables. */ | |
747 | while (insn) | |
748 | { | |
4b4bf941 | 749 | if (BARRIER_P (insn)) |
bc35512f JH |
750 | { |
751 | if (PREV_INSN (insn)) | |
752 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
753 | else | |
370369e1 | 754 | src->il.rtl->footer = NEXT_INSN (insn); |
bc35512f JH |
755 | if (NEXT_INSN (insn)) |
756 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
757 | } | |
4b4bf941 | 758 | if (LABEL_P (insn)) |
bc35512f JH |
759 | break; |
760 | insn = NEXT_INSN (insn); | |
761 | } | |
762 | } | |
763 | else | |
a813c111 | 764 | delete_insn_chain (kill_from, PREV_INSN (BB_HEAD (target))); |
ca6c03ca | 765 | } |
5f0d2358 | 766 | |
ca6c03ca JH |
767 | /* If this already is simplejump, redirect it. */ |
768 | else if (simplejump_p (insn)) | |
769 | { | |
770 | if (e->dest == target) | |
6de9cd9a | 771 | return NULL; |
c263766c RH |
772 | if (dump_file) |
773 | fprintf (dump_file, "Redirecting jump %i from %i to %i.\n", | |
0b17ab2f | 774 | INSN_UID (insn), e->dest->index, target->index); |
6ee3c8e4 JJ |
775 | if (!redirect_jump (insn, block_label (target), 0)) |
776 | { | |
341c100f NS |
777 | gcc_assert (target == EXIT_BLOCK_PTR); |
778 | return NULL; | |
6ee3c8e4 | 779 | } |
ca6c03ca | 780 | } |
5f0d2358 | 781 | |
6ee3c8e4 JJ |
782 | /* Cannot do anything for target exit block. */ |
783 | else if (target == EXIT_BLOCK_PTR) | |
6de9cd9a | 784 | return NULL; |
6ee3c8e4 | 785 | |
ca6c03ca JH |
786 | /* Or replace possibly complicated jump insn by simple jump insn. */ |
787 | else | |
788 | { | |
789 | rtx target_label = block_label (target); | |
eb5b8ad4 | 790 | rtx barrier, label, table; |
ca6c03ca | 791 | |
a7102479 | 792 | emit_jump_insn_after_noloc (gen_jump (target_label), insn); |
a813c111 | 793 | JUMP_LABEL (BB_END (src)) = target_label; |
ca6c03ca | 794 | LABEL_NUSES (target_label)++; |
c263766c RH |
795 | if (dump_file) |
796 | fprintf (dump_file, "Replacing insn %i by jump %i\n", | |
a813c111 | 797 | INSN_UID (insn), INSN_UID (BB_END (src))); |
ca6c03ca | 798 | |
4da2eb6b | 799 | |
ca6c03ca JH |
800 | delete_insn_chain (kill_from, insn); |
801 | ||
4da2eb6b RH |
802 | /* Recognize a tablejump that we are converting to a |
803 | simple jump and remove its associated CODE_LABEL | |
804 | and ADDR_VEC or ADDR_DIFF_VEC. */ | |
3348b696 | 805 | if (tablejump_p (insn, &label, &table)) |
4da2eb6b | 806 | delete_insn_chain (label, table); |
eb5b8ad4 | 807 | |
a813c111 | 808 | barrier = next_nonnote_insn (BB_END (src)); |
4b4bf941 | 809 | if (!barrier || !BARRIER_P (barrier)) |
a813c111 | 810 | emit_barrier_after (BB_END (src)); |
5d693491 JZ |
811 | else |
812 | { | |
a813c111 | 813 | if (barrier != NEXT_INSN (BB_END (src))) |
5d693491 JZ |
814 | { |
815 | /* Move the jump before barrier so that the notes | |
816 | which originally were or were created before jump table are | |
817 | inside the basic block. */ | |
a813c111 | 818 | rtx new_insn = BB_END (src); |
5d693491 JZ |
819 | rtx tmp; |
820 | ||
a813c111 | 821 | for (tmp = NEXT_INSN (BB_END (src)); tmp != barrier; |
5d693491 JZ |
822 | tmp = NEXT_INSN (tmp)) |
823 | set_block_for_insn (tmp, src); | |
824 | ||
825 | NEXT_INSN (PREV_INSN (new_insn)) = NEXT_INSN (new_insn); | |
826 | PREV_INSN (NEXT_INSN (new_insn)) = PREV_INSN (new_insn); | |
827 | ||
828 | NEXT_INSN (new_insn) = barrier; | |
829 | NEXT_INSN (PREV_INSN (barrier)) = new_insn; | |
830 | ||
831 | PREV_INSN (new_insn) = PREV_INSN (barrier); | |
832 | PREV_INSN (barrier) = new_insn; | |
833 | } | |
834 | } | |
ca6c03ca JH |
835 | } |
836 | ||
837 | /* Keep only one edge out and set proper flags. */ | |
c5cbcccf | 838 | if (!single_succ_p (src)) |
628f6a4e | 839 | remove_edge (e); |
c5cbcccf | 840 | gcc_assert (single_succ_p (src)); |
628f6a4e | 841 | |
c5cbcccf | 842 | e = single_succ_edge (src); |
ca6c03ca JH |
843 | if (fallthru) |
844 | e->flags = EDGE_FALLTHRU; | |
845 | else | |
846 | e->flags = 0; | |
5f0d2358 | 847 | |
ca6c03ca JH |
848 | e->probability = REG_BR_PROB_BASE; |
849 | e->count = src->count; | |
850 | ||
851 | /* We don't want a block to end on a line-number note since that has | |
852 | the potential of changing the code between -g and not -g. */ | |
4b4bf941 | 853 | while (NOTE_P (BB_END (e->src)) |
a813c111 SB |
854 | && NOTE_LINE_NUMBER (BB_END (e->src)) >= 0) |
855 | delete_insn (BB_END (e->src)); | |
ca6c03ca JH |
856 | |
857 | if (e->dest != target) | |
858 | redirect_edge_succ (e, target); | |
5f0d2358 | 859 | |
6de9cd9a | 860 | return e; |
ca6c03ca JH |
861 | } |
862 | ||
863 | /* Return last loop_beg note appearing after INSN, before start of next | |
864 | basic block. Return INSN if there are no such notes. | |
865 | ||
09da1532 | 866 | When emitting jump to redirect a fallthru edge, it should always appear |
5f0d2358 RK |
867 | after the LOOP_BEG notes, as loop optimizer expect loop to either start by |
868 | fallthru edge or jump following the LOOP_BEG note jumping to the loop exit | |
869 | test. */ | |
ca6c03ca JH |
870 | |
871 | static rtx | |
d329e058 | 872 | last_loop_beg_note (rtx insn) |
ca6c03ca JH |
873 | { |
874 | rtx last = insn; | |
5f0d2358 | 875 | |
4b4bf941 | 876 | for (insn = NEXT_INSN (insn); insn && NOTE_P (insn) |
5f0d2358 RK |
877 | && NOTE_LINE_NUMBER (insn) != NOTE_INSN_BASIC_BLOCK; |
878 | insn = NEXT_INSN (insn)) | |
879 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
880 | last = insn; | |
881 | ||
ca6c03ca JH |
882 | return last; |
883 | } | |
884 | ||
6de9cd9a DN |
885 | /* Redirect edge representing branch of (un)conditional jump or tablejump, |
886 | NULL on failure */ | |
887 | static edge | |
bc35512f | 888 | redirect_branch_edge (edge e, basic_block target) |
ca6c03ca JH |
889 | { |
890 | rtx tmp; | |
a813c111 | 891 | rtx old_label = BB_HEAD (e->dest); |
ca6c03ca | 892 | basic_block src = e->src; |
a813c111 | 893 | rtx insn = BB_END (src); |
ca6c03ca | 894 | |
ca6c03ca JH |
895 | /* We can only redirect non-fallthru edges of jump insn. */ |
896 | if (e->flags & EDGE_FALLTHRU) | |
6de9cd9a | 897 | return NULL; |
4b4bf941 | 898 | else if (!JUMP_P (insn)) |
6de9cd9a | 899 | return NULL; |
ca6c03ca JH |
900 | |
901 | /* Recognize a tablejump and adjust all matching cases. */ | |
e1233a7d | 902 | if (tablejump_p (insn, NULL, &tmp)) |
ca6c03ca JH |
903 | { |
904 | rtvec vec; | |
905 | int j; | |
906 | rtx new_label = block_label (target); | |
907 | ||
6ee3c8e4 | 908 | if (target == EXIT_BLOCK_PTR) |
6de9cd9a | 909 | return NULL; |
ca6c03ca JH |
910 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) |
911 | vec = XVEC (PATTERN (tmp), 0); | |
912 | else | |
913 | vec = XVEC (PATTERN (tmp), 1); | |
914 | ||
915 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
916 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
917 | { | |
918 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (Pmode, new_label); | |
919 | --LABEL_NUSES (old_label); | |
920 | ++LABEL_NUSES (new_label); | |
921 | } | |
922 | ||
f9da5064 | 923 | /* Handle casesi dispatch insns. */ |
ca6c03ca JH |
924 | if ((tmp = single_set (insn)) != NULL |
925 | && SET_DEST (tmp) == pc_rtx | |
926 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
927 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF | |
928 | && XEXP (XEXP (SET_SRC (tmp), 2), 0) == old_label) | |
929 | { | |
4c33cb26 | 930 | XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (Pmode, |
ca6c03ca JH |
931 | new_label); |
932 | --LABEL_NUSES (old_label); | |
933 | ++LABEL_NUSES (new_label); | |
934 | } | |
935 | } | |
936 | else | |
937 | { | |
938 | /* ?? We may play the games with moving the named labels from | |
939 | one basic block to the other in case only one computed_jump is | |
940 | available. */ | |
5f0d2358 RK |
941 | if (computed_jump_p (insn) |
942 | /* A return instruction can't be redirected. */ | |
943 | || returnjump_p (insn)) | |
6de9cd9a | 944 | return NULL; |
ca6c03ca JH |
945 | |
946 | /* If the insn doesn't go where we think, we're confused. */ | |
341c100f | 947 | gcc_assert (JUMP_LABEL (insn) == old_label); |
6ee3c8e4 JJ |
948 | |
949 | /* If the substitution doesn't succeed, die. This can happen | |
950 | if the back end emitted unrecognizable instructions or if | |
951 | target is exit block on some arches. */ | |
952 | if (!redirect_jump (insn, block_label (target), 0)) | |
953 | { | |
341c100f NS |
954 | gcc_assert (target == EXIT_BLOCK_PTR); |
955 | return NULL; | |
6ee3c8e4 | 956 | } |
ca6c03ca JH |
957 | } |
958 | ||
c263766c RH |
959 | if (dump_file) |
960 | fprintf (dump_file, "Edge %i->%i redirected to %i\n", | |
0b17ab2f | 961 | e->src->index, e->dest->index, target->index); |
5f0d2358 | 962 | |
ca6c03ca | 963 | if (e->dest != target) |
6de9cd9a DN |
964 | e = redirect_edge_succ_nodup (e, target); |
965 | return e; | |
bc35512f JH |
966 | } |
967 | ||
968 | /* Attempt to change code to redirect edge E to TARGET. Don't do that on | |
969 | expense of adding new instructions or reordering basic blocks. | |
970 | ||
971 | Function can be also called with edge destination equivalent to the TARGET. | |
972 | Then it should try the simplifications and do nothing if none is possible. | |
973 | ||
6de9cd9a DN |
974 | Return edge representing the branch if transformation succeeded. Return NULL |
975 | on failure. | |
976 | We still return NULL in case E already destinated TARGET and we didn't | |
977 | managed to simplify instruction stream. */ | |
bc35512f | 978 | |
6de9cd9a | 979 | static edge |
5671bf27 | 980 | rtl_redirect_edge_and_branch (edge e, basic_block target) |
bc35512f | 981 | { |
6de9cd9a | 982 | edge ret; |
f345f21a JH |
983 | basic_block src = e->src; |
984 | ||
bc35512f | 985 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
6de9cd9a | 986 | return NULL; |
bc35512f | 987 | |
3348b696 | 988 | if (e->dest == target) |
6de9cd9a | 989 | return e; |
3348b696 | 990 | |
6de9cd9a | 991 | if ((ret = try_redirect_by_replacing_jump (e, target, false)) != NULL) |
f345f21a JH |
992 | { |
993 | src->flags |= BB_DIRTY; | |
6de9cd9a | 994 | return ret; |
f345f21a | 995 | } |
bc35512f | 996 | |
6de9cd9a DN |
997 | ret = redirect_branch_edge (e, target); |
998 | if (!ret) | |
999 | return NULL; | |
5f0d2358 | 1000 | |
f345f21a | 1001 | src->flags |= BB_DIRTY; |
6de9cd9a | 1002 | return ret; |
ca6c03ca JH |
1003 | } |
1004 | ||
4fe9b91c | 1005 | /* Like force_nonfallthru below, but additionally performs redirection |
ca6c03ca JH |
1006 | Used by redirect_edge_and_branch_force. */ |
1007 | ||
9167e1c0 | 1008 | static basic_block |
d329e058 | 1009 | force_nonfallthru_and_redirect (edge e, basic_block target) |
ca6c03ca | 1010 | { |
a3716585 | 1011 | basic_block jump_block, new_bb = NULL, src = e->src; |
ca6c03ca JH |
1012 | rtx note; |
1013 | edge new_edge; | |
a3716585 | 1014 | int abnormal_edge_flags = 0; |
ca6c03ca | 1015 | |
cb9a1d9b JH |
1016 | /* In the case the last instruction is conditional jump to the next |
1017 | instruction, first redirect the jump itself and then continue | |
b20b352b | 1018 | by creating a basic block afterwards to redirect fallthru edge. */ |
cb9a1d9b | 1019 | if (e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR |
a813c111 | 1020 | && any_condjump_p (BB_END (e->src)) |
a813c111 | 1021 | && JUMP_LABEL (BB_END (e->src)) == BB_HEAD (e->dest)) |
cb9a1d9b JH |
1022 | { |
1023 | rtx note; | |
58e6ae30 | 1024 | edge b = unchecked_make_edge (e->src, target, 0); |
341c100f | 1025 | bool redirected; |
cb9a1d9b | 1026 | |
341c100f NS |
1027 | redirected = redirect_jump (BB_END (e->src), block_label (target), 0); |
1028 | gcc_assert (redirected); | |
1029 | ||
a813c111 | 1030 | note = find_reg_note (BB_END (e->src), REG_BR_PROB, NULL_RTX); |
cb9a1d9b JH |
1031 | if (note) |
1032 | { | |
1033 | int prob = INTVAL (XEXP (note, 0)); | |
1034 | ||
1035 | b->probability = prob; | |
1036 | b->count = e->count * prob / REG_BR_PROB_BASE; | |
1037 | e->probability -= e->probability; | |
1038 | e->count -= b->count; | |
1039 | if (e->probability < 0) | |
1040 | e->probability = 0; | |
1041 | if (e->count < 0) | |
1042 | e->count = 0; | |
1043 | } | |
1044 | } | |
1045 | ||
ca6c03ca | 1046 | if (e->flags & EDGE_ABNORMAL) |
a3716585 JH |
1047 | { |
1048 | /* Irritating special case - fallthru edge to the same block as abnormal | |
1049 | edge. | |
1050 | We can't redirect abnormal edge, but we still can split the fallthru | |
d329e058 | 1051 | one and create separate abnormal edge to original destination. |
a3716585 | 1052 | This allows bb-reorder to make such edge non-fallthru. */ |
341c100f | 1053 | gcc_assert (e->dest == target); |
a3716585 JH |
1054 | abnormal_edge_flags = e->flags & ~(EDGE_FALLTHRU | EDGE_CAN_FALLTHRU); |
1055 | e->flags &= EDGE_FALLTHRU | EDGE_CAN_FALLTHRU; | |
1056 | } | |
341c100f | 1057 | else |
24c545ff | 1058 | { |
341c100f NS |
1059 | gcc_assert (e->flags & EDGE_FALLTHRU); |
1060 | if (e->src == ENTRY_BLOCK_PTR) | |
1061 | { | |
1062 | /* We can't redirect the entry block. Create an empty block | |
628f6a4e BE |
1063 | at the start of the function which we use to add the new |
1064 | jump. */ | |
1065 | edge tmp; | |
1066 | edge_iterator ei; | |
1067 | bool found = false; | |
1068 | ||
1069 | basic_block bb = create_basic_block (BB_HEAD (e->dest), NULL, ENTRY_BLOCK_PTR); | |
1070 | ||
341c100f NS |
1071 | /* Change the existing edge's source to be the new block, and add |
1072 | a new edge from the entry block to the new block. */ | |
1073 | e->src = bb; | |
628f6a4e BE |
1074 | for (ei = ei_start (ENTRY_BLOCK_PTR->succs); (tmp = ei_safe_edge (ei)); ) |
1075 | { | |
1076 | if (tmp == e) | |
1077 | { | |
865851d0 | 1078 | VEC_unordered_remove (edge, ENTRY_BLOCK_PTR->succs, ei.index); |
628f6a4e BE |
1079 | found = true; |
1080 | break; | |
1081 | } | |
1082 | else | |
1083 | ei_next (&ei); | |
1084 | } | |
1085 | ||
1086 | gcc_assert (found); | |
1087 | ||
d4e6fecb | 1088 | VEC_safe_push (edge, gc, bb->succs, e); |
341c100f NS |
1089 | make_single_succ_edge (ENTRY_BLOCK_PTR, bb, EDGE_FALLTHRU); |
1090 | } | |
24c545ff BS |
1091 | } |
1092 | ||
628f6a4e | 1093 | if (EDGE_COUNT (e->src->succs) >= 2 || abnormal_edge_flags) |
ca6c03ca JH |
1094 | { |
1095 | /* Create the new structures. */ | |
31a78298 | 1096 | |
79019985 RH |
1097 | /* If the old block ended with a tablejump, skip its table |
1098 | by searching forward from there. Otherwise start searching | |
1099 | forward from the last instruction of the old block. */ | |
a813c111 SB |
1100 | if (!tablejump_p (BB_END (e->src), NULL, ¬e)) |
1101 | note = BB_END (e->src); | |
79019985 | 1102 | |
31a78298 | 1103 | /* Position the new block correctly relative to loop notes. */ |
79019985 | 1104 | note = last_loop_beg_note (note); |
31a78298 RH |
1105 | note = NEXT_INSN (note); |
1106 | ||
31a78298 | 1107 | jump_block = create_basic_block (note, NULL, e->src); |
ca6c03ca JH |
1108 | jump_block->count = e->count; |
1109 | jump_block->frequency = EDGE_FREQUENCY (e); | |
1110 | jump_block->loop_depth = target->loop_depth; | |
1111 | ||
5e2d947c | 1112 | if (target->il.rtl->global_live_at_start) |
ca6c03ca | 1113 | { |
5e2d947c JH |
1114 | jump_block->il.rtl->global_live_at_start = ALLOC_REG_SET (®_obstack); |
1115 | jump_block->il.rtl->global_live_at_end = ALLOC_REG_SET (®_obstack); | |
1116 | COPY_REG_SET (jump_block->il.rtl->global_live_at_start, | |
1117 | target->il.rtl->global_live_at_start); | |
1118 | COPY_REG_SET (jump_block->il.rtl->global_live_at_end, | |
1119 | target->il.rtl->global_live_at_start); | |
ca6c03ca JH |
1120 | } |
1121 | ||
750054a2 CT |
1122 | /* Make sure new block ends up in correct hot/cold section. */ |
1123 | ||
076c7ab8 | 1124 | BB_COPY_PARTITION (jump_block, e->src); |
9fb32434 | 1125 | if (flag_reorder_blocks_and_partition |
87c8b4be CT |
1126 | && targetm.have_named_sections |
1127 | && JUMP_P (BB_END (jump_block)) | |
1128 | && !any_condjump_p (BB_END (jump_block)) | |
1129 | && (EDGE_SUCC (jump_block, 0)->flags & EDGE_CROSSING)) | |
1130 | REG_NOTES (BB_END (jump_block)) = gen_rtx_EXPR_LIST (REG_CROSSING_JUMP, | |
1131 | NULL_RTX, | |
1132 | REG_NOTES | |
1133 | (BB_END | |
1134 | (jump_block))); | |
1135 | ||
ca6c03ca JH |
1136 | /* Wire edge in. */ |
1137 | new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU); | |
1138 | new_edge->probability = e->probability; | |
1139 | new_edge->count = e->count; | |
1140 | ||
1141 | /* Redirect old edge. */ | |
1142 | redirect_edge_pred (e, jump_block); | |
1143 | e->probability = REG_BR_PROB_BASE; | |
1144 | ||
1145 | new_bb = jump_block; | |
1146 | } | |
1147 | else | |
1148 | jump_block = e->src; | |
5f0d2358 | 1149 | |
ca6c03ca JH |
1150 | e->flags &= ~EDGE_FALLTHRU; |
1151 | if (target == EXIT_BLOCK_PTR) | |
1152 | { | |
cf22ce3c | 1153 | #ifdef HAVE_return |
a7102479 | 1154 | emit_jump_insn_after_noloc (gen_return (), BB_END (jump_block)); |
cf22ce3c | 1155 | #else |
341c100f | 1156 | gcc_unreachable (); |
cf22ce3c | 1157 | #endif |
ca6c03ca JH |
1158 | } |
1159 | else | |
1160 | { | |
1161 | rtx label = block_label (target); | |
a7102479 | 1162 | emit_jump_insn_after_noloc (gen_jump (label), BB_END (jump_block)); |
a813c111 | 1163 | JUMP_LABEL (BB_END (jump_block)) = label; |
ca6c03ca JH |
1164 | LABEL_NUSES (label)++; |
1165 | } | |
5f0d2358 | 1166 | |
a813c111 | 1167 | emit_barrier_after (BB_END (jump_block)); |
ca6c03ca JH |
1168 | redirect_edge_succ_nodup (e, target); |
1169 | ||
a3716585 JH |
1170 | if (abnormal_edge_flags) |
1171 | make_edge (src, target, abnormal_edge_flags); | |
1172 | ||
ca6c03ca JH |
1173 | return new_bb; |
1174 | } | |
1175 | ||
1176 | /* Edge E is assumed to be fallthru edge. Emit needed jump instruction | |
1177 | (and possibly create new basic block) to make edge non-fallthru. | |
1178 | Return newly created BB or NULL if none. */ | |
5f0d2358 | 1179 | |
ca6c03ca | 1180 | basic_block |
d329e058 | 1181 | force_nonfallthru (edge e) |
ca6c03ca JH |
1182 | { |
1183 | return force_nonfallthru_and_redirect (e, e->dest); | |
1184 | } | |
1185 | ||
1186 | /* Redirect edge even at the expense of creating new jump insn or | |
1187 | basic block. Return new basic block if created, NULL otherwise. | |
41806d92 | 1188 | Conversion must be possible. */ |
ca6c03ca | 1189 | |
9ee634e3 | 1190 | static basic_block |
d329e058 | 1191 | rtl_redirect_edge_and_branch_force (edge e, basic_block target) |
ca6c03ca | 1192 | { |
5f0d2358 RK |
1193 | if (redirect_edge_and_branch (e, target) |
1194 | || e->dest == target) | |
ca6c03ca JH |
1195 | return NULL; |
1196 | ||
1197 | /* In case the edge redirection failed, try to force it to be non-fallthru | |
1198 | and redirect newly created simplejump. */ | |
5f0d2358 | 1199 | return force_nonfallthru_and_redirect (e, target); |
ca6c03ca JH |
1200 | } |
1201 | ||
1202 | /* The given edge should potentially be a fallthru edge. If that is in | |
1203 | fact true, delete the jump and barriers that are in the way. */ | |
1204 | ||
f470c378 ZD |
1205 | static void |
1206 | rtl_tidy_fallthru_edge (edge e) | |
ca6c03ca JH |
1207 | { |
1208 | rtx q; | |
f470c378 ZD |
1209 | basic_block b = e->src, c = b->next_bb; |
1210 | ||
ca6c03ca JH |
1211 | /* ??? In a late-running flow pass, other folks may have deleted basic |
1212 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
0fa2e4df | 1213 | and the target label. They ought to be chastised and fixed. |
ca6c03ca JH |
1214 | |
1215 | We can also wind up with a sequence of undeletable labels between | |
1216 | one block and the next. | |
1217 | ||
1218 | So search through a sequence of barriers, labels, and notes for | |
1219 | the head of block C and assert that we really do fall through. */ | |
1220 | ||
a813c111 | 1221 | for (q = NEXT_INSN (BB_END (b)); q != BB_HEAD (c); q = NEXT_INSN (q)) |
9c0a0632 RH |
1222 | if (INSN_P (q)) |
1223 | return; | |
ca6c03ca JH |
1224 | |
1225 | /* Remove what will soon cease being the jump insn from the source block. | |
1226 | If block B consisted only of this single jump, turn it into a deleted | |
1227 | note. */ | |
a813c111 | 1228 | q = BB_END (b); |
4b4bf941 | 1229 | if (JUMP_P (q) |
ca6c03ca JH |
1230 | && onlyjump_p (q) |
1231 | && (any_uncondjump_p (q) | |
c5cbcccf | 1232 | || single_succ_p (b))) |
ca6c03ca JH |
1233 | { |
1234 | #ifdef HAVE_cc0 | |
1235 | /* If this was a conditional jump, we need to also delete | |
1236 | the insn that set cc0. */ | |
1237 | if (any_condjump_p (q) && only_sets_cc0_p (PREV_INSN (q))) | |
1238 | q = PREV_INSN (q); | |
1239 | #endif | |
1240 | ||
1241 | q = PREV_INSN (q); | |
1242 | ||
1243 | /* We don't want a block to end on a line-number note since that has | |
1244 | the potential of changing the code between -g and not -g. */ | |
4b4bf941 | 1245 | while (NOTE_P (q) && NOTE_LINE_NUMBER (q) >= 0) |
ca6c03ca JH |
1246 | q = PREV_INSN (q); |
1247 | } | |
1248 | ||
1249 | /* Selectively unlink the sequence. */ | |
a813c111 SB |
1250 | if (q != PREV_INSN (BB_HEAD (c))) |
1251 | delete_insn_chain (NEXT_INSN (q), PREV_INSN (BB_HEAD (c))); | |
ca6c03ca JH |
1252 | |
1253 | e->flags |= EDGE_FALLTHRU; | |
1254 | } | |
ca6c03ca JH |
1255 | \f |
1256 | /* Helper function for split_edge. Return true in case edge BB2 to BB1 | |
1257 | is back edge of syntactic loop. */ | |
1258 | ||
1259 | static bool | |
d329e058 | 1260 | back_edge_of_syntactic_loop_p (basic_block bb1, basic_block bb2) |
ca6c03ca JH |
1261 | { |
1262 | rtx insn; | |
1263 | int count = 0; | |
bf77398c | 1264 | basic_block bb; |
ca6c03ca | 1265 | |
bf77398c | 1266 | if (bb1 == bb2) |
0b17ab2f | 1267 | return true; |
355e4ec4 | 1268 | |
bf77398c ZD |
1269 | /* ??? Could we guarantee that bb indices are monotone, so that we could |
1270 | just compare them? */ | |
1271 | for (bb = bb1; bb && bb != bb2; bb = bb->next_bb) | |
1272 | continue; | |
1273 | ||
1274 | if (!bb) | |
1275 | return false; | |
1276 | ||
a813c111 | 1277 | for (insn = BB_END (bb1); insn != BB_HEAD (bb2) && count >= 0; |
ca6c03ca | 1278 | insn = NEXT_INSN (insn)) |
4b4bf941 | 1279 | if (NOTE_P (insn)) |
ca6c03ca JH |
1280 | { |
1281 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
1282 | count++; | |
5f0d2358 | 1283 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) |
ca6c03ca JH |
1284 | count--; |
1285 | } | |
1286 | ||
1287 | return count >= 0; | |
1288 | } | |
1289 | ||
f470c378 ZD |
1290 | /* Should move basic block BB after basic block AFTER. NIY. */ |
1291 | ||
1292 | static bool | |
1293 | rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED, | |
1294 | basic_block after ATTRIBUTE_UNUSED) | |
1295 | { | |
1296 | return false; | |
1297 | } | |
1298 | ||
ca6c03ca | 1299 | /* Split a (typically critical) edge. Return the new block. |
41806d92 | 1300 | The edge must not be abnormal. |
ca6c03ca JH |
1301 | |
1302 | ??? The code generally expects to be called on critical edges. | |
1303 | The case of a block ending in an unconditional jump to a | |
1304 | block with multiple predecessors is not handled optimally. */ | |
1305 | ||
8ce33230 | 1306 | static basic_block |
d329e058 | 1307 | rtl_split_edge (edge edge_in) |
ca6c03ca JH |
1308 | { |
1309 | basic_block bb; | |
ca6c03ca JH |
1310 | rtx before; |
1311 | ||
1312 | /* Abnormal edges cannot be split. */ | |
341c100f | 1313 | gcc_assert (!(edge_in->flags & EDGE_ABNORMAL)); |
ca6c03ca JH |
1314 | |
1315 | /* We are going to place the new block in front of edge destination. | |
eaec9b3d | 1316 | Avoid existence of fallthru predecessors. */ |
ca6c03ca JH |
1317 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) |
1318 | { | |
1319 | edge e; | |
628f6a4e | 1320 | edge_iterator ei; |
5f0d2358 | 1321 | |
628f6a4e | 1322 | FOR_EACH_EDGE (e, ei, edge_in->dest->preds) |
ca6c03ca JH |
1323 | if (e->flags & EDGE_FALLTHRU) |
1324 | break; | |
1325 | ||
1326 | if (e) | |
1327 | force_nonfallthru (e); | |
1328 | } | |
1329 | ||
1330 | /* Create the basic block note. | |
1331 | ||
f63d1bf7 | 1332 | Where we place the note can have a noticeable impact on the generated |
ca6c03ca JH |
1333 | code. Consider this cfg: |
1334 | ||
1335 | E | |
1336 | | | |
1337 | 0 | |
1338 | / \ | |
1339 | +->1-->2--->E | |
1340 | | | | |
1341 | +--+ | |
1342 | ||
1343 | If we need to insert an insn on the edge from block 0 to block 1, | |
1344 | we want to ensure the instructions we insert are outside of any | |
1345 | loop notes that physically sit between block 0 and block 1. Otherwise | |
1346 | we confuse the loop optimizer into thinking the loop is a phony. */ | |
1347 | ||
1348 | if (edge_in->dest != EXIT_BLOCK_PTR | |
a813c111 | 1349 | && PREV_INSN (BB_HEAD (edge_in->dest)) |
4b4bf941 | 1350 | && NOTE_P (PREV_INSN (BB_HEAD (edge_in->dest))) |
a813c111 | 1351 | && (NOTE_LINE_NUMBER (PREV_INSN (BB_HEAD (edge_in->dest))) |
5f0d2358 | 1352 | == NOTE_INSN_LOOP_BEG) |
ca6c03ca | 1353 | && !back_edge_of_syntactic_loop_p (edge_in->dest, edge_in->src)) |
a813c111 | 1354 | before = PREV_INSN (BB_HEAD (edge_in->dest)); |
ca6c03ca | 1355 | else if (edge_in->dest != EXIT_BLOCK_PTR) |
a813c111 | 1356 | before = BB_HEAD (edge_in->dest); |
ca6c03ca JH |
1357 | else |
1358 | before = NULL_RTX; | |
1359 | ||
623a66fa R |
1360 | /* If this is a fall through edge to the exit block, the blocks might be |
1361 | not adjacent, and the right place is the after the source. */ | |
1362 | if (edge_in->flags & EDGE_FALLTHRU && edge_in->dest == EXIT_BLOCK_PTR) | |
1363 | { | |
1364 | before = NEXT_INSN (BB_END (edge_in->src)); | |
1365 | if (before | |
4b4bf941 | 1366 | && NOTE_P (before) |
623a66fa R |
1367 | && NOTE_LINE_NUMBER (before) == NOTE_INSN_LOOP_END) |
1368 | before = NEXT_INSN (before); | |
1369 | bb = create_basic_block (before, NULL, edge_in->src); | |
076c7ab8 | 1370 | BB_COPY_PARTITION (bb, edge_in->src); |
623a66fa R |
1371 | } |
1372 | else | |
9fb32434 CT |
1373 | { |
1374 | bb = create_basic_block (before, NULL, edge_in->dest->prev_bb); | |
076c7ab8 ZW |
1375 | /* ??? Why not edge_in->dest->prev_bb here? */ |
1376 | BB_COPY_PARTITION (bb, edge_in->dest); | |
9fb32434 | 1377 | } |
ca6c03ca JH |
1378 | |
1379 | /* ??? This info is likely going to be out of date very soon. */ | |
5e2d947c | 1380 | if (edge_in->dest->il.rtl->global_live_at_start) |
ca6c03ca | 1381 | { |
5e2d947c JH |
1382 | bb->il.rtl->global_live_at_start = ALLOC_REG_SET (®_obstack); |
1383 | bb->il.rtl->global_live_at_end = ALLOC_REG_SET (®_obstack); | |
1384 | COPY_REG_SET (bb->il.rtl->global_live_at_start, | |
1385 | edge_in->dest->il.rtl->global_live_at_start); | |
1386 | COPY_REG_SET (bb->il.rtl->global_live_at_end, | |
1387 | edge_in->dest->il.rtl->global_live_at_start); | |
ca6c03ca JH |
1388 | } |
1389 | ||
4977bab6 | 1390 | make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU); |
ca6c03ca | 1391 | |
4d6922ee | 1392 | /* For non-fallthru edges, we must adjust the predecessor's |
ca6c03ca JH |
1393 | jump instruction to target our new block. */ |
1394 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1395 | { | |
341c100f NS |
1396 | edge redirected = redirect_edge_and_branch (edge_in, bb); |
1397 | gcc_assert (redirected); | |
ca6c03ca JH |
1398 | } |
1399 | else | |
1400 | redirect_edge_succ (edge_in, bb); | |
1401 | ||
1402 | return bb; | |
1403 | } | |
1404 | ||
1405 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1406 | The new instructions and basic blocks (if any) will not appear in the | |
1407 | CFG until commit_edge_insertions is called. */ | |
1408 | ||
1409 | void | |
d329e058 | 1410 | insert_insn_on_edge (rtx pattern, edge e) |
ca6c03ca JH |
1411 | { |
1412 | /* We cannot insert instructions on an abnormal critical edge. | |
1413 | It will be easier to find the culprit if we die now. */ | |
341c100f | 1414 | gcc_assert (!((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e))); |
ca6c03ca | 1415 | |
6de9cd9a | 1416 | if (e->insns.r == NULL_RTX) |
ca6c03ca JH |
1417 | start_sequence (); |
1418 | else | |
6de9cd9a | 1419 | push_to_sequence (e->insns.r); |
ca6c03ca JH |
1420 | |
1421 | emit_insn (pattern); | |
1422 | ||
6de9cd9a | 1423 | e->insns.r = get_insns (); |
ca6c03ca JH |
1424 | end_sequence (); |
1425 | } | |
1426 | ||
ff25ef99 ZD |
1427 | /* Called from safe_insert_insn_on_edge through note_stores, marks live |
1428 | registers that are killed by the store. */ | |
1429 | static void | |
1430 | mark_killed_regs (rtx reg, rtx set ATTRIBUTE_UNUSED, void *data) | |
1431 | { | |
1432 | regset killed = data; | |
1433 | int regno, i; | |
1434 | ||
1435 | if (GET_CODE (reg) == SUBREG) | |
1436 | reg = SUBREG_REG (reg); | |
1437 | if (!REG_P (reg)) | |
1438 | return; | |
1439 | regno = REGNO (reg); | |
1440 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1441 | SET_REGNO_REG_SET (killed, regno); | |
1442 | else | |
1443 | { | |
66fd46b6 | 1444 | for (i = 0; i < (int) hard_regno_nregs[regno][GET_MODE (reg)]; i++) |
ff25ef99 ZD |
1445 | SET_REGNO_REG_SET (killed, regno + i); |
1446 | } | |
1447 | } | |
1448 | ||
1449 | /* Similar to insert_insn_on_edge, tries to put INSN to edge E. Additionally | |
1450 | it checks whether this will not clobber the registers that are live on the | |
e0bb17a8 | 1451 | edge (i.e. it requires liveness information to be up-to-date) and if there |
ff25ef99 | 1452 | are some, then it tries to save and restore them. Returns true if |
e0bb17a8 | 1453 | successful. */ |
ff25ef99 ZD |
1454 | bool |
1455 | safe_insert_insn_on_edge (rtx insn, edge e) | |
1456 | { | |
1457 | rtx x; | |
7932a3db | 1458 | regset killed; |
ff25ef99 | 1459 | rtx save_regs = NULL_RTX; |
3cd8c58a | 1460 | unsigned regno; |
ff25ef99 | 1461 | enum machine_mode mode; |
a2041967 | 1462 | reg_set_iterator rsi; |
ff25ef99 | 1463 | |
04389919 | 1464 | killed = ALLOC_REG_SET (®_obstack); |
7932a3db | 1465 | |
ff25ef99 ZD |
1466 | for (x = insn; x; x = NEXT_INSN (x)) |
1467 | if (INSN_P (x)) | |
1468 | note_stores (PATTERN (x), mark_killed_regs, killed); | |
af9ecd0c ZD |
1469 | |
1470 | /* Mark all hard registers as killed. Register allocator/reload cannot | |
1471 | cope with the situation when life range of hard register spans operation | |
1472 | for that the appropriate register is needed, i.e. it would be unsafe to | |
1473 | extend the life ranges of hard registers. */ | |
1474 | for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) | |
1475 | if (!fixed_regs[regno] | |
1476 | && !REGNO_PTR_FRAME_P (regno)) | |
1477 | SET_REGNO_REG_SET (killed, regno); | |
1478 | ||
5e2d947c | 1479 | bitmap_and_into (killed, e->dest->il.rtl->global_live_at_start); |
ff25ef99 | 1480 | |
a2041967 | 1481 | EXECUTE_IF_SET_IN_REG_SET (killed, 0, regno, rsi) |
ff25ef99 ZD |
1482 | { |
1483 | mode = regno < FIRST_PSEUDO_REGISTER | |
1484 | ? reg_raw_mode[regno] | |
1485 | : GET_MODE (regno_reg_rtx[regno]); | |
1486 | if (mode == VOIDmode) | |
1487 | return false; | |
1488 | ||
e48050bd EB |
1489 | /* Avoid copying in CCmode if we can't. */ |
1490 | if (!can_copy_p (mode)) | |
ff25ef99 ZD |
1491 | return false; |
1492 | ||
1493 | save_regs = alloc_EXPR_LIST (0, | |
1494 | alloc_EXPR_LIST (0, | |
1495 | gen_reg_rtx (mode), | |
1496 | gen_raw_REG (mode, regno)), | |
1497 | save_regs); | |
a2041967 | 1498 | } |
ff25ef99 ZD |
1499 | |
1500 | if (save_regs) | |
1501 | { | |
1502 | rtx from, to; | |
1503 | ||
1504 | start_sequence (); | |
1505 | for (x = save_regs; x; x = XEXP (x, 1)) | |
1506 | { | |
1507 | from = XEXP (XEXP (x, 0), 1); | |
1508 | to = XEXP (XEXP (x, 0), 0); | |
1509 | emit_move_insn (to, from); | |
1510 | } | |
1511 | emit_insn (insn); | |
1512 | for (x = save_regs; x; x = XEXP (x, 1)) | |
1513 | { | |
1514 | from = XEXP (XEXP (x, 0), 0); | |
1515 | to = XEXP (XEXP (x, 0), 1); | |
1516 | emit_move_insn (to, from); | |
1517 | } | |
1518 | insn = get_insns (); | |
1519 | end_sequence (); | |
1520 | free_EXPR_LIST_list (&save_regs); | |
1521 | } | |
1522 | insert_insn_on_edge (insn, e); | |
1523 | ||
1524 | FREE_REG_SET (killed); | |
af9ecd0c | 1525 | |
ff25ef99 ZD |
1526 | return true; |
1527 | } | |
1528 | ||
ca6c03ca JH |
1529 | /* Update the CFG for the instructions queued on edge E. */ |
1530 | ||
1531 | static void | |
d329e058 | 1532 | commit_one_edge_insertion (edge e, int watch_calls) |
ca6c03ca JH |
1533 | { |
1534 | rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last; | |
eae4bc56 | 1535 | basic_block bb = NULL; |
ca6c03ca JH |
1536 | |
1537 | /* Pull the insns off the edge now since the edge might go away. */ | |
6de9cd9a DN |
1538 | insns = e->insns.r; |
1539 | e->insns.r = NULL_RTX; | |
ca6c03ca | 1540 | |
3dec4024 JH |
1541 | /* Special case -- avoid inserting code between call and storing |
1542 | its return value. */ | |
628f6a4e | 1543 | if (watch_calls && (e->flags & EDGE_FALLTHRU) |
c5cbcccf | 1544 | && single_pred_p (e->dest) |
3dec4024 | 1545 | && e->src != ENTRY_BLOCK_PTR |
4b4bf941 | 1546 | && CALL_P (BB_END (e->src))) |
ca6c03ca | 1547 | { |
a813c111 | 1548 | rtx next = next_nonnote_insn (BB_END (e->src)); |
ca6c03ca | 1549 | |
a813c111 | 1550 | after = BB_HEAD (e->dest); |
3dec4024 JH |
1551 | /* The first insn after the call may be a stack pop, skip it. */ |
1552 | while (next | |
1553 | && keep_with_call_p (next)) | |
f87c27b4 KH |
1554 | { |
1555 | after = next; | |
3dec4024 JH |
1556 | next = next_nonnote_insn (next); |
1557 | } | |
1558 | bb = e->dest; | |
ca6c03ca | 1559 | } |
3dec4024 | 1560 | if (!before && !after) |
ca6c03ca | 1561 | { |
3dec4024 JH |
1562 | /* Figure out where to put these things. If the destination has |
1563 | one predecessor, insert there. Except for the exit block. */ | |
c5cbcccf | 1564 | if (single_pred_p (e->dest) && e->dest != EXIT_BLOCK_PTR) |
ca6c03ca | 1565 | { |
3dec4024 JH |
1566 | bb = e->dest; |
1567 | ||
1568 | /* Get the location correct wrt a code label, and "nice" wrt | |
1569 | a basic block note, and before everything else. */ | |
a813c111 | 1570 | tmp = BB_HEAD (bb); |
4b4bf941 | 1571 | if (LABEL_P (tmp)) |
3dec4024 JH |
1572 | tmp = NEXT_INSN (tmp); |
1573 | if (NOTE_INSN_BASIC_BLOCK_P (tmp)) | |
1574 | tmp = NEXT_INSN (tmp); | |
a813c111 | 1575 | if (tmp == BB_HEAD (bb)) |
3dec4024 JH |
1576 | before = tmp; |
1577 | else if (tmp) | |
1578 | after = PREV_INSN (tmp); | |
1579 | else | |
1580 | after = get_last_insn (); | |
1581 | } | |
1582 | ||
1583 | /* If the source has one successor and the edge is not abnormal, | |
1584 | insert there. Except for the entry block. */ | |
1585 | else if ((e->flags & EDGE_ABNORMAL) == 0 | |
c5cbcccf | 1586 | && single_succ_p (e->src) |
3dec4024 JH |
1587 | && e->src != ENTRY_BLOCK_PTR) |
1588 | { | |
1589 | bb = e->src; | |
1590 | ||
1591 | /* It is possible to have a non-simple jump here. Consider a target | |
1592 | where some forms of unconditional jumps clobber a register. This | |
1593 | happens on the fr30 for example. | |
1594 | ||
1595 | We know this block has a single successor, so we can just emit | |
1596 | the queued insns before the jump. */ | |
4b4bf941 | 1597 | if (JUMP_P (BB_END (bb))) |
a813c111 | 1598 | for (before = BB_END (bb); |
4b4bf941 | 1599 | NOTE_P (PREV_INSN (before)) |
3dec4024 JH |
1600 | && NOTE_LINE_NUMBER (PREV_INSN (before)) == |
1601 | NOTE_INSN_LOOP_BEG; before = PREV_INSN (before)) | |
1602 | ; | |
1603 | else | |
1604 | { | |
341c100f NS |
1605 | /* We'd better be fallthru, or we've lost track of |
1606 | what's what. */ | |
1607 | gcc_assert (e->flags & EDGE_FALLTHRU); | |
ca6c03ca | 1608 | |
a813c111 | 1609 | after = BB_END (bb); |
3dec4024 JH |
1610 | } |
1611 | } | |
1612 | /* Otherwise we must split the edge. */ | |
1613 | else | |
1614 | { | |
1615 | bb = split_edge (e); | |
a813c111 | 1616 | after = BB_END (bb); |
750054a2 | 1617 | |
750054a2 | 1618 | if (flag_reorder_blocks_and_partition |
9fb32434 | 1619 | && targetm.have_named_sections |
750054a2 | 1620 | && e->src != ENTRY_BLOCK_PTR |
076c7ab8 | 1621 | && BB_PARTITION (e->src) == BB_COLD_PARTITION |
bd454efd | 1622 | && !(e->flags & EDGE_CROSSING)) |
750054a2 | 1623 | { |
87c8b4be | 1624 | rtx bb_note, cur_insn; |
750054a2 CT |
1625 | |
1626 | bb_note = NULL_RTX; | |
1627 | for (cur_insn = BB_HEAD (bb); cur_insn != NEXT_INSN (BB_END (bb)); | |
1628 | cur_insn = NEXT_INSN (cur_insn)) | |
4b4bf941 | 1629 | if (NOTE_P (cur_insn) |
750054a2 CT |
1630 | && NOTE_LINE_NUMBER (cur_insn) == NOTE_INSN_BASIC_BLOCK) |
1631 | { | |
1632 | bb_note = cur_insn; | |
1633 | break; | |
1634 | } | |
1635 | ||
4b4bf941 | 1636 | if (JUMP_P (BB_END (bb)) |
750054a2 | 1637 | && !any_condjump_p (BB_END (bb)) |
c5cbcccf | 1638 | && (single_succ_edge (bb)->flags & EDGE_CROSSING)) |
750054a2 CT |
1639 | REG_NOTES (BB_END (bb)) = gen_rtx_EXPR_LIST |
1640 | (REG_CROSSING_JUMP, NULL_RTX, REG_NOTES (BB_END (bb))); | |
750054a2 | 1641 | } |
ca6c03ca JH |
1642 | } |
1643 | } | |
1644 | ||
ca6c03ca JH |
1645 | /* Now that we've found the spot, do the insertion. */ |
1646 | ||
1647 | if (before) | |
1648 | { | |
a7102479 | 1649 | emit_insn_before_noloc (insns, before); |
ca6c03ca JH |
1650 | last = prev_nonnote_insn (before); |
1651 | } | |
1652 | else | |
a7102479 | 1653 | last = emit_insn_after_noloc (insns, after); |
ca6c03ca JH |
1654 | |
1655 | if (returnjump_p (last)) | |
1656 | { | |
1657 | /* ??? Remove all outgoing edges from BB and add one for EXIT. | |
1658 | This is not currently a problem because this only happens | |
3dec4024 JH |
1659 | for the (single) epilogue, which already has a fallthru edge |
1660 | to EXIT. */ | |
ca6c03ca | 1661 | |
c5cbcccf | 1662 | e = single_succ_edge (bb); |
341c100f | 1663 | gcc_assert (e->dest == EXIT_BLOCK_PTR |
c5cbcccf | 1664 | && single_succ_p (bb) && (e->flags & EDGE_FALLTHRU)); |
ca6c03ca | 1665 | |
5f0d2358 | 1666 | e->flags &= ~EDGE_FALLTHRU; |
ca6c03ca | 1667 | emit_barrier_after (last); |
0b17ab2f | 1668 | |
ca6c03ca JH |
1669 | if (before) |
1670 | delete_insn (before); | |
1671 | } | |
341c100f NS |
1672 | else |
1673 | gcc_assert (!JUMP_P (last)); | |
5f0d2358 | 1674 | |
12eff7b7 | 1675 | /* Mark the basic block for find_many_sub_basic_blocks. */ |
9dca2ad5 | 1676 | bb->aux = &bb->aux; |
ca6c03ca JH |
1677 | } |
1678 | ||
1679 | /* Update the CFG for all queued instructions. */ | |
1680 | ||
1681 | void | |
d329e058 | 1682 | commit_edge_insertions (void) |
ca6c03ca | 1683 | { |
ca6c03ca | 1684 | basic_block bb; |
9dca2ad5 | 1685 | sbitmap blocks; |
9809a362 | 1686 | bool changed = false; |
ca6c03ca JH |
1687 | |
1688 | #ifdef ENABLE_CHECKING | |
1689 | verify_flow_info (); | |
1690 | #endif | |
1691 | ||
e0082a72 | 1692 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
ca6c03ca | 1693 | { |
628f6a4e BE |
1694 | edge e; |
1695 | edge_iterator ei; | |
ca6c03ca | 1696 | |
628f6a4e BE |
1697 | FOR_EACH_EDGE (e, ei, bb->succs) |
1698 | if (e->insns.r) | |
1699 | { | |
1700 | changed = true; | |
1701 | commit_one_edge_insertion (e, false); | |
1702 | } | |
3dec4024 | 1703 | } |
9dca2ad5 | 1704 | |
9809a362 JH |
1705 | if (!changed) |
1706 | return; | |
1707 | ||
9dca2ad5 JH |
1708 | blocks = sbitmap_alloc (last_basic_block); |
1709 | sbitmap_zero (blocks); | |
1710 | FOR_EACH_BB (bb) | |
1711 | if (bb->aux) | |
1712 | { | |
1713 | SET_BIT (blocks, bb->index); | |
1714 | /* Check for forgotten bb->aux values before commit_edge_insertions | |
1715 | call. */ | |
341c100f | 1716 | gcc_assert (bb->aux == &bb->aux); |
9dca2ad5 JH |
1717 | bb->aux = NULL; |
1718 | } | |
1719 | find_many_sub_basic_blocks (blocks); | |
1720 | sbitmap_free (blocks); | |
3dec4024 JH |
1721 | } |
1722 | \f | |
1723 | /* Update the CFG for all queued instructions, taking special care of inserting | |
1724 | code on edges between call and storing its return value. */ | |
1725 | ||
1726 | void | |
d329e058 | 1727 | commit_edge_insertions_watch_calls (void) |
3dec4024 | 1728 | { |
3dec4024 | 1729 | basic_block bb; |
9809a362 JH |
1730 | sbitmap blocks; |
1731 | bool changed = false; | |
3dec4024 JH |
1732 | |
1733 | #ifdef ENABLE_CHECKING | |
1734 | verify_flow_info (); | |
1735 | #endif | |
1736 | ||
e0082a72 | 1737 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
3dec4024 | 1738 | { |
628f6a4e BE |
1739 | edge e; |
1740 | edge_iterator ei; | |
3dec4024 | 1741 | |
628f6a4e BE |
1742 | FOR_EACH_EDGE (e, ei, bb->succs) |
1743 | if (e->insns.r) | |
1744 | { | |
1745 | changed = true; | |
1746 | commit_one_edge_insertion (e, true); | |
1747 | } | |
ca6c03ca | 1748 | } |
9809a362 JH |
1749 | |
1750 | if (!changed) | |
1751 | return; | |
1752 | ||
1753 | blocks = sbitmap_alloc (last_basic_block); | |
1754 | sbitmap_zero (blocks); | |
1755 | FOR_EACH_BB (bb) | |
1756 | if (bb->aux) | |
1757 | { | |
1758 | SET_BIT (blocks, bb->index); | |
1759 | /* Check for forgotten bb->aux values before commit_edge_insertions | |
1760 | call. */ | |
341c100f | 1761 | gcc_assert (bb->aux == &bb->aux); |
9809a362 JH |
1762 | bb->aux = NULL; |
1763 | } | |
1764 | find_many_sub_basic_blocks (blocks); | |
1765 | sbitmap_free (blocks); | |
ca6c03ca JH |
1766 | } |
1767 | \f | |
f470c378 ZD |
1768 | /* Print out RTL-specific basic block information (live information |
1769 | at start and end). */ | |
ca6c03ca | 1770 | |
10e9fecc | 1771 | static void |
f470c378 | 1772 | rtl_dump_bb (basic_block bb, FILE *outf, int indent) |
ca6c03ca JH |
1773 | { |
1774 | rtx insn; | |
1775 | rtx last; | |
f470c378 | 1776 | char *s_indent; |
ca6c03ca | 1777 | |
400e39e3 KH |
1778 | s_indent = alloca ((size_t) indent + 1); |
1779 | memset (s_indent, ' ', (size_t) indent); | |
f470c378 ZD |
1780 | s_indent[indent] = '\0'; |
1781 | ||
1782 | fprintf (outf, ";;%s Registers live at start: ", s_indent); | |
5e2d947c | 1783 | dump_regset (bb->il.rtl->global_live_at_start, outf); |
ca6c03ca JH |
1784 | putc ('\n', outf); |
1785 | ||
a813c111 | 1786 | for (insn = BB_HEAD (bb), last = NEXT_INSN (BB_END (bb)); insn != last; |
ca6c03ca JH |
1787 | insn = NEXT_INSN (insn)) |
1788 | print_rtl_single (outf, insn); | |
1789 | ||
f470c378 | 1790 | fprintf (outf, ";;%s Registers live at end: ", s_indent); |
5e2d947c | 1791 | dump_regset (bb->il.rtl->global_live_at_end, outf); |
ca6c03ca | 1792 | putc ('\n', outf); |
ca6c03ca JH |
1793 | } |
1794 | \f | |
1795 | /* Like print_rtl, but also print out live information for the start of each | |
1796 | basic block. */ | |
1797 | ||
1798 | void | |
d329e058 | 1799 | print_rtl_with_bb (FILE *outf, rtx rtx_first) |
ca6c03ca | 1800 | { |
b3694847 | 1801 | rtx tmp_rtx; |
ca6c03ca JH |
1802 | |
1803 | if (rtx_first == 0) | |
1804 | fprintf (outf, "(nil)\n"); | |
1805 | else | |
1806 | { | |
ca6c03ca JH |
1807 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
1808 | int max_uid = get_max_uid (); | |
703ad42b KG |
1809 | basic_block *start = xcalloc (max_uid, sizeof (basic_block)); |
1810 | basic_block *end = xcalloc (max_uid, sizeof (basic_block)); | |
1811 | enum bb_state *in_bb_p = xcalloc (max_uid, sizeof (enum bb_state)); | |
ca6c03ca | 1812 | |
e0082a72 ZD |
1813 | basic_block bb; |
1814 | ||
1815 | FOR_EACH_BB_REVERSE (bb) | |
ca6c03ca | 1816 | { |
ca6c03ca JH |
1817 | rtx x; |
1818 | ||
a813c111 SB |
1819 | start[INSN_UID (BB_HEAD (bb))] = bb; |
1820 | end[INSN_UID (BB_END (bb))] = bb; | |
1821 | for (x = BB_HEAD (bb); x != NULL_RTX; x = NEXT_INSN (x)) | |
ca6c03ca JH |
1822 | { |
1823 | enum bb_state state = IN_MULTIPLE_BB; | |
5f0d2358 | 1824 | |
ca6c03ca JH |
1825 | if (in_bb_p[INSN_UID (x)] == NOT_IN_BB) |
1826 | state = IN_ONE_BB; | |
1827 | in_bb_p[INSN_UID (x)] = state; | |
1828 | ||
a813c111 | 1829 | if (x == BB_END (bb)) |
ca6c03ca JH |
1830 | break; |
1831 | } | |
1832 | } | |
1833 | ||
1834 | for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) | |
1835 | { | |
1836 | int did_output; | |
ca6c03ca JH |
1837 | |
1838 | if ((bb = start[INSN_UID (tmp_rtx)]) != NULL) | |
1839 | { | |
1840 | fprintf (outf, ";; Start of basic block %d, registers live:", | |
0b17ab2f | 1841 | bb->index); |
5e2d947c | 1842 | dump_regset (bb->il.rtl->global_live_at_start, outf); |
ca6c03ca JH |
1843 | putc ('\n', outf); |
1844 | } | |
1845 | ||
1846 | if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB | |
4b4bf941 JQ |
1847 | && !NOTE_P (tmp_rtx) |
1848 | && !BARRIER_P (tmp_rtx)) | |
ca6c03ca JH |
1849 | fprintf (outf, ";; Insn is not within a basic block\n"); |
1850 | else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB) | |
1851 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); | |
1852 | ||
1853 | did_output = print_rtl_single (outf, tmp_rtx); | |
1854 | ||
1855 | if ((bb = end[INSN_UID (tmp_rtx)]) != NULL) | |
1856 | { | |
1857 | fprintf (outf, ";; End of basic block %d, registers live:\n", | |
0b17ab2f | 1858 | bb->index); |
5e2d947c | 1859 | dump_regset (bb->il.rtl->global_live_at_end, outf); |
ca6c03ca JH |
1860 | putc ('\n', outf); |
1861 | } | |
1862 | ||
1863 | if (did_output) | |
1864 | putc ('\n', outf); | |
1865 | } | |
1866 | ||
1867 | free (start); | |
1868 | free (end); | |
1869 | free (in_bb_p); | |
1870 | } | |
1871 | ||
1872 | if (current_function_epilogue_delay_list != 0) | |
1873 | { | |
1874 | fprintf (outf, "\n;; Insns in epilogue delay list:\n\n"); | |
1875 | for (tmp_rtx = current_function_epilogue_delay_list; tmp_rtx != 0; | |
1876 | tmp_rtx = XEXP (tmp_rtx, 1)) | |
1877 | print_rtl_single (outf, XEXP (tmp_rtx, 0)); | |
1878 | } | |
1879 | } | |
1880 | \f | |
b446e5a2 | 1881 | void |
d329e058 | 1882 | update_br_prob_note (basic_block bb) |
b446e5a2 JH |
1883 | { |
1884 | rtx note; | |
4b4bf941 | 1885 | if (!JUMP_P (BB_END (bb))) |
b446e5a2 | 1886 | return; |
a813c111 | 1887 | note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX); |
b446e5a2 JH |
1888 | if (!note || INTVAL (XEXP (note, 0)) == BRANCH_EDGE (bb)->probability) |
1889 | return; | |
1890 | XEXP (note, 0) = GEN_INT (BRANCH_EDGE (bb)->probability); | |
1891 | } | |
1892 | \f | |
10e9fecc JH |
1893 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
1894 | cfglayout RTL. | |
ca6c03ca JH |
1895 | |
1896 | Currently it does following checks: | |
1897 | ||
1898 | - test head/end pointers | |
1899 | - overlapping of basic blocks | |
ca6c03ca | 1900 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) |
f63d1bf7 | 1901 | - tails of basic blocks (ensure that boundary is necessary) |
ca6c03ca JH |
1902 | - scans body of the basic block for JUMP_INSN, CODE_LABEL |
1903 | and NOTE_INSN_BASIC_BLOCK | |
750054a2 | 1904 | - verify that no fall_thru edge crosses hot/cold partition boundaries |
ca6c03ca JH |
1905 | |
1906 | In future it can be extended check a lot of other stuff as well | |
1907 | (reachability of basic blocks, life information, etc. etc.). */ | |
f470c378 | 1908 | |
10e9fecc | 1909 | static int |
d329e058 | 1910 | rtl_verify_flow_info_1 (void) |
ca6c03ca JH |
1911 | { |
1912 | const int max_uid = get_max_uid (); | |
ca6c03ca | 1913 | rtx last_head = get_last_insn (); |
10e9fecc | 1914 | basic_block *bb_info; |
ca6c03ca | 1915 | rtx x; |
10e9fecc | 1916 | int err = 0; |
94eb5ddb | 1917 | basic_block bb; |
ca6c03ca | 1918 | |
703ad42b | 1919 | bb_info = xcalloc (max_uid, sizeof (basic_block)); |
ca6c03ca | 1920 | |
e0082a72 | 1921 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1922 | { |
a813c111 SB |
1923 | rtx head = BB_HEAD (bb); |
1924 | rtx end = BB_END (bb); | |
ca6c03ca JH |
1925 | |
1926 | /* Verify the end of the basic block is in the INSN chain. */ | |
1927 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) | |
1928 | if (x == end) | |
1929 | break; | |
5f0d2358 | 1930 | |
5e2d947c JH |
1931 | if (!(bb->flags & BB_RTL)) |
1932 | { | |
1933 | error ("BB_RTL flag not set for block %d", bb->index); | |
1934 | err = 1; | |
1935 | } | |
1936 | ||
ca6c03ca JH |
1937 | if (!x) |
1938 | { | |
1f978f5f | 1939 | error ("end insn %d for block %d not found in the insn stream", |
0b17ab2f | 1940 | INSN_UID (end), bb->index); |
ca6c03ca JH |
1941 | err = 1; |
1942 | } | |
1943 | ||
1944 | /* Work backwards from the end to the head of the basic block | |
1945 | to verify the head is in the RTL chain. */ | |
1946 | for (; x != NULL_RTX; x = PREV_INSN (x)) | |
1947 | { | |
1948 | /* While walking over the insn chain, verify insns appear | |
1949 | in only one basic block and initialize the BB_INFO array | |
1950 | used by other passes. */ | |
1951 | if (bb_info[INSN_UID (x)] != NULL) | |
1952 | { | |
1f978f5f | 1953 | error ("insn %d is in multiple basic blocks (%d and %d)", |
0b17ab2f | 1954 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); |
ca6c03ca JH |
1955 | err = 1; |
1956 | } | |
5f0d2358 | 1957 | |
ca6c03ca JH |
1958 | bb_info[INSN_UID (x)] = bb; |
1959 | ||
1960 | if (x == head) | |
1961 | break; | |
1962 | } | |
1963 | if (!x) | |
1964 | { | |
1f978f5f | 1965 | error ("head insn %d for block %d not found in the insn stream", |
0b17ab2f | 1966 | INSN_UID (head), bb->index); |
ca6c03ca JH |
1967 | err = 1; |
1968 | } | |
1969 | ||
1970 | last_head = x; | |
1971 | } | |
1972 | ||
1973 | /* Now check the basic blocks (boundaries etc.) */ | |
e0082a72 | 1974 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1975 | { |
3dec4024 | 1976 | int n_fallthru = 0, n_eh = 0, n_call = 0, n_abnormal = 0, n_branch = 0; |
3cf54412 | 1977 | edge e, fallthru = NULL; |
5a1a3e5e | 1978 | rtx note; |
628f6a4e | 1979 | edge_iterator ei; |
ca6c03ca | 1980 | |
2085a21f | 1981 | if (JUMP_P (BB_END (bb)) |
a813c111 | 1982 | && (note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX)) |
628f6a4e | 1983 | && EDGE_COUNT (bb->succs) >= 2 |
a813c111 | 1984 | && any_condjump_p (BB_END (bb))) |
5a1a3e5e | 1985 | { |
e53de54d JH |
1986 | if (INTVAL (XEXP (note, 0)) != BRANCH_EDGE (bb)->probability |
1987 | && profile_status != PROFILE_ABSENT) | |
5a1a3e5e | 1988 | { |
0108ae51 | 1989 | error ("verify_flow_info: REG_BR_PROB does not match cfg %wi %i", |
5a1a3e5e JH |
1990 | INTVAL (XEXP (note, 0)), BRANCH_EDGE (bb)->probability); |
1991 | err = 1; | |
1992 | } | |
1993 | } | |
628f6a4e | 1994 | FOR_EACH_EDGE (e, ei, bb->succs) |
ca6c03ca | 1995 | { |
ca6c03ca | 1996 | if (e->flags & EDGE_FALLTHRU) |
750054a2 CT |
1997 | { |
1998 | n_fallthru++, fallthru = e; | |
bd454efd | 1999 | if ((e->flags & EDGE_CROSSING) |
076c7ab8 | 2000 | || (BB_PARTITION (e->src) != BB_PARTITION (e->dest) |
9fb32434 CT |
2001 | && e->src != ENTRY_BLOCK_PTR |
2002 | && e->dest != EXIT_BLOCK_PTR)) | |
2003 | { | |
ab532386 | 2004 | error ("fallthru edge crosses section boundary (bb %i)", |
750054a2 CT |
2005 | e->src->index); |
2006 | err = 1; | |
2007 | } | |
2008 | } | |
3dec4024 | 2009 | |
65f43cdf ZD |
2010 | if ((e->flags & ~(EDGE_DFS_BACK |
2011 | | EDGE_CAN_FALLTHRU | |
2012 | | EDGE_IRREDUCIBLE_LOOP | |
9beb1c84 CT |
2013 | | EDGE_LOOP_EXIT |
2014 | | EDGE_CROSSING)) == 0) | |
3dec4024 JH |
2015 | n_branch++; |
2016 | ||
2017 | if (e->flags & EDGE_ABNORMAL_CALL) | |
2018 | n_call++; | |
2019 | ||
2020 | if (e->flags & EDGE_EH) | |
2021 | n_eh++; | |
2022 | else if (e->flags & EDGE_ABNORMAL) | |
2023 | n_abnormal++; | |
ca6c03ca | 2024 | } |
5f0d2358 | 2025 | |
a813c111 SB |
2026 | if (n_eh && GET_CODE (PATTERN (BB_END (bb))) != RESX |
2027 | && !find_reg_note (BB_END (bb), REG_EH_REGION, NULL_RTX)) | |
3dec4024 | 2028 | { |
ab532386 | 2029 | error ("missing REG_EH_REGION note in the end of bb %i", bb->index); |
3dec4024 JH |
2030 | err = 1; |
2031 | } | |
2032 | if (n_branch | |
4b4bf941 | 2033 | && (!JUMP_P (BB_END (bb)) |
a813c111 SB |
2034 | || (n_branch > 1 && (any_uncondjump_p (BB_END (bb)) |
2035 | || any_condjump_p (BB_END (bb)))))) | |
3dec4024 | 2036 | { |
ab532386 | 2037 | error ("too many outgoing branch edges from bb %i", bb->index); |
3dec4024 JH |
2038 | err = 1; |
2039 | } | |
a813c111 | 2040 | if (n_fallthru && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 2041 | { |
ab532386 | 2042 | error ("fallthru edge after unconditional jump %i", bb->index); |
3dec4024 JH |
2043 | err = 1; |
2044 | } | |
a813c111 | 2045 | if (n_branch != 1 && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 2046 | { |
ab532386 | 2047 | error ("wrong amount of branch edges after unconditional jump %i", bb->index); |
3dec4024 JH |
2048 | err = 1; |
2049 | } | |
a813c111 | 2050 | if (n_branch != 1 && any_condjump_p (BB_END (bb)) |
c11fd0b2 | 2051 | && JUMP_LABEL (BB_END (bb)) != BB_HEAD (fallthru->dest)) |
3dec4024 | 2052 | { |
c11fd0b2 RG |
2053 | error ("wrong amount of branch edges after conditional jump %i", |
2054 | bb->index); | |
3dec4024 JH |
2055 | err = 1; |
2056 | } | |
4b4bf941 | 2057 | if (n_call && !CALL_P (BB_END (bb))) |
3dec4024 | 2058 | { |
ab532386 | 2059 | error ("call edges for non-call insn in bb %i", bb->index); |
3dec4024 JH |
2060 | err = 1; |
2061 | } | |
2062 | if (n_abnormal | |
4b4bf941 JQ |
2063 | && (!CALL_P (BB_END (bb)) && n_call != n_abnormal) |
2064 | && (!JUMP_P (BB_END (bb)) | |
a813c111 SB |
2065 | || any_condjump_p (BB_END (bb)) |
2066 | || any_uncondjump_p (BB_END (bb)))) | |
3dec4024 | 2067 | { |
ab532386 | 2068 | error ("abnormal edges for no purpose in bb %i", bb->index); |
3dec4024 JH |
2069 | err = 1; |
2070 | } | |
f87c27b4 | 2071 | |
a813c111 | 2072 | for (x = BB_HEAD (bb); x != NEXT_INSN (BB_END (bb)); x = NEXT_INSN (x)) |
0ca541aa | 2073 | /* We may have a barrier inside a basic block before dead code |
9524880c HPN |
2074 | elimination. There is no BLOCK_FOR_INSN field in a barrier. */ |
2075 | if (!BARRIER_P (x) && BLOCK_FOR_INSN (x) != bb) | |
5f0d2358 RK |
2076 | { |
2077 | debug_rtx (x); | |
2078 | if (! BLOCK_FOR_INSN (x)) | |
2079 | error | |
2080 | ("insn %d inside basic block %d but block_for_insn is NULL", | |
0b17ab2f | 2081 | INSN_UID (x), bb->index); |
5f0d2358 RK |
2082 | else |
2083 | error | |
2084 | ("insn %d inside basic block %d but block_for_insn is %i", | |
0b17ab2f | 2085 | INSN_UID (x), bb->index, BLOCK_FOR_INSN (x)->index); |
5f0d2358 RK |
2086 | |
2087 | err = 1; | |
2088 | } | |
ca6c03ca JH |
2089 | |
2090 | /* OK pointers are correct. Now check the header of basic | |
2091 | block. It ought to contain optional CODE_LABEL followed | |
2092 | by NOTE_BASIC_BLOCK. */ | |
a813c111 | 2093 | x = BB_HEAD (bb); |
4b4bf941 | 2094 | if (LABEL_P (x)) |
ca6c03ca | 2095 | { |
a813c111 | 2096 | if (BB_END (bb) == x) |
ca6c03ca JH |
2097 | { |
2098 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 2099 | bb->index); |
ca6c03ca JH |
2100 | err = 1; |
2101 | } | |
5f0d2358 | 2102 | |
ca6c03ca JH |
2103 | x = NEXT_INSN (x); |
2104 | } | |
5f0d2358 | 2105 | |
ca6c03ca JH |
2106 | if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb) |
2107 | { | |
2108 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 2109 | bb->index); |
ca6c03ca JH |
2110 | err = 1; |
2111 | } | |
2112 | ||
a813c111 | 2113 | if (BB_END (bb) == x) |
49243025 | 2114 | /* Do checks for empty blocks here. */ |
5f0d2358 | 2115 | ; |
ca6c03ca | 2116 | else |
5f0d2358 RK |
2117 | for (x = NEXT_INSN (x); x; x = NEXT_INSN (x)) |
2118 | { | |
2119 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2120 | { | |
2121 | error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d", | |
0b17ab2f | 2122 | INSN_UID (x), bb->index); |
5f0d2358 RK |
2123 | err = 1; |
2124 | } | |
2125 | ||
a813c111 | 2126 | if (x == BB_END (bb)) |
5f0d2358 | 2127 | break; |
ca6c03ca | 2128 | |
83fd323c | 2129 | if (control_flow_insn_p (x)) |
5f0d2358 | 2130 | { |
0b17ab2f | 2131 | error ("in basic block %d:", bb->index); |
5f0d2358 RK |
2132 | fatal_insn ("flow control insn inside a basic block", x); |
2133 | } | |
2134 | } | |
ca6c03ca JH |
2135 | } |
2136 | ||
10e9fecc JH |
2137 | /* Clean up. */ |
2138 | free (bb_info); | |
2139 | return err; | |
2140 | } | |
5f0d2358 | 2141 | |
10e9fecc JH |
2142 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
2143 | cfglayout RTL. | |
5f0d2358 | 2144 | |
10e9fecc JH |
2145 | Currently it does following checks: |
2146 | - all checks of rtl_verify_flow_info_1 | |
2147 | - check that all insns are in the basic blocks | |
2148 | (except the switch handling code, barriers and notes) | |
2149 | - check that all returns are followed by barriers | |
2150 | - check that all fallthru edge points to the adjacent blocks. */ | |
2151 | static int | |
d329e058 | 2152 | rtl_verify_flow_info (void) |
10e9fecc JH |
2153 | { |
2154 | basic_block bb; | |
2155 | int err = rtl_verify_flow_info_1 (); | |
2156 | rtx x; | |
2157 | int num_bb_notes; | |
2158 | const rtx rtx_first = get_insns (); | |
2159 | basic_block last_bb_seen = ENTRY_BLOCK_PTR, curr_bb = NULL; | |
ca6c03ca | 2160 | |
10e9fecc JH |
2161 | FOR_EACH_BB_REVERSE (bb) |
2162 | { | |
2163 | edge e; | |
628f6a4e BE |
2164 | edge_iterator ei; |
2165 | ||
a00d11f0 JH |
2166 | if (bb->predictions) |
2167 | { | |
2168 | error ("bb prediction set for block %i, but it is not used in RTL land", bb->index); | |
2169 | err = 1; | |
2170 | } | |
2171 | ||
628f6a4e | 2172 | FOR_EACH_EDGE (e, ei, bb->succs) |
10e9fecc JH |
2173 | if (e->flags & EDGE_FALLTHRU) |
2174 | break; | |
2175 | if (!e) | |
2176 | { | |
2177 | rtx insn; | |
2178 | ||
2179 | /* Ensure existence of barrier in BB with no fallthru edges. */ | |
4b4bf941 | 2180 | for (insn = BB_END (bb); !insn || !BARRIER_P (insn); |
10e9fecc JH |
2181 | insn = NEXT_INSN (insn)) |
2182 | if (!insn | |
4b4bf941 | 2183 | || (NOTE_P (insn) |
10e9fecc JH |
2184 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_BASIC_BLOCK)) |
2185 | { | |
2186 | error ("missing barrier after block %i", bb->index); | |
2187 | err = 1; | |
2188 | break; | |
2189 | } | |
2190 | } | |
2191 | else if (e->src != ENTRY_BLOCK_PTR | |
2192 | && e->dest != EXIT_BLOCK_PTR) | |
2193 | { | |
2194 | rtx insn; | |
2195 | ||
2196 | if (e->src->next_bb != e->dest) | |
2197 | { | |
2198 | error | |
2199 | ("verify_flow_info: Incorrect blocks for fallthru %i->%i", | |
2200 | e->src->index, e->dest->index); | |
2201 | err = 1; | |
2202 | } | |
2203 | else | |
a813c111 | 2204 | for (insn = NEXT_INSN (BB_END (e->src)); insn != BB_HEAD (e->dest); |
10e9fecc | 2205 | insn = NEXT_INSN (insn)) |
6be85b25 | 2206 | if (BARRIER_P (insn) || INSN_P (insn)) |
10e9fecc JH |
2207 | { |
2208 | error ("verify_flow_info: Incorrect fallthru %i->%i", | |
2209 | e->src->index, e->dest->index); | |
2210 | fatal_insn ("wrong insn in the fallthru edge", insn); | |
2211 | err = 1; | |
2212 | } | |
2213 | } | |
2214 | } | |
ca6c03ca | 2215 | |
ca6c03ca | 2216 | num_bb_notes = 0; |
e0082a72 ZD |
2217 | last_bb_seen = ENTRY_BLOCK_PTR; |
2218 | ||
5f0d2358 | 2219 | for (x = rtx_first; x; x = NEXT_INSN (x)) |
ca6c03ca JH |
2220 | { |
2221 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2222 | { | |
bf77398c | 2223 | bb = NOTE_BASIC_BLOCK (x); |
5f0d2358 | 2224 | |
ca6c03ca | 2225 | num_bb_notes++; |
e0082a72 | 2226 | if (bb != last_bb_seen->next_bb) |
10e9fecc | 2227 | internal_error ("basic blocks not laid down consecutively"); |
ca6c03ca | 2228 | |
10e9fecc | 2229 | curr_bb = last_bb_seen = bb; |
ca6c03ca JH |
2230 | } |
2231 | ||
10e9fecc | 2232 | if (!curr_bb) |
ca6c03ca JH |
2233 | { |
2234 | switch (GET_CODE (x)) | |
2235 | { | |
2236 | case BARRIER: | |
2237 | case NOTE: | |
2238 | break; | |
2239 | ||
2240 | case CODE_LABEL: | |
666c27b9 | 2241 | /* An addr_vec is placed outside any basic block. */ |
ca6c03ca | 2242 | if (NEXT_INSN (x) |
4b4bf941 | 2243 | && JUMP_P (NEXT_INSN (x)) |
ca6c03ca JH |
2244 | && (GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_DIFF_VEC |
2245 | || GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_VEC)) | |
5f0d2358 | 2246 | x = NEXT_INSN (x); |
ca6c03ca JH |
2247 | |
2248 | /* But in any case, non-deletable labels can appear anywhere. */ | |
2249 | break; | |
2250 | ||
2251 | default: | |
1f978f5f | 2252 | fatal_insn ("insn outside basic block", x); |
ca6c03ca JH |
2253 | } |
2254 | } | |
2255 | ||
26cae194 | 2256 | if (JUMP_P (x) |
ca6c03ca | 2257 | && returnjump_p (x) && ! condjump_p (x) |
4b4bf941 | 2258 | && ! (NEXT_INSN (x) && BARRIER_P (NEXT_INSN (x)))) |
1f978f5f | 2259 | fatal_insn ("return not followed by barrier", x); |
a813c111 | 2260 | if (curr_bb && x == BB_END (curr_bb)) |
10e9fecc | 2261 | curr_bb = NULL; |
ca6c03ca JH |
2262 | } |
2263 | ||
24bd1a0b | 2264 | if (num_bb_notes != n_basic_blocks - NUM_FIXED_BLOCKS) |
ca6c03ca | 2265 | internal_error |
0b17ab2f RH |
2266 | ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)", |
2267 | num_bb_notes, n_basic_blocks); | |
ca6c03ca | 2268 | |
10e9fecc | 2269 | return err; |
ca6c03ca JH |
2270 | } |
2271 | \f | |
eaec9b3d | 2272 | /* Assume that the preceding pass has possibly eliminated jump instructions |
ca6c03ca JH |
2273 | or converted the unconditional jumps. Eliminate the edges from CFG. |
2274 | Return true if any edges are eliminated. */ | |
2275 | ||
2276 | bool | |
d329e058 | 2277 | purge_dead_edges (basic_block bb) |
ca6c03ca | 2278 | { |
628f6a4e | 2279 | edge e; |
a813c111 | 2280 | rtx insn = BB_END (bb), note; |
ca6c03ca | 2281 | bool purged = false; |
628f6a4e BE |
2282 | bool found; |
2283 | edge_iterator ei; | |
ca6c03ca | 2284 | |
70da1d03 | 2285 | /* If this instruction cannot trap, remove REG_EH_REGION notes. */ |
4b4bf941 | 2286 | if (NONJUMP_INSN_P (insn) |
70da1d03 JH |
2287 | && (note = find_reg_note (insn, REG_EH_REGION, NULL))) |
2288 | { | |
2289 | rtx eqnote; | |
2290 | ||
2291 | if (! may_trap_p (PATTERN (insn)) | |
2292 | || ((eqnote = find_reg_equal_equiv_note (insn)) | |
2293 | && ! may_trap_p (XEXP (eqnote, 0)))) | |
2294 | remove_note (insn, note); | |
2295 | } | |
2296 | ||
546c093e | 2297 | /* Cleanup abnormal edges caused by exceptions or non-local gotos. */ |
628f6a4e | 2298 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
546c093e | 2299 | { |
e5f9a909 JW |
2300 | /* There are three types of edges we need to handle correctly here: EH |
2301 | edges, abnormal call EH edges, and abnormal call non-EH edges. The | |
2302 | latter can appear when nonlocal gotos are used. */ | |
2303 | if (e->flags & EDGE_EH) | |
546c093e | 2304 | { |
e5f9a909 JW |
2305 | if (can_throw_internal (BB_END (bb)) |
2306 | /* If this is a call edge, verify that this is a call insn. */ | |
2307 | && (! (e->flags & EDGE_ABNORMAL_CALL) | |
2308 | || CALL_P (BB_END (bb)))) | |
628f6a4e BE |
2309 | { |
2310 | ei_next (&ei); | |
2311 | continue; | |
2312 | } | |
546c093e | 2313 | } |
e5f9a909 | 2314 | else if (e->flags & EDGE_ABNORMAL_CALL) |
546c093e | 2315 | { |
e5f9a909 JW |
2316 | if (CALL_P (BB_END (bb)) |
2317 | && (! (note = find_reg_note (insn, REG_EH_REGION, NULL)) | |
2318 | || INTVAL (XEXP (note, 0)) >= 0)) | |
628f6a4e BE |
2319 | { |
2320 | ei_next (&ei); | |
2321 | continue; | |
2322 | } | |
546c093e RH |
2323 | } |
2324 | else | |
628f6a4e BE |
2325 | { |
2326 | ei_next (&ei); | |
2327 | continue; | |
2328 | } | |
546c093e RH |
2329 | |
2330 | remove_edge (e); | |
2331 | bb->flags |= BB_DIRTY; | |
2332 | purged = true; | |
2333 | } | |
5f0d2358 | 2334 | |
4b4bf941 | 2335 | if (JUMP_P (insn)) |
ca6c03ca JH |
2336 | { |
2337 | rtx note; | |
2338 | edge b,f; | |
628f6a4e | 2339 | edge_iterator ei; |
5f0d2358 | 2340 | |
ca6c03ca JH |
2341 | /* We do care only about conditional jumps and simplejumps. */ |
2342 | if (!any_condjump_p (insn) | |
2343 | && !returnjump_p (insn) | |
2344 | && !simplejump_p (insn)) | |
c51d95ec | 2345 | return purged; |
5f0d2358 | 2346 | |
5a1a3e5e JH |
2347 | /* Branch probability/prediction notes are defined only for |
2348 | condjumps. We've possibly turned condjump into simplejump. */ | |
2349 | if (simplejump_p (insn)) | |
2350 | { | |
2351 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2352 | if (note) | |
2353 | remove_note (insn, note); | |
2354 | while ((note = find_reg_note (insn, REG_BR_PRED, NULL))) | |
2355 | remove_note (insn, note); | |
2356 | } | |
2357 | ||
628f6a4e | 2358 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
ca6c03ca | 2359 | { |
7fcd7218 JH |
2360 | /* Avoid abnormal flags to leak from computed jumps turned |
2361 | into simplejumps. */ | |
f87c27b4 | 2362 | |
0e1638d4 | 2363 | e->flags &= ~EDGE_ABNORMAL; |
7fcd7218 | 2364 | |
5a566bed MM |
2365 | /* See if this edge is one we should keep. */ |
2366 | if ((e->flags & EDGE_FALLTHRU) && any_condjump_p (insn)) | |
2367 | /* A conditional jump can fall through into the next | |
2368 | block, so we should keep the edge. */ | |
628f6a4e BE |
2369 | { |
2370 | ei_next (&ei); | |
2371 | continue; | |
2372 | } | |
5f0d2358 | 2373 | else if (e->dest != EXIT_BLOCK_PTR |
a813c111 | 2374 | && BB_HEAD (e->dest) == JUMP_LABEL (insn)) |
5a566bed MM |
2375 | /* If the destination block is the target of the jump, |
2376 | keep the edge. */ | |
628f6a4e BE |
2377 | { |
2378 | ei_next (&ei); | |
2379 | continue; | |
2380 | } | |
5a566bed MM |
2381 | else if (e->dest == EXIT_BLOCK_PTR && returnjump_p (insn)) |
2382 | /* If the destination block is the exit block, and this | |
2383 | instruction is a return, then keep the edge. */ | |
628f6a4e BE |
2384 | { |
2385 | ei_next (&ei); | |
2386 | continue; | |
2387 | } | |
5a566bed MM |
2388 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) |
2389 | /* Keep the edges that correspond to exceptions thrown by | |
0b75beaa EB |
2390 | this instruction and rematerialize the EDGE_ABNORMAL |
2391 | flag we just cleared above. */ | |
2392 | { | |
2393 | e->flags |= EDGE_ABNORMAL; | |
628f6a4e | 2394 | ei_next (&ei); |
0b75beaa EB |
2395 | continue; |
2396 | } | |
5f0d2358 | 2397 | |
5a566bed | 2398 | /* We do not need this edge. */ |
c51d95ec | 2399 | bb->flags |= BB_DIRTY; |
ca6c03ca JH |
2400 | purged = true; |
2401 | remove_edge (e); | |
2402 | } | |
5f0d2358 | 2403 | |
628f6a4e | 2404 | if (EDGE_COUNT (bb->succs) == 0 || !purged) |
c51d95ec | 2405 | return purged; |
5f0d2358 | 2406 | |
c263766c RH |
2407 | if (dump_file) |
2408 | fprintf (dump_file, "Purged edges from bb %i\n", bb->index); | |
5f0d2358 | 2409 | |
ca6c03ca JH |
2410 | if (!optimize) |
2411 | return purged; | |
2412 | ||
2413 | /* Redistribute probabilities. */ | |
c5cbcccf | 2414 | if (single_succ_p (bb)) |
ca6c03ca | 2415 | { |
c5cbcccf ZD |
2416 | single_succ_edge (bb)->probability = REG_BR_PROB_BASE; |
2417 | single_succ_edge (bb)->count = bb->count; | |
f87c27b4 | 2418 | } |
ca6c03ca JH |
2419 | else |
2420 | { | |
2421 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2422 | if (!note) | |
2423 | return purged; | |
5f0d2358 | 2424 | |
ca6c03ca JH |
2425 | b = BRANCH_EDGE (bb); |
2426 | f = FALLTHRU_EDGE (bb); | |
2427 | b->probability = INTVAL (XEXP (note, 0)); | |
2428 | f->probability = REG_BR_PROB_BASE - b->probability; | |
2429 | b->count = bb->count * b->probability / REG_BR_PROB_BASE; | |
2430 | f->count = bb->count * f->probability / REG_BR_PROB_BASE; | |
2431 | } | |
5f0d2358 | 2432 | |
ca6c03ca JH |
2433 | return purged; |
2434 | } | |
4b4bf941 | 2435 | else if (CALL_P (insn) && SIBLING_CALL_P (insn)) |
1722c2c8 RH |
2436 | { |
2437 | /* First, there should not be any EH or ABCALL edges resulting | |
2438 | from non-local gotos and the like. If there were, we shouldn't | |
2439 | have created the sibcall in the first place. Second, there | |
2440 | should of course never have been a fallthru edge. */ | |
c5cbcccf ZD |
2441 | gcc_assert (single_succ_p (bb)); |
2442 | gcc_assert (single_succ_edge (bb)->flags | |
2443 | == (EDGE_SIBCALL | EDGE_ABNORMAL)); | |
1722c2c8 RH |
2444 | |
2445 | return 0; | |
2446 | } | |
ca6c03ca | 2447 | |
ca6c03ca JH |
2448 | /* If we don't see a jump insn, we don't know exactly why the block would |
2449 | have been broken at this point. Look for a simple, non-fallthru edge, | |
2450 | as these are only created by conditional branches. If we find such an | |
2451 | edge we know that there used to be a jump here and can then safely | |
2452 | remove all non-fallthru edges. */ | |
628f6a4e BE |
2453 | found = false; |
2454 | FOR_EACH_EDGE (e, ei, bb->succs) | |
2455 | if (! (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU))) | |
2456 | { | |
2457 | found = true; | |
2458 | break; | |
2459 | } | |
5f0d2358 | 2460 | |
628f6a4e | 2461 | if (!found) |
ca6c03ca | 2462 | return purged; |
5f0d2358 | 2463 | |
2afa8dce DB |
2464 | /* Remove all but the fake and fallthru edges. The fake edge may be |
2465 | the only successor for this block in the case of noreturn | |
2466 | calls. */ | |
628f6a4e | 2467 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
ca6c03ca | 2468 | { |
2afa8dce | 2469 | if (!(e->flags & (EDGE_FALLTHRU | EDGE_FAKE))) |
c51d95ec JH |
2470 | { |
2471 | bb->flags |= BB_DIRTY; | |
2472 | remove_edge (e); | |
2473 | purged = true; | |
2474 | } | |
628f6a4e BE |
2475 | else |
2476 | ei_next (&ei); | |
ca6c03ca | 2477 | } |
5f0d2358 | 2478 | |
c5cbcccf | 2479 | gcc_assert (single_succ_p (bb)); |
5f0d2358 | 2480 | |
c5cbcccf ZD |
2481 | single_succ_edge (bb)->probability = REG_BR_PROB_BASE; |
2482 | single_succ_edge (bb)->count = bb->count; | |
ca6c03ca | 2483 | |
c263766c RH |
2484 | if (dump_file) |
2485 | fprintf (dump_file, "Purged non-fallthru edges from bb %i\n", | |
0b17ab2f | 2486 | bb->index); |
ca6c03ca JH |
2487 | return purged; |
2488 | } | |
2489 | ||
5f0d2358 RK |
2490 | /* Search all basic blocks for potentially dead edges and purge them. Return |
2491 | true if some edge has been eliminated. */ | |
ca6c03ca JH |
2492 | |
2493 | bool | |
25cd19de | 2494 | purge_all_dead_edges (void) |
ca6c03ca | 2495 | { |
e0082a72 | 2496 | int purged = false; |
e0082a72 | 2497 | basic_block bb; |
473fb060 | 2498 | |
e0082a72 | 2499 | FOR_EACH_BB (bb) |
473fb060 | 2500 | { |
e0082a72 | 2501 | bool purged_here = purge_dead_edges (bb); |
5f0d2358 | 2502 | |
473fb060 | 2503 | purged |= purged_here; |
473fb060 | 2504 | } |
5f0d2358 | 2505 | |
ca6c03ca JH |
2506 | return purged; |
2507 | } | |
9ee634e3 JH |
2508 | |
2509 | /* Same as split_block but update cfg_layout structures. */ | |
f470c378 ZD |
2510 | |
2511 | static basic_block | |
d329e058 | 2512 | cfg_layout_split_block (basic_block bb, void *insnp) |
9ee634e3 JH |
2513 | { |
2514 | rtx insn = insnp; | |
f470c378 | 2515 | basic_block new_bb = rtl_split_block (bb, insn); |
9ee634e3 | 2516 | |
370369e1 JH |
2517 | new_bb->il.rtl->footer = bb->il.rtl->footer; |
2518 | bb->il.rtl->footer = NULL; | |
9ee634e3 | 2519 | |
f470c378 | 2520 | return new_bb; |
9ee634e3 JH |
2521 | } |
2522 | ||
2523 | ||
2524 | /* Redirect Edge to DEST. */ | |
6de9cd9a | 2525 | static edge |
d329e058 | 2526 | cfg_layout_redirect_edge_and_branch (edge e, basic_block dest) |
9ee634e3 JH |
2527 | { |
2528 | basic_block src = e->src; | |
6de9cd9a | 2529 | edge ret; |
9ee634e3 | 2530 | |
bc35512f | 2531 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
6de9cd9a | 2532 | return NULL; |
bc35512f | 2533 | |
3348b696 | 2534 | if (e->dest == dest) |
6de9cd9a | 2535 | return e; |
bc35512f | 2536 | |
3348b696 | 2537 | if (e->src != ENTRY_BLOCK_PTR |
6de9cd9a | 2538 | && (ret = try_redirect_by_replacing_jump (e, dest, true))) |
f345f21a JH |
2539 | { |
2540 | src->flags |= BB_DIRTY; | |
6de9cd9a | 2541 | return ret; |
f345f21a | 2542 | } |
bc35512f JH |
2543 | |
2544 | if (e->src == ENTRY_BLOCK_PTR | |
2545 | && (e->flags & EDGE_FALLTHRU) && !(e->flags & EDGE_COMPLEX)) | |
2546 | { | |
c263766c RH |
2547 | if (dump_file) |
2548 | fprintf (dump_file, "Redirecting entry edge from bb %i to %i\n", | |
bc35512f JH |
2549 | e->src->index, dest->index); |
2550 | ||
f345f21a | 2551 | e->src->flags |= BB_DIRTY; |
bc35512f | 2552 | redirect_edge_succ (e, dest); |
6de9cd9a | 2553 | return e; |
bc35512f JH |
2554 | } |
2555 | ||
9ee634e3 JH |
2556 | /* Redirect_edge_and_branch may decide to turn branch into fallthru edge |
2557 | in the case the basic block appears to be in sequence. Avoid this | |
2558 | transformation. */ | |
2559 | ||
9ee634e3 JH |
2560 | if (e->flags & EDGE_FALLTHRU) |
2561 | { | |
2562 | /* Redirect any branch edges unified with the fallthru one. */ | |
4b4bf941 | 2563 | if (JUMP_P (BB_END (src)) |
432f982f JH |
2564 | && label_is_jump_target_p (BB_HEAD (e->dest), |
2565 | BB_END (src))) | |
9ee634e3 | 2566 | { |
341c100f NS |
2567 | edge redirected; |
2568 | ||
c263766c RH |
2569 | if (dump_file) |
2570 | fprintf (dump_file, "Fallthru edge unified with branch " | |
432f982f JH |
2571 | "%i->%i redirected to %i\n", |
2572 | e->src->index, e->dest->index, dest->index); | |
2573 | e->flags &= ~EDGE_FALLTHRU; | |
341c100f NS |
2574 | redirected = redirect_branch_edge (e, dest); |
2575 | gcc_assert (redirected); | |
432f982f | 2576 | e->flags |= EDGE_FALLTHRU; |
f345f21a | 2577 | e->src->flags |= BB_DIRTY; |
6de9cd9a | 2578 | return e; |
9ee634e3 JH |
2579 | } |
2580 | /* In case we are redirecting fallthru edge to the branch edge | |
2581 | of conditional jump, remove it. */ | |
628f6a4e | 2582 | if (EDGE_COUNT (src->succs) == 2) |
9ee634e3 | 2583 | { |
03101c6f KH |
2584 | /* Find the edge that is different from E. */ |
2585 | edge s = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e); | |
628f6a4e | 2586 | |
9ee634e3 | 2587 | if (s->dest == dest |
a813c111 SB |
2588 | && any_condjump_p (BB_END (src)) |
2589 | && onlyjump_p (BB_END (src))) | |
2590 | delete_insn (BB_END (src)); | |
9ee634e3 | 2591 | } |
6de9cd9a | 2592 | ret = redirect_edge_succ_nodup (e, dest); |
c263766c RH |
2593 | if (dump_file) |
2594 | fprintf (dump_file, "Fallthru edge %i->%i redirected to %i\n", | |
bc35512f | 2595 | e->src->index, e->dest->index, dest->index); |
9ee634e3 JH |
2596 | } |
2597 | else | |
bc35512f | 2598 | ret = redirect_branch_edge (e, dest); |
9ee634e3 JH |
2599 | |
2600 | /* We don't want simplejumps in the insn stream during cfglayout. */ | |
341c100f | 2601 | gcc_assert (!simplejump_p (BB_END (src))); |
9ee634e3 | 2602 | |
f345f21a | 2603 | src->flags |= BB_DIRTY; |
9ee634e3 JH |
2604 | return ret; |
2605 | } | |
2606 | ||
2607 | /* Simple wrapper as we always can redirect fallthru edges. */ | |
2608 | static basic_block | |
d329e058 | 2609 | cfg_layout_redirect_edge_and_branch_force (edge e, basic_block dest) |
9ee634e3 | 2610 | { |
341c100f NS |
2611 | edge redirected = cfg_layout_redirect_edge_and_branch (e, dest); |
2612 | ||
2613 | gcc_assert (redirected); | |
9ee634e3 JH |
2614 | return NULL; |
2615 | } | |
2616 | ||
f470c378 ZD |
2617 | /* Same as delete_basic_block but update cfg_layout structures. */ |
2618 | ||
9ee634e3 | 2619 | static void |
d329e058 | 2620 | cfg_layout_delete_block (basic_block bb) |
9ee634e3 | 2621 | { |
a813c111 | 2622 | rtx insn, next, prev = PREV_INSN (BB_HEAD (bb)), *to, remaints; |
9ee634e3 | 2623 | |
370369e1 | 2624 | if (bb->il.rtl->header) |
9ee634e3 | 2625 | { |
a813c111 | 2626 | next = BB_HEAD (bb); |
9ee634e3 | 2627 | if (prev) |
370369e1 | 2628 | NEXT_INSN (prev) = bb->il.rtl->header; |
9ee634e3 | 2629 | else |
370369e1 JH |
2630 | set_first_insn (bb->il.rtl->header); |
2631 | PREV_INSN (bb->il.rtl->header) = prev; | |
2632 | insn = bb->il.rtl->header; | |
9ee634e3 JH |
2633 | while (NEXT_INSN (insn)) |
2634 | insn = NEXT_INSN (insn); | |
2635 | NEXT_INSN (insn) = next; | |
2636 | PREV_INSN (next) = insn; | |
2637 | } | |
a813c111 | 2638 | next = NEXT_INSN (BB_END (bb)); |
370369e1 | 2639 | if (bb->il.rtl->footer) |
9ee634e3 | 2640 | { |
370369e1 | 2641 | insn = bb->il.rtl->footer; |
bc35512f JH |
2642 | while (insn) |
2643 | { | |
4b4bf941 | 2644 | if (BARRIER_P (insn)) |
bc35512f JH |
2645 | { |
2646 | if (PREV_INSN (insn)) | |
2647 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
2648 | else | |
370369e1 | 2649 | bb->il.rtl->footer = NEXT_INSN (insn); |
bc35512f JH |
2650 | if (NEXT_INSN (insn)) |
2651 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
2652 | } | |
4b4bf941 | 2653 | if (LABEL_P (insn)) |
bc35512f JH |
2654 | break; |
2655 | insn = NEXT_INSN (insn); | |
2656 | } | |
370369e1 | 2657 | if (bb->il.rtl->footer) |
bc35512f | 2658 | { |
a813c111 | 2659 | insn = BB_END (bb); |
370369e1 JH |
2660 | NEXT_INSN (insn) = bb->il.rtl->footer; |
2661 | PREV_INSN (bb->il.rtl->footer) = insn; | |
bc35512f JH |
2662 | while (NEXT_INSN (insn)) |
2663 | insn = NEXT_INSN (insn); | |
2664 | NEXT_INSN (insn) = next; | |
2665 | if (next) | |
2666 | PREV_INSN (next) = insn; | |
2667 | else | |
2668 | set_last_insn (insn); | |
2669 | } | |
9ee634e3 JH |
2670 | } |
2671 | if (bb->next_bb != EXIT_BLOCK_PTR) | |
370369e1 | 2672 | to = &bb->next_bb->il.rtl->header; |
9ee634e3 JH |
2673 | else |
2674 | to = &cfg_layout_function_footer; | |
997de8ed | 2675 | |
9ee634e3 JH |
2676 | rtl_delete_block (bb); |
2677 | ||
2678 | if (prev) | |
2679 | prev = NEXT_INSN (prev); | |
d329e058 | 2680 | else |
9ee634e3 JH |
2681 | prev = get_insns (); |
2682 | if (next) | |
2683 | next = PREV_INSN (next); | |
d329e058 | 2684 | else |
9ee634e3 JH |
2685 | next = get_last_insn (); |
2686 | ||
2687 | if (next && NEXT_INSN (next) != prev) | |
2688 | { | |
2689 | remaints = unlink_insn_chain (prev, next); | |
2690 | insn = remaints; | |
2691 | while (NEXT_INSN (insn)) | |
2692 | insn = NEXT_INSN (insn); | |
2693 | NEXT_INSN (insn) = *to; | |
2694 | if (*to) | |
2695 | PREV_INSN (*to) = insn; | |
2696 | *to = remaints; | |
2697 | } | |
2698 | } | |
2699 | ||
beb235f8 | 2700 | /* Return true when blocks A and B can be safely merged. */ |
bc35512f JH |
2701 | static bool |
2702 | cfg_layout_can_merge_blocks_p (basic_block a, basic_block b) | |
2703 | { | |
750054a2 CT |
2704 | /* If we are partitioning hot/cold basic blocks, we don't want to |
2705 | mess up unconditional or indirect jumps that cross between hot | |
076c7ab8 ZW |
2706 | and cold sections. |
2707 | ||
8e8d5162 CT |
2708 | Basic block partitioning may result in some jumps that appear to |
2709 | be optimizable (or blocks that appear to be mergeable), but which really | |
2710 | must be left untouched (they are required to make it safely across | |
2711 | partition boundaries). See the comments at the top of | |
2712 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ | |
2713 | ||
87c8b4be | 2714 | if (BB_PARTITION (a) != BB_PARTITION (b)) |
076c7ab8 | 2715 | return false; |
750054a2 | 2716 | |
bc35512f | 2717 | /* There must be exactly one edge in between the blocks. */ |
c5cbcccf ZD |
2718 | return (single_succ_p (a) |
2719 | && single_succ (a) == b | |
2720 | && single_pred_p (b) == 1 | |
628f6a4e | 2721 | && a != b |
bc35512f | 2722 | /* Must be simple edge. */ |
c5cbcccf | 2723 | && !(single_succ_edge (a)->flags & EDGE_COMPLEX) |
bc35512f JH |
2724 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR |
2725 | /* If the jump insn has side effects, | |
2726 | we can't kill the edge. */ | |
4b4bf941 | 2727 | && (!JUMP_P (BB_END (a)) |
e24e7211 | 2728 | || (reload_completed |
a813c111 | 2729 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f JH |
2730 | } |
2731 | ||
41806d92 NS |
2732 | /* Merge block A and B. The blocks must be mergeable. */ |
2733 | ||
bc35512f JH |
2734 | static void |
2735 | cfg_layout_merge_blocks (basic_block a, basic_block b) | |
2736 | { | |
2737 | #ifdef ENABLE_CHECKING | |
341c100f | 2738 | gcc_assert (cfg_layout_can_merge_blocks_p (a, b)); |
bc35512f JH |
2739 | #endif |
2740 | ||
2741 | /* If there was a CODE_LABEL beginning B, delete it. */ | |
4b4bf941 | 2742 | if (LABEL_P (BB_HEAD (b))) |
2c97f8e4 RH |
2743 | { |
2744 | /* This might have been an EH label that no longer has incoming | |
2745 | EH edges. Update data structures to match. */ | |
2746 | maybe_remove_eh_handler (BB_HEAD (b)); | |
2747 | ||
2748 | delete_insn (BB_HEAD (b)); | |
2749 | } | |
bc35512f JH |
2750 | |
2751 | /* We should have fallthru edge in a, or we can do dummy redirection to get | |
2752 | it cleaned up. */ | |
4b4bf941 | 2753 | if (JUMP_P (BB_END (a))) |
628f6a4e | 2754 | try_redirect_by_replacing_jump (EDGE_SUCC (a, 0), b, true); |
341c100f | 2755 | gcc_assert (!JUMP_P (BB_END (a))); |
bc35512f JH |
2756 | |
2757 | /* Possible line number notes should appear in between. */ | |
370369e1 | 2758 | if (b->il.rtl->header) |
bc35512f | 2759 | { |
a813c111 | 2760 | rtx first = BB_END (a), last; |
bc35512f | 2761 | |
370369e1 | 2762 | last = emit_insn_after_noloc (b->il.rtl->header, BB_END (a)); |
bc35512f | 2763 | delete_insn_chain (NEXT_INSN (first), last); |
370369e1 | 2764 | b->il.rtl->header = NULL; |
bc35512f JH |
2765 | } |
2766 | ||
2767 | /* In the case basic blocks are not adjacent, move them around. */ | |
a813c111 | 2768 | if (NEXT_INSN (BB_END (a)) != BB_HEAD (b)) |
bc35512f | 2769 | { |
a813c111 | 2770 | rtx first = unlink_insn_chain (BB_HEAD (b), BB_END (b)); |
bc35512f | 2771 | |
a7102479 | 2772 | emit_insn_after_noloc (first, BB_END (a)); |
bc35512f JH |
2773 | /* Skip possible DELETED_LABEL insn. */ |
2774 | if (!NOTE_INSN_BASIC_BLOCK_P (first)) | |
2775 | first = NEXT_INSN (first); | |
341c100f | 2776 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (first)); |
a813c111 | 2777 | BB_HEAD (b) = NULL; |
bc35512f JH |
2778 | delete_insn (first); |
2779 | } | |
2780 | /* Otherwise just re-associate the instructions. */ | |
2781 | else | |
2782 | { | |
2783 | rtx insn; | |
2784 | ||
a813c111 SB |
2785 | for (insn = BB_HEAD (b); |
2786 | insn != NEXT_INSN (BB_END (b)); | |
2787 | insn = NEXT_INSN (insn)) | |
bc35512f | 2788 | set_block_for_insn (insn, a); |
a813c111 | 2789 | insn = BB_HEAD (b); |
bc35512f JH |
2790 | /* Skip possible DELETED_LABEL insn. */ |
2791 | if (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
2792 | insn = NEXT_INSN (insn); | |
341c100f | 2793 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn)); |
a813c111 SB |
2794 | BB_HEAD (b) = NULL; |
2795 | BB_END (a) = BB_END (b); | |
bc35512f JH |
2796 | delete_insn (insn); |
2797 | } | |
2798 | ||
2799 | /* Possible tablejumps and barriers should appear after the block. */ | |
370369e1 | 2800 | if (b->il.rtl->footer) |
bc35512f | 2801 | { |
370369e1 JH |
2802 | if (!a->il.rtl->footer) |
2803 | a->il.rtl->footer = b->il.rtl->footer; | |
bc35512f JH |
2804 | else |
2805 | { | |
370369e1 | 2806 | rtx last = a->il.rtl->footer; |
bc35512f JH |
2807 | |
2808 | while (NEXT_INSN (last)) | |
2809 | last = NEXT_INSN (last); | |
370369e1 JH |
2810 | NEXT_INSN (last) = b->il.rtl->footer; |
2811 | PREV_INSN (b->il.rtl->footer) = last; | |
bc35512f | 2812 | } |
370369e1 | 2813 | b->il.rtl->footer = NULL; |
bc35512f | 2814 | } |
5e2d947c | 2815 | a->il.rtl->global_live_at_end = b->il.rtl->global_live_at_end; |
bc35512f | 2816 | |
c263766c RH |
2817 | if (dump_file) |
2818 | fprintf (dump_file, "Merged blocks %d and %d.\n", | |
bc35512f | 2819 | a->index, b->index); |
bc35512f JH |
2820 | } |
2821 | ||
2822 | /* Split edge E. */ | |
f470c378 | 2823 | |
bc35512f JH |
2824 | static basic_block |
2825 | cfg_layout_split_edge (edge e) | |
2826 | { | |
bc35512f JH |
2827 | basic_block new_bb = |
2828 | create_basic_block (e->src != ENTRY_BLOCK_PTR | |
a813c111 | 2829 | ? NEXT_INSN (BB_END (e->src)) : get_insns (), |
bc35512f JH |
2830 | NULL_RTX, e->src); |
2831 | ||
af874237 JW |
2832 | /* ??? This info is likely going to be out of date very soon, but we must |
2833 | create it to avoid getting an ICE later. */ | |
5e2d947c | 2834 | if (e->dest->il.rtl->global_live_at_start) |
af874237 | 2835 | { |
5e2d947c JH |
2836 | new_bb->il.rtl->global_live_at_start = ALLOC_REG_SET (®_obstack); |
2837 | new_bb->il.rtl->global_live_at_end = ALLOC_REG_SET (®_obstack); | |
2838 | COPY_REG_SET (new_bb->il.rtl->global_live_at_start, | |
2839 | e->dest->il.rtl->global_live_at_start); | |
2840 | COPY_REG_SET (new_bb->il.rtl->global_live_at_end, | |
2841 | e->dest->il.rtl->global_live_at_start); | |
af874237 JW |
2842 | } |
2843 | ||
a9b2ee88 | 2844 | make_edge (new_bb, e->dest, EDGE_FALLTHRU); |
bc35512f JH |
2845 | redirect_edge_and_branch_force (e, new_bb); |
2846 | ||
2847 | return new_bb; | |
2848 | } | |
2849 | ||
f470c378 ZD |
2850 | /* Do postprocessing after making a forwarder block joined by edge FALLTHRU. */ |
2851 | ||
2852 | static void | |
2853 | rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED) | |
2854 | { | |
2855 | } | |
2856 | ||
6de9cd9a DN |
2857 | /* Return 1 if BB ends with a call, possibly followed by some |
2858 | instructions that must stay with the call, 0 otherwise. */ | |
2859 | ||
2860 | static bool | |
2861 | rtl_block_ends_with_call_p (basic_block bb) | |
2862 | { | |
2863 | rtx insn = BB_END (bb); | |
2864 | ||
4b4bf941 | 2865 | while (!CALL_P (insn) |
6de9cd9a DN |
2866 | && insn != BB_HEAD (bb) |
2867 | && keep_with_call_p (insn)) | |
2868 | insn = PREV_INSN (insn); | |
4b4bf941 | 2869 | return (CALL_P (insn)); |
6de9cd9a DN |
2870 | } |
2871 | ||
2872 | /* Return 1 if BB ends with a conditional branch, 0 otherwise. */ | |
2873 | ||
2874 | static bool | |
2875 | rtl_block_ends_with_condjump_p (basic_block bb) | |
2876 | { | |
2877 | return any_condjump_p (BB_END (bb)); | |
2878 | } | |
2879 | ||
2880 | /* Return true if we need to add fake edge to exit. | |
2881 | Helper function for rtl_flow_call_edges_add. */ | |
2882 | ||
2883 | static bool | |
2884 | need_fake_edge_p (rtx insn) | |
2885 | { | |
2886 | if (!INSN_P (insn)) | |
2887 | return false; | |
2888 | ||
4b4bf941 | 2889 | if ((CALL_P (insn) |
6de9cd9a DN |
2890 | && !SIBLING_CALL_P (insn) |
2891 | && !find_reg_note (insn, REG_NORETURN, NULL) | |
6de9cd9a DN |
2892 | && !CONST_OR_PURE_CALL_P (insn))) |
2893 | return true; | |
2894 | ||
2895 | return ((GET_CODE (PATTERN (insn)) == ASM_OPERANDS | |
2896 | && MEM_VOLATILE_P (PATTERN (insn))) | |
2897 | || (GET_CODE (PATTERN (insn)) == PARALLEL | |
2898 | && asm_noperands (insn) != -1 | |
2899 | && MEM_VOLATILE_P (XVECEXP (PATTERN (insn), 0, 0))) | |
2900 | || GET_CODE (PATTERN (insn)) == ASM_INPUT); | |
2901 | } | |
2902 | ||
2903 | /* Add fake edges to the function exit for any non constant and non noreturn | |
2904 | calls, volatile inline assembly in the bitmap of blocks specified by | |
2905 | BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks | |
2906 | that were split. | |
2907 | ||
2908 | The goal is to expose cases in which entering a basic block does not imply | |
2909 | that all subsequent instructions must be executed. */ | |
2910 | ||
2911 | static int | |
2912 | rtl_flow_call_edges_add (sbitmap blocks) | |
2913 | { | |
2914 | int i; | |
2915 | int blocks_split = 0; | |
2916 | int last_bb = last_basic_block; | |
2917 | bool check_last_block = false; | |
2918 | ||
24bd1a0b | 2919 | if (n_basic_blocks == NUM_FIXED_BLOCKS) |
6de9cd9a DN |
2920 | return 0; |
2921 | ||
2922 | if (! blocks) | |
2923 | check_last_block = true; | |
2924 | else | |
2925 | check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index); | |
2926 | ||
2927 | /* In the last basic block, before epilogue generation, there will be | |
2928 | a fallthru edge to EXIT. Special care is required if the last insn | |
2929 | of the last basic block is a call because make_edge folds duplicate | |
2930 | edges, which would result in the fallthru edge also being marked | |
2931 | fake, which would result in the fallthru edge being removed by | |
2932 | remove_fake_edges, which would result in an invalid CFG. | |
2933 | ||
2934 | Moreover, we can't elide the outgoing fake edge, since the block | |
2935 | profiler needs to take this into account in order to solve the minimal | |
2936 | spanning tree in the case that the call doesn't return. | |
2937 | ||
2938 | Handle this by adding a dummy instruction in a new last basic block. */ | |
2939 | if (check_last_block) | |
2940 | { | |
2941 | basic_block bb = EXIT_BLOCK_PTR->prev_bb; | |
2942 | rtx insn = BB_END (bb); | |
2943 | ||
2944 | /* Back up past insns that must be kept in the same block as a call. */ | |
2945 | while (insn != BB_HEAD (bb) | |
2946 | && keep_with_call_p (insn)) | |
2947 | insn = PREV_INSN (insn); | |
2948 | ||
2949 | if (need_fake_edge_p (insn)) | |
2950 | { | |
2951 | edge e; | |
2952 | ||
9ff3d2de JL |
2953 | e = find_edge (bb, EXIT_BLOCK_PTR); |
2954 | if (e) | |
2955 | { | |
2956 | insert_insn_on_edge (gen_rtx_USE (VOIDmode, const0_rtx), e); | |
2957 | commit_edge_insertions (); | |
2958 | } | |
6de9cd9a DN |
2959 | } |
2960 | } | |
2961 | ||
2962 | /* Now add fake edges to the function exit for any non constant | |
2963 | calls since there is no way that we can determine if they will | |
2964 | return or not... */ | |
2965 | ||
24bd1a0b | 2966 | for (i = NUM_FIXED_BLOCKS; i < last_bb; i++) |
6de9cd9a DN |
2967 | { |
2968 | basic_block bb = BASIC_BLOCK (i); | |
2969 | rtx insn; | |
2970 | rtx prev_insn; | |
2971 | ||
2972 | if (!bb) | |
2973 | continue; | |
2974 | ||
2975 | if (blocks && !TEST_BIT (blocks, i)) | |
2976 | continue; | |
2977 | ||
2978 | for (insn = BB_END (bb); ; insn = prev_insn) | |
2979 | { | |
2980 | prev_insn = PREV_INSN (insn); | |
2981 | if (need_fake_edge_p (insn)) | |
2982 | { | |
2983 | edge e; | |
2984 | rtx split_at_insn = insn; | |
2985 | ||
2986 | /* Don't split the block between a call and an insn that should | |
2987 | remain in the same block as the call. */ | |
4b4bf941 | 2988 | if (CALL_P (insn)) |
6de9cd9a DN |
2989 | while (split_at_insn != BB_END (bb) |
2990 | && keep_with_call_p (NEXT_INSN (split_at_insn))) | |
2991 | split_at_insn = NEXT_INSN (split_at_insn); | |
2992 | ||
2993 | /* The handling above of the final block before the epilogue | |
2994 | should be enough to verify that there is no edge to the exit | |
2995 | block in CFG already. Calling make_edge in such case would | |
2996 | cause us to mark that edge as fake and remove it later. */ | |
2997 | ||
2998 | #ifdef ENABLE_CHECKING | |
2999 | if (split_at_insn == BB_END (bb)) | |
628f6a4e | 3000 | { |
9ff3d2de JL |
3001 | e = find_edge (bb, EXIT_BLOCK_PTR); |
3002 | gcc_assert (e == NULL); | |
628f6a4e | 3003 | } |
6de9cd9a DN |
3004 | #endif |
3005 | ||
3006 | /* Note that the following may create a new basic block | |
3007 | and renumber the existing basic blocks. */ | |
3008 | if (split_at_insn != BB_END (bb)) | |
3009 | { | |
3010 | e = split_block (bb, split_at_insn); | |
3011 | if (e) | |
3012 | blocks_split++; | |
3013 | } | |
3014 | ||
3015 | make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE); | |
3016 | } | |
3017 | ||
3018 | if (insn == BB_HEAD (bb)) | |
3019 | break; | |
3020 | } | |
3021 | } | |
3022 | ||
3023 | if (blocks_split) | |
3024 | verify_flow_info (); | |
3025 | ||
3026 | return blocks_split; | |
3027 | } | |
3028 | ||
1cb7dfc3 | 3029 | /* Add COMP_RTX as a condition at end of COND_BB. FIRST_HEAD is |
315682fb | 3030 | the conditional branch target, SECOND_HEAD should be the fall-thru |
1cb7dfc3 MH |
3031 | there is no need to handle this here the loop versioning code handles |
3032 | this. the reason for SECON_HEAD is that it is needed for condition | |
3033 | in trees, and this should be of the same type since it is a hook. */ | |
3034 | static void | |
3035 | rtl_lv_add_condition_to_bb (basic_block first_head , | |
3036 | basic_block second_head ATTRIBUTE_UNUSED, | |
3037 | basic_block cond_bb, void *comp_rtx) | |
3038 | { | |
3039 | rtx label, seq, jump; | |
3040 | rtx op0 = XEXP ((rtx)comp_rtx, 0); | |
3041 | rtx op1 = XEXP ((rtx)comp_rtx, 1); | |
3042 | enum rtx_code comp = GET_CODE ((rtx)comp_rtx); | |
3043 | enum machine_mode mode; | |
3044 | ||
3045 | ||
3046 | label = block_label (first_head); | |
3047 | mode = GET_MODE (op0); | |
3048 | if (mode == VOIDmode) | |
3049 | mode = GET_MODE (op1); | |
3050 | ||
3051 | start_sequence (); | |
3052 | op0 = force_operand (op0, NULL_RTX); | |
3053 | op1 = force_operand (op1, NULL_RTX); | |
3054 | do_compare_rtx_and_jump (op0, op1, comp, 0, | |
3055 | mode, NULL_RTX, NULL_RTX, label); | |
3056 | jump = get_last_insn (); | |
3057 | JUMP_LABEL (jump) = label; | |
3058 | LABEL_NUSES (label)++; | |
3059 | seq = get_insns (); | |
3060 | end_sequence (); | |
3061 | ||
3062 | /* Add the new cond , in the new head. */ | |
3063 | emit_insn_after(seq, BB_END(cond_bb)); | |
3064 | } | |
3065 | ||
3066 | ||
3067 | /* Given a block B with unconditional branch at its end, get the | |
3068 | store the return the branch edge and the fall-thru edge in | |
3069 | BRANCH_EDGE and FALLTHRU_EDGE respectively. */ | |
3070 | static void | |
3071 | rtl_extract_cond_bb_edges (basic_block b, edge *branch_edge, | |
3072 | edge *fallthru_edge) | |
3073 | { | |
3074 | edge e = EDGE_SUCC (b, 0); | |
3075 | ||
3076 | if (e->flags & EDGE_FALLTHRU) | |
3077 | { | |
3078 | *fallthru_edge = e; | |
3079 | *branch_edge = EDGE_SUCC (b, 1); | |
3080 | } | |
3081 | else | |
3082 | { | |
3083 | *branch_edge = e; | |
3084 | *fallthru_edge = EDGE_SUCC (b, 1); | |
3085 | } | |
3086 | } | |
3087 | ||
5e2d947c JH |
3088 | void |
3089 | init_rtl_bb_info (basic_block bb) | |
3090 | { | |
3091 | gcc_assert (!bb->il.rtl); | |
3092 | bb->il.rtl = ggc_alloc_cleared (sizeof (struct rtl_bb_info)); | |
3093 | } | |
3094 | ||
1cb7dfc3 | 3095 | |
9ee634e3 JH |
3096 | /* Implementation of CFG manipulation for linearized RTL. */ |
3097 | struct cfg_hooks rtl_cfg_hooks = { | |
f470c378 | 3098 | "rtl", |
9ee634e3 | 3099 | rtl_verify_flow_info, |
10e9fecc | 3100 | rtl_dump_bb, |
bc35512f | 3101 | rtl_create_basic_block, |
9ee634e3 JH |
3102 | rtl_redirect_edge_and_branch, |
3103 | rtl_redirect_edge_and_branch_force, | |
3104 | rtl_delete_block, | |
3105 | rtl_split_block, | |
f470c378 | 3106 | rtl_move_block_after, |
bc35512f JH |
3107 | rtl_can_merge_blocks, /* can_merge_blocks_p */ |
3108 | rtl_merge_blocks, | |
6de9cd9a DN |
3109 | rtl_predict_edge, |
3110 | rtl_predicted_by_p, | |
3111 | NULL, /* can_duplicate_block_p */ | |
3112 | NULL, /* duplicate_block */ | |
f470c378 ZD |
3113 | rtl_split_edge, |
3114 | rtl_make_forwarder_block, | |
6de9cd9a DN |
3115 | rtl_tidy_fallthru_edge, |
3116 | rtl_block_ends_with_call_p, | |
3117 | rtl_block_ends_with_condjump_p, | |
d9d4706f KH |
3118 | rtl_flow_call_edges_add, |
3119 | NULL, /* execute_on_growing_pred */ | |
1cb7dfc3 MH |
3120 | NULL, /* execute_on_shrinking_pred */ |
3121 | NULL, /* duplicate loop for trees */ | |
3122 | NULL, /* lv_add_condition_to_bb */ | |
3123 | NULL, /* lv_adjust_loop_header_phi*/ | |
3124 | NULL, /* extract_cond_bb_edges */ | |
3125 | NULL /* flush_pending_stmts */ | |
9ee634e3 JH |
3126 | }; |
3127 | ||
3128 | /* Implementation of CFG manipulation for cfg layout RTL, where | |
3129 | basic block connected via fallthru edges does not have to be adjacent. | |
3130 | This representation will hopefully become the default one in future | |
3131 | version of the compiler. */ | |
6de9cd9a DN |
3132 | |
3133 | /* We do not want to declare these functions in a header file, since they | |
3134 | should only be used through the cfghooks interface, and we do not want to | |
3135 | move them here since it would require also moving quite a lot of related | |
3136 | code. */ | |
3137 | extern bool cfg_layout_can_duplicate_bb_p (basic_block); | |
3138 | extern basic_block cfg_layout_duplicate_bb (basic_block); | |
3139 | ||
9ee634e3 | 3140 | struct cfg_hooks cfg_layout_rtl_cfg_hooks = { |
f470c378 | 3141 | "cfglayout mode", |
bc35512f | 3142 | rtl_verify_flow_info_1, |
10e9fecc | 3143 | rtl_dump_bb, |
bc35512f | 3144 | cfg_layout_create_basic_block, |
9ee634e3 JH |
3145 | cfg_layout_redirect_edge_and_branch, |
3146 | cfg_layout_redirect_edge_and_branch_force, | |
3147 | cfg_layout_delete_block, | |
3148 | cfg_layout_split_block, | |
f470c378 | 3149 | rtl_move_block_after, |
bc35512f JH |
3150 | cfg_layout_can_merge_blocks_p, |
3151 | cfg_layout_merge_blocks, | |
6de9cd9a DN |
3152 | rtl_predict_edge, |
3153 | rtl_predicted_by_p, | |
3154 | cfg_layout_can_duplicate_bb_p, | |
3155 | cfg_layout_duplicate_bb, | |
f470c378 ZD |
3156 | cfg_layout_split_edge, |
3157 | rtl_make_forwarder_block, | |
6de9cd9a DN |
3158 | NULL, |
3159 | rtl_block_ends_with_call_p, | |
3160 | rtl_block_ends_with_condjump_p, | |
d9d4706f KH |
3161 | rtl_flow_call_edges_add, |
3162 | NULL, /* execute_on_growing_pred */ | |
1cb7dfc3 MH |
3163 | NULL, /* execute_on_shrinking_pred */ |
3164 | duplicate_loop_to_header_edge, /* duplicate loop for trees */ | |
3165 | rtl_lv_add_condition_to_bb, /* lv_add_condition_to_bb */ | |
3166 | NULL, /* lv_adjust_loop_header_phi*/ | |
3167 | rtl_extract_cond_bb_edges, /* extract_cond_bb_edges */ | |
3168 | NULL /* flush_pending_stmts */ | |
9ee634e3 | 3169 | }; |
6de9cd9a | 3170 |