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b36d64df | 1 | /* Control flow graph manipulation code for GNU compiler. |
2 | Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, | |
3072d30e | 3 | 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 |
4 | Free Software Foundation, Inc. | |
b36d64df | 5 | |
6 | This file is part of GCC. | |
7 | ||
8 | GCC is free software; you can redistribute it and/or modify it under | |
9 | the terms of the GNU General Public License as published by the Free | |
10 | Software Foundation; either version 2, or (at your option) any later | |
11 | version. | |
12 | ||
13 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
14 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with GCC; see the file COPYING. If not, write to the Free | |
67ce556b | 20 | Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA |
21 | 02110-1301, USA. */ | |
b36d64df | 22 | |
5cc577b6 | 23 | /* This file contains low level functions to manipulate the CFG and analyze it |
24 | that are aware of the RTL intermediate language. | |
b36d64df | 25 | |
26 | Available functionality: | |
c60fa3a7 | 27 | - Basic CFG/RTL manipulation API documented in cfghooks.h |
5cc577b6 | 28 | - CFG-aware instruction chain manipulation |
b36d64df | 29 | delete_insn, delete_insn_chain |
c60fa3a7 | 30 | - Edge splitting and committing to edges |
31 | insert_insn_on_edge, commit_edge_insertions | |
32 | - CFG updating after insn simplification | |
33 | purge_dead_edges, purge_all_dead_edges | |
34 | ||
35 | Functions not supposed for generic use: | |
5cc577b6 | 36 | - Infrastructure to determine quickly basic block for insn |
b36d64df | 37 | compute_bb_for_insn, update_bb_for_insn, set_block_for_insn, |
5cc577b6 | 38 | - Edge redirection with updating and optimizing of insn chain |
c60fa3a7 | 39 | block_label, tidy_fallthru_edge, force_nonfallthru */ |
b36d64df | 40 | \f |
41 | #include "config.h" | |
42 | #include "system.h" | |
805e22b2 | 43 | #include "coretypes.h" |
44 | #include "tm.h" | |
b36d64df | 45 | #include "tree.h" |
46 | #include "rtl.h" | |
47 | #include "hard-reg-set.h" | |
48 | #include "basic-block.h" | |
49 | #include "regs.h" | |
50 | #include "flags.h" | |
51 | #include "output.h" | |
52 | #include "function.h" | |
53 | #include "except.h" | |
54 | #include "toplev.h" | |
55 | #include "tm_p.h" | |
56 | #include "obstack.h" | |
26fb1781 | 57 | #include "insn-config.h" |
1026363d | 58 | #include "cfglayout.h" |
804e497b | 59 | #include "expr.h" |
065efcb1 | 60 | #include "target.h" |
c50ae675 | 61 | #include "cfgloop.h" |
e0dde8f8 | 62 | #include "ggc.h" |
77fce4cd | 63 | #include "tree-pass.h" |
3072d30e | 64 | #include "df.h" |
b36d64df | 65 | |
4c9e08a4 | 66 | static int can_delete_note_p (rtx); |
67 | static int can_delete_label_p (rtx); | |
ca462ec0 | 68 | static void commit_one_edge_insertion (edge); |
4c9e08a4 | 69 | static basic_block rtl_split_edge (edge); |
5f5d4cd1 | 70 | static bool rtl_move_block_after (basic_block, basic_block); |
4c9e08a4 | 71 | static int rtl_verify_flow_info (void); |
5f5d4cd1 | 72 | static basic_block cfg_layout_split_block (basic_block, void *); |
4ee9c684 | 73 | static edge cfg_layout_redirect_edge_and_branch (edge, basic_block); |
4c9e08a4 | 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); | |
4ee9c684 | 78 | static edge rtl_redirect_edge_and_branch (edge, basic_block); |
5f5d4cd1 | 79 | static basic_block rtl_split_block (basic_block, void *); |
80 | static void rtl_dump_bb (basic_block, FILE *, int); | |
4c9e08a4 | 81 | static int rtl_verify_flow_info_1 (void); |
5f5d4cd1 | 82 | static void rtl_make_forwarder_block (edge); |
b36d64df | 83 | \f |
84 | /* Return true if NOTE is not one of the ones that must be kept paired, | |
5cc577b6 | 85 | so that we may simply delete it. */ |
b36d64df | 86 | |
87 | static int | |
4c9e08a4 | 88 | can_delete_note_p (rtx note) |
b36d64df | 89 | { |
ad4583d9 | 90 | return (NOTE_KIND (note) == NOTE_INSN_DELETED |
91 | || NOTE_KIND (note) == NOTE_INSN_BASIC_BLOCK); | |
b36d64df | 92 | } |
93 | ||
94 | /* True if a given label can be deleted. */ | |
95 | ||
96 | static int | |
4c9e08a4 | 97 | can_delete_label_p (rtx label) |
b36d64df | 98 | { |
5cc577b6 | 99 | return (!LABEL_PRESERVE_P (label) |
100 | /* User declared labels must be preserved. */ | |
101 | && LABEL_NAME (label) == 0 | |
2f138c1c | 102 | && !in_expr_list_p (forced_labels, label)); |
b36d64df | 103 | } |
104 | ||
105 | /* Delete INSN by patching it out. Return the next insn. */ | |
106 | ||
107 | rtx | |
4c9e08a4 | 108 | delete_insn (rtx insn) |
b36d64df | 109 | { |
110 | rtx next = NEXT_INSN (insn); | |
111 | rtx note; | |
112 | bool really_delete = true; | |
113 | ||
6d7dc5b9 | 114 | if (LABEL_P (insn)) |
b36d64df | 115 | { |
116 | /* Some labels can't be directly removed from the INSN chain, as they | |
a0c938f0 | 117 | might be references via variables, constant pool etc. |
118 | Convert them to the special NOTE_INSN_DELETED_LABEL note. */ | |
b36d64df | 119 | if (! can_delete_label_p (insn)) |
120 | { | |
121 | const char *name = LABEL_NAME (insn); | |
122 | ||
123 | really_delete = false; | |
124 | PUT_CODE (insn, NOTE); | |
ad4583d9 | 125 | NOTE_KIND (insn) = NOTE_INSN_DELETED_LABEL; |
7bd3dcc4 | 126 | NOTE_DELETED_LABEL_NAME (insn) = name; |
b36d64df | 127 | } |
5cc577b6 | 128 | |
b36d64df | 129 | remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels); |
130 | } | |
131 | ||
132 | if (really_delete) | |
133 | { | |
e172357f | 134 | /* If this insn has already been deleted, something is very wrong. */ |
cc636d56 | 135 | gcc_assert (!INSN_DELETED_P (insn)); |
b36d64df | 136 | remove_insn (insn); |
137 | INSN_DELETED_P (insn) = 1; | |
138 | } | |
139 | ||
140 | /* If deleting a jump, decrement the use count of the label. Deleting | |
141 | the label itself should happen in the normal course of block merging. */ | |
6d7dc5b9 | 142 | if (JUMP_P (insn) |
b36d64df | 143 | && JUMP_LABEL (insn) |
6d7dc5b9 | 144 | && LABEL_P (JUMP_LABEL (insn))) |
b36d64df | 145 | LABEL_NUSES (JUMP_LABEL (insn))--; |
146 | ||
147 | /* Also if deleting an insn that references a label. */ | |
242dafee | 148 | else |
149 | { | |
150 | while ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)) != NULL_RTX | |
6d7dc5b9 | 151 | && LABEL_P (XEXP (note, 0))) |
242dafee | 152 | { |
153 | LABEL_NUSES (XEXP (note, 0))--; | |
154 | remove_note (insn, note); | |
155 | } | |
156 | } | |
b36d64df | 157 | |
6d7dc5b9 | 158 | if (JUMP_P (insn) |
b36d64df | 159 | && (GET_CODE (PATTERN (insn)) == ADDR_VEC |
160 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)) | |
161 | { | |
162 | rtx pat = PATTERN (insn); | |
163 | int diff_vec_p = GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC; | |
164 | int len = XVECLEN (pat, diff_vec_p); | |
165 | int i; | |
166 | ||
167 | for (i = 0; i < len; i++) | |
fd0d7f8c | 168 | { |
169 | rtx label = XEXP (XVECEXP (pat, diff_vec_p, i), 0); | |
170 | ||
171 | /* When deleting code in bulk (e.g. removing many unreachable | |
172 | blocks) we can delete a label that's a target of the vector | |
173 | before deleting the vector itself. */ | |
6d7dc5b9 | 174 | if (!NOTE_P (label)) |
fd0d7f8c | 175 | LABEL_NUSES (label)--; |
176 | } | |
b36d64df | 177 | } |
178 | ||
179 | return next; | |
180 | } | |
181 | ||
fb20d6fa | 182 | /* Like delete_insn but also purge dead edges from BB. */ |
183 | rtx | |
4c9e08a4 | 184 | delete_insn_and_edges (rtx insn) |
fb20d6fa | 185 | { |
186 | rtx x; | |
187 | bool purge = false; | |
188 | ||
ab87d1bc | 189 | if (INSN_P (insn) |
fb20d6fa | 190 | && BLOCK_FOR_INSN (insn) |
5496dbfc | 191 | && BB_END (BLOCK_FOR_INSN (insn)) == insn) |
fb20d6fa | 192 | purge = true; |
193 | x = delete_insn (insn); | |
194 | if (purge) | |
195 | purge_dead_edges (BLOCK_FOR_INSN (insn)); | |
196 | return x; | |
197 | } | |
198 | ||
b36d64df | 199 | /* Unlink a chain of insns between START and FINISH, leaving notes |
39257eb5 | 200 | that must be paired. If CLEAR_BB is true, we set bb field for |
201 | insns that cannot be removed to NULL. */ | |
b36d64df | 202 | |
203 | void | |
39257eb5 | 204 | delete_insn_chain (rtx start, rtx finish, bool clear_bb) |
b36d64df | 205 | { |
b36d64df | 206 | rtx next; |
207 | ||
5cc577b6 | 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. */ | |
b36d64df | 211 | while (1) |
212 | { | |
213 | next = NEXT_INSN (start); | |
6d7dc5b9 | 214 | if (NOTE_P (start) && !can_delete_note_p (start)) |
b36d64df | 215 | ; |
216 | else | |
217 | next = delete_insn (start); | |
218 | ||
39257eb5 | 219 | if (clear_bb && !INSN_DELETED_P (start)) |
220 | set_block_for_insn (start, NULL); | |
221 | ||
b36d64df | 222 | if (start == finish) |
223 | break; | |
224 | start = next; | |
225 | } | |
226 | } | |
fb20d6fa | 227 | |
228 | /* Like delete_insn but also purge dead edges from BB. */ | |
229 | void | |
4c9e08a4 | 230 | delete_insn_chain_and_edges (rtx first, rtx last) |
fb20d6fa | 231 | { |
232 | bool purge = false; | |
233 | ||
ab87d1bc | 234 | if (INSN_P (last) |
fb20d6fa | 235 | && BLOCK_FOR_INSN (last) |
5496dbfc | 236 | && BB_END (BLOCK_FOR_INSN (last)) == last) |
fb20d6fa | 237 | purge = true; |
39257eb5 | 238 | delete_insn_chain (first, last, false); |
fb20d6fa | 239 | if (purge) |
240 | purge_dead_edges (BLOCK_FOR_INSN (last)); | |
241 | } | |
b36d64df | 242 | \f |
5cc577b6 | 243 | /* Create a new basic block consisting of the instructions between HEAD and END |
244 | inclusive. This function is designed to allow fast BB construction - reuses | |
245 | the note and basic block struct in BB_NOTE, if any and do not grow | |
246 | BASIC_BLOCK chain and should be used directly only by CFG construction code. | |
247 | END can be NULL in to create new empty basic block before HEAD. Both END | |
7fa55aef | 248 | and HEAD can be NULL to create basic block at the end of INSN chain. |
249 | AFTER is the basic block we should be put after. */ | |
b36d64df | 250 | |
251 | basic_block | |
4c9e08a4 | 252 | create_basic_block_structure (rtx head, rtx end, rtx bb_note, basic_block after) |
b36d64df | 253 | { |
254 | basic_block bb; | |
255 | ||
256 | if (bb_note | |
b36d64df | 257 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL |
258 | && bb->aux == NULL) | |
259 | { | |
260 | /* If we found an existing note, thread it back onto the chain. */ | |
261 | ||
262 | rtx after; | |
263 | ||
6d7dc5b9 | 264 | if (LABEL_P (head)) |
b36d64df | 265 | after = head; |
266 | else | |
267 | { | |
268 | after = PREV_INSN (head); | |
269 | head = bb_note; | |
270 | } | |
271 | ||
272 | if (after != bb_note && NEXT_INSN (after) != bb_note) | |
ab87d1bc | 273 | reorder_insns_nobb (bb_note, bb_note, after); |
b36d64df | 274 | } |
275 | else | |
276 | { | |
277 | /* Otherwise we must create a note and a basic block structure. */ | |
278 | ||
279 | bb = alloc_block (); | |
280 | ||
e0dde8f8 | 281 | init_rtl_bb_info (bb); |
b36d64df | 282 | if (!head && !end) |
5cc577b6 | 283 | head = end = bb_note |
284 | = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); | |
6d7dc5b9 | 285 | else if (LABEL_P (head) && end) |
b36d64df | 286 | { |
287 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); | |
288 | if (head == end) | |
289 | end = bb_note; | |
290 | } | |
291 | else | |
292 | { | |
293 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); | |
294 | head = bb_note; | |
295 | if (!end) | |
296 | end = head; | |
297 | } | |
5cc577b6 | 298 | |
b36d64df | 299 | NOTE_BASIC_BLOCK (bb_note) = bb; |
300 | } | |
301 | ||
302 | /* Always include the bb note in the block. */ | |
303 | if (NEXT_INSN (end) == bb_note) | |
304 | end = bb_note; | |
305 | ||
5496dbfc | 306 | BB_HEAD (bb) = head; |
307 | BB_END (bb) = end; | |
f23d9a22 | 308 | bb->index = last_basic_block++; |
e0dde8f8 | 309 | bb->flags = BB_NEW | BB_RTL; |
7fa55aef | 310 | link_block (bb, after); |
85b938d0 | 311 | SET_BASIC_BLOCK (bb->index, bb); |
3072d30e | 312 | df_bb_refs_record (bb->index, false); |
ab87d1bc | 313 | update_bb_for_insn (bb); |
7562ed74 | 314 | BB_SET_PARTITION (bb, BB_UNPARTITIONED); |
b36d64df | 315 | |
316 | /* Tag the block so that we know it has been used when considering | |
317 | other basic block notes. */ | |
318 | bb->aux = bb; | |
319 | ||
320 | return bb; | |
321 | } | |
322 | ||
5cc577b6 | 323 | /* Create new basic block consisting of instructions in between HEAD and END |
7fa55aef | 324 | and place it to the BB chain after block AFTER. END can be NULL in to |
5cc577b6 | 325 | create new empty basic block before HEAD. Both END and HEAD can be NULL to |
326 | create basic block at the end of INSN chain. */ | |
b36d64df | 327 | |
c60fa3a7 | 328 | static basic_block |
329 | rtl_create_basic_block (void *headp, void *endp, basic_block after) | |
b36d64df | 330 | { |
f780cc25 | 331 | rtx head = (rtx) headp, end = (rtx) endp; |
b36d64df | 332 | basic_block bb; |
b3d6de89 | 333 | |
743ff5bb | 334 | /* Grow the basic block array if needed. */ |
85b938d0 | 335 | if ((size_t) last_basic_block >= VEC_length (basic_block, basic_block_info)) |
743ff5bb | 336 | { |
337 | size_t new_size = last_basic_block + (last_basic_block + 3) / 4; | |
e85c2c2d | 338 | VEC_safe_grow_cleared (basic_block, gc, basic_block_info, new_size); |
743ff5bb | 339 | } |
b3d6de89 | 340 | |
3c0a32c9 | 341 | n_basic_blocks++; |
b36d64df | 342 | |
f23d9a22 | 343 | bb = create_basic_block_structure (head, end, NULL, after); |
b36d64df | 344 | bb->aux = NULL; |
345 | return bb; | |
346 | } | |
c60fa3a7 | 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 | ||
c60fa3a7 | 353 | return newbb; |
354 | } | |
b36d64df | 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 | ||
5f704f9f | 364 | static void |
4c9e08a4 | 365 | rtl_delete_block (basic_block b) |
b36d64df | 366 | { |
5d65a39c | 367 | rtx insn, end; |
b36d64df | 368 | |
369 | /* If the head of this block is a CODE_LABEL, then it might be the | |
57548910 | 370 | label for an exception handler which can't be reached. We need |
371 | to remove the label from the exception_handler_label list. */ | |
5496dbfc | 372 | insn = BB_HEAD (b); |
6d7dc5b9 | 373 | if (LABEL_P (insn)) |
b36d64df | 374 | maybe_remove_eh_handler (insn); |
375 | ||
5d65a39c | 376 | end = get_last_bb_insn (b); |
b36d64df | 377 | |
378 | /* Selectively delete the entire chain. */ | |
5496dbfc | 379 | BB_HEAD (b) = NULL; |
39257eb5 | 380 | delete_insn_chain (insn, end, true); |
381 | ||
3072d30e | 382 | |
383 | if (dump_file) | |
384 | fprintf (dump_file, "deleting block %d\n", b->index); | |
385 | df_bb_delete (b->index); | |
b36d64df | 386 | } |
387 | \f | |
f23d9a22 | 388 | /* Records the basic block struct in BLOCK_FOR_INSN for every insn. */ |
b36d64df | 389 | |
390 | void | |
4c9e08a4 | 391 | compute_bb_for_insn (void) |
b36d64df | 392 | { |
4c26117a | 393 | basic_block bb; |
b36d64df | 394 | |
4c26117a | 395 | FOR_EACH_BB (bb) |
b36d64df | 396 | { |
5496dbfc | 397 | rtx end = BB_END (bb); |
5cc577b6 | 398 | rtx insn; |
b36d64df | 399 | |
5496dbfc | 400 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
b36d64df | 401 | { |
ab87d1bc | 402 | BLOCK_FOR_INSN (insn) = bb; |
b36d64df | 403 | if (insn == end) |
404 | break; | |
b36d64df | 405 | } |
406 | } | |
407 | } | |
408 | ||
409 | /* Release the basic_block_for_insn array. */ | |
410 | ||
2a1990e9 | 411 | unsigned int |
4c9e08a4 | 412 | free_bb_for_insn (void) |
b36d64df | 413 | { |
ab87d1bc | 414 | rtx insn; |
415 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) | |
6d7dc5b9 | 416 | if (!BARRIER_P (insn)) |
ab87d1bc | 417 | BLOCK_FOR_INSN (insn) = NULL; |
2a1990e9 | 418 | return 0; |
b36d64df | 419 | } |
420 | ||
77fce4cd | 421 | struct tree_opt_pass pass_free_cfg = |
422 | { | |
423 | NULL, /* name */ | |
424 | NULL, /* gate */ | |
425 | free_bb_for_insn, /* execute */ | |
426 | NULL, /* sub */ | |
427 | NULL, /* next */ | |
428 | 0, /* static_pass_number */ | |
429 | 0, /* tv_id */ | |
430 | 0, /* properties_required */ | |
431 | 0, /* properties_provided */ | |
432 | PROP_cfg, /* properties_destroyed */ | |
433 | 0, /* todo_flags_start */ | |
434 | 0, /* todo_flags_finish */ | |
435 | 0 /* letter */ | |
436 | }; | |
437 | ||
a0fee14a | 438 | /* Return RTX to emit after when we want to emit code on the entry of function. */ |
439 | rtx | |
440 | entry_of_function (void) | |
441 | { | |
a0c938f0 | 442 | return (n_basic_blocks > NUM_FIXED_BLOCKS ? |
4d2e5d52 | 443 | BB_HEAD (ENTRY_BLOCK_PTR->next_bb) : get_insns ()); |
a0fee14a | 444 | } |
445 | ||
aa02fa19 | 446 | /* Emit INSN at the entry point of the function, ensuring that it is only |
447 | executed once per function. */ | |
448 | void | |
449 | emit_insn_at_entry (rtx insn) | |
450 | { | |
451 | edge_iterator ei = ei_start (ENTRY_BLOCK_PTR->succs); | |
452 | edge e = ei_safe_edge (ei); | |
1db61145 | 453 | gcc_assert (e->flags & EDGE_FALLTHRU); |
aa02fa19 | 454 | |
455 | insert_insn_on_edge (insn, e); | |
456 | commit_edge_insertions (); | |
457 | } | |
458 | ||
b36d64df | 459 | /* Update insns block within BB. */ |
460 | ||
461 | void | |
4c9e08a4 | 462 | update_bb_for_insn (basic_block bb) |
b36d64df | 463 | { |
464 | rtx insn; | |
465 | ||
5496dbfc | 466 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
b36d64df | 467 | { |
6d7dc5b9 | 468 | if (!BARRIER_P (insn)) |
3072d30e | 469 | { |
470 | set_block_for_insn (insn, bb); | |
471 | df_insn_change_bb (insn); | |
472 | } | |
5496dbfc | 473 | if (insn == BB_END (bb)) |
b36d64df | 474 | break; |
475 | } | |
476 | } | |
b36d64df | 477 | \f |
3072d30e | 478 | /* Return the INSN immediately following the NOTE_INSN_BASIC_BLOCK |
479 | note associated with the BLOCK. */ | |
480 | ||
481 | static rtx | |
482 | first_insn_after_basic_block_note (basic_block block) | |
483 | { | |
484 | rtx insn; | |
485 | ||
486 | /* Get the first instruction in the block. */ | |
487 | insn = BB_HEAD (block); | |
488 | ||
489 | if (insn == NULL_RTX) | |
490 | return NULL_RTX; | |
491 | if (LABEL_P (insn)) | |
492 | insn = NEXT_INSN (insn); | |
493 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn)); | |
494 | ||
495 | return NEXT_INSN (insn); | |
496 | } | |
497 | ||
5f5d4cd1 | 498 | /* Creates a new basic block just after basic block B by splitting |
499 | everything after specified instruction I. */ | |
b36d64df | 500 | |
5f5d4cd1 | 501 | static basic_block |
4c9e08a4 | 502 | rtl_split_block (basic_block bb, void *insnp) |
b36d64df | 503 | { |
504 | basic_block new_bb; | |
f780cc25 | 505 | rtx insn = (rtx) insnp; |
5f5d4cd1 | 506 | edge e; |
cd665a06 | 507 | edge_iterator ei; |
b36d64df | 508 | |
5f5d4cd1 | 509 | if (!insn) |
510 | { | |
511 | insn = first_insn_after_basic_block_note (bb); | |
512 | ||
513 | if (insn) | |
514 | insn = PREV_INSN (insn); | |
515 | else | |
516 | insn = get_last_insn (); | |
517 | } | |
518 | ||
519 | /* We probably should check type of the insn so that we do not create | |
520 | inconsistent cfg. It is checked in verify_flow_info anyway, so do not | |
521 | bother. */ | |
522 | if (insn == BB_END (bb)) | |
523 | emit_note_after (NOTE_INSN_DELETED, insn); | |
b36d64df | 524 | |
525 | /* Create the new basic block. */ | |
5496dbfc | 526 | new_bb = create_basic_block (NEXT_INSN (insn), BB_END (bb), bb); |
7562ed74 | 527 | BB_COPY_PARTITION (new_bb, bb); |
5496dbfc | 528 | BB_END (bb) = insn; |
b36d64df | 529 | |
530 | /* Redirect the outgoing edges. */ | |
cd665a06 | 531 | new_bb->succs = bb->succs; |
532 | bb->succs = NULL; | |
533 | FOR_EACH_EDGE (e, ei, new_bb->succs) | |
b36d64df | 534 | e->src = new_bb; |
535 | ||
3072d30e | 536 | /* The new block starts off being dirty. */ |
537 | df_set_bb_dirty (bb); | |
5f5d4cd1 | 538 | return new_bb; |
c60fa3a7 | 539 | } |
540 | ||
b36d64df | 541 | /* Blocks A and B are to be merged into a single block A. The insns |
c60fa3a7 | 542 | are already contiguous. */ |
b36d64df | 543 | |
c60fa3a7 | 544 | static void |
545 | rtl_merge_blocks (basic_block a, basic_block b) | |
b36d64df | 546 | { |
5496dbfc | 547 | rtx b_head = BB_HEAD (b), b_end = BB_END (b), a_end = BB_END (a); |
b36d64df | 548 | rtx del_first = NULL_RTX, del_last = NULL_RTX; |
549 | int b_empty = 0; | |
550 | ||
3072d30e | 551 | if (dump_file) |
552 | fprintf (dump_file, "merging block %d into block %d\n", b->index, a->index); | |
553 | ||
b36d64df | 554 | /* If there was a CODE_LABEL beginning B, delete it. */ |
6d7dc5b9 | 555 | if (LABEL_P (b_head)) |
b36d64df | 556 | { |
7b07eae7 | 557 | /* This might have been an EH label that no longer has incoming |
558 | EH edges. Update data structures to match. */ | |
559 | maybe_remove_eh_handler (b_head); | |
a0c938f0 | 560 | |
b36d64df | 561 | /* Detect basic blocks with nothing but a label. This can happen |
562 | in particular at the end of a function. */ | |
563 | if (b_head == b_end) | |
564 | b_empty = 1; | |
5cc577b6 | 565 | |
b36d64df | 566 | del_first = del_last = b_head; |
567 | b_head = NEXT_INSN (b_head); | |
568 | } | |
569 | ||
5cc577b6 | 570 | /* Delete the basic block note and handle blocks containing just that |
571 | note. */ | |
b36d64df | 572 | if (NOTE_INSN_BASIC_BLOCK_P (b_head)) |
573 | { | |
574 | if (b_head == b_end) | |
575 | b_empty = 1; | |
576 | if (! del_last) | |
577 | del_first = b_head; | |
5cc577b6 | 578 | |
b36d64df | 579 | del_last = b_head; |
580 | b_head = NEXT_INSN (b_head); | |
581 | } | |
582 | ||
583 | /* If there was a jump out of A, delete it. */ | |
6d7dc5b9 | 584 | if (JUMP_P (a_end)) |
b36d64df | 585 | { |
586 | rtx prev; | |
587 | ||
588 | for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev)) | |
6d7dc5b9 | 589 | if (!NOTE_P (prev) |
ad4583d9 | 590 | || NOTE_INSN_BASIC_BLOCK_P (prev) |
5496dbfc | 591 | || prev == BB_HEAD (a)) |
b36d64df | 592 | break; |
593 | ||
594 | del_first = a_end; | |
595 | ||
596 | #ifdef HAVE_cc0 | |
597 | /* If this was a conditional jump, we need to also delete | |
598 | the insn that set cc0. */ | |
599 | if (only_sets_cc0_p (prev)) | |
600 | { | |
601 | rtx tmp = prev; | |
5cc577b6 | 602 | |
b36d64df | 603 | prev = prev_nonnote_insn (prev); |
604 | if (!prev) | |
5496dbfc | 605 | prev = BB_HEAD (a); |
b36d64df | 606 | del_first = tmp; |
607 | } | |
608 | #endif | |
609 | ||
610 | a_end = PREV_INSN (del_first); | |
611 | } | |
6d7dc5b9 | 612 | else if (BARRIER_P (NEXT_INSN (a_end))) |
b36d64df | 613 | del_first = NEXT_INSN (a_end); |
614 | ||
b36d64df | 615 | /* Delete everything marked above as well as crap that might be |
616 | hanging out between the two blocks. */ | |
5f5d4cd1 | 617 | BB_HEAD (b) = NULL; |
39257eb5 | 618 | delete_insn_chain (del_first, del_last, true); |
b36d64df | 619 | |
620 | /* Reassociate the insns of B with A. */ | |
621 | if (!b_empty) | |
622 | { | |
ab87d1bc | 623 | rtx x; |
5cc577b6 | 624 | |
ab87d1bc | 625 | for (x = a_end; x != b_end; x = NEXT_INSN (x)) |
3072d30e | 626 | { |
627 | set_block_for_insn (x, a); | |
628 | df_insn_change_bb (x); | |
629 | } | |
5cc577b6 | 630 | |
ab87d1bc | 631 | set_block_for_insn (b_end, a); |
3072d30e | 632 | df_insn_change_bb (b_end); |
5cc577b6 | 633 | |
b36d64df | 634 | a_end = b_end; |
635 | } | |
5cc577b6 | 636 | |
3072d30e | 637 | df_bb_delete (b->index); |
5496dbfc | 638 | BB_END (a) = a_end; |
b36d64df | 639 | } |
c60fa3a7 | 640 | |
3072d30e | 641 | |
c60fa3a7 | 642 | /* Return true when block A and B can be merged. */ |
643 | static bool | |
644 | rtl_can_merge_blocks (basic_block a,basic_block b) | |
645 | { | |
4f18499c | 646 | /* If we are partitioning hot/cold basic blocks, we don't want to |
647 | mess up unconditional or indirect jumps that cross between hot | |
7562ed74 | 648 | and cold sections. |
649 | ||
1118aef7 | 650 | Basic block partitioning may result in some jumps that appear to |
a0c938f0 | 651 | be optimizable (or blocks that appear to be mergeable), but which really |
652 | must be left untouched (they are required to make it safely across | |
653 | partition boundaries). See the comments at the top of | |
1118aef7 | 654 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
7562ed74 | 655 | |
1897b881 | 656 | if (BB_PARTITION (a) != BB_PARTITION (b)) |
7562ed74 | 657 | return false; |
4f18499c | 658 | |
c60fa3a7 | 659 | /* There must be exactly one edge in between the blocks. */ |
ea091dfd | 660 | return (single_succ_p (a) |
661 | && single_succ (a) == b | |
662 | && single_pred_p (b) | |
cd665a06 | 663 | && a != b |
c60fa3a7 | 664 | /* Must be simple edge. */ |
ea091dfd | 665 | && !(single_succ_edge (a)->flags & EDGE_COMPLEX) |
c60fa3a7 | 666 | && a->next_bb == b |
667 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR | |
668 | /* If the jump insn has side effects, | |
669 | we can't kill the edge. */ | |
6d7dc5b9 | 670 | && (!JUMP_P (BB_END (a)) |
18f811c9 | 671 | || (reload_completed |
5496dbfc | 672 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
c60fa3a7 | 673 | } |
b36d64df | 674 | \f |
5cc577b6 | 675 | /* Return the label in the head of basic block BLOCK. Create one if it doesn't |
676 | exist. */ | |
b36d64df | 677 | |
678 | rtx | |
4c9e08a4 | 679 | block_label (basic_block block) |
b36d64df | 680 | { |
681 | if (block == EXIT_BLOCK_PTR) | |
682 | return NULL_RTX; | |
5cc577b6 | 683 | |
6d7dc5b9 | 684 | if (!LABEL_P (BB_HEAD (block))) |
b36d64df | 685 | { |
5496dbfc | 686 | BB_HEAD (block) = emit_label_before (gen_label_rtx (), BB_HEAD (block)); |
b36d64df | 687 | } |
5cc577b6 | 688 | |
5496dbfc | 689 | return BB_HEAD (block); |
b36d64df | 690 | } |
691 | ||
692 | /* Attempt to perform edge redirection by replacing possibly complex jump | |
5cc577b6 | 693 | instruction by unconditional jump or removing jump completely. This can |
694 | apply only if all edges now point to the same block. The parameters and | |
695 | return values are equivalent to redirect_edge_and_branch. */ | |
b36d64df | 696 | |
4ee9c684 | 697 | edge |
c60fa3a7 | 698 | try_redirect_by_replacing_jump (edge e, basic_block target, bool in_cfglayout) |
b36d64df | 699 | { |
700 | basic_block src = e->src; | |
5496dbfc | 701 | rtx insn = BB_END (src), kill_from; |
b19beda9 | 702 | rtx set; |
b36d64df | 703 | int fallthru = 0; |
4f18499c | 704 | |
705 | /* If we are partitioning hot/cold basic blocks, we don't want to | |
706 | mess up unconditional or indirect jumps that cross between hot | |
1118aef7 | 707 | and cold sections. |
708 | ||
709 | Basic block partitioning may result in some jumps that appear to | |
a0c938f0 | 710 | be optimizable (or blocks that appear to be mergeable), but which really |
711 | must be left untouched (they are required to make it safely across | |
712 | partition boundaries). See the comments at the top of | |
1118aef7 | 713 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
a0c938f0 | 714 | |
1897b881 | 715 | if (find_reg_note (insn, REG_CROSSING_JUMP, NULL_RTX) |
716 | || BB_PARTITION (src) != BB_PARTITION (target)) | |
53f8294f | 717 | return NULL; |
4f18499c | 718 | |
34f05bfa | 719 | /* We can replace or remove a complex jump only when we have exactly |
720 | two edges. Also, if we have exactly one outgoing edge, we can | |
721 | redirect that. */ | |
722 | if (EDGE_COUNT (src->succs) >= 3 | |
723 | /* Verify that all targets will be TARGET. Specifically, the | |
724 | edge that is not E must also go to TARGET. */ | |
725 | || (EDGE_COUNT (src->succs) == 2 | |
726 | && EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)) | |
727 | return NULL; | |
5cc577b6 | 728 | |
34f05bfa | 729 | if (!onlyjump_p (insn)) |
4ee9c684 | 730 | return NULL; |
e5562ab8 | 731 | if ((!optimize || reload_completed) && tablejump_p (insn, NULL, NULL)) |
4ee9c684 | 732 | return NULL; |
b36d64df | 733 | |
734 | /* Avoid removing branch with side effects. */ | |
735 | set = single_set (insn); | |
736 | if (!set || side_effects_p (set)) | |
4ee9c684 | 737 | return NULL; |
b36d64df | 738 | |
739 | /* In case we zap a conditional jump, we'll need to kill | |
740 | the cc0 setter too. */ | |
741 | kill_from = insn; | |
742 | #ifdef HAVE_cc0 | |
3d5a3e76 | 743 | if (reg_mentioned_p (cc0_rtx, PATTERN (insn)) |
744 | && only_sets_cc0_p (PREV_INSN (insn))) | |
b36d64df | 745 | kill_from = PREV_INSN (insn); |
746 | #endif | |
747 | ||
748 | /* See if we can create the fallthru edge. */ | |
c60fa3a7 | 749 | if (in_cfglayout || can_fallthru (src, target)) |
b36d64df | 750 | { |
450d042a | 751 | if (dump_file) |
752 | fprintf (dump_file, "Removing jump %i.\n", INSN_UID (insn)); | |
b36d64df | 753 | fallthru = 1; |
754 | ||
4a82352a | 755 | /* Selectively unlink whole insn chain. */ |
c60fa3a7 | 756 | if (in_cfglayout) |
757 | { | |
bc5f266a | 758 | rtx insn = src->il.rtl->footer; |
c60fa3a7 | 759 | |
39257eb5 | 760 | delete_insn_chain (kill_from, BB_END (src), false); |
c60fa3a7 | 761 | |
762 | /* Remove barriers but keep jumptables. */ | |
763 | while (insn) | |
764 | { | |
6d7dc5b9 | 765 | if (BARRIER_P (insn)) |
c60fa3a7 | 766 | { |
767 | if (PREV_INSN (insn)) | |
768 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
769 | else | |
bc5f266a | 770 | src->il.rtl->footer = NEXT_INSN (insn); |
c60fa3a7 | 771 | if (NEXT_INSN (insn)) |
772 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
773 | } | |
6d7dc5b9 | 774 | if (LABEL_P (insn)) |
c60fa3a7 | 775 | break; |
776 | insn = NEXT_INSN (insn); | |
777 | } | |
778 | } | |
779 | else | |
39257eb5 | 780 | delete_insn_chain (kill_from, PREV_INSN (BB_HEAD (target)), |
781 | false); | |
b36d64df | 782 | } |
5cc577b6 | 783 | |
b36d64df | 784 | /* If this already is simplejump, redirect it. */ |
785 | else if (simplejump_p (insn)) | |
786 | { | |
787 | if (e->dest == target) | |
4ee9c684 | 788 | return NULL; |
450d042a | 789 | if (dump_file) |
790 | fprintf (dump_file, "Redirecting jump %i from %i to %i.\n", | |
b3d6de89 | 791 | INSN_UID (insn), e->dest->index, target->index); |
8963581a | 792 | if (!redirect_jump (insn, block_label (target), 0)) |
793 | { | |
cc636d56 | 794 | gcc_assert (target == EXIT_BLOCK_PTR); |
795 | return NULL; | |
8963581a | 796 | } |
b36d64df | 797 | } |
5cc577b6 | 798 | |
8963581a | 799 | /* Cannot do anything for target exit block. */ |
800 | else if (target == EXIT_BLOCK_PTR) | |
4ee9c684 | 801 | return NULL; |
8963581a | 802 | |
b36d64df | 803 | /* Or replace possibly complicated jump insn by simple jump insn. */ |
804 | else | |
805 | { | |
806 | rtx target_label = block_label (target); | |
669f9131 | 807 | rtx barrier, label, table; |
b36d64df | 808 | |
0891f67c | 809 | emit_jump_insn_after_noloc (gen_jump (target_label), insn); |
5496dbfc | 810 | JUMP_LABEL (BB_END (src)) = target_label; |
b36d64df | 811 | LABEL_NUSES (target_label)++; |
450d042a | 812 | if (dump_file) |
813 | fprintf (dump_file, "Replacing insn %i by jump %i\n", | |
5496dbfc | 814 | INSN_UID (insn), INSN_UID (BB_END (src))); |
b36d64df | 815 | |
1ed8ccdb | 816 | |
39257eb5 | 817 | delete_insn_chain (kill_from, insn, false); |
b36d64df | 818 | |
1ed8ccdb | 819 | /* Recognize a tablejump that we are converting to a |
820 | simple jump and remove its associated CODE_LABEL | |
821 | and ADDR_VEC or ADDR_DIFF_VEC. */ | |
e5562ab8 | 822 | if (tablejump_p (insn, &label, &table)) |
39257eb5 | 823 | delete_insn_chain (label, table, false); |
669f9131 | 824 | |
5496dbfc | 825 | barrier = next_nonnote_insn (BB_END (src)); |
6d7dc5b9 | 826 | if (!barrier || !BARRIER_P (barrier)) |
5496dbfc | 827 | emit_barrier_after (BB_END (src)); |
1824678b | 828 | else |
829 | { | |
5496dbfc | 830 | if (barrier != NEXT_INSN (BB_END (src))) |
1824678b | 831 | { |
832 | /* Move the jump before barrier so that the notes | |
833 | which originally were or were created before jump table are | |
834 | inside the basic block. */ | |
5496dbfc | 835 | rtx new_insn = BB_END (src); |
1824678b | 836 | rtx tmp; |
837 | ||
5496dbfc | 838 | for (tmp = NEXT_INSN (BB_END (src)); tmp != barrier; |
1824678b | 839 | tmp = NEXT_INSN (tmp)) |
3072d30e | 840 | { |
841 | set_block_for_insn (tmp, src); | |
842 | df_insn_change_bb (tmp); | |
843 | } | |
1824678b | 844 | |
845 | NEXT_INSN (PREV_INSN (new_insn)) = NEXT_INSN (new_insn); | |
846 | PREV_INSN (NEXT_INSN (new_insn)) = PREV_INSN (new_insn); | |
847 | ||
848 | NEXT_INSN (new_insn) = barrier; | |
849 | NEXT_INSN (PREV_INSN (barrier)) = new_insn; | |
850 | ||
851 | PREV_INSN (new_insn) = PREV_INSN (barrier); | |
852 | PREV_INSN (barrier) = new_insn; | |
853 | } | |
854 | } | |
b36d64df | 855 | } |
856 | ||
857 | /* Keep only one edge out and set proper flags. */ | |
ea091dfd | 858 | if (!single_succ_p (src)) |
cd665a06 | 859 | remove_edge (e); |
ea091dfd | 860 | gcc_assert (single_succ_p (src)); |
cd665a06 | 861 | |
ea091dfd | 862 | e = single_succ_edge (src); |
b36d64df | 863 | if (fallthru) |
864 | e->flags = EDGE_FALLTHRU; | |
865 | else | |
866 | e->flags = 0; | |
5cc577b6 | 867 | |
b36d64df | 868 | e->probability = REG_BR_PROB_BASE; |
869 | e->count = src->count; | |
870 | ||
b36d64df | 871 | if (e->dest != target) |
872 | redirect_edge_succ (e, target); | |
4ee9c684 | 873 | return e; |
b36d64df | 874 | } |
875 | ||
4ee9c684 | 876 | /* Redirect edge representing branch of (un)conditional jump or tablejump, |
877 | NULL on failure */ | |
878 | static edge | |
c60fa3a7 | 879 | redirect_branch_edge (edge e, basic_block target) |
b36d64df | 880 | { |
881 | rtx tmp; | |
5496dbfc | 882 | rtx old_label = BB_HEAD (e->dest); |
b36d64df | 883 | basic_block src = e->src; |
5496dbfc | 884 | rtx insn = BB_END (src); |
b36d64df | 885 | |
b36d64df | 886 | /* We can only redirect non-fallthru edges of jump insn. */ |
887 | if (e->flags & EDGE_FALLTHRU) | |
4ee9c684 | 888 | return NULL; |
6d7dc5b9 | 889 | else if (!JUMP_P (insn)) |
4ee9c684 | 890 | return NULL; |
b36d64df | 891 | |
892 | /* Recognize a tablejump and adjust all matching cases. */ | |
b19beda9 | 893 | if (tablejump_p (insn, NULL, &tmp)) |
b36d64df | 894 | { |
895 | rtvec vec; | |
896 | int j; | |
897 | rtx new_label = block_label (target); | |
898 | ||
8963581a | 899 | if (target == EXIT_BLOCK_PTR) |
4ee9c684 | 900 | return NULL; |
b36d64df | 901 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) |
902 | vec = XVEC (PATTERN (tmp), 0); | |
903 | else | |
904 | vec = XVEC (PATTERN (tmp), 1); | |
905 | ||
906 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
907 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
908 | { | |
909 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (Pmode, new_label); | |
910 | --LABEL_NUSES (old_label); | |
911 | ++LABEL_NUSES (new_label); | |
912 | } | |
913 | ||
2358393e | 914 | /* Handle casesi dispatch insns. */ |
b36d64df | 915 | if ((tmp = single_set (insn)) != NULL |
916 | && SET_DEST (tmp) == pc_rtx | |
917 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
918 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF | |
919 | && XEXP (XEXP (SET_SRC (tmp), 2), 0) == old_label) | |
920 | { | |
514b43f8 | 921 | XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (Pmode, |
b36d64df | 922 | new_label); |
923 | --LABEL_NUSES (old_label); | |
924 | ++LABEL_NUSES (new_label); | |
925 | } | |
926 | } | |
927 | else | |
928 | { | |
929 | /* ?? We may play the games with moving the named labels from | |
930 | one basic block to the other in case only one computed_jump is | |
931 | available. */ | |
5cc577b6 | 932 | if (computed_jump_p (insn) |
933 | /* A return instruction can't be redirected. */ | |
934 | || returnjump_p (insn)) | |
4ee9c684 | 935 | return NULL; |
b36d64df | 936 | |
937 | /* If the insn doesn't go where we think, we're confused. */ | |
cc636d56 | 938 | gcc_assert (JUMP_LABEL (insn) == old_label); |
8963581a | 939 | |
940 | /* If the substitution doesn't succeed, die. This can happen | |
941 | if the back end emitted unrecognizable instructions or if | |
942 | target is exit block on some arches. */ | |
943 | if (!redirect_jump (insn, block_label (target), 0)) | |
944 | { | |
cc636d56 | 945 | gcc_assert (target == EXIT_BLOCK_PTR); |
946 | return NULL; | |
8963581a | 947 | } |
b36d64df | 948 | } |
949 | ||
450d042a | 950 | if (dump_file) |
951 | fprintf (dump_file, "Edge %i->%i redirected to %i\n", | |
b3d6de89 | 952 | e->src->index, e->dest->index, target->index); |
5cc577b6 | 953 | |
b36d64df | 954 | if (e->dest != target) |
4ee9c684 | 955 | e = redirect_edge_succ_nodup (e, target); |
3072d30e | 956 | |
4ee9c684 | 957 | return e; |
c60fa3a7 | 958 | } |
959 | ||
960 | /* Attempt to change code to redirect edge E to TARGET. Don't do that on | |
961 | expense of adding new instructions or reordering basic blocks. | |
962 | ||
963 | Function can be also called with edge destination equivalent to the TARGET. | |
964 | Then it should try the simplifications and do nothing if none is possible. | |
965 | ||
4ee9c684 | 966 | Return edge representing the branch if transformation succeeded. Return NULL |
967 | on failure. | |
968 | We still return NULL in case E already destinated TARGET and we didn't | |
969 | managed to simplify instruction stream. */ | |
c60fa3a7 | 970 | |
4ee9c684 | 971 | static edge |
f82b06e0 | 972 | rtl_redirect_edge_and_branch (edge e, basic_block target) |
c60fa3a7 | 973 | { |
4ee9c684 | 974 | edge ret; |
adee86a0 | 975 | basic_block src = e->src; |
976 | ||
c60fa3a7 | 977 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
4ee9c684 | 978 | return NULL; |
c60fa3a7 | 979 | |
e5562ab8 | 980 | if (e->dest == target) |
4ee9c684 | 981 | return e; |
e5562ab8 | 982 | |
4ee9c684 | 983 | if ((ret = try_redirect_by_replacing_jump (e, target, false)) != NULL) |
adee86a0 | 984 | { |
3072d30e | 985 | df_set_bb_dirty (src); |
4ee9c684 | 986 | return ret; |
adee86a0 | 987 | } |
c60fa3a7 | 988 | |
4ee9c684 | 989 | ret = redirect_branch_edge (e, target); |
990 | if (!ret) | |
991 | return NULL; | |
5cc577b6 | 992 | |
3072d30e | 993 | df_set_bb_dirty (src); |
4ee9c684 | 994 | return ret; |
b36d64df | 995 | } |
996 | ||
20dd417a | 997 | /* Like force_nonfallthru below, but additionally performs redirection |
b36d64df | 998 | Used by redirect_edge_and_branch_force. */ |
999 | ||
109c6afa | 1000 | static basic_block |
4c9e08a4 | 1001 | force_nonfallthru_and_redirect (edge e, basic_block target) |
b36d64df | 1002 | { |
498d173d | 1003 | basic_block jump_block, new_bb = NULL, src = e->src; |
b36d64df | 1004 | rtx note; |
1005 | edge new_edge; | |
498d173d | 1006 | int abnormal_edge_flags = 0; |
b36d64df | 1007 | |
accd6c44 | 1008 | /* In the case the last instruction is conditional jump to the next |
1009 | instruction, first redirect the jump itself and then continue | |
df07c3ae | 1010 | by creating a basic block afterwards to redirect fallthru edge. */ |
accd6c44 | 1011 | if (e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR |
5496dbfc | 1012 | && any_condjump_p (BB_END (e->src)) |
5496dbfc | 1013 | && JUMP_LABEL (BB_END (e->src)) == BB_HEAD (e->dest)) |
accd6c44 | 1014 | { |
1015 | rtx note; | |
d9aa52be | 1016 | edge b = unchecked_make_edge (e->src, target, 0); |
cc636d56 | 1017 | bool redirected; |
accd6c44 | 1018 | |
cc636d56 | 1019 | redirected = redirect_jump (BB_END (e->src), block_label (target), 0); |
1020 | gcc_assert (redirected); | |
a0c938f0 | 1021 | |
5496dbfc | 1022 | note = find_reg_note (BB_END (e->src), REG_BR_PROB, NULL_RTX); |
accd6c44 | 1023 | if (note) |
1024 | { | |
1025 | int prob = INTVAL (XEXP (note, 0)); | |
1026 | ||
1027 | b->probability = prob; | |
1028 | b->count = e->count * prob / REG_BR_PROB_BASE; | |
1029 | e->probability -= e->probability; | |
1030 | e->count -= b->count; | |
1031 | if (e->probability < 0) | |
1032 | e->probability = 0; | |
1033 | if (e->count < 0) | |
1034 | e->count = 0; | |
1035 | } | |
1036 | } | |
1037 | ||
b36d64df | 1038 | if (e->flags & EDGE_ABNORMAL) |
498d173d | 1039 | { |
1040 | /* Irritating special case - fallthru edge to the same block as abnormal | |
1041 | edge. | |
1042 | We can't redirect abnormal edge, but we still can split the fallthru | |
4c9e08a4 | 1043 | one and create separate abnormal edge to original destination. |
498d173d | 1044 | This allows bb-reorder to make such edge non-fallthru. */ |
cc636d56 | 1045 | gcc_assert (e->dest == target); |
498d173d | 1046 | abnormal_edge_flags = e->flags & ~(EDGE_FALLTHRU | EDGE_CAN_FALLTHRU); |
1047 | e->flags &= EDGE_FALLTHRU | EDGE_CAN_FALLTHRU; | |
1048 | } | |
cc636d56 | 1049 | else |
76cc9616 | 1050 | { |
cc636d56 | 1051 | gcc_assert (e->flags & EDGE_FALLTHRU); |
1052 | if (e->src == ENTRY_BLOCK_PTR) | |
1053 | { | |
1054 | /* We can't redirect the entry block. Create an empty block | |
cd665a06 | 1055 | at the start of the function which we use to add the new |
1056 | jump. */ | |
1057 | edge tmp; | |
1058 | edge_iterator ei; | |
1059 | bool found = false; | |
a0c938f0 | 1060 | |
cd665a06 | 1061 | basic_block bb = create_basic_block (BB_HEAD (e->dest), NULL, ENTRY_BLOCK_PTR); |
a0c938f0 | 1062 | |
cc636d56 | 1063 | /* Change the existing edge's source to be the new block, and add |
1064 | a new edge from the entry block to the new block. */ | |
1065 | e->src = bb; | |
cd665a06 | 1066 | for (ei = ei_start (ENTRY_BLOCK_PTR->succs); (tmp = ei_safe_edge (ei)); ) |
1067 | { | |
1068 | if (tmp == e) | |
1069 | { | |
55b71d24 | 1070 | VEC_unordered_remove (edge, ENTRY_BLOCK_PTR->succs, ei.index); |
cd665a06 | 1071 | found = true; |
1072 | break; | |
1073 | } | |
1074 | else | |
1075 | ei_next (&ei); | |
1076 | } | |
a0c938f0 | 1077 | |
cd665a06 | 1078 | gcc_assert (found); |
a0c938f0 | 1079 | |
046bfc77 | 1080 | VEC_safe_push (edge, gc, bb->succs, e); |
cc636d56 | 1081 | make_single_succ_edge (ENTRY_BLOCK_PTR, bb, EDGE_FALLTHRU); |
1082 | } | |
76cc9616 | 1083 | } |
1084 | ||
cd665a06 | 1085 | if (EDGE_COUNT (e->src->succs) >= 2 || abnormal_edge_flags) |
b36d64df | 1086 | { |
1087 | /* Create the new structures. */ | |
3160014e | 1088 | |
7a1fee99 | 1089 | /* If the old block ended with a tablejump, skip its table |
1090 | by searching forward from there. Otherwise start searching | |
1091 | forward from the last instruction of the old block. */ | |
5496dbfc | 1092 | if (!tablejump_p (BB_END (e->src), NULL, ¬e)) |
1093 | note = BB_END (e->src); | |
3160014e | 1094 | note = NEXT_INSN (note); |
1095 | ||
3160014e | 1096 | jump_block = create_basic_block (note, NULL, e->src); |
b36d64df | 1097 | jump_block->count = e->count; |
1098 | jump_block->frequency = EDGE_FREQUENCY (e); | |
1099 | jump_block->loop_depth = target->loop_depth; | |
1100 | ||
4f18499c | 1101 | /* Make sure new block ends up in correct hot/cold section. */ |
1102 | ||
7562ed74 | 1103 | BB_COPY_PARTITION (jump_block, e->src); |
065efcb1 | 1104 | if (flag_reorder_blocks_and_partition |
1897b881 | 1105 | && targetm.have_named_sections |
1106 | && JUMP_P (BB_END (jump_block)) | |
1107 | && !any_condjump_p (BB_END (jump_block)) | |
1108 | && (EDGE_SUCC (jump_block, 0)->flags & EDGE_CROSSING)) | |
1109 | REG_NOTES (BB_END (jump_block)) = gen_rtx_EXPR_LIST (REG_CROSSING_JUMP, | |
1110 | NULL_RTX, | |
1111 | REG_NOTES | |
1112 | (BB_END | |
a0c938f0 | 1113 | (jump_block))); |
1114 | ||
b36d64df | 1115 | /* Wire edge in. */ |
1116 | new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU); | |
1117 | new_edge->probability = e->probability; | |
1118 | new_edge->count = e->count; | |
1119 | ||
1120 | /* Redirect old edge. */ | |
1121 | redirect_edge_pred (e, jump_block); | |
1122 | e->probability = REG_BR_PROB_BASE; | |
1123 | ||
1124 | new_bb = jump_block; | |
1125 | } | |
1126 | else | |
1127 | jump_block = e->src; | |
5cc577b6 | 1128 | |
b36d64df | 1129 | e->flags &= ~EDGE_FALLTHRU; |
1130 | if (target == EXIT_BLOCK_PTR) | |
1131 | { | |
38c95e2f | 1132 | #ifdef HAVE_return |
0891f67c | 1133 | emit_jump_insn_after_noloc (gen_return (), BB_END (jump_block)); |
38c95e2f | 1134 | #else |
cc636d56 | 1135 | gcc_unreachable (); |
38c95e2f | 1136 | #endif |
b36d64df | 1137 | } |
1138 | else | |
1139 | { | |
1140 | rtx label = block_label (target); | |
0891f67c | 1141 | emit_jump_insn_after_noloc (gen_jump (label), BB_END (jump_block)); |
5496dbfc | 1142 | JUMP_LABEL (BB_END (jump_block)) = label; |
b36d64df | 1143 | LABEL_NUSES (label)++; |
1144 | } | |
5cc577b6 | 1145 | |
5496dbfc | 1146 | emit_barrier_after (BB_END (jump_block)); |
b36d64df | 1147 | redirect_edge_succ_nodup (e, target); |
1148 | ||
498d173d | 1149 | if (abnormal_edge_flags) |
1150 | make_edge (src, target, abnormal_edge_flags); | |
1151 | ||
3072d30e | 1152 | df_mark_solutions_dirty (); |
b36d64df | 1153 | return new_bb; |
1154 | } | |
1155 | ||
1156 | /* Edge E is assumed to be fallthru edge. Emit needed jump instruction | |
1157 | (and possibly create new basic block) to make edge non-fallthru. | |
1158 | Return newly created BB or NULL if none. */ | |
5cc577b6 | 1159 | |
b36d64df | 1160 | basic_block |
4c9e08a4 | 1161 | force_nonfallthru (edge e) |
b36d64df | 1162 | { |
1163 | return force_nonfallthru_and_redirect (e, e->dest); | |
1164 | } | |
1165 | ||
1166 | /* Redirect edge even at the expense of creating new jump insn or | |
1167 | basic block. Return new basic block if created, NULL otherwise. | |
a53ff4c1 | 1168 | Conversion must be possible. */ |
b36d64df | 1169 | |
1026363d | 1170 | static basic_block |
4c9e08a4 | 1171 | rtl_redirect_edge_and_branch_force (edge e, basic_block target) |
b36d64df | 1172 | { |
5cc577b6 | 1173 | if (redirect_edge_and_branch (e, target) |
1174 | || e->dest == target) | |
b36d64df | 1175 | return NULL; |
1176 | ||
1177 | /* In case the edge redirection failed, try to force it to be non-fallthru | |
1178 | and redirect newly created simplejump. */ | |
3072d30e | 1179 | df_set_bb_dirty (e->src); |
5cc577b6 | 1180 | return force_nonfallthru_and_redirect (e, target); |
b36d64df | 1181 | } |
1182 | ||
1183 | /* The given edge should potentially be a fallthru edge. If that is in | |
1184 | fact true, delete the jump and barriers that are in the way. */ | |
1185 | ||
5f5d4cd1 | 1186 | static void |
1187 | rtl_tidy_fallthru_edge (edge e) | |
b36d64df | 1188 | { |
1189 | rtx q; | |
5f5d4cd1 | 1190 | basic_block b = e->src, c = b->next_bb; |
1191 | ||
b36d64df | 1192 | /* ??? In a late-running flow pass, other folks may have deleted basic |
1193 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
442e3cb9 | 1194 | and the target label. They ought to be chastised and fixed. |
b36d64df | 1195 | |
1196 | We can also wind up with a sequence of undeletable labels between | |
1197 | one block and the next. | |
1198 | ||
1199 | So search through a sequence of barriers, labels, and notes for | |
1200 | the head of block C and assert that we really do fall through. */ | |
1201 | ||
5496dbfc | 1202 | for (q = NEXT_INSN (BB_END (b)); q != BB_HEAD (c); q = NEXT_INSN (q)) |
ac25a327 | 1203 | if (INSN_P (q)) |
1204 | return; | |
b36d64df | 1205 | |
1206 | /* Remove what will soon cease being the jump insn from the source block. | |
1207 | If block B consisted only of this single jump, turn it into a deleted | |
1208 | note. */ | |
5496dbfc | 1209 | q = BB_END (b); |
6d7dc5b9 | 1210 | if (JUMP_P (q) |
b36d64df | 1211 | && onlyjump_p (q) |
1212 | && (any_uncondjump_p (q) | |
ea091dfd | 1213 | || single_succ_p (b))) |
b36d64df | 1214 | { |
1215 | #ifdef HAVE_cc0 | |
1216 | /* If this was a conditional jump, we need to also delete | |
1217 | the insn that set cc0. */ | |
1218 | if (any_condjump_p (q) && only_sets_cc0_p (PREV_INSN (q))) | |
1219 | q = PREV_INSN (q); | |
1220 | #endif | |
1221 | ||
1222 | q = PREV_INSN (q); | |
b36d64df | 1223 | } |
1224 | ||
1225 | /* Selectively unlink the sequence. */ | |
5496dbfc | 1226 | if (q != PREV_INSN (BB_HEAD (c))) |
39257eb5 | 1227 | delete_insn_chain (NEXT_INSN (q), PREV_INSN (BB_HEAD (c)), false); |
b36d64df | 1228 | |
1229 | e->flags |= EDGE_FALLTHRU; | |
1230 | } | |
b36d64df | 1231 | \f |
5f5d4cd1 | 1232 | /* Should move basic block BB after basic block AFTER. NIY. */ |
1233 | ||
1234 | static bool | |
1235 | rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED, | |
1236 | basic_block after ATTRIBUTE_UNUSED) | |
1237 | { | |
1238 | return false; | |
1239 | } | |
1240 | ||
b36d64df | 1241 | /* Split a (typically critical) edge. Return the new block. |
a53ff4c1 | 1242 | The edge must not be abnormal. |
b36d64df | 1243 | |
1244 | ??? The code generally expects to be called on critical edges. | |
1245 | The case of a block ending in an unconditional jump to a | |
1246 | block with multiple predecessors is not handled optimally. */ | |
1247 | ||
9140e457 | 1248 | static basic_block |
4c9e08a4 | 1249 | rtl_split_edge (edge edge_in) |
b36d64df | 1250 | { |
1251 | basic_block bb; | |
b36d64df | 1252 | rtx before; |
1253 | ||
1254 | /* Abnormal edges cannot be split. */ | |
cc636d56 | 1255 | gcc_assert (!(edge_in->flags & EDGE_ABNORMAL)); |
b36d64df | 1256 | |
1257 | /* We are going to place the new block in front of edge destination. | |
4a82352a | 1258 | Avoid existence of fallthru predecessors. */ |
b36d64df | 1259 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) |
1260 | { | |
1261 | edge e; | |
cd665a06 | 1262 | edge_iterator ei; |
5cc577b6 | 1263 | |
cd665a06 | 1264 | FOR_EACH_EDGE (e, ei, edge_in->dest->preds) |
b36d64df | 1265 | if (e->flags & EDGE_FALLTHRU) |
1266 | break; | |
1267 | ||
1268 | if (e) | |
1269 | force_nonfallthru (e); | |
1270 | } | |
1271 | ||
588aadb7 | 1272 | /* Create the basic block note. */ |
1273 | if (edge_in->dest != EXIT_BLOCK_PTR) | |
5496dbfc | 1274 | before = BB_HEAD (edge_in->dest); |
b36d64df | 1275 | else |
1276 | before = NULL_RTX; | |
1277 | ||
9bb8a4af | 1278 | /* If this is a fall through edge to the exit block, the blocks might be |
1279 | not adjacent, and the right place is the after the source. */ | |
1280 | if (edge_in->flags & EDGE_FALLTHRU && edge_in->dest == EXIT_BLOCK_PTR) | |
1281 | { | |
1282 | before = NEXT_INSN (BB_END (edge_in->src)); | |
9bb8a4af | 1283 | bb = create_basic_block (before, NULL, edge_in->src); |
7562ed74 | 1284 | BB_COPY_PARTITION (bb, edge_in->src); |
9bb8a4af | 1285 | } |
1286 | else | |
065efcb1 | 1287 | { |
1288 | bb = create_basic_block (before, NULL, edge_in->dest->prev_bb); | |
7562ed74 | 1289 | /* ??? Why not edge_in->dest->prev_bb here? */ |
1290 | BB_COPY_PARTITION (bb, edge_in->dest); | |
065efcb1 | 1291 | } |
b36d64df | 1292 | |
805e22b2 | 1293 | make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU); |
b36d64df | 1294 | |
917bbcab | 1295 | /* For non-fallthru edges, we must adjust the predecessor's |
b36d64df | 1296 | jump instruction to target our new block. */ |
1297 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1298 | { | |
cc636d56 | 1299 | edge redirected = redirect_edge_and_branch (edge_in, bb); |
1300 | gcc_assert (redirected); | |
b36d64df | 1301 | } |
1302 | else | |
1303 | redirect_edge_succ (edge_in, bb); | |
1304 | ||
1305 | return bb; | |
1306 | } | |
1307 | ||
1308 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1309 | The new instructions and basic blocks (if any) will not appear in the | |
1310 | CFG until commit_edge_insertions is called. */ | |
1311 | ||
1312 | void | |
4c9e08a4 | 1313 | insert_insn_on_edge (rtx pattern, edge e) |
b36d64df | 1314 | { |
1315 | /* We cannot insert instructions on an abnormal critical edge. | |
1316 | It will be easier to find the culprit if we die now. */ | |
cc636d56 | 1317 | gcc_assert (!((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e))); |
b36d64df | 1318 | |
4ee9c684 | 1319 | if (e->insns.r == NULL_RTX) |
b36d64df | 1320 | start_sequence (); |
1321 | else | |
4ee9c684 | 1322 | push_to_sequence (e->insns.r); |
b36d64df | 1323 | |
1324 | emit_insn (pattern); | |
1325 | ||
4ee9c684 | 1326 | e->insns.r = get_insns (); |
b36d64df | 1327 | end_sequence (); |
1328 | } | |
1329 | ||
1330 | /* Update the CFG for the instructions queued on edge E. */ | |
1331 | ||
1332 | static void | |
ca462ec0 | 1333 | commit_one_edge_insertion (edge e) |
b36d64df | 1334 | { |
1335 | rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last; | |
f1593de0 | 1336 | basic_block bb = NULL; |
b36d64df | 1337 | |
1338 | /* Pull the insns off the edge now since the edge might go away. */ | |
4ee9c684 | 1339 | insns = e->insns.r; |
1340 | e->insns.r = NULL_RTX; | |
b36d64df | 1341 | |
fb20d6fa | 1342 | if (!before && !after) |
b36d64df | 1343 | { |
fb20d6fa | 1344 | /* Figure out where to put these things. If the destination has |
a0c938f0 | 1345 | one predecessor, insert there. Except for the exit block. */ |
ea091dfd | 1346 | if (single_pred_p (e->dest) && e->dest != EXIT_BLOCK_PTR) |
b36d64df | 1347 | { |
fb20d6fa | 1348 | bb = e->dest; |
1349 | ||
1350 | /* Get the location correct wrt a code label, and "nice" wrt | |
1351 | a basic block note, and before everything else. */ | |
5496dbfc | 1352 | tmp = BB_HEAD (bb); |
6d7dc5b9 | 1353 | if (LABEL_P (tmp)) |
fb20d6fa | 1354 | tmp = NEXT_INSN (tmp); |
1355 | if (NOTE_INSN_BASIC_BLOCK_P (tmp)) | |
1356 | tmp = NEXT_INSN (tmp); | |
5496dbfc | 1357 | if (tmp == BB_HEAD (bb)) |
fb20d6fa | 1358 | before = tmp; |
1359 | else if (tmp) | |
1360 | after = PREV_INSN (tmp); | |
1361 | else | |
1362 | after = get_last_insn (); | |
1363 | } | |
1364 | ||
1365 | /* If the source has one successor and the edge is not abnormal, | |
a0c938f0 | 1366 | insert there. Except for the entry block. */ |
fb20d6fa | 1367 | else if ((e->flags & EDGE_ABNORMAL) == 0 |
ea091dfd | 1368 | && single_succ_p (e->src) |
fb20d6fa | 1369 | && e->src != ENTRY_BLOCK_PTR) |
1370 | { | |
1371 | bb = e->src; | |
1372 | ||
1373 | /* It is possible to have a non-simple jump here. Consider a target | |
1374 | where some forms of unconditional jumps clobber a register. This | |
1375 | happens on the fr30 for example. | |
1376 | ||
1377 | We know this block has a single successor, so we can just emit | |
1378 | the queued insns before the jump. */ | |
6d7dc5b9 | 1379 | if (JUMP_P (BB_END (bb))) |
588aadb7 | 1380 | before = BB_END (bb); |
fb20d6fa | 1381 | else |
1382 | { | |
cc636d56 | 1383 | /* We'd better be fallthru, or we've lost track of |
1384 | what's what. */ | |
1385 | gcc_assert (e->flags & EDGE_FALLTHRU); | |
b36d64df | 1386 | |
5496dbfc | 1387 | after = BB_END (bb); |
fb20d6fa | 1388 | } |
1389 | } | |
1390 | /* Otherwise we must split the edge. */ | |
1391 | else | |
1392 | { | |
1393 | bb = split_edge (e); | |
5496dbfc | 1394 | after = BB_END (bb); |
4f18499c | 1395 | |
4f18499c | 1396 | if (flag_reorder_blocks_and_partition |
065efcb1 | 1397 | && targetm.have_named_sections |
4f18499c | 1398 | && e->src != ENTRY_BLOCK_PTR |
7562ed74 | 1399 | && BB_PARTITION (e->src) == BB_COLD_PARTITION |
9858d888 | 1400 | && !(e->flags & EDGE_CROSSING)) |
4f18499c | 1401 | { |
1897b881 | 1402 | rtx bb_note, cur_insn; |
4f18499c | 1403 | |
1404 | bb_note = NULL_RTX; | |
1405 | for (cur_insn = BB_HEAD (bb); cur_insn != NEXT_INSN (BB_END (bb)); | |
1406 | cur_insn = NEXT_INSN (cur_insn)) | |
ad4583d9 | 1407 | if (NOTE_INSN_BASIC_BLOCK_P (cur_insn)) |
4f18499c | 1408 | { |
1409 | bb_note = cur_insn; | |
1410 | break; | |
1411 | } | |
1412 | ||
6d7dc5b9 | 1413 | if (JUMP_P (BB_END (bb)) |
4f18499c | 1414 | && !any_condjump_p (BB_END (bb)) |
a0c938f0 | 1415 | && (single_succ_edge (bb)->flags & EDGE_CROSSING)) |
1416 | REG_NOTES (BB_END (bb)) = gen_rtx_EXPR_LIST | |
4f18499c | 1417 | (REG_CROSSING_JUMP, NULL_RTX, REG_NOTES (BB_END (bb))); |
4f18499c | 1418 | } |
b36d64df | 1419 | } |
1420 | } | |
1421 | ||
b36d64df | 1422 | /* Now that we've found the spot, do the insertion. */ |
1423 | ||
1424 | if (before) | |
1425 | { | |
3072d30e | 1426 | emit_insn_before_noloc (insns, before, bb); |
b36d64df | 1427 | last = prev_nonnote_insn (before); |
1428 | } | |
1429 | else | |
3072d30e | 1430 | last = emit_insn_after_noloc (insns, after, bb); |
b36d64df | 1431 | |
1432 | if (returnjump_p (last)) | |
1433 | { | |
1434 | /* ??? Remove all outgoing edges from BB and add one for EXIT. | |
a0c938f0 | 1435 | This is not currently a problem because this only happens |
1436 | for the (single) epilogue, which already has a fallthru edge | |
1437 | to EXIT. */ | |
b36d64df | 1438 | |
ea091dfd | 1439 | e = single_succ_edge (bb); |
cc636d56 | 1440 | gcc_assert (e->dest == EXIT_BLOCK_PTR |
ea091dfd | 1441 | && single_succ_p (bb) && (e->flags & EDGE_FALLTHRU)); |
b36d64df | 1442 | |
5cc577b6 | 1443 | e->flags &= ~EDGE_FALLTHRU; |
b36d64df | 1444 | emit_barrier_after (last); |
b3d6de89 | 1445 | |
b36d64df | 1446 | if (before) |
1447 | delete_insn (before); | |
1448 | } | |
cc636d56 | 1449 | else |
1450 | gcc_assert (!JUMP_P (last)); | |
5cc577b6 | 1451 | |
794d8e3f | 1452 | /* Mark the basic block for find_many_sub_basic_blocks. */ |
eea7b156 | 1453 | if (current_ir_type () != IR_RTL_CFGLAYOUT) |
1454 | bb->aux = &bb->aux; | |
b36d64df | 1455 | } |
1456 | ||
1457 | /* Update the CFG for all queued instructions. */ | |
1458 | ||
1459 | void | |
4c9e08a4 | 1460 | commit_edge_insertions (void) |
b36d64df | 1461 | { |
b36d64df | 1462 | basic_block bb; |
43585301 | 1463 | sbitmap blocks; |
c96040c6 | 1464 | bool changed = false; |
b36d64df | 1465 | |
1466 | #ifdef ENABLE_CHECKING | |
1467 | verify_flow_info (); | |
1468 | #endif | |
1469 | ||
4c26117a | 1470 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
b36d64df | 1471 | { |
cd665a06 | 1472 | edge e; |
1473 | edge_iterator ei; | |
b36d64df | 1474 | |
cd665a06 | 1475 | FOR_EACH_EDGE (e, ei, bb->succs) |
1476 | if (e->insns.r) | |
1477 | { | |
1478 | changed = true; | |
ca462ec0 | 1479 | commit_one_edge_insertion (e); |
cd665a06 | 1480 | } |
fb20d6fa | 1481 | } |
43585301 | 1482 | |
c96040c6 | 1483 | if (!changed) |
1484 | return; | |
1485 | ||
eea7b156 | 1486 | /* In the old rtl CFG API, it was OK to insert control flow on an |
1487 | edge, apparently? In cfglayout mode, this will *not* work, and | |
1488 | the caller is responsible for making sure that control flow is | |
1489 | valid at all times. */ | |
1490 | if (current_ir_type () == IR_RTL_CFGLAYOUT) | |
1491 | return; | |
1492 | ||
c96040c6 | 1493 | blocks = sbitmap_alloc (last_basic_block); |
1494 | sbitmap_zero (blocks); | |
1495 | FOR_EACH_BB (bb) | |
1496 | if (bb->aux) | |
1497 | { | |
a0c938f0 | 1498 | SET_BIT (blocks, bb->index); |
c96040c6 | 1499 | /* Check for forgotten bb->aux values before commit_edge_insertions |
1500 | call. */ | |
cc636d56 | 1501 | gcc_assert (bb->aux == &bb->aux); |
c96040c6 | 1502 | bb->aux = NULL; |
1503 | } | |
1504 | find_many_sub_basic_blocks (blocks); | |
1505 | sbitmap_free (blocks); | |
b36d64df | 1506 | } |
1507 | \f | |
3072d30e | 1508 | |
5f5d4cd1 | 1509 | /* Print out RTL-specific basic block information (live information |
1510 | at start and end). */ | |
b36d64df | 1511 | |
028f8cc7 | 1512 | static void |
5f5d4cd1 | 1513 | rtl_dump_bb (basic_block bb, FILE *outf, int indent) |
b36d64df | 1514 | { |
1515 | rtx insn; | |
1516 | rtx last; | |
5f5d4cd1 | 1517 | char *s_indent; |
b36d64df | 1518 | |
f780cc25 | 1519 | s_indent = (char *) alloca ((size_t) indent + 1); |
4acc30e5 | 1520 | memset (s_indent, ' ', (size_t) indent); |
5f5d4cd1 | 1521 | s_indent[indent] = '\0'; |
3072d30e | 1522 | |
1523 | if (df) | |
1524 | { | |
1525 | df_dump_top (bb, outf); | |
1526 | putc ('\n', outf); | |
1527 | } | |
b36d64df | 1528 | |
5496dbfc | 1529 | for (insn = BB_HEAD (bb), last = NEXT_INSN (BB_END (bb)); insn != last; |
b36d64df | 1530 | insn = NEXT_INSN (insn)) |
1531 | print_rtl_single (outf, insn); | |
1532 | ||
3072d30e | 1533 | if (df) |
1534 | { | |
1535 | df_dump_bottom (bb, outf); | |
1536 | putc ('\n', outf); | |
1537 | } | |
1538 | ||
b36d64df | 1539 | } |
1540 | \f | |
1541 | /* Like print_rtl, but also print out live information for the start of each | |
1542 | basic block. */ | |
1543 | ||
1544 | void | |
4c9e08a4 | 1545 | print_rtl_with_bb (FILE *outf, rtx rtx_first) |
b36d64df | 1546 | { |
19cb6b50 | 1547 | rtx tmp_rtx; |
b36d64df | 1548 | if (rtx_first == 0) |
1549 | fprintf (outf, "(nil)\n"); | |
1550 | else | |
1551 | { | |
b36d64df | 1552 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
1553 | int max_uid = get_max_uid (); | |
4c36ffe6 | 1554 | basic_block *start = XCNEWVEC (basic_block, max_uid); |
1555 | basic_block *end = XCNEWVEC (basic_block, max_uid); | |
1556 | enum bb_state *in_bb_p = XCNEWVEC (enum bb_state, max_uid); | |
b36d64df | 1557 | |
4c26117a | 1558 | basic_block bb; |
1559 | ||
3072d30e | 1560 | if (df) |
1561 | df_dump_start (outf); | |
1562 | ||
4c26117a | 1563 | FOR_EACH_BB_REVERSE (bb) |
b36d64df | 1564 | { |
b36d64df | 1565 | rtx x; |
1566 | ||
5496dbfc | 1567 | start[INSN_UID (BB_HEAD (bb))] = bb; |
1568 | end[INSN_UID (BB_END (bb))] = bb; | |
1569 | for (x = BB_HEAD (bb); x != NULL_RTX; x = NEXT_INSN (x)) | |
b36d64df | 1570 | { |
1571 | enum bb_state state = IN_MULTIPLE_BB; | |
5cc577b6 | 1572 | |
b36d64df | 1573 | if (in_bb_p[INSN_UID (x)] == NOT_IN_BB) |
1574 | state = IN_ONE_BB; | |
1575 | in_bb_p[INSN_UID (x)] = state; | |
1576 | ||
5496dbfc | 1577 | if (x == BB_END (bb)) |
b36d64df | 1578 | break; |
1579 | } | |
1580 | } | |
1581 | ||
1582 | for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) | |
1583 | { | |
1584 | int did_output; | |
b36d64df | 1585 | if ((bb = start[INSN_UID (tmp_rtx)]) != NULL) |
1586 | { | |
3072d30e | 1587 | edge e; |
1588 | edge_iterator ei; | |
1589 | ||
1590 | fprintf (outf, ";; Start of basic block ("); | |
1591 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1592 | fprintf (outf, " %d", e->src->index); | |
1593 | fprintf (outf, ") -> %d\n", bb->index); | |
1594 | ||
1595 | if (df) | |
1596 | { | |
1597 | df_dump_top (bb, outf); | |
1598 | putc ('\n', outf); | |
1599 | } | |
3471582e | 1600 | FOR_EACH_EDGE (e, ei, bb->preds) |
1601 | { | |
1602 | fputs (";; Pred edge ", outf); | |
1603 | dump_edge_info (outf, e, 0); | |
1604 | fputc ('\n', outf); | |
1605 | } | |
b36d64df | 1606 | } |
1607 | ||
1608 | if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB | |
6d7dc5b9 | 1609 | && !NOTE_P (tmp_rtx) |
1610 | && !BARRIER_P (tmp_rtx)) | |
b36d64df | 1611 | fprintf (outf, ";; Insn is not within a basic block\n"); |
1612 | else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB) | |
1613 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); | |
1614 | ||
1615 | did_output = print_rtl_single (outf, tmp_rtx); | |
1616 | ||
1617 | if ((bb = end[INSN_UID (tmp_rtx)]) != NULL) | |
1618 | { | |
3072d30e | 1619 | edge e; |
1620 | edge_iterator ei; | |
1621 | ||
1622 | fprintf (outf, ";; End of basic block %d -> (", bb->index); | |
1623 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1624 | fprintf (outf, " %d", e->dest->index); | |
1625 | fprintf (outf, ")\n"); | |
1626 | ||
1627 | if (df) | |
1628 | { | |
1629 | df_dump_bottom (bb, outf); | |
1630 | putc ('\n', outf); | |
1631 | } | |
b36d64df | 1632 | putc ('\n', outf); |
3471582e | 1633 | FOR_EACH_EDGE (e, ei, bb->succs) |
1634 | { | |
1635 | fputs (";; Succ edge ", outf); | |
1636 | dump_edge_info (outf, e, 1); | |
1637 | fputc ('\n', outf); | |
1638 | } | |
b36d64df | 1639 | } |
b36d64df | 1640 | if (did_output) |
1641 | putc ('\n', outf); | |
1642 | } | |
1643 | ||
1644 | free (start); | |
1645 | free (end); | |
1646 | free (in_bb_p); | |
1647 | } | |
1648 | ||
1649 | if (current_function_epilogue_delay_list != 0) | |
1650 | { | |
1651 | fprintf (outf, "\n;; Insns in epilogue delay list:\n\n"); | |
1652 | for (tmp_rtx = current_function_epilogue_delay_list; tmp_rtx != 0; | |
1653 | tmp_rtx = XEXP (tmp_rtx, 1)) | |
1654 | print_rtl_single (outf, XEXP (tmp_rtx, 0)); | |
1655 | } | |
1656 | } | |
1657 | \f | |
f884e43f | 1658 | void |
4c9e08a4 | 1659 | update_br_prob_note (basic_block bb) |
f884e43f | 1660 | { |
1661 | rtx note; | |
6d7dc5b9 | 1662 | if (!JUMP_P (BB_END (bb))) |
f884e43f | 1663 | return; |
5496dbfc | 1664 | note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX); |
f884e43f | 1665 | if (!note || INTVAL (XEXP (note, 0)) == BRANCH_EDGE (bb)->probability) |
1666 | return; | |
1667 | XEXP (note, 0) = GEN_INT (BRANCH_EDGE (bb)->probability); | |
1668 | } | |
5d65a39c | 1669 | |
1670 | /* Get the last insn associated with block BB (that includes barriers and | |
1671 | tablejumps after BB). */ | |
1672 | rtx | |
1673 | get_last_bb_insn (basic_block bb) | |
1674 | { | |
1675 | rtx tmp; | |
1676 | rtx end = BB_END (bb); | |
1677 | ||
1678 | /* Include any jump table following the basic block. */ | |
1679 | if (tablejump_p (end, NULL, &tmp)) | |
1680 | end = tmp; | |
1681 | ||
1682 | /* Include any barriers that may follow the basic block. */ | |
1683 | tmp = next_nonnote_insn (end); | |
1684 | while (tmp && BARRIER_P (tmp)) | |
1685 | { | |
1686 | end = tmp; | |
1687 | tmp = next_nonnote_insn (end); | |
1688 | } | |
1689 | ||
1690 | return end; | |
1691 | } | |
f884e43f | 1692 | \f |
028f8cc7 | 1693 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
1694 | cfglayout RTL. | |
b36d64df | 1695 | |
1696 | Currently it does following checks: | |
1697 | ||
b36d64df | 1698 | - overlapping of basic blocks |
fcde5c9e | 1699 | - insns with wrong BLOCK_FOR_INSN pointers |
b36d64df | 1700 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) |
dd5b4b36 | 1701 | - tails of basic blocks (ensure that boundary is necessary) |
b36d64df | 1702 | - scans body of the basic block for JUMP_INSN, CODE_LABEL |
1703 | and NOTE_INSN_BASIC_BLOCK | |
4f18499c | 1704 | - verify that no fall_thru edge crosses hot/cold partition boundaries |
fcde5c9e | 1705 | - verify that there are no pending RTL branch predictions |
b36d64df | 1706 | |
1707 | In future it can be extended check a lot of other stuff as well | |
1708 | (reachability of basic blocks, life information, etc. etc.). */ | |
5f5d4cd1 | 1709 | |
028f8cc7 | 1710 | static int |
4c9e08a4 | 1711 | rtl_verify_flow_info_1 (void) |
b36d64df | 1712 | { |
b36d64df | 1713 | rtx x; |
028f8cc7 | 1714 | int err = 0; |
d207f783 | 1715 | basic_block bb; |
b36d64df | 1716 | |
fcde5c9e | 1717 | /* Check the general integrity of the basic blocks. */ |
4c26117a | 1718 | FOR_EACH_BB_REVERSE (bb) |
b36d64df | 1719 | { |
fcde5c9e | 1720 | rtx insn; |
5cc577b6 | 1721 | |
e0dde8f8 | 1722 | if (!(bb->flags & BB_RTL)) |
1723 | { | |
1724 | error ("BB_RTL flag not set for block %d", bb->index); | |
1725 | err = 1; | |
1726 | } | |
1727 | ||
fcde5c9e | 1728 | FOR_BB_INSNS (bb, insn) |
1729 | if (BLOCK_FOR_INSN (insn) != bb) | |
1730 | { | |
1731 | error ("insn %d basic block pointer is %d, should be %d", | |
1732 | INSN_UID (insn), | |
1733 | BLOCK_FOR_INSN (insn) ? BLOCK_FOR_INSN (insn)->index : 0, | |
1734 | bb->index); | |
1735 | err = 1; | |
1736 | } | |
39257eb5 | 1737 | |
1738 | for (insn = bb->il.rtl->header; insn; insn = NEXT_INSN (insn)) | |
1739 | if (!BARRIER_P (insn) | |
1740 | && BLOCK_FOR_INSN (insn) != NULL) | |
1741 | { | |
1742 | error ("insn %d in header of bb %d has non-NULL basic block", | |
1743 | INSN_UID (insn), bb->index); | |
1744 | err = 1; | |
1745 | } | |
1746 | for (insn = bb->il.rtl->footer; insn; insn = NEXT_INSN (insn)) | |
1747 | if (!BARRIER_P (insn) | |
1748 | && BLOCK_FOR_INSN (insn) != NULL) | |
1749 | { | |
1750 | error ("insn %d in footer of bb %d has non-NULL basic block", | |
1751 | INSN_UID (insn), bb->index); | |
1752 | err = 1; | |
1753 | } | |
b36d64df | 1754 | } |
1755 | ||
1756 | /* Now check the basic blocks (boundaries etc.) */ | |
4c26117a | 1757 | FOR_EACH_BB_REVERSE (bb) |
b36d64df | 1758 | { |
fb20d6fa | 1759 | int n_fallthru = 0, n_eh = 0, n_call = 0, n_abnormal = 0, n_branch = 0; |
e6261ab0 | 1760 | edge e, fallthru = NULL; |
a2e42321 | 1761 | rtx note; |
cd665a06 | 1762 | edge_iterator ei; |
b36d64df | 1763 | |
e6d1500f | 1764 | if (JUMP_P (BB_END (bb)) |
5496dbfc | 1765 | && (note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX)) |
cd665a06 | 1766 | && EDGE_COUNT (bb->succs) >= 2 |
5496dbfc | 1767 | && any_condjump_p (BB_END (bb))) |
a2e42321 | 1768 | { |
d8c70625 | 1769 | if (INTVAL (XEXP (note, 0)) != BRANCH_EDGE (bb)->probability |
1770 | && profile_status != PROFILE_ABSENT) | |
a2e42321 | 1771 | { |
d9f38790 | 1772 | error ("verify_flow_info: REG_BR_PROB does not match cfg %wi %i", |
a2e42321 | 1773 | INTVAL (XEXP (note, 0)), BRANCH_EDGE (bb)->probability); |
1774 | err = 1; | |
1775 | } | |
1776 | } | |
cd665a06 | 1777 | FOR_EACH_EDGE (e, ei, bb->succs) |
b36d64df | 1778 | { |
b36d64df | 1779 | if (e->flags & EDGE_FALLTHRU) |
4f18499c | 1780 | { |
1781 | n_fallthru++, fallthru = e; | |
9858d888 | 1782 | if ((e->flags & EDGE_CROSSING) |
7562ed74 | 1783 | || (BB_PARTITION (e->src) != BB_PARTITION (e->dest) |
065efcb1 | 1784 | && e->src != ENTRY_BLOCK_PTR |
1785 | && e->dest != EXIT_BLOCK_PTR)) | |
a0c938f0 | 1786 | { |
0a81f5a0 | 1787 | error ("fallthru edge crosses section boundary (bb %i)", |
4f18499c | 1788 | e->src->index); |
1789 | err = 1; | |
1790 | } | |
1791 | } | |
fb20d6fa | 1792 | |
7f42fe24 | 1793 | if ((e->flags & ~(EDGE_DFS_BACK |
1794 | | EDGE_CAN_FALLTHRU | |
1795 | | EDGE_IRREDUCIBLE_LOOP | |
f50b5bd0 | 1796 | | EDGE_LOOP_EXIT |
1797 | | EDGE_CROSSING)) == 0) | |
fb20d6fa | 1798 | n_branch++; |
1799 | ||
1800 | if (e->flags & EDGE_ABNORMAL_CALL) | |
1801 | n_call++; | |
1802 | ||
1803 | if (e->flags & EDGE_EH) | |
1804 | n_eh++; | |
1805 | else if (e->flags & EDGE_ABNORMAL) | |
1806 | n_abnormal++; | |
b36d64df | 1807 | } |
5cc577b6 | 1808 | |
5496dbfc | 1809 | if (n_eh && GET_CODE (PATTERN (BB_END (bb))) != RESX |
1810 | && !find_reg_note (BB_END (bb), REG_EH_REGION, NULL_RTX)) | |
fb20d6fa | 1811 | { |
0a81f5a0 | 1812 | error ("missing REG_EH_REGION note in the end of bb %i", bb->index); |
fb20d6fa | 1813 | err = 1; |
1814 | } | |
1815 | if (n_branch | |
6d7dc5b9 | 1816 | && (!JUMP_P (BB_END (bb)) |
5496dbfc | 1817 | || (n_branch > 1 && (any_uncondjump_p (BB_END (bb)) |
1818 | || any_condjump_p (BB_END (bb)))))) | |
fb20d6fa | 1819 | { |
0a81f5a0 | 1820 | error ("too many outgoing branch edges from bb %i", bb->index); |
fb20d6fa | 1821 | err = 1; |
1822 | } | |
5496dbfc | 1823 | if (n_fallthru && any_uncondjump_p (BB_END (bb))) |
fb20d6fa | 1824 | { |
0a81f5a0 | 1825 | error ("fallthru edge after unconditional jump %i", bb->index); |
fb20d6fa | 1826 | err = 1; |
1827 | } | |
5496dbfc | 1828 | if (n_branch != 1 && any_uncondjump_p (BB_END (bb))) |
fb20d6fa | 1829 | { |
0a81f5a0 | 1830 | error ("wrong amount of branch edges after unconditional jump %i", bb->index); |
fb20d6fa | 1831 | err = 1; |
1832 | } | |
5496dbfc | 1833 | if (n_branch != 1 && any_condjump_p (BB_END (bb)) |
8345ac1a | 1834 | && JUMP_LABEL (BB_END (bb)) != BB_HEAD (fallthru->dest)) |
fb20d6fa | 1835 | { |
8345ac1a | 1836 | error ("wrong amount of branch edges after conditional jump %i", |
1837 | bb->index); | |
fb20d6fa | 1838 | err = 1; |
1839 | } | |
6d7dc5b9 | 1840 | if (n_call && !CALL_P (BB_END (bb))) |
fb20d6fa | 1841 | { |
0a81f5a0 | 1842 | error ("call edges for non-call insn in bb %i", bb->index); |
fb20d6fa | 1843 | err = 1; |
1844 | } | |
1845 | if (n_abnormal | |
6d7dc5b9 | 1846 | && (!CALL_P (BB_END (bb)) && n_call != n_abnormal) |
1847 | && (!JUMP_P (BB_END (bb)) | |
5496dbfc | 1848 | || any_condjump_p (BB_END (bb)) |
1849 | || any_uncondjump_p (BB_END (bb)))) | |
fb20d6fa | 1850 | { |
0a81f5a0 | 1851 | error ("abnormal edges for no purpose in bb %i", bb->index); |
fb20d6fa | 1852 | err = 1; |
1853 | } | |
db34a109 | 1854 | |
5496dbfc | 1855 | for (x = BB_HEAD (bb); x != NEXT_INSN (BB_END (bb)); x = NEXT_INSN (x)) |
fdd27295 | 1856 | /* We may have a barrier inside a basic block before dead code |
f5310810 | 1857 | elimination. There is no BLOCK_FOR_INSN field in a barrier. */ |
1858 | if (!BARRIER_P (x) && BLOCK_FOR_INSN (x) != bb) | |
5cc577b6 | 1859 | { |
1860 | debug_rtx (x); | |
1861 | if (! BLOCK_FOR_INSN (x)) | |
1862 | error | |
1863 | ("insn %d inside basic block %d but block_for_insn is NULL", | |
b3d6de89 | 1864 | INSN_UID (x), bb->index); |
5cc577b6 | 1865 | else |
1866 | error | |
1867 | ("insn %d inside basic block %d but block_for_insn is %i", | |
b3d6de89 | 1868 | INSN_UID (x), bb->index, BLOCK_FOR_INSN (x)->index); |
5cc577b6 | 1869 | |
1870 | err = 1; | |
1871 | } | |
b36d64df | 1872 | |
1873 | /* OK pointers are correct. Now check the header of basic | |
a0c938f0 | 1874 | block. It ought to contain optional CODE_LABEL followed |
b36d64df | 1875 | by NOTE_BASIC_BLOCK. */ |
5496dbfc | 1876 | x = BB_HEAD (bb); |
6d7dc5b9 | 1877 | if (LABEL_P (x)) |
b36d64df | 1878 | { |
5496dbfc | 1879 | if (BB_END (bb) == x) |
b36d64df | 1880 | { |
1881 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
b3d6de89 | 1882 | bb->index); |
b36d64df | 1883 | err = 1; |
1884 | } | |
5cc577b6 | 1885 | |
b36d64df | 1886 | x = NEXT_INSN (x); |
1887 | } | |
5cc577b6 | 1888 | |
b36d64df | 1889 | if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb) |
1890 | { | |
1891 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
b3d6de89 | 1892 | bb->index); |
b36d64df | 1893 | err = 1; |
1894 | } | |
1895 | ||
5496dbfc | 1896 | if (BB_END (bb) == x) |
f3e2a363 | 1897 | /* Do checks for empty blocks here. */ |
5cc577b6 | 1898 | ; |
b36d64df | 1899 | else |
5cc577b6 | 1900 | for (x = NEXT_INSN (x); x; x = NEXT_INSN (x)) |
1901 | { | |
1902 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
1903 | { | |
1904 | error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d", | |
b3d6de89 | 1905 | INSN_UID (x), bb->index); |
5cc577b6 | 1906 | err = 1; |
1907 | } | |
1908 | ||
5496dbfc | 1909 | if (x == BB_END (bb)) |
5cc577b6 | 1910 | break; |
b36d64df | 1911 | |
aaf52ffb | 1912 | if (control_flow_insn_p (x)) |
5cc577b6 | 1913 | { |
b3d6de89 | 1914 | error ("in basic block %d:", bb->index); |
5cc577b6 | 1915 | fatal_insn ("flow control insn inside a basic block", x); |
1916 | } | |
1917 | } | |
b36d64df | 1918 | } |
1919 | ||
028f8cc7 | 1920 | /* Clean up. */ |
028f8cc7 | 1921 | return err; |
1922 | } | |
5cc577b6 | 1923 | |
028f8cc7 | 1924 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
1925 | cfglayout RTL. | |
5cc577b6 | 1926 | |
028f8cc7 | 1927 | Currently it does following checks: |
1928 | - all checks of rtl_verify_flow_info_1 | |
fcde5c9e | 1929 | - test head/end pointers |
028f8cc7 | 1930 | - check that all insns are in the basic blocks |
1931 | (except the switch handling code, barriers and notes) | |
1932 | - check that all returns are followed by barriers | |
1933 | - check that all fallthru edge points to the adjacent blocks. */ | |
fcde5c9e | 1934 | |
028f8cc7 | 1935 | static int |
4c9e08a4 | 1936 | rtl_verify_flow_info (void) |
028f8cc7 | 1937 | { |
1938 | basic_block bb; | |
1939 | int err = rtl_verify_flow_info_1 (); | |
1940 | rtx x; | |
fcde5c9e | 1941 | rtx last_head = get_last_insn (); |
1942 | basic_block *bb_info; | |
028f8cc7 | 1943 | int num_bb_notes; |
1944 | const rtx rtx_first = get_insns (); | |
1945 | basic_block last_bb_seen = ENTRY_BLOCK_PTR, curr_bb = NULL; | |
fcde5c9e | 1946 | const int max_uid = get_max_uid (); |
1947 | ||
1948 | bb_info = XCNEWVEC (basic_block, max_uid); | |
b36d64df | 1949 | |
028f8cc7 | 1950 | FOR_EACH_BB_REVERSE (bb) |
1951 | { | |
1952 | edge e; | |
cd665a06 | 1953 | edge_iterator ei; |
fcde5c9e | 1954 | rtx head = BB_HEAD (bb); |
1955 | rtx end = BB_END (bb); | |
cd665a06 | 1956 | |
fcde5c9e | 1957 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) |
39257eb5 | 1958 | { |
1959 | /* Verify the end of the basic block is in the INSN chain. */ | |
1960 | if (x == end) | |
1961 | break; | |
1962 | ||
1963 | /* And that the code outside of basic blocks has NULL bb field. */ | |
1964 | if (!BARRIER_P (x) | |
1965 | && BLOCK_FOR_INSN (x) != NULL) | |
1966 | { | |
1967 | error ("insn %d outside of basic blocks has non-NULL bb field", | |
1968 | INSN_UID (x)); | |
1969 | err = 1; | |
1970 | } | |
1971 | } | |
fcde5c9e | 1972 | |
1973 | if (!x) | |
1974 | { | |
1975 | error ("end insn %d for block %d not found in the insn stream", | |
1976 | INSN_UID (end), bb->index); | |
1977 | err = 1; | |
1978 | } | |
1979 | ||
1980 | /* Work backwards from the end to the head of the basic block | |
1981 | to verify the head is in the RTL chain. */ | |
1982 | for (; x != NULL_RTX; x = PREV_INSN (x)) | |
d5043f32 | 1983 | { |
fcde5c9e | 1984 | /* While walking over the insn chain, verify insns appear |
1985 | in only one basic block. */ | |
1986 | if (bb_info[INSN_UID (x)] != NULL) | |
1987 | { | |
1988 | error ("insn %d is in multiple basic blocks (%d and %d)", | |
1989 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); | |
1990 | err = 1; | |
1991 | } | |
1992 | ||
1993 | bb_info[INSN_UID (x)] = bb; | |
1994 | ||
1995 | if (x == head) | |
1996 | break; | |
1997 | } | |
1998 | if (!x) | |
1999 | { | |
2000 | error ("head insn %d for block %d not found in the insn stream", | |
2001 | INSN_UID (head), bb->index); | |
d5043f32 | 2002 | err = 1; |
2003 | } | |
2004 | ||
39257eb5 | 2005 | last_head = PREV_INSN (x); |
fcde5c9e | 2006 | |
cd665a06 | 2007 | FOR_EACH_EDGE (e, ei, bb->succs) |
028f8cc7 | 2008 | if (e->flags & EDGE_FALLTHRU) |
2009 | break; | |
2010 | if (!e) | |
2011 | { | |
2012 | rtx insn; | |
2013 | ||
2014 | /* Ensure existence of barrier in BB with no fallthru edges. */ | |
6d7dc5b9 | 2015 | for (insn = BB_END (bb); !insn || !BARRIER_P (insn); |
028f8cc7 | 2016 | insn = NEXT_INSN (insn)) |
2017 | if (!insn | |
ad4583d9 | 2018 | || NOTE_INSN_BASIC_BLOCK_P (insn)) |
028f8cc7 | 2019 | { |
2020 | error ("missing barrier after block %i", bb->index); | |
2021 | err = 1; | |
2022 | break; | |
2023 | } | |
2024 | } | |
2025 | else if (e->src != ENTRY_BLOCK_PTR | |
2026 | && e->dest != EXIT_BLOCK_PTR) | |
a0c938f0 | 2027 | { |
028f8cc7 | 2028 | rtx insn; |
2029 | ||
2030 | if (e->src->next_bb != e->dest) | |
2031 | { | |
2032 | error | |
2033 | ("verify_flow_info: Incorrect blocks for fallthru %i->%i", | |
2034 | e->src->index, e->dest->index); | |
2035 | err = 1; | |
2036 | } | |
2037 | else | |
5496dbfc | 2038 | for (insn = NEXT_INSN (BB_END (e->src)); insn != BB_HEAD (e->dest); |
028f8cc7 | 2039 | insn = NEXT_INSN (insn)) |
ac7d3688 | 2040 | if (BARRIER_P (insn) || INSN_P (insn)) |
028f8cc7 | 2041 | { |
2042 | error ("verify_flow_info: Incorrect fallthru %i->%i", | |
2043 | e->src->index, e->dest->index); | |
2044 | fatal_insn ("wrong insn in the fallthru edge", insn); | |
2045 | err = 1; | |
2046 | } | |
a0c938f0 | 2047 | } |
028f8cc7 | 2048 | } |
b36d64df | 2049 | |
39257eb5 | 2050 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) |
2051 | { | |
2052 | /* Check that the code before the first basic block has NULL | |
2053 | bb field. */ | |
2054 | if (!BARRIER_P (x) | |
2055 | && BLOCK_FOR_INSN (x) != NULL) | |
2056 | { | |
2057 | error ("insn %d outside of basic blocks has non-NULL bb field", | |
2058 | INSN_UID (x)); | |
2059 | err = 1; | |
2060 | } | |
2061 | } | |
fcde5c9e | 2062 | free (bb_info); |
2063 | ||
b36d64df | 2064 | num_bb_notes = 0; |
4c26117a | 2065 | last_bb_seen = ENTRY_BLOCK_PTR; |
2066 | ||
5cc577b6 | 2067 | for (x = rtx_first; x; x = NEXT_INSN (x)) |
b36d64df | 2068 | { |
2069 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2070 | { | |
3c0a32c9 | 2071 | bb = NOTE_BASIC_BLOCK (x); |
5cc577b6 | 2072 | |
b36d64df | 2073 | num_bb_notes++; |
4c26117a | 2074 | if (bb != last_bb_seen->next_bb) |
028f8cc7 | 2075 | internal_error ("basic blocks not laid down consecutively"); |
b36d64df | 2076 | |
028f8cc7 | 2077 | curr_bb = last_bb_seen = bb; |
b36d64df | 2078 | } |
2079 | ||
028f8cc7 | 2080 | if (!curr_bb) |
b36d64df | 2081 | { |
2082 | switch (GET_CODE (x)) | |
2083 | { | |
2084 | case BARRIER: | |
2085 | case NOTE: | |
2086 | break; | |
2087 | ||
2088 | case CODE_LABEL: | |
af6ed417 | 2089 | /* An addr_vec is placed outside any basic block. */ |
b36d64df | 2090 | if (NEXT_INSN (x) |
6d7dc5b9 | 2091 | && JUMP_P (NEXT_INSN (x)) |
b36d64df | 2092 | && (GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_DIFF_VEC |
2093 | || GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_VEC)) | |
5cc577b6 | 2094 | x = NEXT_INSN (x); |
b36d64df | 2095 | |
2096 | /* But in any case, non-deletable labels can appear anywhere. */ | |
2097 | break; | |
2098 | ||
2099 | default: | |
cb8bacb6 | 2100 | fatal_insn ("insn outside basic block", x); |
b36d64df | 2101 | } |
2102 | } | |
2103 | ||
345f9e8c | 2104 | if (JUMP_P (x) |
b36d64df | 2105 | && returnjump_p (x) && ! condjump_p (x) |
8fcc0f14 | 2106 | && ! (next_nonnote_insn (x) && BARRIER_P (next_nonnote_insn (x)))) |
cb8bacb6 | 2107 | fatal_insn ("return not followed by barrier", x); |
5496dbfc | 2108 | if (curr_bb && x == BB_END (curr_bb)) |
028f8cc7 | 2109 | curr_bb = NULL; |
b36d64df | 2110 | } |
2111 | ||
4d2e5d52 | 2112 | if (num_bb_notes != n_basic_blocks - NUM_FIXED_BLOCKS) |
b36d64df | 2113 | internal_error |
b3d6de89 | 2114 | ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)", |
2115 | num_bb_notes, n_basic_blocks); | |
b36d64df | 2116 | |
028f8cc7 | 2117 | return err; |
b36d64df | 2118 | } |
2119 | \f | |
4a82352a | 2120 | /* Assume that the preceding pass has possibly eliminated jump instructions |
b36d64df | 2121 | or converted the unconditional jumps. Eliminate the edges from CFG. |
2122 | Return true if any edges are eliminated. */ | |
2123 | ||
2124 | bool | |
4c9e08a4 | 2125 | purge_dead_edges (basic_block bb) |
b36d64df | 2126 | { |
cd665a06 | 2127 | edge e; |
5496dbfc | 2128 | rtx insn = BB_END (bb), note; |
b36d64df | 2129 | bool purged = false; |
cd665a06 | 2130 | bool found; |
2131 | edge_iterator ei; | |
b36d64df | 2132 | |
11808932 | 2133 | /* If this instruction cannot trap, remove REG_EH_REGION notes. */ |
6d7dc5b9 | 2134 | if (NONJUMP_INSN_P (insn) |
11808932 | 2135 | && (note = find_reg_note (insn, REG_EH_REGION, NULL))) |
2136 | { | |
2137 | rtx eqnote; | |
2138 | ||
2139 | if (! may_trap_p (PATTERN (insn)) | |
2140 | || ((eqnote = find_reg_equal_equiv_note (insn)) | |
2141 | && ! may_trap_p (XEXP (eqnote, 0)))) | |
2142 | remove_note (insn, note); | |
2143 | } | |
2144 | ||
f178f44b | 2145 | /* Cleanup abnormal edges caused by exceptions or non-local gotos. */ |
cd665a06 | 2146 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
f178f44b | 2147 | { |
04166d08 | 2148 | /* There are three types of edges we need to handle correctly here: EH |
2149 | edges, abnormal call EH edges, and abnormal call non-EH edges. The | |
2150 | latter can appear when nonlocal gotos are used. */ | |
2151 | if (e->flags & EDGE_EH) | |
f178f44b | 2152 | { |
04166d08 | 2153 | if (can_throw_internal (BB_END (bb)) |
2154 | /* If this is a call edge, verify that this is a call insn. */ | |
2155 | && (! (e->flags & EDGE_ABNORMAL_CALL) | |
2156 | || CALL_P (BB_END (bb)))) | |
cd665a06 | 2157 | { |
2158 | ei_next (&ei); | |
2159 | continue; | |
2160 | } | |
f178f44b | 2161 | } |
04166d08 | 2162 | else if (e->flags & EDGE_ABNORMAL_CALL) |
f178f44b | 2163 | { |
04166d08 | 2164 | if (CALL_P (BB_END (bb)) |
2165 | && (! (note = find_reg_note (insn, REG_EH_REGION, NULL)) | |
2166 | || INTVAL (XEXP (note, 0)) >= 0)) | |
cd665a06 | 2167 | { |
2168 | ei_next (&ei); | |
2169 | continue; | |
2170 | } | |
f178f44b | 2171 | } |
2172 | else | |
cd665a06 | 2173 | { |
2174 | ei_next (&ei); | |
2175 | continue; | |
2176 | } | |
f178f44b | 2177 | |
2178 | remove_edge (e); | |
3072d30e | 2179 | df_set_bb_dirty (bb); |
f178f44b | 2180 | purged = true; |
2181 | } | |
5cc577b6 | 2182 | |
6d7dc5b9 | 2183 | if (JUMP_P (insn)) |
b36d64df | 2184 | { |
2185 | rtx note; | |
2186 | edge b,f; | |
cd665a06 | 2187 | edge_iterator ei; |
5cc577b6 | 2188 | |
b36d64df | 2189 | /* We do care only about conditional jumps and simplejumps. */ |
2190 | if (!any_condjump_p (insn) | |
2191 | && !returnjump_p (insn) | |
2192 | && !simplejump_p (insn)) | |
461eeb14 | 2193 | return purged; |
5cc577b6 | 2194 | |
a2e42321 | 2195 | /* Branch probability/prediction notes are defined only for |
2196 | condjumps. We've possibly turned condjump into simplejump. */ | |
2197 | if (simplejump_p (insn)) | |
2198 | { | |
2199 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2200 | if (note) | |
2201 | remove_note (insn, note); | |
2202 | while ((note = find_reg_note (insn, REG_BR_PRED, NULL))) | |
2203 | remove_note (insn, note); | |
2204 | } | |
2205 | ||
cd665a06 | 2206 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
b36d64df | 2207 | { |
4270b4b9 | 2208 | /* Avoid abnormal flags to leak from computed jumps turned |
2209 | into simplejumps. */ | |
db34a109 | 2210 | |
a0fb7382 | 2211 | e->flags &= ~EDGE_ABNORMAL; |
4270b4b9 | 2212 | |
14abf923 | 2213 | /* See if this edge is one we should keep. */ |
2214 | if ((e->flags & EDGE_FALLTHRU) && any_condjump_p (insn)) | |
2215 | /* A conditional jump can fall through into the next | |
2216 | block, so we should keep the edge. */ | |
cd665a06 | 2217 | { |
2218 | ei_next (&ei); | |
2219 | continue; | |
2220 | } | |
5cc577b6 | 2221 | else if (e->dest != EXIT_BLOCK_PTR |
5496dbfc | 2222 | && BB_HEAD (e->dest) == JUMP_LABEL (insn)) |
14abf923 | 2223 | /* If the destination block is the target of the jump, |
2224 | keep the edge. */ | |
cd665a06 | 2225 | { |
2226 | ei_next (&ei); | |
2227 | continue; | |
2228 | } | |
14abf923 | 2229 | else if (e->dest == EXIT_BLOCK_PTR && returnjump_p (insn)) |
2230 | /* If the destination block is the exit block, and this | |
2231 | instruction is a return, then keep the edge. */ | |
cd665a06 | 2232 | { |
2233 | ei_next (&ei); | |
2234 | continue; | |
2235 | } | |
14abf923 | 2236 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) |
2237 | /* Keep the edges that correspond to exceptions thrown by | |
1b64239d | 2238 | this instruction and rematerialize the EDGE_ABNORMAL |
2239 | flag we just cleared above. */ | |
2240 | { | |
2241 | e->flags |= EDGE_ABNORMAL; | |
cd665a06 | 2242 | ei_next (&ei); |
1b64239d | 2243 | continue; |
2244 | } | |
5cc577b6 | 2245 | |
14abf923 | 2246 | /* We do not need this edge. */ |
3072d30e | 2247 | df_set_bb_dirty (bb); |
b36d64df | 2248 | purged = true; |
2249 | remove_edge (e); | |
2250 | } | |
5cc577b6 | 2251 | |
cd665a06 | 2252 | if (EDGE_COUNT (bb->succs) == 0 || !purged) |
461eeb14 | 2253 | return purged; |
5cc577b6 | 2254 | |
450d042a | 2255 | if (dump_file) |
2256 | fprintf (dump_file, "Purged edges from bb %i\n", bb->index); | |
5cc577b6 | 2257 | |
b36d64df | 2258 | if (!optimize) |
2259 | return purged; | |
2260 | ||
2261 | /* Redistribute probabilities. */ | |
ea091dfd | 2262 | if (single_succ_p (bb)) |
b36d64df | 2263 | { |
ea091dfd | 2264 | single_succ_edge (bb)->probability = REG_BR_PROB_BASE; |
2265 | single_succ_edge (bb)->count = bb->count; | |
db34a109 | 2266 | } |
b36d64df | 2267 | else |
2268 | { | |
2269 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2270 | if (!note) | |
2271 | return purged; | |
5cc577b6 | 2272 | |
b36d64df | 2273 | b = BRANCH_EDGE (bb); |
2274 | f = FALLTHRU_EDGE (bb); | |
2275 | b->probability = INTVAL (XEXP (note, 0)); | |
2276 | f->probability = REG_BR_PROB_BASE - b->probability; | |
2277 | b->count = bb->count * b->probability / REG_BR_PROB_BASE; | |
2278 | f->count = bb->count * f->probability / REG_BR_PROB_BASE; | |
2279 | } | |
5cc577b6 | 2280 | |
b36d64df | 2281 | return purged; |
2282 | } | |
6d7dc5b9 | 2283 | else if (CALL_P (insn) && SIBLING_CALL_P (insn)) |
bf4311e9 | 2284 | { |
2285 | /* First, there should not be any EH or ABCALL edges resulting | |
2286 | from non-local gotos and the like. If there were, we shouldn't | |
2287 | have created the sibcall in the first place. Second, there | |
2288 | should of course never have been a fallthru edge. */ | |
ea091dfd | 2289 | gcc_assert (single_succ_p (bb)); |
2290 | gcc_assert (single_succ_edge (bb)->flags | |
2291 | == (EDGE_SIBCALL | EDGE_ABNORMAL)); | |
bf4311e9 | 2292 | |
2293 | return 0; | |
2294 | } | |
b36d64df | 2295 | |
b36d64df | 2296 | /* If we don't see a jump insn, we don't know exactly why the block would |
2297 | have been broken at this point. Look for a simple, non-fallthru edge, | |
2298 | as these are only created by conditional branches. If we find such an | |
2299 | edge we know that there used to be a jump here and can then safely | |
2300 | remove all non-fallthru edges. */ | |
cd665a06 | 2301 | found = false; |
2302 | FOR_EACH_EDGE (e, ei, bb->succs) | |
2303 | if (! (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU))) | |
2304 | { | |
2305 | found = true; | |
2306 | break; | |
2307 | } | |
5cc577b6 | 2308 | |
cd665a06 | 2309 | if (!found) |
b36d64df | 2310 | return purged; |
5cc577b6 | 2311 | |
6e81a369 | 2312 | /* Remove all but the fake and fallthru edges. The fake edge may be |
2313 | the only successor for this block in the case of noreturn | |
2314 | calls. */ | |
cd665a06 | 2315 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
b36d64df | 2316 | { |
6e81a369 | 2317 | if (!(e->flags & (EDGE_FALLTHRU | EDGE_FAKE))) |
461eeb14 | 2318 | { |
3072d30e | 2319 | df_set_bb_dirty (bb); |
461eeb14 | 2320 | remove_edge (e); |
2321 | purged = true; | |
2322 | } | |
cd665a06 | 2323 | else |
2324 | ei_next (&ei); | |
b36d64df | 2325 | } |
5cc577b6 | 2326 | |
ea091dfd | 2327 | gcc_assert (single_succ_p (bb)); |
5cc577b6 | 2328 | |
ea091dfd | 2329 | single_succ_edge (bb)->probability = REG_BR_PROB_BASE; |
2330 | single_succ_edge (bb)->count = bb->count; | |
b36d64df | 2331 | |
450d042a | 2332 | if (dump_file) |
2333 | fprintf (dump_file, "Purged non-fallthru edges from bb %i\n", | |
b3d6de89 | 2334 | bb->index); |
b36d64df | 2335 | return purged; |
2336 | } | |
2337 | ||
5cc577b6 | 2338 | /* Search all basic blocks for potentially dead edges and purge them. Return |
2339 | true if some edge has been eliminated. */ | |
b36d64df | 2340 | |
2341 | bool | |
94ee50e8 | 2342 | purge_all_dead_edges (void) |
b36d64df | 2343 | { |
4c26117a | 2344 | int purged = false; |
4c26117a | 2345 | basic_block bb; |
0922c912 | 2346 | |
4c26117a | 2347 | FOR_EACH_BB (bb) |
0922c912 | 2348 | { |
4c26117a | 2349 | bool purged_here = purge_dead_edges (bb); |
5cc577b6 | 2350 | |
0922c912 | 2351 | purged |= purged_here; |
0922c912 | 2352 | } |
5cc577b6 | 2353 | |
b36d64df | 2354 | return purged; |
2355 | } | |
1026363d | 2356 | |
2357 | /* Same as split_block but update cfg_layout structures. */ | |
5f5d4cd1 | 2358 | |
2359 | static basic_block | |
4c9e08a4 | 2360 | cfg_layout_split_block (basic_block bb, void *insnp) |
1026363d | 2361 | { |
f780cc25 | 2362 | rtx insn = (rtx) insnp; |
5f5d4cd1 | 2363 | basic_block new_bb = rtl_split_block (bb, insn); |
1026363d | 2364 | |
bc5f266a | 2365 | new_bb->il.rtl->footer = bb->il.rtl->footer; |
2366 | bb->il.rtl->footer = NULL; | |
1026363d | 2367 | |
5f5d4cd1 | 2368 | return new_bb; |
1026363d | 2369 | } |
2370 | ||
1026363d | 2371 | /* Redirect Edge to DEST. */ |
4ee9c684 | 2372 | static edge |
4c9e08a4 | 2373 | cfg_layout_redirect_edge_and_branch (edge e, basic_block dest) |
1026363d | 2374 | { |
2375 | basic_block src = e->src; | |
4ee9c684 | 2376 | edge ret; |
1026363d | 2377 | |
c60fa3a7 | 2378 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
4ee9c684 | 2379 | return NULL; |
c60fa3a7 | 2380 | |
e5562ab8 | 2381 | if (e->dest == dest) |
4ee9c684 | 2382 | return e; |
c60fa3a7 | 2383 | |
e5562ab8 | 2384 | if (e->src != ENTRY_BLOCK_PTR |
4ee9c684 | 2385 | && (ret = try_redirect_by_replacing_jump (e, dest, true))) |
adee86a0 | 2386 | { |
3072d30e | 2387 | df_set_bb_dirty (src); |
4ee9c684 | 2388 | return ret; |
adee86a0 | 2389 | } |
c60fa3a7 | 2390 | |
2391 | if (e->src == ENTRY_BLOCK_PTR | |
2392 | && (e->flags & EDGE_FALLTHRU) && !(e->flags & EDGE_COMPLEX)) | |
2393 | { | |
450d042a | 2394 | if (dump_file) |
2395 | fprintf (dump_file, "Redirecting entry edge from bb %i to %i\n", | |
c60fa3a7 | 2396 | e->src->index, dest->index); |
2397 | ||
3072d30e | 2398 | df_set_bb_dirty (e->src); |
c60fa3a7 | 2399 | redirect_edge_succ (e, dest); |
4ee9c684 | 2400 | return e; |
c60fa3a7 | 2401 | } |
2402 | ||
1026363d | 2403 | /* Redirect_edge_and_branch may decide to turn branch into fallthru edge |
2404 | in the case the basic block appears to be in sequence. Avoid this | |
2405 | transformation. */ | |
2406 | ||
1026363d | 2407 | if (e->flags & EDGE_FALLTHRU) |
2408 | { | |
2409 | /* Redirect any branch edges unified with the fallthru one. */ | |
6d7dc5b9 | 2410 | if (JUMP_P (BB_END (src)) |
b9de5542 | 2411 | && label_is_jump_target_p (BB_HEAD (e->dest), |
2412 | BB_END (src))) | |
1026363d | 2413 | { |
cc636d56 | 2414 | edge redirected; |
a0c938f0 | 2415 | |
450d042a | 2416 | if (dump_file) |
2417 | fprintf (dump_file, "Fallthru edge unified with branch " | |
b9de5542 | 2418 | "%i->%i redirected to %i\n", |
2419 | e->src->index, e->dest->index, dest->index); | |
2420 | e->flags &= ~EDGE_FALLTHRU; | |
cc636d56 | 2421 | redirected = redirect_branch_edge (e, dest); |
2422 | gcc_assert (redirected); | |
b9de5542 | 2423 | e->flags |= EDGE_FALLTHRU; |
3072d30e | 2424 | df_set_bb_dirty (e->src); |
4ee9c684 | 2425 | return e; |
1026363d | 2426 | } |
2427 | /* In case we are redirecting fallthru edge to the branch edge | |
a0c938f0 | 2428 | of conditional jump, remove it. */ |
cd665a06 | 2429 | if (EDGE_COUNT (src->succs) == 2) |
1026363d | 2430 | { |
9ea57afb | 2431 | /* Find the edge that is different from E. */ |
2432 | edge s = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e); | |
cd665a06 | 2433 | |
1026363d | 2434 | if (s->dest == dest |
5496dbfc | 2435 | && any_condjump_p (BB_END (src)) |
2436 | && onlyjump_p (BB_END (src))) | |
2437 | delete_insn (BB_END (src)); | |
1026363d | 2438 | } |
4ee9c684 | 2439 | ret = redirect_edge_succ_nodup (e, dest); |
450d042a | 2440 | if (dump_file) |
2441 | fprintf (dump_file, "Fallthru edge %i->%i redirected to %i\n", | |
c60fa3a7 | 2442 | e->src->index, e->dest->index, dest->index); |
1026363d | 2443 | } |
2444 | else | |
c60fa3a7 | 2445 | ret = redirect_branch_edge (e, dest); |
1026363d | 2446 | |
2447 | /* We don't want simplejumps in the insn stream during cfglayout. */ | |
cc636d56 | 2448 | gcc_assert (!simplejump_p (BB_END (src))); |
1026363d | 2449 | |
3072d30e | 2450 | df_set_bb_dirty (src); |
1026363d | 2451 | return ret; |
2452 | } | |
2453 | ||
2454 | /* Simple wrapper as we always can redirect fallthru edges. */ | |
2455 | static basic_block | |
4c9e08a4 | 2456 | cfg_layout_redirect_edge_and_branch_force (edge e, basic_block dest) |
1026363d | 2457 | { |
cc636d56 | 2458 | edge redirected = cfg_layout_redirect_edge_and_branch (e, dest); |
2459 | ||
2460 | gcc_assert (redirected); | |
1026363d | 2461 | return NULL; |
2462 | } | |
2463 | ||
5f5d4cd1 | 2464 | /* Same as delete_basic_block but update cfg_layout structures. */ |
2465 | ||
1026363d | 2466 | static void |
4c9e08a4 | 2467 | cfg_layout_delete_block (basic_block bb) |
1026363d | 2468 | { |
5496dbfc | 2469 | rtx insn, next, prev = PREV_INSN (BB_HEAD (bb)), *to, remaints; |
1026363d | 2470 | |
bc5f266a | 2471 | if (bb->il.rtl->header) |
1026363d | 2472 | { |
5496dbfc | 2473 | next = BB_HEAD (bb); |
1026363d | 2474 | if (prev) |
bc5f266a | 2475 | NEXT_INSN (prev) = bb->il.rtl->header; |
1026363d | 2476 | else |
bc5f266a | 2477 | set_first_insn (bb->il.rtl->header); |
2478 | PREV_INSN (bb->il.rtl->header) = prev; | |
2479 | insn = bb->il.rtl->header; | |
1026363d | 2480 | while (NEXT_INSN (insn)) |
2481 | insn = NEXT_INSN (insn); | |
2482 | NEXT_INSN (insn) = next; | |
2483 | PREV_INSN (next) = insn; | |
2484 | } | |
5496dbfc | 2485 | next = NEXT_INSN (BB_END (bb)); |
bc5f266a | 2486 | if (bb->il.rtl->footer) |
1026363d | 2487 | { |
bc5f266a | 2488 | insn = bb->il.rtl->footer; |
c60fa3a7 | 2489 | while (insn) |
2490 | { | |
6d7dc5b9 | 2491 | if (BARRIER_P (insn)) |
c60fa3a7 | 2492 | { |
2493 | if (PREV_INSN (insn)) | |
2494 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
2495 | else | |
bc5f266a | 2496 | bb->il.rtl->footer = NEXT_INSN (insn); |
c60fa3a7 | 2497 | if (NEXT_INSN (insn)) |
2498 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
2499 | } | |
6d7dc5b9 | 2500 | if (LABEL_P (insn)) |
c60fa3a7 | 2501 | break; |
2502 | insn = NEXT_INSN (insn); | |
2503 | } | |
bc5f266a | 2504 | if (bb->il.rtl->footer) |
c60fa3a7 | 2505 | { |
5496dbfc | 2506 | insn = BB_END (bb); |
bc5f266a | 2507 | NEXT_INSN (insn) = bb->il.rtl->footer; |
2508 | PREV_INSN (bb->il.rtl->footer) = insn; | |
c60fa3a7 | 2509 | while (NEXT_INSN (insn)) |
2510 | insn = NEXT_INSN (insn); | |
2511 | NEXT_INSN (insn) = next; | |
2512 | if (next) | |
2513 | PREV_INSN (next) = insn; | |
2514 | else | |
2515 | set_last_insn (insn); | |
2516 | } | |
1026363d | 2517 | } |
2518 | if (bb->next_bb != EXIT_BLOCK_PTR) | |
bc5f266a | 2519 | to = &bb->next_bb->il.rtl->header; |
1026363d | 2520 | else |
2521 | to = &cfg_layout_function_footer; | |
7a22afab | 2522 | |
1026363d | 2523 | rtl_delete_block (bb); |
2524 | ||
2525 | if (prev) | |
2526 | prev = NEXT_INSN (prev); | |
4c9e08a4 | 2527 | else |
1026363d | 2528 | prev = get_insns (); |
2529 | if (next) | |
2530 | next = PREV_INSN (next); | |
4c9e08a4 | 2531 | else |
1026363d | 2532 | next = get_last_insn (); |
2533 | ||
2534 | if (next && NEXT_INSN (next) != prev) | |
2535 | { | |
2536 | remaints = unlink_insn_chain (prev, next); | |
2537 | insn = remaints; | |
2538 | while (NEXT_INSN (insn)) | |
2539 | insn = NEXT_INSN (insn); | |
2540 | NEXT_INSN (insn) = *to; | |
2541 | if (*to) | |
2542 | PREV_INSN (*to) = insn; | |
2543 | *to = remaints; | |
2544 | } | |
2545 | } | |
2546 | ||
139c3f48 | 2547 | /* Return true when blocks A and B can be safely merged. */ |
c60fa3a7 | 2548 | static bool |
2549 | cfg_layout_can_merge_blocks_p (basic_block a, basic_block b) | |
2550 | { | |
4f18499c | 2551 | /* If we are partitioning hot/cold basic blocks, we don't want to |
2552 | mess up unconditional or indirect jumps that cross between hot | |
7562ed74 | 2553 | and cold sections. |
2554 | ||
1118aef7 | 2555 | Basic block partitioning may result in some jumps that appear to |
a0c938f0 | 2556 | be optimizable (or blocks that appear to be mergeable), but which really |
2557 | must be left untouched (they are required to make it safely across | |
2558 | partition boundaries). See the comments at the top of | |
1118aef7 | 2559 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
2560 | ||
1897b881 | 2561 | if (BB_PARTITION (a) != BB_PARTITION (b)) |
7562ed74 | 2562 | return false; |
4f18499c | 2563 | |
c60fa3a7 | 2564 | /* There must be exactly one edge in between the blocks. */ |
ea091dfd | 2565 | return (single_succ_p (a) |
2566 | && single_succ (a) == b | |
2567 | && single_pred_p (b) == 1 | |
cd665a06 | 2568 | && a != b |
c60fa3a7 | 2569 | /* Must be simple edge. */ |
ea091dfd | 2570 | && !(single_succ_edge (a)->flags & EDGE_COMPLEX) |
c60fa3a7 | 2571 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR |
4aaec180 | 2572 | /* If the jump insn has side effects, we can't kill the edge. |
2573 | When not optimizing, try_redirect_by_replacing_jump will | |
2574 | not allow us to redirect an edge by replacing a table jump. */ | |
6d7dc5b9 | 2575 | && (!JUMP_P (BB_END (a)) |
4aaec180 | 2576 | || ((!optimize || reload_completed) |
5496dbfc | 2577 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
c60fa3a7 | 2578 | } |
2579 | ||
a53ff4c1 | 2580 | /* Merge block A and B. The blocks must be mergeable. */ |
2581 | ||
c60fa3a7 | 2582 | static void |
2583 | cfg_layout_merge_blocks (basic_block a, basic_block b) | |
2584 | { | |
2585 | #ifdef ENABLE_CHECKING | |
cc636d56 | 2586 | gcc_assert (cfg_layout_can_merge_blocks_p (a, b)); |
c60fa3a7 | 2587 | #endif |
2588 | ||
3072d30e | 2589 | if (dump_file) |
2590 | fprintf (dump_file, "merging block %d into block %d\n", b->index, a->index); | |
2591 | ||
c60fa3a7 | 2592 | /* If there was a CODE_LABEL beginning B, delete it. */ |
6d7dc5b9 | 2593 | if (LABEL_P (BB_HEAD (b))) |
7b07eae7 | 2594 | { |
2595 | /* This might have been an EH label that no longer has incoming | |
2596 | EH edges. Update data structures to match. */ | |
2597 | maybe_remove_eh_handler (BB_HEAD (b)); | |
a0c938f0 | 2598 | |
7b07eae7 | 2599 | delete_insn (BB_HEAD (b)); |
2600 | } | |
c60fa3a7 | 2601 | |
2602 | /* We should have fallthru edge in a, or we can do dummy redirection to get | |
2603 | it cleaned up. */ | |
6d7dc5b9 | 2604 | if (JUMP_P (BB_END (a))) |
cd665a06 | 2605 | try_redirect_by_replacing_jump (EDGE_SUCC (a, 0), b, true); |
cc636d56 | 2606 | gcc_assert (!JUMP_P (BB_END (a))); |
c60fa3a7 | 2607 | |
2608 | /* Possible line number notes should appear in between. */ | |
bc5f266a | 2609 | if (b->il.rtl->header) |
c60fa3a7 | 2610 | { |
5496dbfc | 2611 | rtx first = BB_END (a), last; |
c60fa3a7 | 2612 | |
3072d30e | 2613 | last = emit_insn_after_noloc (b->il.rtl->header, BB_END (a), a); |
39257eb5 | 2614 | delete_insn_chain (NEXT_INSN (first), last, false); |
bc5f266a | 2615 | b->il.rtl->header = NULL; |
c60fa3a7 | 2616 | } |
2617 | ||
2618 | /* In the case basic blocks are not adjacent, move them around. */ | |
5496dbfc | 2619 | if (NEXT_INSN (BB_END (a)) != BB_HEAD (b)) |
c60fa3a7 | 2620 | { |
5496dbfc | 2621 | rtx first = unlink_insn_chain (BB_HEAD (b), BB_END (b)); |
c60fa3a7 | 2622 | |
3072d30e | 2623 | emit_insn_after_noloc (first, BB_END (a), a); |
c60fa3a7 | 2624 | /* Skip possible DELETED_LABEL insn. */ |
2625 | if (!NOTE_INSN_BASIC_BLOCK_P (first)) | |
2626 | first = NEXT_INSN (first); | |
cc636d56 | 2627 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (first)); |
5496dbfc | 2628 | BB_HEAD (b) = NULL; |
c60fa3a7 | 2629 | delete_insn (first); |
2630 | } | |
2631 | /* Otherwise just re-associate the instructions. */ | |
2632 | else | |
2633 | { | |
2634 | rtx insn; | |
2635 | ||
5496dbfc | 2636 | for (insn = BB_HEAD (b); |
2637 | insn != NEXT_INSN (BB_END (b)); | |
2638 | insn = NEXT_INSN (insn)) | |
3072d30e | 2639 | { |
2640 | set_block_for_insn (insn, a); | |
2641 | df_insn_change_bb (insn); | |
2642 | } | |
2643 | ||
5496dbfc | 2644 | insn = BB_HEAD (b); |
c60fa3a7 | 2645 | /* Skip possible DELETED_LABEL insn. */ |
2646 | if (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
2647 | insn = NEXT_INSN (insn); | |
cc636d56 | 2648 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn)); |
5496dbfc | 2649 | BB_HEAD (b) = NULL; |
2650 | BB_END (a) = BB_END (b); | |
c60fa3a7 | 2651 | delete_insn (insn); |
2652 | } | |
2653 | ||
3072d30e | 2654 | df_bb_delete (b->index); |
2655 | ||
c60fa3a7 | 2656 | /* Possible tablejumps and barriers should appear after the block. */ |
bc5f266a | 2657 | if (b->il.rtl->footer) |
c60fa3a7 | 2658 | { |
bc5f266a | 2659 | if (!a->il.rtl->footer) |
2660 | a->il.rtl->footer = b->il.rtl->footer; | |
c60fa3a7 | 2661 | else |
2662 | { | |
bc5f266a | 2663 | rtx last = a->il.rtl->footer; |
c60fa3a7 | 2664 | |
2665 | while (NEXT_INSN (last)) | |
2666 | last = NEXT_INSN (last); | |
bc5f266a | 2667 | NEXT_INSN (last) = b->il.rtl->footer; |
2668 | PREV_INSN (b->il.rtl->footer) = last; | |
c60fa3a7 | 2669 | } |
bc5f266a | 2670 | b->il.rtl->footer = NULL; |
c60fa3a7 | 2671 | } |
2672 | ||
450d042a | 2673 | if (dump_file) |
2674 | fprintf (dump_file, "Merged blocks %d and %d.\n", | |
c60fa3a7 | 2675 | a->index, b->index); |
c60fa3a7 | 2676 | } |
2677 | ||
2678 | /* Split edge E. */ | |
5f5d4cd1 | 2679 | |
c60fa3a7 | 2680 | static basic_block |
2681 | cfg_layout_split_edge (edge e) | |
2682 | { | |
c60fa3a7 | 2683 | basic_block new_bb = |
2684 | create_basic_block (e->src != ENTRY_BLOCK_PTR | |
5496dbfc | 2685 | ? NEXT_INSN (BB_END (e->src)) : get_insns (), |
c60fa3a7 | 2686 | NULL_RTX, e->src); |
2687 | ||
3bdc4312 | 2688 | make_edge (new_bb, e->dest, EDGE_FALLTHRU); |
c60fa3a7 | 2689 | redirect_edge_and_branch_force (e, new_bb); |
2690 | ||
2691 | return new_bb; | |
2692 | } | |
2693 | ||
5f5d4cd1 | 2694 | /* Do postprocessing after making a forwarder block joined by edge FALLTHRU. */ |
2695 | ||
2696 | static void | |
2697 | rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED) | |
2698 | { | |
2699 | } | |
2700 | ||
4ee9c684 | 2701 | /* Return 1 if BB ends with a call, possibly followed by some |
2702 | instructions that must stay with the call, 0 otherwise. */ | |
2703 | ||
2704 | static bool | |
2705 | rtl_block_ends_with_call_p (basic_block bb) | |
2706 | { | |
2707 | rtx insn = BB_END (bb); | |
2708 | ||
6d7dc5b9 | 2709 | while (!CALL_P (insn) |
4ee9c684 | 2710 | && insn != BB_HEAD (bb) |
2711 | && keep_with_call_p (insn)) | |
2712 | insn = PREV_INSN (insn); | |
6d7dc5b9 | 2713 | return (CALL_P (insn)); |
4ee9c684 | 2714 | } |
2715 | ||
2716 | /* Return 1 if BB ends with a conditional branch, 0 otherwise. */ | |
2717 | ||
2718 | static bool | |
2719 | rtl_block_ends_with_condjump_p (basic_block bb) | |
2720 | { | |
2721 | return any_condjump_p (BB_END (bb)); | |
2722 | } | |
2723 | ||
2724 | /* Return true if we need to add fake edge to exit. | |
2725 | Helper function for rtl_flow_call_edges_add. */ | |
2726 | ||
2727 | static bool | |
2728 | need_fake_edge_p (rtx insn) | |
2729 | { | |
2730 | if (!INSN_P (insn)) | |
2731 | return false; | |
2732 | ||
6d7dc5b9 | 2733 | if ((CALL_P (insn) |
4ee9c684 | 2734 | && !SIBLING_CALL_P (insn) |
2735 | && !find_reg_note (insn, REG_NORETURN, NULL) | |
4ee9c684 | 2736 | && !CONST_OR_PURE_CALL_P (insn))) |
2737 | return true; | |
2738 | ||
2739 | return ((GET_CODE (PATTERN (insn)) == ASM_OPERANDS | |
2740 | && MEM_VOLATILE_P (PATTERN (insn))) | |
2741 | || (GET_CODE (PATTERN (insn)) == PARALLEL | |
2742 | && asm_noperands (insn) != -1 | |
2743 | && MEM_VOLATILE_P (XVECEXP (PATTERN (insn), 0, 0))) | |
2744 | || GET_CODE (PATTERN (insn)) == ASM_INPUT); | |
2745 | } | |
2746 | ||
2747 | /* Add fake edges to the function exit for any non constant and non noreturn | |
2748 | calls, volatile inline assembly in the bitmap of blocks specified by | |
2749 | BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks | |
2750 | that were split. | |
2751 | ||
2752 | The goal is to expose cases in which entering a basic block does not imply | |
2753 | that all subsequent instructions must be executed. */ | |
2754 | ||
2755 | static int | |
2756 | rtl_flow_call_edges_add (sbitmap blocks) | |
2757 | { | |
2758 | int i; | |
2759 | int blocks_split = 0; | |
2760 | int last_bb = last_basic_block; | |
2761 | bool check_last_block = false; | |
2762 | ||
4d2e5d52 | 2763 | if (n_basic_blocks == NUM_FIXED_BLOCKS) |
4ee9c684 | 2764 | return 0; |
2765 | ||
2766 | if (! blocks) | |
2767 | check_last_block = true; | |
2768 | else | |
2769 | check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index); | |
2770 | ||
2771 | /* In the last basic block, before epilogue generation, there will be | |
2772 | a fallthru edge to EXIT. Special care is required if the last insn | |
2773 | of the last basic block is a call because make_edge folds duplicate | |
2774 | edges, which would result in the fallthru edge also being marked | |
2775 | fake, which would result in the fallthru edge being removed by | |
2776 | remove_fake_edges, which would result in an invalid CFG. | |
2777 | ||
2778 | Moreover, we can't elide the outgoing fake edge, since the block | |
2779 | profiler needs to take this into account in order to solve the minimal | |
2780 | spanning tree in the case that the call doesn't return. | |
2781 | ||
2782 | Handle this by adding a dummy instruction in a new last basic block. */ | |
2783 | if (check_last_block) | |
2784 | { | |
2785 | basic_block bb = EXIT_BLOCK_PTR->prev_bb; | |
2786 | rtx insn = BB_END (bb); | |
2787 | ||
2788 | /* Back up past insns that must be kept in the same block as a call. */ | |
2789 | while (insn != BB_HEAD (bb) | |
2790 | && keep_with_call_p (insn)) | |
2791 | insn = PREV_INSN (insn); | |
2792 | ||
2793 | if (need_fake_edge_p (insn)) | |
2794 | { | |
2795 | edge e; | |
2796 | ||
c6356c17 | 2797 | e = find_edge (bb, EXIT_BLOCK_PTR); |
2798 | if (e) | |
2799 | { | |
2800 | insert_insn_on_edge (gen_rtx_USE (VOIDmode, const0_rtx), e); | |
2801 | commit_edge_insertions (); | |
2802 | } | |
4ee9c684 | 2803 | } |
2804 | } | |
2805 | ||
2806 | /* Now add fake edges to the function exit for any non constant | |
2807 | calls since there is no way that we can determine if they will | |
2808 | return or not... */ | |
2809 | ||
4d2e5d52 | 2810 | for (i = NUM_FIXED_BLOCKS; i < last_bb; i++) |
4ee9c684 | 2811 | { |
2812 | basic_block bb = BASIC_BLOCK (i); | |
2813 | rtx insn; | |
2814 | rtx prev_insn; | |
2815 | ||
2816 | if (!bb) | |
2817 | continue; | |
2818 | ||
2819 | if (blocks && !TEST_BIT (blocks, i)) | |
2820 | continue; | |
2821 | ||
2822 | for (insn = BB_END (bb); ; insn = prev_insn) | |
2823 | { | |
2824 | prev_insn = PREV_INSN (insn); | |
2825 | if (need_fake_edge_p (insn)) | |
2826 | { | |
2827 | edge e; | |
2828 | rtx split_at_insn = insn; | |
2829 | ||
2830 | /* Don't split the block between a call and an insn that should | |
a0c938f0 | 2831 | remain in the same block as the call. */ |
6d7dc5b9 | 2832 | if (CALL_P (insn)) |
4ee9c684 | 2833 | while (split_at_insn != BB_END (bb) |
2834 | && keep_with_call_p (NEXT_INSN (split_at_insn))) | |
2835 | split_at_insn = NEXT_INSN (split_at_insn); | |
2836 | ||
2837 | /* The handling above of the final block before the epilogue | |
a0c938f0 | 2838 | should be enough to verify that there is no edge to the exit |
4ee9c684 | 2839 | block in CFG already. Calling make_edge in such case would |
2840 | cause us to mark that edge as fake and remove it later. */ | |
2841 | ||
2842 | #ifdef ENABLE_CHECKING | |
2843 | if (split_at_insn == BB_END (bb)) | |
cd665a06 | 2844 | { |
c6356c17 | 2845 | e = find_edge (bb, EXIT_BLOCK_PTR); |
2846 | gcc_assert (e == NULL); | |
cd665a06 | 2847 | } |
4ee9c684 | 2848 | #endif |
2849 | ||
2850 | /* Note that the following may create a new basic block | |
2851 | and renumber the existing basic blocks. */ | |
2852 | if (split_at_insn != BB_END (bb)) | |
2853 | { | |
2854 | e = split_block (bb, split_at_insn); | |
2855 | if (e) | |
2856 | blocks_split++; | |
2857 | } | |
2858 | ||
2859 | make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE); | |
2860 | } | |
2861 | ||
2862 | if (insn == BB_HEAD (bb)) | |
2863 | break; | |
2864 | } | |
2865 | } | |
2866 | ||
2867 | if (blocks_split) | |
2868 | verify_flow_info (); | |
2869 | ||
2870 | return blocks_split; | |
2871 | } | |
2872 | ||
c50ae675 | 2873 | /* Add COMP_RTX as a condition at end of COND_BB. FIRST_HEAD is |
d90dbd3e | 2874 | the conditional branch target, SECOND_HEAD should be the fall-thru |
c50ae675 | 2875 | there is no need to handle this here the loop versioning code handles |
2876 | this. the reason for SECON_HEAD is that it is needed for condition | |
2877 | in trees, and this should be of the same type since it is a hook. */ | |
2878 | static void | |
2879 | rtl_lv_add_condition_to_bb (basic_block first_head , | |
a0c938f0 | 2880 | basic_block second_head ATTRIBUTE_UNUSED, |
2881 | basic_block cond_bb, void *comp_rtx) | |
c50ae675 | 2882 | { |
2883 | rtx label, seq, jump; | |
2884 | rtx op0 = XEXP ((rtx)comp_rtx, 0); | |
2885 | rtx op1 = XEXP ((rtx)comp_rtx, 1); | |
2886 | enum rtx_code comp = GET_CODE ((rtx)comp_rtx); | |
2887 | enum machine_mode mode; | |
2888 | ||
2889 | ||
2890 | label = block_label (first_head); | |
2891 | mode = GET_MODE (op0); | |
2892 | if (mode == VOIDmode) | |
2893 | mode = GET_MODE (op1); | |
2894 | ||
2895 | start_sequence (); | |
2896 | op0 = force_operand (op0, NULL_RTX); | |
2897 | op1 = force_operand (op1, NULL_RTX); | |
2898 | do_compare_rtx_and_jump (op0, op1, comp, 0, | |
2899 | mode, NULL_RTX, NULL_RTX, label); | |
2900 | jump = get_last_insn (); | |
2901 | JUMP_LABEL (jump) = label; | |
2902 | LABEL_NUSES (label)++; | |
2903 | seq = get_insns (); | |
2904 | end_sequence (); | |
2905 | ||
2906 | /* Add the new cond , in the new head. */ | |
2907 | emit_insn_after(seq, BB_END(cond_bb)); | |
2908 | } | |
2909 | ||
2910 | ||
2911 | /* Given a block B with unconditional branch at its end, get the | |
2912 | store the return the branch edge and the fall-thru edge in | |
2913 | BRANCH_EDGE and FALLTHRU_EDGE respectively. */ | |
2914 | static void | |
2915 | rtl_extract_cond_bb_edges (basic_block b, edge *branch_edge, | |
2916 | edge *fallthru_edge) | |
2917 | { | |
2918 | edge e = EDGE_SUCC (b, 0); | |
2919 | ||
2920 | if (e->flags & EDGE_FALLTHRU) | |
2921 | { | |
2922 | *fallthru_edge = e; | |
2923 | *branch_edge = EDGE_SUCC (b, 1); | |
2924 | } | |
2925 | else | |
2926 | { | |
2927 | *branch_edge = e; | |
2928 | *fallthru_edge = EDGE_SUCC (b, 1); | |
2929 | } | |
2930 | } | |
2931 | ||
e0dde8f8 | 2932 | void |
2933 | init_rtl_bb_info (basic_block bb) | |
2934 | { | |
2935 | gcc_assert (!bb->il.rtl); | |
f780cc25 | 2936 | bb->il.rtl = GGC_CNEW (struct rtl_bb_info); |
e0dde8f8 | 2937 | } |
2938 | ||
c50ae675 | 2939 | |
2b74c150 | 2940 | /* Add EXPR to the end of basic block BB. */ |
2941 | ||
2942 | rtx | |
2943 | insert_insn_end_bb_new (rtx pat, basic_block bb) | |
2944 | { | |
2945 | rtx insn = BB_END (bb); | |
2946 | rtx new_insn; | |
2947 | rtx pat_end = pat; | |
2948 | ||
2949 | while (NEXT_INSN (pat_end) != NULL_RTX) | |
2950 | pat_end = NEXT_INSN (pat_end); | |
2951 | ||
2952 | /* If the last insn is a jump, insert EXPR in front [taking care to | |
2953 | handle cc0, etc. properly]. Similarly we need to care trapping | |
2954 | instructions in presence of non-call exceptions. */ | |
2955 | ||
2956 | if (JUMP_P (insn) | |
2957 | || (NONJUMP_INSN_P (insn) | |
2958 | && (!single_succ_p (bb) | |
2959 | || single_succ_edge (bb)->flags & EDGE_ABNORMAL))) | |
2960 | { | |
2961 | #ifdef HAVE_cc0 | |
2962 | rtx note; | |
2963 | #endif | |
2964 | /* If this is a jump table, then we can't insert stuff here. Since | |
2965 | we know the previous real insn must be the tablejump, we insert | |
2966 | the new instruction just before the tablejump. */ | |
2967 | if (GET_CODE (PATTERN (insn)) == ADDR_VEC | |
2968 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC) | |
2969 | insn = prev_real_insn (insn); | |
2970 | ||
2971 | #ifdef HAVE_cc0 | |
2972 | /* FIXME: 'twould be nice to call prev_cc0_setter here but it aborts | |
2973 | if cc0 isn't set. */ | |
2974 | note = find_reg_note (insn, REG_CC_SETTER, NULL_RTX); | |
2975 | if (note) | |
2976 | insn = XEXP (note, 0); | |
2977 | else | |
2978 | { | |
2979 | rtx maybe_cc0_setter = prev_nonnote_insn (insn); | |
2980 | if (maybe_cc0_setter | |
2981 | && INSN_P (maybe_cc0_setter) | |
2982 | && sets_cc0_p (PATTERN (maybe_cc0_setter))) | |
2983 | insn = maybe_cc0_setter; | |
2984 | } | |
2985 | #endif | |
2986 | /* FIXME: What if something in cc0/jump uses value set in new | |
2987 | insn? */ | |
3072d30e | 2988 | new_insn = emit_insn_before_noloc (pat, insn, bb); |
2b74c150 | 2989 | } |
2990 | ||
2991 | /* Likewise if the last insn is a call, as will happen in the presence | |
2992 | of exception handling. */ | |
2993 | else if (CALL_P (insn) | |
2994 | && (!single_succ_p (bb) | |
2995 | || single_succ_edge (bb)->flags & EDGE_ABNORMAL)) | |
2996 | { | |
2997 | /* Keeping in mind SMALL_REGISTER_CLASSES and parameters in registers, | |
2998 | we search backward and place the instructions before the first | |
2999 | parameter is loaded. Do this for everyone for consistency and a | |
3000 | presumption that we'll get better code elsewhere as well. */ | |
3001 | ||
3002 | /* Since different machines initialize their parameter registers | |
3003 | in different orders, assume nothing. Collect the set of all | |
3004 | parameter registers. */ | |
3005 | insn = find_first_parameter_load (insn, BB_HEAD (bb)); | |
3006 | ||
3007 | /* If we found all the parameter loads, then we want to insert | |
3008 | before the first parameter load. | |
3009 | ||
3010 | If we did not find all the parameter loads, then we might have | |
3011 | stopped on the head of the block, which could be a CODE_LABEL. | |
3012 | If we inserted before the CODE_LABEL, then we would be putting | |
3013 | the insn in the wrong basic block. In that case, put the insn | |
3014 | after the CODE_LABEL. Also, respect NOTE_INSN_BASIC_BLOCK. */ | |
3015 | while (LABEL_P (insn) | |
3016 | || NOTE_INSN_BASIC_BLOCK_P (insn)) | |
3017 | insn = NEXT_INSN (insn); | |
3018 | ||
3072d30e | 3019 | new_insn = emit_insn_before_noloc (pat, insn, bb); |
2b74c150 | 3020 | } |
3021 | else | |
3072d30e | 3022 | new_insn = emit_insn_after_noloc (pat, insn, bb); |
2b74c150 | 3023 | |
3024 | return new_insn; | |
3025 | } | |
3026 | ||
611d2ac1 | 3027 | /* Returns true if it is possible to remove edge E by redirecting |
3028 | it to the destination of the other edge from E->src. */ | |
3029 | ||
3030 | static bool | |
3031 | rtl_can_remove_branch_p (edge e) | |
3032 | { | |
3033 | basic_block src = e->src; | |
3034 | basic_block target = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest; | |
3035 | rtx insn = BB_END (src), set; | |
3036 | ||
3037 | /* The conditions are taken from try_redirect_by_replacing_jump. */ | |
3038 | if (target == EXIT_BLOCK_PTR) | |
3039 | return false; | |
3040 | ||
3041 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) | |
3042 | return false; | |
3043 | ||
3044 | if (find_reg_note (insn, REG_CROSSING_JUMP, NULL_RTX) | |
3045 | || BB_PARTITION (src) != BB_PARTITION (target)) | |
3046 | return false; | |
3047 | ||
3048 | if (!onlyjump_p (insn) | |
3049 | || tablejump_p (insn, NULL, NULL)) | |
3050 | return false; | |
3051 | ||
3052 | set = single_set (insn); | |
3053 | if (!set || side_effects_p (set)) | |
3054 | return false; | |
3055 | ||
3056 | return true; | |
3057 | } | |
3058 | ||
1026363d | 3059 | /* Implementation of CFG manipulation for linearized RTL. */ |
3060 | struct cfg_hooks rtl_cfg_hooks = { | |
5f5d4cd1 | 3061 | "rtl", |
1026363d | 3062 | rtl_verify_flow_info, |
028f8cc7 | 3063 | rtl_dump_bb, |
c60fa3a7 | 3064 | rtl_create_basic_block, |
1026363d | 3065 | rtl_redirect_edge_and_branch, |
3066 | rtl_redirect_edge_and_branch_force, | |
611d2ac1 | 3067 | rtl_can_remove_branch_p, |
1026363d | 3068 | rtl_delete_block, |
3069 | rtl_split_block, | |
5f5d4cd1 | 3070 | rtl_move_block_after, |
c60fa3a7 | 3071 | rtl_can_merge_blocks, /* can_merge_blocks_p */ |
3072 | rtl_merge_blocks, | |
4ee9c684 | 3073 | rtl_predict_edge, |
3074 | rtl_predicted_by_p, | |
3075 | NULL, /* can_duplicate_block_p */ | |
3076 | NULL, /* duplicate_block */ | |
5f5d4cd1 | 3077 | rtl_split_edge, |
3078 | rtl_make_forwarder_block, | |
4ee9c684 | 3079 | rtl_tidy_fallthru_edge, |
3080 | rtl_block_ends_with_call_p, | |
3081 | rtl_block_ends_with_condjump_p, | |
26b12c91 | 3082 | rtl_flow_call_edges_add, |
3083 | NULL, /* execute_on_growing_pred */ | |
c50ae675 | 3084 | NULL, /* execute_on_shrinking_pred */ |
3085 | NULL, /* duplicate loop for trees */ | |
3086 | NULL, /* lv_add_condition_to_bb */ | |
3087 | NULL, /* lv_adjust_loop_header_phi*/ | |
3088 | NULL, /* extract_cond_bb_edges */ | |
a0c938f0 | 3089 | NULL /* flush_pending_stmts */ |
1026363d | 3090 | }; |
3091 | ||
3092 | /* Implementation of CFG manipulation for cfg layout RTL, where | |
3093 | basic block connected via fallthru edges does not have to be adjacent. | |
3094 | This representation will hopefully become the default one in future | |
3095 | version of the compiler. */ | |
4ee9c684 | 3096 | |
3097 | /* We do not want to declare these functions in a header file, since they | |
3098 | should only be used through the cfghooks interface, and we do not want to | |
3099 | move them here since it would require also moving quite a lot of related | |
3072d30e | 3100 | code. They are in cfglayout.c. */ |
4ee9c684 | 3101 | extern bool cfg_layout_can_duplicate_bb_p (basic_block); |
3102 | extern basic_block cfg_layout_duplicate_bb (basic_block); | |
3103 | ||
1026363d | 3104 | struct cfg_hooks cfg_layout_rtl_cfg_hooks = { |
5f5d4cd1 | 3105 | "cfglayout mode", |
c60fa3a7 | 3106 | rtl_verify_flow_info_1, |
028f8cc7 | 3107 | rtl_dump_bb, |
c60fa3a7 | 3108 | cfg_layout_create_basic_block, |
1026363d | 3109 | cfg_layout_redirect_edge_and_branch, |
3110 | cfg_layout_redirect_edge_and_branch_force, | |
611d2ac1 | 3111 | rtl_can_remove_branch_p, |
1026363d | 3112 | cfg_layout_delete_block, |
3113 | cfg_layout_split_block, | |
5f5d4cd1 | 3114 | rtl_move_block_after, |
c60fa3a7 | 3115 | cfg_layout_can_merge_blocks_p, |
3116 | cfg_layout_merge_blocks, | |
4ee9c684 | 3117 | rtl_predict_edge, |
3118 | rtl_predicted_by_p, | |
3119 | cfg_layout_can_duplicate_bb_p, | |
3120 | cfg_layout_duplicate_bb, | |
5f5d4cd1 | 3121 | cfg_layout_split_edge, |
3122 | rtl_make_forwarder_block, | |
4ee9c684 | 3123 | NULL, |
3124 | rtl_block_ends_with_call_p, | |
3125 | rtl_block_ends_with_condjump_p, | |
26b12c91 | 3126 | rtl_flow_call_edges_add, |
3127 | NULL, /* execute_on_growing_pred */ | |
c50ae675 | 3128 | NULL, /* execute_on_shrinking_pred */ |
3129 | duplicate_loop_to_header_edge, /* duplicate loop for trees */ | |
3130 | rtl_lv_add_condition_to_bb, /* lv_add_condition_to_bb */ | |
3131 | NULL, /* lv_adjust_loop_header_phi*/ | |
3132 | rtl_extract_cond_bb_edges, /* extract_cond_bb_edges */ | |
a0c938f0 | 3133 | NULL /* flush_pending_stmts */ |
1026363d | 3134 | }; |