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Commit | Line | Data |
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ca6c03ca JH |
1 | /* Control flow graph manipulation code for GNU compiler. |
2 | Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, | |
4ab80063 | 3 | 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. |
ca6c03ca JH |
4 | |
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it under | |
8 | the terms of the GNU General Public License as published by the Free | |
9 | Software Foundation; either version 2, or (at your option) any later | |
10 | version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING. If not, write to the Free | |
19 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA | |
20 | 02111-1307, USA. */ | |
21 | ||
5f0d2358 RK |
22 | /* This file contains low level functions to manipulate the CFG and analyze it |
23 | that are aware of the RTL intermediate language. | |
ca6c03ca JH |
24 | |
25 | Available functionality: | |
bc35512f | 26 | - Basic CFG/RTL manipulation API documented in cfghooks.h |
5f0d2358 | 27 | - CFG-aware instruction chain manipulation |
ca6c03ca | 28 | delete_insn, delete_insn_chain |
bc35512f JH |
29 | - Edge splitting and committing to edges |
30 | insert_insn_on_edge, commit_edge_insertions | |
31 | - CFG updating after insn simplification | |
32 | purge_dead_edges, purge_all_dead_edges | |
33 | ||
34 | Functions not supposed for generic use: | |
5f0d2358 | 35 | - Infrastructure to determine quickly basic block for insn |
ca6c03ca | 36 | compute_bb_for_insn, update_bb_for_insn, set_block_for_insn, |
5f0d2358 | 37 | - Edge redirection with updating and optimizing of insn chain |
bc35512f | 38 | block_label, tidy_fallthru_edge, force_nonfallthru */ |
ca6c03ca JH |
39 | \f |
40 | #include "config.h" | |
41 | #include "system.h" | |
4977bab6 ZW |
42 | #include "coretypes.h" |
43 | #include "tm.h" | |
ca6c03ca JH |
44 | #include "tree.h" |
45 | #include "rtl.h" | |
46 | #include "hard-reg-set.h" | |
47 | #include "basic-block.h" | |
48 | #include "regs.h" | |
49 | #include "flags.h" | |
50 | #include "output.h" | |
51 | #include "function.h" | |
52 | #include "except.h" | |
53 | #include "toplev.h" | |
54 | #include "tm_p.h" | |
55 | #include "obstack.h" | |
0a2ed1f1 | 56 | #include "insn-config.h" |
9ee634e3 | 57 | #include "cfglayout.h" |
ff25ef99 | 58 | #include "expr.h" |
9fb32434 | 59 | #include "target.h" |
1cb7dfc3 | 60 | #include "cfgloop.h" |
ca6c03ca | 61 | |
ca6c03ca JH |
62 | /* The labels mentioned in non-jump rtl. Valid during find_basic_blocks. */ |
63 | /* ??? Should probably be using LABEL_NUSES instead. It would take a | |
64 | bit of surgery to be able to use or co-opt the routines in jump. */ | |
ca6c03ca | 65 | rtx label_value_list; |
ca6c03ca | 66 | |
d329e058 AJ |
67 | static int can_delete_note_p (rtx); |
68 | static int can_delete_label_p (rtx); | |
69 | static void commit_one_edge_insertion (edge, int); | |
d329e058 AJ |
70 | static rtx last_loop_beg_note (rtx); |
71 | static bool back_edge_of_syntactic_loop_p (basic_block, basic_block); | |
d329e058 | 72 | static basic_block rtl_split_edge (edge); |
f470c378 | 73 | static bool rtl_move_block_after (basic_block, basic_block); |
d329e058 | 74 | static int rtl_verify_flow_info (void); |
f470c378 | 75 | static basic_block cfg_layout_split_block (basic_block, void *); |
6de9cd9a | 76 | static edge cfg_layout_redirect_edge_and_branch (edge, basic_block); |
d329e058 AJ |
77 | static basic_block cfg_layout_redirect_edge_and_branch_force (edge, basic_block); |
78 | static void cfg_layout_delete_block (basic_block); | |
79 | static void rtl_delete_block (basic_block); | |
80 | static basic_block rtl_redirect_edge_and_branch_force (edge, basic_block); | |
6de9cd9a | 81 | static edge rtl_redirect_edge_and_branch (edge, basic_block); |
f470c378 ZD |
82 | static basic_block rtl_split_block (basic_block, void *); |
83 | static void rtl_dump_bb (basic_block, FILE *, int); | |
d329e058 | 84 | static int rtl_verify_flow_info_1 (void); |
ff25ef99 | 85 | static void mark_killed_regs (rtx, rtx, void *); |
f470c378 | 86 | static void rtl_make_forwarder_block (edge); |
ca6c03ca JH |
87 | \f |
88 | /* Return true if NOTE is not one of the ones that must be kept paired, | |
5f0d2358 | 89 | so that we may simply delete it. */ |
ca6c03ca JH |
90 | |
91 | static int | |
d329e058 | 92 | can_delete_note_p (rtx note) |
ca6c03ca JH |
93 | { |
94 | return (NOTE_LINE_NUMBER (note) == NOTE_INSN_DELETED | |
87c8b4be | 95 | || NOTE_LINE_NUMBER (note) == NOTE_INSN_BASIC_BLOCK); |
ca6c03ca JH |
96 | } |
97 | ||
98 | /* True if a given label can be deleted. */ | |
99 | ||
100 | static int | |
d329e058 | 101 | can_delete_label_p (rtx label) |
ca6c03ca | 102 | { |
5f0d2358 RK |
103 | return (!LABEL_PRESERVE_P (label) |
104 | /* User declared labels must be preserved. */ | |
105 | && LABEL_NAME (label) == 0 | |
106 | && !in_expr_list_p (forced_labels, label) | |
6a58eee9 | 107 | && !in_expr_list_p (label_value_list, label)); |
ca6c03ca JH |
108 | } |
109 | ||
110 | /* Delete INSN by patching it out. Return the next insn. */ | |
111 | ||
112 | rtx | |
d329e058 | 113 | delete_insn (rtx insn) |
ca6c03ca JH |
114 | { |
115 | rtx next = NEXT_INSN (insn); | |
116 | rtx note; | |
117 | bool really_delete = true; | |
118 | ||
4b4bf941 | 119 | if (LABEL_P (insn)) |
ca6c03ca JH |
120 | { |
121 | /* Some labels can't be directly removed from the INSN chain, as they | |
f87c27b4 | 122 | might be references via variables, constant pool etc. |
ca6c03ca JH |
123 | Convert them to the special NOTE_INSN_DELETED_LABEL note. */ |
124 | if (! can_delete_label_p (insn)) | |
125 | { | |
126 | const char *name = LABEL_NAME (insn); | |
127 | ||
128 | really_delete = false; | |
129 | PUT_CODE (insn, NOTE); | |
130 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED_LABEL; | |
6773e15f | 131 | NOTE_DELETED_LABEL_NAME (insn) = name; |
ca6c03ca | 132 | } |
5f0d2358 | 133 | |
ca6c03ca JH |
134 | remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels); |
135 | } | |
136 | ||
137 | if (really_delete) | |
138 | { | |
cda94cbb | 139 | /* If this insn has already been deleted, something is very wrong. */ |
341c100f | 140 | gcc_assert (!INSN_DELETED_P (insn)); |
ca6c03ca JH |
141 | remove_insn (insn); |
142 | INSN_DELETED_P (insn) = 1; | |
143 | } | |
144 | ||
145 | /* If deleting a jump, decrement the use count of the label. Deleting | |
146 | the label itself should happen in the normal course of block merging. */ | |
4b4bf941 | 147 | if (JUMP_P (insn) |
ca6c03ca | 148 | && JUMP_LABEL (insn) |
4b4bf941 | 149 | && LABEL_P (JUMP_LABEL (insn))) |
ca6c03ca JH |
150 | LABEL_NUSES (JUMP_LABEL (insn))--; |
151 | ||
152 | /* Also if deleting an insn that references a label. */ | |
9295a326 JZ |
153 | else |
154 | { | |
155 | while ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)) != NULL_RTX | |
4b4bf941 | 156 | && LABEL_P (XEXP (note, 0))) |
9295a326 JZ |
157 | { |
158 | LABEL_NUSES (XEXP (note, 0))--; | |
159 | remove_note (insn, note); | |
160 | } | |
161 | } | |
ca6c03ca | 162 | |
4b4bf941 | 163 | if (JUMP_P (insn) |
ca6c03ca JH |
164 | && (GET_CODE (PATTERN (insn)) == ADDR_VEC |
165 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)) | |
166 | { | |
167 | rtx pat = PATTERN (insn); | |
168 | int diff_vec_p = GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC; | |
169 | int len = XVECLEN (pat, diff_vec_p); | |
170 | int i; | |
171 | ||
172 | for (i = 0; i < len; i++) | |
a124fcda RH |
173 | { |
174 | rtx label = XEXP (XVECEXP (pat, diff_vec_p, i), 0); | |
175 | ||
176 | /* When deleting code in bulk (e.g. removing many unreachable | |
177 | blocks) we can delete a label that's a target of the vector | |
178 | before deleting the vector itself. */ | |
4b4bf941 | 179 | if (!NOTE_P (label)) |
a124fcda RH |
180 | LABEL_NUSES (label)--; |
181 | } | |
ca6c03ca JH |
182 | } |
183 | ||
184 | return next; | |
185 | } | |
186 | ||
3dec4024 JH |
187 | /* Like delete_insn but also purge dead edges from BB. */ |
188 | rtx | |
d329e058 | 189 | delete_insn_and_edges (rtx insn) |
3dec4024 JH |
190 | { |
191 | rtx x; | |
192 | bool purge = false; | |
193 | ||
ba4f7968 | 194 | if (INSN_P (insn) |
3dec4024 | 195 | && BLOCK_FOR_INSN (insn) |
a813c111 | 196 | && BB_END (BLOCK_FOR_INSN (insn)) == insn) |
3dec4024 JH |
197 | purge = true; |
198 | x = delete_insn (insn); | |
199 | if (purge) | |
200 | purge_dead_edges (BLOCK_FOR_INSN (insn)); | |
201 | return x; | |
202 | } | |
203 | ||
ca6c03ca JH |
204 | /* Unlink a chain of insns between START and FINISH, leaving notes |
205 | that must be paired. */ | |
206 | ||
207 | void | |
d329e058 | 208 | delete_insn_chain (rtx start, rtx finish) |
ca6c03ca | 209 | { |
ca6c03ca JH |
210 | rtx next; |
211 | ||
5f0d2358 RK |
212 | /* Unchain the insns one by one. It would be quicker to delete all of these |
213 | with a single unchaining, rather than one at a time, but we need to keep | |
214 | the NOTE's. */ | |
ca6c03ca JH |
215 | while (1) |
216 | { | |
217 | next = NEXT_INSN (start); | |
4b4bf941 | 218 | if (NOTE_P (start) && !can_delete_note_p (start)) |
ca6c03ca JH |
219 | ; |
220 | else | |
221 | next = delete_insn (start); | |
222 | ||
223 | if (start == finish) | |
224 | break; | |
225 | start = next; | |
226 | } | |
227 | } | |
3dec4024 JH |
228 | |
229 | /* Like delete_insn but also purge dead edges from BB. */ | |
230 | void | |
d329e058 | 231 | delete_insn_chain_and_edges (rtx first, rtx last) |
3dec4024 JH |
232 | { |
233 | bool purge = false; | |
234 | ||
ba4f7968 | 235 | if (INSN_P (last) |
3dec4024 | 236 | && BLOCK_FOR_INSN (last) |
a813c111 | 237 | && BB_END (BLOCK_FOR_INSN (last)) == last) |
3dec4024 JH |
238 | purge = true; |
239 | delete_insn_chain (first, last); | |
240 | if (purge) | |
241 | purge_dead_edges (BLOCK_FOR_INSN (last)); | |
242 | } | |
ca6c03ca | 243 | \f |
5f0d2358 RK |
244 | /* Create a new basic block consisting of the instructions between HEAD and END |
245 | inclusive. This function is designed to allow fast BB construction - reuses | |
246 | the note and basic block struct in BB_NOTE, if any and do not grow | |
247 | BASIC_BLOCK chain and should be used directly only by CFG construction code. | |
248 | END can be NULL in to create new empty basic block before HEAD. Both END | |
918ed612 ZD |
249 | and HEAD can be NULL to create basic block at the end of INSN chain. |
250 | AFTER is the basic block we should be put after. */ | |
ca6c03ca JH |
251 | |
252 | basic_block | |
d329e058 | 253 | create_basic_block_structure (rtx head, rtx end, rtx bb_note, basic_block after) |
ca6c03ca JH |
254 | { |
255 | basic_block bb; | |
256 | ||
257 | if (bb_note | |
ca6c03ca JH |
258 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL |
259 | && bb->aux == NULL) | |
260 | { | |
261 | /* If we found an existing note, thread it back onto the chain. */ | |
262 | ||
263 | rtx after; | |
264 | ||
4b4bf941 | 265 | if (LABEL_P (head)) |
ca6c03ca JH |
266 | after = head; |
267 | else | |
268 | { | |
269 | after = PREV_INSN (head); | |
270 | head = bb_note; | |
271 | } | |
272 | ||
273 | if (after != bb_note && NEXT_INSN (after) != bb_note) | |
ba4f7968 | 274 | reorder_insns_nobb (bb_note, bb_note, after); |
ca6c03ca JH |
275 | } |
276 | else | |
277 | { | |
278 | /* Otherwise we must create a note and a basic block structure. */ | |
279 | ||
280 | bb = alloc_block (); | |
281 | ||
282 | if (!head && !end) | |
5f0d2358 RK |
283 | head = end = bb_note |
284 | = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); | |
4b4bf941 | 285 | else if (LABEL_P (head) && end) |
ca6c03ca JH |
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 | } | |
5f0d2358 | 298 | |
ca6c03ca JH |
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 | ||
a813c111 SB |
306 | BB_HEAD (bb) = head; |
307 | BB_END (bb) = end; | |
852c6ec7 | 308 | bb->index = last_basic_block++; |
38c1593d | 309 | bb->flags = BB_NEW; |
918ed612 | 310 | link_block (bb, after); |
852c6ec7 | 311 | BASIC_BLOCK (bb->index) = bb; |
ba4f7968 | 312 | update_bb_for_insn (bb); |
076c7ab8 | 313 | BB_SET_PARTITION (bb, BB_UNPARTITIONED); |
ca6c03ca JH |
314 | |
315 | /* Tag the block so that we know it has been used when considering | |
316 | other basic block notes. */ | |
317 | bb->aux = bb; | |
318 | ||
319 | return bb; | |
320 | } | |
321 | ||
5f0d2358 | 322 | /* Create new basic block consisting of instructions in between HEAD and END |
918ed612 | 323 | and place it to the BB chain after block AFTER. END can be NULL in to |
5f0d2358 RK |
324 | create new empty basic block before HEAD. Both END and HEAD can be NULL to |
325 | create basic block at the end of INSN chain. */ | |
ca6c03ca | 326 | |
bc35512f JH |
327 | static basic_block |
328 | rtl_create_basic_block (void *headp, void *endp, basic_block after) | |
ca6c03ca | 329 | { |
bc35512f | 330 | rtx head = headp, end = endp; |
ca6c03ca | 331 | basic_block bb; |
0b17ab2f | 332 | |
7eca0767 JH |
333 | /* Grow the basic block array if needed. */ |
334 | if ((size_t) last_basic_block >= VARRAY_SIZE (basic_block_info)) | |
335 | { | |
336 | size_t new_size = last_basic_block + (last_basic_block + 3) / 4; | |
337 | VARRAY_GROW (basic_block_info, new_size); | |
338 | } | |
0b17ab2f | 339 | |
bf77398c | 340 | n_basic_blocks++; |
ca6c03ca | 341 | |
852c6ec7 | 342 | bb = create_basic_block_structure (head, end, NULL, after); |
ca6c03ca JH |
343 | bb->aux = NULL; |
344 | return bb; | |
345 | } | |
bc35512f JH |
346 | |
347 | static basic_block | |
348 | cfg_layout_create_basic_block (void *head, void *end, basic_block after) | |
349 | { | |
350 | basic_block newbb = rtl_create_basic_block (head, end, after); | |
351 | ||
6de9cd9a | 352 | initialize_bb_rbi (newbb); |
bc35512f JH |
353 | return newbb; |
354 | } | |
ca6c03ca JH |
355 | \f |
356 | /* Delete the insns in a (non-live) block. We physically delete every | |
357 | non-deleted-note insn, and update the flow graph appropriately. | |
358 | ||
359 | Return nonzero if we deleted an exception handler. */ | |
360 | ||
361 | /* ??? Preserving all such notes strikes me as wrong. It would be nice | |
362 | to post-process the stream to remove empty blocks, loops, ranges, etc. */ | |
363 | ||
f0fda11c | 364 | static void |
d329e058 | 365 | rtl_delete_block (basic_block b) |
ca6c03ca | 366 | { |
ca6c03ca JH |
367 | rtx insn, end, tmp; |
368 | ||
369 | /* If the head of this block is a CODE_LABEL, then it might be the | |
f39e46ba SB |
370 | label for an exception handler which can't be reached. We need |
371 | to remove the label from the exception_handler_label list. */ | |
a813c111 | 372 | insn = BB_HEAD (b); |
4b4bf941 | 373 | if (LABEL_P (insn)) |
ca6c03ca JH |
374 | maybe_remove_eh_handler (insn); |
375 | ||
376 | /* Include any jump table following the basic block. */ | |
a813c111 | 377 | end = BB_END (b); |
e1233a7d | 378 | if (tablejump_p (end, NULL, &tmp)) |
ca6c03ca JH |
379 | end = tmp; |
380 | ||
4ab80063 | 381 | /* Include any barriers that may follow the basic block. */ |
ca6c03ca | 382 | tmp = next_nonnote_insn (end); |
4ab80063 RS |
383 | while (tmp && BARRIER_P (tmp)) |
384 | { | |
385 | end = tmp; | |
386 | tmp = next_nonnote_insn (end); | |
387 | } | |
ca6c03ca JH |
388 | |
389 | /* Selectively delete the entire chain. */ | |
a813c111 | 390 | BB_HEAD (b) = NULL; |
ca6c03ca | 391 | delete_insn_chain (insn, end); |
ca6c03ca JH |
392 | } |
393 | \f | |
852c6ec7 | 394 | /* Records the basic block struct in BLOCK_FOR_INSN for every insn. */ |
ca6c03ca JH |
395 | |
396 | void | |
d329e058 | 397 | compute_bb_for_insn (void) |
ca6c03ca | 398 | { |
e0082a72 | 399 | basic_block bb; |
ca6c03ca | 400 | |
e0082a72 | 401 | FOR_EACH_BB (bb) |
ca6c03ca | 402 | { |
a813c111 | 403 | rtx end = BB_END (bb); |
5f0d2358 | 404 | rtx insn; |
ca6c03ca | 405 | |
a813c111 | 406 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
ca6c03ca | 407 | { |
ba4f7968 | 408 | BLOCK_FOR_INSN (insn) = bb; |
ca6c03ca JH |
409 | if (insn == end) |
410 | break; | |
ca6c03ca JH |
411 | } |
412 | } | |
413 | } | |
414 | ||
415 | /* Release the basic_block_for_insn array. */ | |
416 | ||
417 | void | |
d329e058 | 418 | free_bb_for_insn (void) |
ca6c03ca | 419 | { |
ba4f7968 JH |
420 | rtx insn; |
421 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) | |
4b4bf941 | 422 | if (!BARRIER_P (insn)) |
ba4f7968 | 423 | BLOCK_FOR_INSN (insn) = NULL; |
ca6c03ca JH |
424 | } |
425 | ||
91278841 AP |
426 | /* Return RTX to emit after when we want to emit code on the entry of function. */ |
427 | rtx | |
428 | entry_of_function (void) | |
429 | { | |
430 | return (n_basic_blocks ? BB_HEAD (ENTRY_BLOCK_PTR->next_bb) : get_insns ()); | |
431 | } | |
432 | ||
ca6c03ca JH |
433 | /* Update insns block within BB. */ |
434 | ||
435 | void | |
d329e058 | 436 | update_bb_for_insn (basic_block bb) |
ca6c03ca JH |
437 | { |
438 | rtx insn; | |
439 | ||
a813c111 | 440 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
ca6c03ca | 441 | { |
4b4bf941 | 442 | if (!BARRIER_P (insn)) |
bcc53e2a | 443 | set_block_for_insn (insn, bb); |
a813c111 | 444 | if (insn == BB_END (bb)) |
ca6c03ca JH |
445 | break; |
446 | } | |
447 | } | |
ca6c03ca | 448 | \f |
f470c378 ZD |
449 | /* Creates a new basic block just after basic block B by splitting |
450 | everything after specified instruction I. */ | |
ca6c03ca | 451 | |
f470c378 | 452 | static basic_block |
d329e058 | 453 | rtl_split_block (basic_block bb, void *insnp) |
ca6c03ca JH |
454 | { |
455 | basic_block new_bb; | |
9ee634e3 | 456 | rtx insn = insnp; |
f470c378 | 457 | edge e; |
628f6a4e | 458 | edge_iterator ei; |
ca6c03ca | 459 | |
f470c378 ZD |
460 | if (!insn) |
461 | { | |
462 | insn = first_insn_after_basic_block_note (bb); | |
463 | ||
464 | if (insn) | |
465 | insn = PREV_INSN (insn); | |
466 | else | |
467 | insn = get_last_insn (); | |
468 | } | |
469 | ||
470 | /* We probably should check type of the insn so that we do not create | |
471 | inconsistent cfg. It is checked in verify_flow_info anyway, so do not | |
472 | bother. */ | |
473 | if (insn == BB_END (bb)) | |
474 | emit_note_after (NOTE_INSN_DELETED, insn); | |
ca6c03ca JH |
475 | |
476 | /* Create the new basic block. */ | |
a813c111 | 477 | new_bb = create_basic_block (NEXT_INSN (insn), BB_END (bb), bb); |
076c7ab8 | 478 | BB_COPY_PARTITION (new_bb, bb); |
a813c111 | 479 | BB_END (bb) = insn; |
ca6c03ca JH |
480 | |
481 | /* Redirect the outgoing edges. */ | |
628f6a4e BE |
482 | new_bb->succs = bb->succs; |
483 | bb->succs = NULL; | |
484 | FOR_EACH_EDGE (e, ei, new_bb->succs) | |
ca6c03ca JH |
485 | e->src = new_bb; |
486 | ||
ca6c03ca JH |
487 | if (bb->global_live_at_start) |
488 | { | |
04389919 NS |
489 | new_bb->global_live_at_start = ALLOC_REG_SET (®_obstack); |
490 | new_bb->global_live_at_end = ALLOC_REG_SET (®_obstack); | |
ca6c03ca JH |
491 | COPY_REG_SET (new_bb->global_live_at_end, bb->global_live_at_end); |
492 | ||
493 | /* We now have to calculate which registers are live at the end | |
494 | of the split basic block and at the start of the new basic | |
495 | block. Start with those registers that are known to be live | |
496 | at the end of the original basic block and get | |
497 | propagate_block to determine which registers are live. */ | |
498 | COPY_REG_SET (new_bb->global_live_at_start, bb->global_live_at_end); | |
499 | propagate_block (new_bb, new_bb->global_live_at_start, NULL, NULL, 0); | |
500 | COPY_REG_SET (bb->global_live_at_end, | |
501 | new_bb->global_live_at_start); | |
0a2ed1f1 JH |
502 | #ifdef HAVE_conditional_execution |
503 | /* In the presence of conditional execution we are not able to update | |
504 | liveness precisely. */ | |
505 | if (reload_completed) | |
506 | { | |
507 | bb->flags |= BB_DIRTY; | |
508 | new_bb->flags |= BB_DIRTY; | |
509 | } | |
510 | #endif | |
ca6c03ca JH |
511 | } |
512 | ||
f470c378 | 513 | return new_bb; |
bc35512f JH |
514 | } |
515 | ||
ca6c03ca | 516 | /* Blocks A and B are to be merged into a single block A. The insns |
bc35512f | 517 | are already contiguous. */ |
ca6c03ca | 518 | |
bc35512f JH |
519 | static void |
520 | rtl_merge_blocks (basic_block a, basic_block b) | |
ca6c03ca | 521 | { |
a813c111 | 522 | rtx b_head = BB_HEAD (b), b_end = BB_END (b), a_end = BB_END (a); |
ca6c03ca JH |
523 | rtx del_first = NULL_RTX, del_last = NULL_RTX; |
524 | int b_empty = 0; | |
525 | ||
526 | /* If there was a CODE_LABEL beginning B, delete it. */ | |
4b4bf941 | 527 | if (LABEL_P (b_head)) |
ca6c03ca JH |
528 | { |
529 | /* Detect basic blocks with nothing but a label. This can happen | |
530 | in particular at the end of a function. */ | |
531 | if (b_head == b_end) | |
532 | b_empty = 1; | |
5f0d2358 | 533 | |
ca6c03ca JH |
534 | del_first = del_last = b_head; |
535 | b_head = NEXT_INSN (b_head); | |
536 | } | |
537 | ||
5f0d2358 RK |
538 | /* Delete the basic block note and handle blocks containing just that |
539 | note. */ | |
ca6c03ca JH |
540 | if (NOTE_INSN_BASIC_BLOCK_P (b_head)) |
541 | { | |
542 | if (b_head == b_end) | |
543 | b_empty = 1; | |
544 | if (! del_last) | |
545 | del_first = b_head; | |
5f0d2358 | 546 | |
ca6c03ca JH |
547 | del_last = b_head; |
548 | b_head = NEXT_INSN (b_head); | |
549 | } | |
550 | ||
551 | /* If there was a jump out of A, delete it. */ | |
4b4bf941 | 552 | if (JUMP_P (a_end)) |
ca6c03ca JH |
553 | { |
554 | rtx prev; | |
555 | ||
556 | for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev)) | |
4b4bf941 | 557 | if (!NOTE_P (prev) |
ca6c03ca | 558 | || NOTE_LINE_NUMBER (prev) == NOTE_INSN_BASIC_BLOCK |
a813c111 | 559 | || prev == BB_HEAD (a)) |
ca6c03ca JH |
560 | break; |
561 | ||
562 | del_first = a_end; | |
563 | ||
564 | #ifdef HAVE_cc0 | |
565 | /* If this was a conditional jump, we need to also delete | |
566 | the insn that set cc0. */ | |
567 | if (only_sets_cc0_p (prev)) | |
568 | { | |
569 | rtx tmp = prev; | |
5f0d2358 | 570 | |
ca6c03ca JH |
571 | prev = prev_nonnote_insn (prev); |
572 | if (!prev) | |
a813c111 | 573 | prev = BB_HEAD (a); |
ca6c03ca JH |
574 | del_first = tmp; |
575 | } | |
576 | #endif | |
577 | ||
578 | a_end = PREV_INSN (del_first); | |
579 | } | |
4b4bf941 | 580 | else if (BARRIER_P (NEXT_INSN (a_end))) |
ca6c03ca JH |
581 | del_first = NEXT_INSN (a_end); |
582 | ||
ca6c03ca JH |
583 | /* Delete everything marked above as well as crap that might be |
584 | hanging out between the two blocks. */ | |
f470c378 | 585 | BB_HEAD (b) = NULL; |
ca6c03ca JH |
586 | delete_insn_chain (del_first, del_last); |
587 | ||
588 | /* Reassociate the insns of B with A. */ | |
589 | if (!b_empty) | |
590 | { | |
ba4f7968 | 591 | rtx x; |
5f0d2358 | 592 | |
ba4f7968 JH |
593 | for (x = a_end; x != b_end; x = NEXT_INSN (x)) |
594 | set_block_for_insn (x, a); | |
5f0d2358 | 595 | |
ba4f7968 | 596 | set_block_for_insn (b_end, a); |
5f0d2358 | 597 | |
ca6c03ca JH |
598 | a_end = b_end; |
599 | } | |
5f0d2358 | 600 | |
a813c111 | 601 | BB_END (a) = a_end; |
ca6c03ca | 602 | } |
bc35512f JH |
603 | |
604 | /* Return true when block A and B can be merged. */ | |
605 | static bool | |
606 | rtl_can_merge_blocks (basic_block a,basic_block b) | |
607 | { | |
750054a2 CT |
608 | /* If we are partitioning hot/cold basic blocks, we don't want to |
609 | mess up unconditional or indirect jumps that cross between hot | |
076c7ab8 ZW |
610 | and cold sections. |
611 | ||
8e8d5162 CT |
612 | Basic block partitioning may result in some jumps that appear to |
613 | be optimizable (or blocks that appear to be mergeable), but which really | |
614 | must be left untouched (they are required to make it safely across | |
615 | partition boundaries). See the comments at the top of | |
616 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ | |
076c7ab8 | 617 | |
87c8b4be | 618 | if (BB_PARTITION (a) != BB_PARTITION (b)) |
076c7ab8 | 619 | return false; |
750054a2 | 620 | |
bc35512f | 621 | /* There must be exactly one edge in between the blocks. */ |
c5cbcccf ZD |
622 | return (single_succ_p (a) |
623 | && single_succ (a) == b | |
624 | && single_pred_p (b) | |
628f6a4e | 625 | && a != b |
bc35512f | 626 | /* Must be simple edge. */ |
c5cbcccf | 627 | && !(single_succ_edge (a)->flags & EDGE_COMPLEX) |
bc35512f JH |
628 | && a->next_bb == b |
629 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR | |
630 | /* If the jump insn has side effects, | |
631 | we can't kill the edge. */ | |
4b4bf941 | 632 | && (!JUMP_P (BB_END (a)) |
e24e7211 | 633 | || (reload_completed |
a813c111 | 634 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f | 635 | } |
ca6c03ca | 636 | \f |
5f0d2358 RK |
637 | /* Return the label in the head of basic block BLOCK. Create one if it doesn't |
638 | exist. */ | |
ca6c03ca JH |
639 | |
640 | rtx | |
d329e058 | 641 | block_label (basic_block block) |
ca6c03ca JH |
642 | { |
643 | if (block == EXIT_BLOCK_PTR) | |
644 | return NULL_RTX; | |
5f0d2358 | 645 | |
4b4bf941 | 646 | if (!LABEL_P (BB_HEAD (block))) |
ca6c03ca | 647 | { |
a813c111 | 648 | BB_HEAD (block) = emit_label_before (gen_label_rtx (), BB_HEAD (block)); |
ca6c03ca | 649 | } |
5f0d2358 | 650 | |
a813c111 | 651 | return BB_HEAD (block); |
ca6c03ca JH |
652 | } |
653 | ||
654 | /* Attempt to perform edge redirection by replacing possibly complex jump | |
5f0d2358 RK |
655 | instruction by unconditional jump or removing jump completely. This can |
656 | apply only if all edges now point to the same block. The parameters and | |
657 | return values are equivalent to redirect_edge_and_branch. */ | |
ca6c03ca | 658 | |
6de9cd9a | 659 | edge |
bc35512f | 660 | try_redirect_by_replacing_jump (edge e, basic_block target, bool in_cfglayout) |
ca6c03ca JH |
661 | { |
662 | basic_block src = e->src; | |
a813c111 | 663 | rtx insn = BB_END (src), kill_from; |
e1233a7d | 664 | rtx set; |
ca6c03ca | 665 | int fallthru = 0; |
750054a2 CT |
666 | |
667 | /* If we are partitioning hot/cold basic blocks, we don't want to | |
668 | mess up unconditional or indirect jumps that cross between hot | |
8e8d5162 CT |
669 | and cold sections. |
670 | ||
671 | Basic block partitioning may result in some jumps that appear to | |
672 | be optimizable (or blocks that appear to be mergeable), but which really | |
673 | must be left untouched (they are required to make it safely across | |
674 | partition boundaries). See the comments at the top of | |
675 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ | |
750054a2 | 676 | |
87c8b4be CT |
677 | if (find_reg_note (insn, REG_CROSSING_JUMP, NULL_RTX) |
678 | || BB_PARTITION (src) != BB_PARTITION (target)) | |
9cf84a3c | 679 | return NULL; |
750054a2 | 680 | |
6a66a8a7 KH |
681 | /* We can replace or remove a complex jump only when we have exactly |
682 | two edges. Also, if we have exactly one outgoing edge, we can | |
683 | redirect that. */ | |
684 | if (EDGE_COUNT (src->succs) >= 3 | |
685 | /* Verify that all targets will be TARGET. Specifically, the | |
686 | edge that is not E must also go to TARGET. */ | |
687 | || (EDGE_COUNT (src->succs) == 2 | |
688 | && EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)) | |
689 | return NULL; | |
5f0d2358 | 690 | |
6a66a8a7 | 691 | if (!onlyjump_p (insn)) |
6de9cd9a | 692 | return NULL; |
3348b696 | 693 | if ((!optimize || reload_completed) && tablejump_p (insn, NULL, NULL)) |
6de9cd9a | 694 | return NULL; |
ca6c03ca JH |
695 | |
696 | /* Avoid removing branch with side effects. */ | |
697 | set = single_set (insn); | |
698 | if (!set || side_effects_p (set)) | |
6de9cd9a | 699 | return NULL; |
ca6c03ca JH |
700 | |
701 | /* In case we zap a conditional jump, we'll need to kill | |
702 | the cc0 setter too. */ | |
703 | kill_from = insn; | |
704 | #ifdef HAVE_cc0 | |
705 | if (reg_mentioned_p (cc0_rtx, PATTERN (insn))) | |
706 | kill_from = PREV_INSN (insn); | |
707 | #endif | |
708 | ||
709 | /* See if we can create the fallthru edge. */ | |
bc35512f | 710 | if (in_cfglayout || can_fallthru (src, target)) |
ca6c03ca | 711 | { |
c263766c RH |
712 | if (dump_file) |
713 | fprintf (dump_file, "Removing jump %i.\n", INSN_UID (insn)); | |
ca6c03ca JH |
714 | fallthru = 1; |
715 | ||
eaec9b3d | 716 | /* Selectively unlink whole insn chain. */ |
bc35512f JH |
717 | if (in_cfglayout) |
718 | { | |
719 | rtx insn = src->rbi->footer; | |
720 | ||
a813c111 | 721 | delete_insn_chain (kill_from, BB_END (src)); |
bc35512f JH |
722 | |
723 | /* Remove barriers but keep jumptables. */ | |
724 | while (insn) | |
725 | { | |
4b4bf941 | 726 | if (BARRIER_P (insn)) |
bc35512f JH |
727 | { |
728 | if (PREV_INSN (insn)) | |
729 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
730 | else | |
731 | src->rbi->footer = NEXT_INSN (insn); | |
732 | if (NEXT_INSN (insn)) | |
733 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
734 | } | |
4b4bf941 | 735 | if (LABEL_P (insn)) |
bc35512f JH |
736 | break; |
737 | insn = NEXT_INSN (insn); | |
738 | } | |
739 | } | |
740 | else | |
a813c111 | 741 | delete_insn_chain (kill_from, PREV_INSN (BB_HEAD (target))); |
ca6c03ca | 742 | } |
5f0d2358 | 743 | |
ca6c03ca JH |
744 | /* If this already is simplejump, redirect it. */ |
745 | else if (simplejump_p (insn)) | |
746 | { | |
747 | if (e->dest == target) | |
6de9cd9a | 748 | return NULL; |
c263766c RH |
749 | if (dump_file) |
750 | fprintf (dump_file, "Redirecting jump %i from %i to %i.\n", | |
0b17ab2f | 751 | INSN_UID (insn), e->dest->index, target->index); |
6ee3c8e4 JJ |
752 | if (!redirect_jump (insn, block_label (target), 0)) |
753 | { | |
341c100f NS |
754 | gcc_assert (target == EXIT_BLOCK_PTR); |
755 | return NULL; | |
6ee3c8e4 | 756 | } |
ca6c03ca | 757 | } |
5f0d2358 | 758 | |
6ee3c8e4 JJ |
759 | /* Cannot do anything for target exit block. */ |
760 | else if (target == EXIT_BLOCK_PTR) | |
6de9cd9a | 761 | return NULL; |
6ee3c8e4 | 762 | |
ca6c03ca JH |
763 | /* Or replace possibly complicated jump insn by simple jump insn. */ |
764 | else | |
765 | { | |
766 | rtx target_label = block_label (target); | |
eb5b8ad4 | 767 | rtx barrier, label, table; |
ca6c03ca | 768 | |
a7102479 | 769 | emit_jump_insn_after_noloc (gen_jump (target_label), insn); |
a813c111 | 770 | JUMP_LABEL (BB_END (src)) = target_label; |
ca6c03ca | 771 | LABEL_NUSES (target_label)++; |
c263766c RH |
772 | if (dump_file) |
773 | fprintf (dump_file, "Replacing insn %i by jump %i\n", | |
a813c111 | 774 | INSN_UID (insn), INSN_UID (BB_END (src))); |
ca6c03ca | 775 | |
4da2eb6b | 776 | |
ca6c03ca JH |
777 | delete_insn_chain (kill_from, insn); |
778 | ||
4da2eb6b RH |
779 | /* Recognize a tablejump that we are converting to a |
780 | simple jump and remove its associated CODE_LABEL | |
781 | and ADDR_VEC or ADDR_DIFF_VEC. */ | |
3348b696 | 782 | if (tablejump_p (insn, &label, &table)) |
4da2eb6b | 783 | delete_insn_chain (label, table); |
eb5b8ad4 | 784 | |
a813c111 | 785 | barrier = next_nonnote_insn (BB_END (src)); |
4b4bf941 | 786 | if (!barrier || !BARRIER_P (barrier)) |
a813c111 | 787 | emit_barrier_after (BB_END (src)); |
5d693491 JZ |
788 | else |
789 | { | |
a813c111 | 790 | if (barrier != NEXT_INSN (BB_END (src))) |
5d693491 JZ |
791 | { |
792 | /* Move the jump before barrier so that the notes | |
793 | which originally were or were created before jump table are | |
794 | inside the basic block. */ | |
a813c111 | 795 | rtx new_insn = BB_END (src); |
5d693491 JZ |
796 | rtx tmp; |
797 | ||
a813c111 | 798 | for (tmp = NEXT_INSN (BB_END (src)); tmp != barrier; |
5d693491 JZ |
799 | tmp = NEXT_INSN (tmp)) |
800 | set_block_for_insn (tmp, src); | |
801 | ||
802 | NEXT_INSN (PREV_INSN (new_insn)) = NEXT_INSN (new_insn); | |
803 | PREV_INSN (NEXT_INSN (new_insn)) = PREV_INSN (new_insn); | |
804 | ||
805 | NEXT_INSN (new_insn) = barrier; | |
806 | NEXT_INSN (PREV_INSN (barrier)) = new_insn; | |
807 | ||
808 | PREV_INSN (new_insn) = PREV_INSN (barrier); | |
809 | PREV_INSN (barrier) = new_insn; | |
810 | } | |
811 | } | |
ca6c03ca JH |
812 | } |
813 | ||
814 | /* Keep only one edge out and set proper flags. */ | |
c5cbcccf | 815 | if (!single_succ_p (src)) |
628f6a4e | 816 | remove_edge (e); |
c5cbcccf | 817 | gcc_assert (single_succ_p (src)); |
628f6a4e | 818 | |
c5cbcccf | 819 | e = single_succ_edge (src); |
ca6c03ca JH |
820 | if (fallthru) |
821 | e->flags = EDGE_FALLTHRU; | |
822 | else | |
823 | e->flags = 0; | |
5f0d2358 | 824 | |
ca6c03ca JH |
825 | e->probability = REG_BR_PROB_BASE; |
826 | e->count = src->count; | |
827 | ||
828 | /* We don't want a block to end on a line-number note since that has | |
829 | the potential of changing the code between -g and not -g. */ | |
4b4bf941 | 830 | while (NOTE_P (BB_END (e->src)) |
a813c111 SB |
831 | && NOTE_LINE_NUMBER (BB_END (e->src)) >= 0) |
832 | delete_insn (BB_END (e->src)); | |
ca6c03ca JH |
833 | |
834 | if (e->dest != target) | |
835 | redirect_edge_succ (e, target); | |
5f0d2358 | 836 | |
6de9cd9a | 837 | return e; |
ca6c03ca JH |
838 | } |
839 | ||
840 | /* Return last loop_beg note appearing after INSN, before start of next | |
841 | basic block. Return INSN if there are no such notes. | |
842 | ||
09da1532 | 843 | When emitting jump to redirect a fallthru edge, it should always appear |
5f0d2358 RK |
844 | after the LOOP_BEG notes, as loop optimizer expect loop to either start by |
845 | fallthru edge or jump following the LOOP_BEG note jumping to the loop exit | |
846 | test. */ | |
ca6c03ca JH |
847 | |
848 | static rtx | |
d329e058 | 849 | last_loop_beg_note (rtx insn) |
ca6c03ca JH |
850 | { |
851 | rtx last = insn; | |
5f0d2358 | 852 | |
4b4bf941 | 853 | for (insn = NEXT_INSN (insn); insn && NOTE_P (insn) |
5f0d2358 RK |
854 | && NOTE_LINE_NUMBER (insn) != NOTE_INSN_BASIC_BLOCK; |
855 | insn = NEXT_INSN (insn)) | |
856 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
857 | last = insn; | |
858 | ||
ca6c03ca JH |
859 | return last; |
860 | } | |
861 | ||
6de9cd9a DN |
862 | /* Redirect edge representing branch of (un)conditional jump or tablejump, |
863 | NULL on failure */ | |
864 | static edge | |
bc35512f | 865 | redirect_branch_edge (edge e, basic_block target) |
ca6c03ca JH |
866 | { |
867 | rtx tmp; | |
a813c111 | 868 | rtx old_label = BB_HEAD (e->dest); |
ca6c03ca | 869 | basic_block src = e->src; |
a813c111 | 870 | rtx insn = BB_END (src); |
ca6c03ca | 871 | |
ca6c03ca JH |
872 | /* We can only redirect non-fallthru edges of jump insn. */ |
873 | if (e->flags & EDGE_FALLTHRU) | |
6de9cd9a | 874 | return NULL; |
4b4bf941 | 875 | else if (!JUMP_P (insn)) |
6de9cd9a | 876 | return NULL; |
ca6c03ca JH |
877 | |
878 | /* Recognize a tablejump and adjust all matching cases. */ | |
e1233a7d | 879 | if (tablejump_p (insn, NULL, &tmp)) |
ca6c03ca JH |
880 | { |
881 | rtvec vec; | |
882 | int j; | |
883 | rtx new_label = block_label (target); | |
884 | ||
6ee3c8e4 | 885 | if (target == EXIT_BLOCK_PTR) |
6de9cd9a | 886 | return NULL; |
ca6c03ca JH |
887 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) |
888 | vec = XVEC (PATTERN (tmp), 0); | |
889 | else | |
890 | vec = XVEC (PATTERN (tmp), 1); | |
891 | ||
892 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
893 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
894 | { | |
895 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (Pmode, new_label); | |
896 | --LABEL_NUSES (old_label); | |
897 | ++LABEL_NUSES (new_label); | |
898 | } | |
899 | ||
f9da5064 | 900 | /* Handle casesi dispatch insns. */ |
ca6c03ca JH |
901 | if ((tmp = single_set (insn)) != NULL |
902 | && SET_DEST (tmp) == pc_rtx | |
903 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
904 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF | |
905 | && XEXP (XEXP (SET_SRC (tmp), 2), 0) == old_label) | |
906 | { | |
907 | XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (VOIDmode, | |
908 | new_label); | |
909 | --LABEL_NUSES (old_label); | |
910 | ++LABEL_NUSES (new_label); | |
911 | } | |
912 | } | |
913 | else | |
914 | { | |
915 | /* ?? We may play the games with moving the named labels from | |
916 | one basic block to the other in case only one computed_jump is | |
917 | available. */ | |
5f0d2358 RK |
918 | if (computed_jump_p (insn) |
919 | /* A return instruction can't be redirected. */ | |
920 | || returnjump_p (insn)) | |
6de9cd9a | 921 | return NULL; |
ca6c03ca JH |
922 | |
923 | /* If the insn doesn't go where we think, we're confused. */ | |
341c100f | 924 | gcc_assert (JUMP_LABEL (insn) == old_label); |
6ee3c8e4 JJ |
925 | |
926 | /* If the substitution doesn't succeed, die. This can happen | |
927 | if the back end emitted unrecognizable instructions or if | |
928 | target is exit block on some arches. */ | |
929 | if (!redirect_jump (insn, block_label (target), 0)) | |
930 | { | |
341c100f NS |
931 | gcc_assert (target == EXIT_BLOCK_PTR); |
932 | return NULL; | |
6ee3c8e4 | 933 | } |
ca6c03ca JH |
934 | } |
935 | ||
c263766c RH |
936 | if (dump_file) |
937 | fprintf (dump_file, "Edge %i->%i redirected to %i\n", | |
0b17ab2f | 938 | e->src->index, e->dest->index, target->index); |
5f0d2358 | 939 | |
ca6c03ca | 940 | if (e->dest != target) |
6de9cd9a DN |
941 | e = redirect_edge_succ_nodup (e, target); |
942 | return e; | |
bc35512f JH |
943 | } |
944 | ||
945 | /* Attempt to change code to redirect edge E to TARGET. Don't do that on | |
946 | expense of adding new instructions or reordering basic blocks. | |
947 | ||
948 | Function can be also called with edge destination equivalent to the TARGET. | |
949 | Then it should try the simplifications and do nothing if none is possible. | |
950 | ||
6de9cd9a DN |
951 | Return edge representing the branch if transformation succeeded. Return NULL |
952 | on failure. | |
953 | We still return NULL in case E already destinated TARGET and we didn't | |
954 | managed to simplify instruction stream. */ | |
bc35512f | 955 | |
6de9cd9a | 956 | static edge |
5671bf27 | 957 | rtl_redirect_edge_and_branch (edge e, basic_block target) |
bc35512f | 958 | { |
6de9cd9a | 959 | edge ret; |
f345f21a JH |
960 | basic_block src = e->src; |
961 | ||
bc35512f | 962 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
6de9cd9a | 963 | return NULL; |
bc35512f | 964 | |
3348b696 | 965 | if (e->dest == target) |
6de9cd9a | 966 | return e; |
3348b696 | 967 | |
6de9cd9a | 968 | if ((ret = try_redirect_by_replacing_jump (e, target, false)) != NULL) |
f345f21a JH |
969 | { |
970 | src->flags |= BB_DIRTY; | |
6de9cd9a | 971 | return ret; |
f345f21a | 972 | } |
bc35512f | 973 | |
6de9cd9a DN |
974 | ret = redirect_branch_edge (e, target); |
975 | if (!ret) | |
976 | return NULL; | |
5f0d2358 | 977 | |
f345f21a | 978 | src->flags |= BB_DIRTY; |
6de9cd9a | 979 | return ret; |
ca6c03ca JH |
980 | } |
981 | ||
4fe9b91c | 982 | /* Like force_nonfallthru below, but additionally performs redirection |
ca6c03ca JH |
983 | Used by redirect_edge_and_branch_force. */ |
984 | ||
9167e1c0 | 985 | static basic_block |
d329e058 | 986 | force_nonfallthru_and_redirect (edge e, basic_block target) |
ca6c03ca | 987 | { |
a3716585 | 988 | basic_block jump_block, new_bb = NULL, src = e->src; |
ca6c03ca JH |
989 | rtx note; |
990 | edge new_edge; | |
a3716585 | 991 | int abnormal_edge_flags = 0; |
ca6c03ca | 992 | |
cb9a1d9b JH |
993 | /* In the case the last instruction is conditional jump to the next |
994 | instruction, first redirect the jump itself and then continue | |
b20b352b | 995 | by creating a basic block afterwards to redirect fallthru edge. */ |
cb9a1d9b | 996 | if (e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR |
a813c111 | 997 | && any_condjump_p (BB_END (e->src)) |
cde1d5bf | 998 | /* When called from cfglayout, fallthru edges do not |
e0bb17a8 | 999 | necessarily go to the next block. */ |
cde1d5bf | 1000 | && e->src->next_bb == e->dest |
a813c111 | 1001 | && JUMP_LABEL (BB_END (e->src)) == BB_HEAD (e->dest)) |
cb9a1d9b JH |
1002 | { |
1003 | rtx note; | |
58e6ae30 | 1004 | edge b = unchecked_make_edge (e->src, target, 0); |
341c100f | 1005 | bool redirected; |
cb9a1d9b | 1006 | |
341c100f NS |
1007 | redirected = redirect_jump (BB_END (e->src), block_label (target), 0); |
1008 | gcc_assert (redirected); | |
1009 | ||
a813c111 | 1010 | note = find_reg_note (BB_END (e->src), REG_BR_PROB, NULL_RTX); |
cb9a1d9b JH |
1011 | if (note) |
1012 | { | |
1013 | int prob = INTVAL (XEXP (note, 0)); | |
1014 | ||
1015 | b->probability = prob; | |
1016 | b->count = e->count * prob / REG_BR_PROB_BASE; | |
1017 | e->probability -= e->probability; | |
1018 | e->count -= b->count; | |
1019 | if (e->probability < 0) | |
1020 | e->probability = 0; | |
1021 | if (e->count < 0) | |
1022 | e->count = 0; | |
1023 | } | |
1024 | } | |
1025 | ||
ca6c03ca | 1026 | if (e->flags & EDGE_ABNORMAL) |
a3716585 JH |
1027 | { |
1028 | /* Irritating special case - fallthru edge to the same block as abnormal | |
1029 | edge. | |
1030 | We can't redirect abnormal edge, but we still can split the fallthru | |
d329e058 | 1031 | one and create separate abnormal edge to original destination. |
a3716585 | 1032 | This allows bb-reorder to make such edge non-fallthru. */ |
341c100f | 1033 | gcc_assert (e->dest == target); |
a3716585 JH |
1034 | abnormal_edge_flags = e->flags & ~(EDGE_FALLTHRU | EDGE_CAN_FALLTHRU); |
1035 | e->flags &= EDGE_FALLTHRU | EDGE_CAN_FALLTHRU; | |
1036 | } | |
341c100f | 1037 | else |
24c545ff | 1038 | { |
341c100f NS |
1039 | gcc_assert (e->flags & EDGE_FALLTHRU); |
1040 | if (e->src == ENTRY_BLOCK_PTR) | |
1041 | { | |
1042 | /* We can't redirect the entry block. Create an empty block | |
628f6a4e BE |
1043 | at the start of the function which we use to add the new |
1044 | jump. */ | |
1045 | edge tmp; | |
1046 | edge_iterator ei; | |
1047 | bool found = false; | |
1048 | ||
1049 | basic_block bb = create_basic_block (BB_HEAD (e->dest), NULL, ENTRY_BLOCK_PTR); | |
1050 | ||
341c100f NS |
1051 | /* Change the existing edge's source to be the new block, and add |
1052 | a new edge from the entry block to the new block. */ | |
1053 | e->src = bb; | |
628f6a4e BE |
1054 | for (ei = ei_start (ENTRY_BLOCK_PTR->succs); (tmp = ei_safe_edge (ei)); ) |
1055 | { | |
1056 | if (tmp == e) | |
1057 | { | |
865851d0 | 1058 | VEC_unordered_remove (edge, ENTRY_BLOCK_PTR->succs, ei.index); |
628f6a4e BE |
1059 | found = true; |
1060 | break; | |
1061 | } | |
1062 | else | |
1063 | ei_next (&ei); | |
1064 | } | |
1065 | ||
1066 | gcc_assert (found); | |
1067 | ||
d4e6fecb | 1068 | VEC_safe_push (edge, gc, bb->succs, e); |
341c100f NS |
1069 | make_single_succ_edge (ENTRY_BLOCK_PTR, bb, EDGE_FALLTHRU); |
1070 | } | |
24c545ff BS |
1071 | } |
1072 | ||
628f6a4e | 1073 | if (EDGE_COUNT (e->src->succs) >= 2 || abnormal_edge_flags) |
ca6c03ca JH |
1074 | { |
1075 | /* Create the new structures. */ | |
31a78298 | 1076 | |
79019985 RH |
1077 | /* If the old block ended with a tablejump, skip its table |
1078 | by searching forward from there. Otherwise start searching | |
1079 | forward from the last instruction of the old block. */ | |
a813c111 SB |
1080 | if (!tablejump_p (BB_END (e->src), NULL, ¬e)) |
1081 | note = BB_END (e->src); | |
79019985 | 1082 | |
31a78298 | 1083 | /* Position the new block correctly relative to loop notes. */ |
79019985 | 1084 | note = last_loop_beg_note (note); |
31a78298 RH |
1085 | note = NEXT_INSN (note); |
1086 | ||
31a78298 | 1087 | jump_block = create_basic_block (note, NULL, e->src); |
ca6c03ca JH |
1088 | jump_block->count = e->count; |
1089 | jump_block->frequency = EDGE_FREQUENCY (e); | |
1090 | jump_block->loop_depth = target->loop_depth; | |
1091 | ||
1092 | if (target->global_live_at_start) | |
1093 | { | |
04389919 NS |
1094 | jump_block->global_live_at_start = ALLOC_REG_SET (®_obstack); |
1095 | jump_block->global_live_at_end = ALLOC_REG_SET (®_obstack); | |
ca6c03ca JH |
1096 | COPY_REG_SET (jump_block->global_live_at_start, |
1097 | target->global_live_at_start); | |
1098 | COPY_REG_SET (jump_block->global_live_at_end, | |
1099 | target->global_live_at_start); | |
1100 | } | |
1101 | ||
750054a2 CT |
1102 | /* Make sure new block ends up in correct hot/cold section. */ |
1103 | ||
076c7ab8 | 1104 | BB_COPY_PARTITION (jump_block, e->src); |
9fb32434 | 1105 | if (flag_reorder_blocks_and_partition |
87c8b4be CT |
1106 | && targetm.have_named_sections |
1107 | && JUMP_P (BB_END (jump_block)) | |
1108 | && !any_condjump_p (BB_END (jump_block)) | |
1109 | && (EDGE_SUCC (jump_block, 0)->flags & EDGE_CROSSING)) | |
1110 | REG_NOTES (BB_END (jump_block)) = gen_rtx_EXPR_LIST (REG_CROSSING_JUMP, | |
1111 | NULL_RTX, | |
1112 | REG_NOTES | |
1113 | (BB_END | |
1114 | (jump_block))); | |
1115 | ||
ca6c03ca JH |
1116 | /* Wire edge in. */ |
1117 | new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU); | |
1118 | new_edge->probability = e->probability; | |
1119 | new_edge->count = e->count; | |
1120 | ||
1121 | /* Redirect old edge. */ | |
1122 | redirect_edge_pred (e, jump_block); | |
1123 | e->probability = REG_BR_PROB_BASE; | |
1124 | ||
1125 | new_bb = jump_block; | |
1126 | } | |
1127 | else | |
1128 | jump_block = e->src; | |
5f0d2358 | 1129 | |
ca6c03ca JH |
1130 | e->flags &= ~EDGE_FALLTHRU; |
1131 | if (target == EXIT_BLOCK_PTR) | |
1132 | { | |
cf22ce3c | 1133 | #ifdef HAVE_return |
a7102479 | 1134 | emit_jump_insn_after_noloc (gen_return (), BB_END (jump_block)); |
cf22ce3c | 1135 | #else |
341c100f | 1136 | gcc_unreachable (); |
cf22ce3c | 1137 | #endif |
ca6c03ca JH |
1138 | } |
1139 | else | |
1140 | { | |
1141 | rtx label = block_label (target); | |
a7102479 | 1142 | emit_jump_insn_after_noloc (gen_jump (label), BB_END (jump_block)); |
a813c111 | 1143 | JUMP_LABEL (BB_END (jump_block)) = label; |
ca6c03ca JH |
1144 | LABEL_NUSES (label)++; |
1145 | } | |
5f0d2358 | 1146 | |
a813c111 | 1147 | emit_barrier_after (BB_END (jump_block)); |
ca6c03ca JH |
1148 | redirect_edge_succ_nodup (e, target); |
1149 | ||
a3716585 JH |
1150 | if (abnormal_edge_flags) |
1151 | make_edge (src, target, abnormal_edge_flags); | |
1152 | ||
ca6c03ca JH |
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. */ | |
5f0d2358 | 1159 | |
ca6c03ca | 1160 | basic_block |
d329e058 | 1161 | force_nonfallthru (edge e) |
ca6c03ca JH |
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. | |
eaec9b3d | 1168 | Abort if conversion is impossible. */ |
ca6c03ca | 1169 | |
9ee634e3 | 1170 | static basic_block |
d329e058 | 1171 | rtl_redirect_edge_and_branch_force (edge e, basic_block target) |
ca6c03ca | 1172 | { |
5f0d2358 RK |
1173 | if (redirect_edge_and_branch (e, target) |
1174 | || e->dest == target) | |
ca6c03ca JH |
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. */ | |
5f0d2358 | 1179 | return force_nonfallthru_and_redirect (e, target); |
ca6c03ca JH |
1180 | } |
1181 | ||
1182 | /* The given edge should potentially be a fallthru edge. If that is in | |
1183 | fact true, delete the jump and barriers that are in the way. */ | |
1184 | ||
f470c378 ZD |
1185 | static void |
1186 | rtl_tidy_fallthru_edge (edge e) | |
ca6c03ca JH |
1187 | { |
1188 | rtx q; | |
f470c378 ZD |
1189 | basic_block b = e->src, c = b->next_bb; |
1190 | ||
ca6c03ca JH |
1191 | /* ??? In a late-running flow pass, other folks may have deleted basic |
1192 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
1193 | and the target label. They ought to be chastized and fixed. | |
1194 | ||
1195 | We can also wind up with a sequence of undeletable labels between | |
1196 | one block and the next. | |
1197 | ||
1198 | So search through a sequence of barriers, labels, and notes for | |
1199 | the head of block C and assert that we really do fall through. */ | |
1200 | ||
a813c111 | 1201 | for (q = NEXT_INSN (BB_END (b)); q != BB_HEAD (c); q = NEXT_INSN (q)) |
9c0a0632 RH |
1202 | if (INSN_P (q)) |
1203 | return; | |
ca6c03ca JH |
1204 | |
1205 | /* Remove what will soon cease being the jump insn from the source block. | |
1206 | If block B consisted only of this single jump, turn it into a deleted | |
1207 | note. */ | |
a813c111 | 1208 | q = BB_END (b); |
4b4bf941 | 1209 | if (JUMP_P (q) |
ca6c03ca JH |
1210 | && onlyjump_p (q) |
1211 | && (any_uncondjump_p (q) | |
c5cbcccf | 1212 | || single_succ_p (b))) |
ca6c03ca JH |
1213 | { |
1214 | #ifdef HAVE_cc0 | |
1215 | /* If this was a conditional jump, we need to also delete | |
1216 | the insn that set cc0. */ | |
1217 | if (any_condjump_p (q) && only_sets_cc0_p (PREV_INSN (q))) | |
1218 | q = PREV_INSN (q); | |
1219 | #endif | |
1220 | ||
1221 | q = PREV_INSN (q); | |
1222 | ||
1223 | /* We don't want a block to end on a line-number note since that has | |
1224 | the potential of changing the code between -g and not -g. */ | |
4b4bf941 | 1225 | while (NOTE_P (q) && NOTE_LINE_NUMBER (q) >= 0) |
ca6c03ca JH |
1226 | q = PREV_INSN (q); |
1227 | } | |
1228 | ||
1229 | /* Selectively unlink the sequence. */ | |
a813c111 SB |
1230 | if (q != PREV_INSN (BB_HEAD (c))) |
1231 | delete_insn_chain (NEXT_INSN (q), PREV_INSN (BB_HEAD (c))); | |
ca6c03ca JH |
1232 | |
1233 | e->flags |= EDGE_FALLTHRU; | |
1234 | } | |
ca6c03ca JH |
1235 | \f |
1236 | /* Helper function for split_edge. Return true in case edge BB2 to BB1 | |
1237 | is back edge of syntactic loop. */ | |
1238 | ||
1239 | static bool | |
d329e058 | 1240 | back_edge_of_syntactic_loop_p (basic_block bb1, basic_block bb2) |
ca6c03ca JH |
1241 | { |
1242 | rtx insn; | |
1243 | int count = 0; | |
bf77398c | 1244 | basic_block bb; |
ca6c03ca | 1245 | |
bf77398c | 1246 | if (bb1 == bb2) |
0b17ab2f | 1247 | return true; |
355e4ec4 | 1248 | |
bf77398c ZD |
1249 | /* ??? Could we guarantee that bb indices are monotone, so that we could |
1250 | just compare them? */ | |
1251 | for (bb = bb1; bb && bb != bb2; bb = bb->next_bb) | |
1252 | continue; | |
1253 | ||
1254 | if (!bb) | |
1255 | return false; | |
1256 | ||
a813c111 | 1257 | for (insn = BB_END (bb1); insn != BB_HEAD (bb2) && count >= 0; |
ca6c03ca | 1258 | insn = NEXT_INSN (insn)) |
4b4bf941 | 1259 | if (NOTE_P (insn)) |
ca6c03ca JH |
1260 | { |
1261 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
1262 | count++; | |
5f0d2358 | 1263 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) |
ca6c03ca JH |
1264 | count--; |
1265 | } | |
1266 | ||
1267 | return count >= 0; | |
1268 | } | |
1269 | ||
f470c378 ZD |
1270 | /* Should move basic block BB after basic block AFTER. NIY. */ |
1271 | ||
1272 | static bool | |
1273 | rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED, | |
1274 | basic_block after ATTRIBUTE_UNUSED) | |
1275 | { | |
1276 | return false; | |
1277 | } | |
1278 | ||
ca6c03ca JH |
1279 | /* Split a (typically critical) edge. Return the new block. |
1280 | Abort on abnormal edges. | |
1281 | ||
1282 | ??? The code generally expects to be called on critical edges. | |
1283 | The case of a block ending in an unconditional jump to a | |
1284 | block with multiple predecessors is not handled optimally. */ | |
1285 | ||
8ce33230 | 1286 | static basic_block |
d329e058 | 1287 | rtl_split_edge (edge edge_in) |
ca6c03ca JH |
1288 | { |
1289 | basic_block bb; | |
ca6c03ca JH |
1290 | rtx before; |
1291 | ||
1292 | /* Abnormal edges cannot be split. */ | |
341c100f | 1293 | gcc_assert (!(edge_in->flags & EDGE_ABNORMAL)); |
ca6c03ca JH |
1294 | |
1295 | /* We are going to place the new block in front of edge destination. | |
eaec9b3d | 1296 | Avoid existence of fallthru predecessors. */ |
ca6c03ca JH |
1297 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) |
1298 | { | |
1299 | edge e; | |
628f6a4e | 1300 | edge_iterator ei; |
5f0d2358 | 1301 | |
628f6a4e | 1302 | FOR_EACH_EDGE (e, ei, edge_in->dest->preds) |
ca6c03ca JH |
1303 | if (e->flags & EDGE_FALLTHRU) |
1304 | break; | |
1305 | ||
1306 | if (e) | |
1307 | force_nonfallthru (e); | |
1308 | } | |
1309 | ||
1310 | /* Create the basic block note. | |
1311 | ||
f63d1bf7 | 1312 | Where we place the note can have a noticeable impact on the generated |
ca6c03ca JH |
1313 | code. Consider this cfg: |
1314 | ||
1315 | E | |
1316 | | | |
1317 | 0 | |
1318 | / \ | |
1319 | +->1-->2--->E | |
1320 | | | | |
1321 | +--+ | |
1322 | ||
1323 | If we need to insert an insn on the edge from block 0 to block 1, | |
1324 | we want to ensure the instructions we insert are outside of any | |
1325 | loop notes that physically sit between block 0 and block 1. Otherwise | |
1326 | we confuse the loop optimizer into thinking the loop is a phony. */ | |
1327 | ||
1328 | if (edge_in->dest != EXIT_BLOCK_PTR | |
a813c111 | 1329 | && PREV_INSN (BB_HEAD (edge_in->dest)) |
4b4bf941 | 1330 | && NOTE_P (PREV_INSN (BB_HEAD (edge_in->dest))) |
a813c111 | 1331 | && (NOTE_LINE_NUMBER (PREV_INSN (BB_HEAD (edge_in->dest))) |
5f0d2358 | 1332 | == NOTE_INSN_LOOP_BEG) |
ca6c03ca | 1333 | && !back_edge_of_syntactic_loop_p (edge_in->dest, edge_in->src)) |
a813c111 | 1334 | before = PREV_INSN (BB_HEAD (edge_in->dest)); |
ca6c03ca | 1335 | else if (edge_in->dest != EXIT_BLOCK_PTR) |
a813c111 | 1336 | before = BB_HEAD (edge_in->dest); |
ca6c03ca JH |
1337 | else |
1338 | before = NULL_RTX; | |
1339 | ||
623a66fa R |
1340 | /* If this is a fall through edge to the exit block, the blocks might be |
1341 | not adjacent, and the right place is the after the source. */ | |
1342 | if (edge_in->flags & EDGE_FALLTHRU && edge_in->dest == EXIT_BLOCK_PTR) | |
1343 | { | |
1344 | before = NEXT_INSN (BB_END (edge_in->src)); | |
1345 | if (before | |
4b4bf941 | 1346 | && NOTE_P (before) |
623a66fa R |
1347 | && NOTE_LINE_NUMBER (before) == NOTE_INSN_LOOP_END) |
1348 | before = NEXT_INSN (before); | |
1349 | bb = create_basic_block (before, NULL, edge_in->src); | |
076c7ab8 | 1350 | BB_COPY_PARTITION (bb, edge_in->src); |
623a66fa R |
1351 | } |
1352 | else | |
9fb32434 CT |
1353 | { |
1354 | bb = create_basic_block (before, NULL, edge_in->dest->prev_bb); | |
076c7ab8 ZW |
1355 | /* ??? Why not edge_in->dest->prev_bb here? */ |
1356 | BB_COPY_PARTITION (bb, edge_in->dest); | |
9fb32434 | 1357 | } |
ca6c03ca JH |
1358 | |
1359 | /* ??? This info is likely going to be out of date very soon. */ | |
1360 | if (edge_in->dest->global_live_at_start) | |
1361 | { | |
04389919 NS |
1362 | bb->global_live_at_start = ALLOC_REG_SET (®_obstack); |
1363 | bb->global_live_at_end = ALLOC_REG_SET (®_obstack); | |
5f0d2358 RK |
1364 | COPY_REG_SET (bb->global_live_at_start, |
1365 | edge_in->dest->global_live_at_start); | |
1366 | COPY_REG_SET (bb->global_live_at_end, | |
1367 | edge_in->dest->global_live_at_start); | |
ca6c03ca JH |
1368 | } |
1369 | ||
4977bab6 | 1370 | make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU); |
ca6c03ca | 1371 | |
4d6922ee | 1372 | /* For non-fallthru edges, we must adjust the predecessor's |
ca6c03ca JH |
1373 | jump instruction to target our new block. */ |
1374 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1375 | { | |
341c100f NS |
1376 | edge redirected = redirect_edge_and_branch (edge_in, bb); |
1377 | gcc_assert (redirected); | |
ca6c03ca JH |
1378 | } |
1379 | else | |
1380 | redirect_edge_succ (edge_in, bb); | |
1381 | ||
1382 | return bb; | |
1383 | } | |
1384 | ||
1385 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1386 | The new instructions and basic blocks (if any) will not appear in the | |
1387 | CFG until commit_edge_insertions is called. */ | |
1388 | ||
1389 | void | |
d329e058 | 1390 | insert_insn_on_edge (rtx pattern, edge e) |
ca6c03ca JH |
1391 | { |
1392 | /* We cannot insert instructions on an abnormal critical edge. | |
1393 | It will be easier to find the culprit if we die now. */ | |
341c100f | 1394 | gcc_assert (!((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e))); |
ca6c03ca | 1395 | |
6de9cd9a | 1396 | if (e->insns.r == NULL_RTX) |
ca6c03ca JH |
1397 | start_sequence (); |
1398 | else | |
6de9cd9a | 1399 | push_to_sequence (e->insns.r); |
ca6c03ca JH |
1400 | |
1401 | emit_insn (pattern); | |
1402 | ||
6de9cd9a | 1403 | e->insns.r = get_insns (); |
ca6c03ca JH |
1404 | end_sequence (); |
1405 | } | |
1406 | ||
ff25ef99 ZD |
1407 | /* Called from safe_insert_insn_on_edge through note_stores, marks live |
1408 | registers that are killed by the store. */ | |
1409 | static void | |
1410 | mark_killed_regs (rtx reg, rtx set ATTRIBUTE_UNUSED, void *data) | |
1411 | { | |
1412 | regset killed = data; | |
1413 | int regno, i; | |
1414 | ||
1415 | if (GET_CODE (reg) == SUBREG) | |
1416 | reg = SUBREG_REG (reg); | |
1417 | if (!REG_P (reg)) | |
1418 | return; | |
1419 | regno = REGNO (reg); | |
1420 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1421 | SET_REGNO_REG_SET (killed, regno); | |
1422 | else | |
1423 | { | |
66fd46b6 | 1424 | for (i = 0; i < (int) hard_regno_nregs[regno][GET_MODE (reg)]; i++) |
ff25ef99 ZD |
1425 | SET_REGNO_REG_SET (killed, regno + i); |
1426 | } | |
1427 | } | |
1428 | ||
1429 | /* Similar to insert_insn_on_edge, tries to put INSN to edge E. Additionally | |
1430 | it checks whether this will not clobber the registers that are live on the | |
e0bb17a8 | 1431 | edge (i.e. it requires liveness information to be up-to-date) and if there |
ff25ef99 | 1432 | are some, then it tries to save and restore them. Returns true if |
e0bb17a8 | 1433 | successful. */ |
ff25ef99 ZD |
1434 | bool |
1435 | safe_insert_insn_on_edge (rtx insn, edge e) | |
1436 | { | |
1437 | rtx x; | |
7932a3db | 1438 | regset killed; |
ff25ef99 | 1439 | rtx save_regs = NULL_RTX; |
3cd8c58a NS |
1440 | unsigned regno; |
1441 | int noccmode; | |
ff25ef99 | 1442 | enum machine_mode mode; |
a2041967 | 1443 | reg_set_iterator rsi; |
ff25ef99 ZD |
1444 | |
1445 | #ifdef AVOID_CCMODE_COPIES | |
1446 | noccmode = true; | |
1447 | #else | |
1448 | noccmode = false; | |
1449 | #endif | |
1450 | ||
04389919 | 1451 | killed = ALLOC_REG_SET (®_obstack); |
7932a3db | 1452 | |
ff25ef99 ZD |
1453 | for (x = insn; x; x = NEXT_INSN (x)) |
1454 | if (INSN_P (x)) | |
1455 | note_stores (PATTERN (x), mark_killed_regs, killed); | |
af9ecd0c ZD |
1456 | |
1457 | /* Mark all hard registers as killed. Register allocator/reload cannot | |
1458 | cope with the situation when life range of hard register spans operation | |
1459 | for that the appropriate register is needed, i.e. it would be unsafe to | |
1460 | extend the life ranges of hard registers. */ | |
1461 | for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) | |
1462 | if (!fixed_regs[regno] | |
1463 | && !REGNO_PTR_FRAME_P (regno)) | |
1464 | SET_REGNO_REG_SET (killed, regno); | |
1465 | ||
eb59b8de | 1466 | bitmap_and_into (killed, e->dest->global_live_at_start); |
ff25ef99 | 1467 | |
a2041967 | 1468 | EXECUTE_IF_SET_IN_REG_SET (killed, 0, regno, rsi) |
ff25ef99 ZD |
1469 | { |
1470 | mode = regno < FIRST_PSEUDO_REGISTER | |
1471 | ? reg_raw_mode[regno] | |
1472 | : GET_MODE (regno_reg_rtx[regno]); | |
1473 | if (mode == VOIDmode) | |
1474 | return false; | |
1475 | ||
1476 | if (noccmode && mode == CCmode) | |
1477 | return false; | |
1478 | ||
1479 | save_regs = alloc_EXPR_LIST (0, | |
1480 | alloc_EXPR_LIST (0, | |
1481 | gen_reg_rtx (mode), | |
1482 | gen_raw_REG (mode, regno)), | |
1483 | save_regs); | |
a2041967 | 1484 | } |
ff25ef99 ZD |
1485 | |
1486 | if (save_regs) | |
1487 | { | |
1488 | rtx from, to; | |
1489 | ||
1490 | start_sequence (); | |
1491 | for (x = save_regs; x; x = XEXP (x, 1)) | |
1492 | { | |
1493 | from = XEXP (XEXP (x, 0), 1); | |
1494 | to = XEXP (XEXP (x, 0), 0); | |
1495 | emit_move_insn (to, from); | |
1496 | } | |
1497 | emit_insn (insn); | |
1498 | for (x = save_regs; x; x = XEXP (x, 1)) | |
1499 | { | |
1500 | from = XEXP (XEXP (x, 0), 0); | |
1501 | to = XEXP (XEXP (x, 0), 1); | |
1502 | emit_move_insn (to, from); | |
1503 | } | |
1504 | insn = get_insns (); | |
1505 | end_sequence (); | |
1506 | free_EXPR_LIST_list (&save_regs); | |
1507 | } | |
1508 | insert_insn_on_edge (insn, e); | |
1509 | ||
1510 | FREE_REG_SET (killed); | |
af9ecd0c | 1511 | |
ff25ef99 ZD |
1512 | return true; |
1513 | } | |
1514 | ||
ca6c03ca JH |
1515 | /* Update the CFG for the instructions queued on edge E. */ |
1516 | ||
1517 | static void | |
d329e058 | 1518 | commit_one_edge_insertion (edge e, int watch_calls) |
ca6c03ca JH |
1519 | { |
1520 | rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last; | |
eae4bc56 | 1521 | basic_block bb = NULL; |
ca6c03ca JH |
1522 | |
1523 | /* Pull the insns off the edge now since the edge might go away. */ | |
6de9cd9a DN |
1524 | insns = e->insns.r; |
1525 | e->insns.r = NULL_RTX; | |
ca6c03ca | 1526 | |
3dec4024 JH |
1527 | /* Special case -- avoid inserting code between call and storing |
1528 | its return value. */ | |
628f6a4e | 1529 | if (watch_calls && (e->flags & EDGE_FALLTHRU) |
c5cbcccf | 1530 | && single_pred_p (e->dest) |
3dec4024 | 1531 | && e->src != ENTRY_BLOCK_PTR |
4b4bf941 | 1532 | && CALL_P (BB_END (e->src))) |
ca6c03ca | 1533 | { |
a813c111 | 1534 | rtx next = next_nonnote_insn (BB_END (e->src)); |
ca6c03ca | 1535 | |
a813c111 | 1536 | after = BB_HEAD (e->dest); |
3dec4024 JH |
1537 | /* The first insn after the call may be a stack pop, skip it. */ |
1538 | while (next | |
1539 | && keep_with_call_p (next)) | |
f87c27b4 KH |
1540 | { |
1541 | after = next; | |
3dec4024 JH |
1542 | next = next_nonnote_insn (next); |
1543 | } | |
1544 | bb = e->dest; | |
ca6c03ca | 1545 | } |
3dec4024 | 1546 | if (!before && !after) |
ca6c03ca | 1547 | { |
3dec4024 JH |
1548 | /* Figure out where to put these things. If the destination has |
1549 | one predecessor, insert there. Except for the exit block. */ | |
c5cbcccf | 1550 | if (single_pred_p (e->dest) && e->dest != EXIT_BLOCK_PTR) |
ca6c03ca | 1551 | { |
3dec4024 JH |
1552 | bb = e->dest; |
1553 | ||
1554 | /* Get the location correct wrt a code label, and "nice" wrt | |
1555 | a basic block note, and before everything else. */ | |
a813c111 | 1556 | tmp = BB_HEAD (bb); |
4b4bf941 | 1557 | if (LABEL_P (tmp)) |
3dec4024 JH |
1558 | tmp = NEXT_INSN (tmp); |
1559 | if (NOTE_INSN_BASIC_BLOCK_P (tmp)) | |
1560 | tmp = NEXT_INSN (tmp); | |
a813c111 | 1561 | if (tmp == BB_HEAD (bb)) |
3dec4024 JH |
1562 | before = tmp; |
1563 | else if (tmp) | |
1564 | after = PREV_INSN (tmp); | |
1565 | else | |
1566 | after = get_last_insn (); | |
1567 | } | |
1568 | ||
1569 | /* If the source has one successor and the edge is not abnormal, | |
1570 | insert there. Except for the entry block. */ | |
1571 | else if ((e->flags & EDGE_ABNORMAL) == 0 | |
c5cbcccf | 1572 | && single_succ_p (e->src) |
3dec4024 JH |
1573 | && e->src != ENTRY_BLOCK_PTR) |
1574 | { | |
1575 | bb = e->src; | |
1576 | ||
1577 | /* It is possible to have a non-simple jump here. Consider a target | |
1578 | where some forms of unconditional jumps clobber a register. This | |
1579 | happens on the fr30 for example. | |
1580 | ||
1581 | We know this block has a single successor, so we can just emit | |
1582 | the queued insns before the jump. */ | |
4b4bf941 | 1583 | if (JUMP_P (BB_END (bb))) |
a813c111 | 1584 | for (before = BB_END (bb); |
4b4bf941 | 1585 | NOTE_P (PREV_INSN (before)) |
3dec4024 JH |
1586 | && NOTE_LINE_NUMBER (PREV_INSN (before)) == |
1587 | NOTE_INSN_LOOP_BEG; before = PREV_INSN (before)) | |
1588 | ; | |
1589 | else | |
1590 | { | |
341c100f NS |
1591 | /* We'd better be fallthru, or we've lost track of |
1592 | what's what. */ | |
1593 | gcc_assert (e->flags & EDGE_FALLTHRU); | |
ca6c03ca | 1594 | |
a813c111 | 1595 | after = BB_END (bb); |
3dec4024 JH |
1596 | } |
1597 | } | |
1598 | /* Otherwise we must split the edge. */ | |
1599 | else | |
1600 | { | |
1601 | bb = split_edge (e); | |
a813c111 | 1602 | after = BB_END (bb); |
750054a2 | 1603 | |
750054a2 | 1604 | if (flag_reorder_blocks_and_partition |
9fb32434 | 1605 | && targetm.have_named_sections |
750054a2 | 1606 | && e->src != ENTRY_BLOCK_PTR |
076c7ab8 | 1607 | && BB_PARTITION (e->src) == BB_COLD_PARTITION |
bd454efd | 1608 | && !(e->flags & EDGE_CROSSING)) |
750054a2 | 1609 | { |
87c8b4be | 1610 | rtx bb_note, cur_insn; |
750054a2 CT |
1611 | |
1612 | bb_note = NULL_RTX; | |
1613 | for (cur_insn = BB_HEAD (bb); cur_insn != NEXT_INSN (BB_END (bb)); | |
1614 | cur_insn = NEXT_INSN (cur_insn)) | |
4b4bf941 | 1615 | if (NOTE_P (cur_insn) |
750054a2 CT |
1616 | && NOTE_LINE_NUMBER (cur_insn) == NOTE_INSN_BASIC_BLOCK) |
1617 | { | |
1618 | bb_note = cur_insn; | |
1619 | break; | |
1620 | } | |
1621 | ||
4b4bf941 | 1622 | if (JUMP_P (BB_END (bb)) |
750054a2 | 1623 | && !any_condjump_p (BB_END (bb)) |
c5cbcccf | 1624 | && (single_succ_edge (bb)->flags & EDGE_CROSSING)) |
750054a2 CT |
1625 | REG_NOTES (BB_END (bb)) = gen_rtx_EXPR_LIST |
1626 | (REG_CROSSING_JUMP, NULL_RTX, REG_NOTES (BB_END (bb))); | |
750054a2 | 1627 | } |
ca6c03ca JH |
1628 | } |
1629 | } | |
1630 | ||
ca6c03ca JH |
1631 | /* Now that we've found the spot, do the insertion. */ |
1632 | ||
1633 | if (before) | |
1634 | { | |
a7102479 | 1635 | emit_insn_before_noloc (insns, before); |
ca6c03ca JH |
1636 | last = prev_nonnote_insn (before); |
1637 | } | |
1638 | else | |
a7102479 | 1639 | last = emit_insn_after_noloc (insns, after); |
ca6c03ca JH |
1640 | |
1641 | if (returnjump_p (last)) | |
1642 | { | |
1643 | /* ??? Remove all outgoing edges from BB and add one for EXIT. | |
1644 | This is not currently a problem because this only happens | |
3dec4024 JH |
1645 | for the (single) epilogue, which already has a fallthru edge |
1646 | to EXIT. */ | |
ca6c03ca | 1647 | |
c5cbcccf | 1648 | e = single_succ_edge (bb); |
341c100f | 1649 | gcc_assert (e->dest == EXIT_BLOCK_PTR |
c5cbcccf | 1650 | && single_succ_p (bb) && (e->flags & EDGE_FALLTHRU)); |
ca6c03ca | 1651 | |
5f0d2358 | 1652 | e->flags &= ~EDGE_FALLTHRU; |
ca6c03ca | 1653 | emit_barrier_after (last); |
0b17ab2f | 1654 | |
ca6c03ca JH |
1655 | if (before) |
1656 | delete_insn (before); | |
1657 | } | |
341c100f NS |
1658 | else |
1659 | gcc_assert (!JUMP_P (last)); | |
5f0d2358 | 1660 | |
12eff7b7 | 1661 | /* Mark the basic block for find_many_sub_basic_blocks. */ |
9dca2ad5 | 1662 | bb->aux = &bb->aux; |
ca6c03ca JH |
1663 | } |
1664 | ||
1665 | /* Update the CFG for all queued instructions. */ | |
1666 | ||
1667 | void | |
d329e058 | 1668 | commit_edge_insertions (void) |
ca6c03ca | 1669 | { |
ca6c03ca | 1670 | basic_block bb; |
9dca2ad5 | 1671 | sbitmap blocks; |
9809a362 | 1672 | bool changed = false; |
ca6c03ca JH |
1673 | |
1674 | #ifdef ENABLE_CHECKING | |
1675 | verify_flow_info (); | |
1676 | #endif | |
1677 | ||
e0082a72 | 1678 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
ca6c03ca | 1679 | { |
628f6a4e BE |
1680 | edge e; |
1681 | edge_iterator ei; | |
ca6c03ca | 1682 | |
628f6a4e BE |
1683 | FOR_EACH_EDGE (e, ei, bb->succs) |
1684 | if (e->insns.r) | |
1685 | { | |
1686 | changed = true; | |
1687 | commit_one_edge_insertion (e, false); | |
1688 | } | |
3dec4024 | 1689 | } |
9dca2ad5 | 1690 | |
9809a362 JH |
1691 | if (!changed) |
1692 | return; | |
1693 | ||
9dca2ad5 JH |
1694 | blocks = sbitmap_alloc (last_basic_block); |
1695 | sbitmap_zero (blocks); | |
1696 | FOR_EACH_BB (bb) | |
1697 | if (bb->aux) | |
1698 | { | |
1699 | SET_BIT (blocks, bb->index); | |
1700 | /* Check for forgotten bb->aux values before commit_edge_insertions | |
1701 | call. */ | |
341c100f | 1702 | gcc_assert (bb->aux == &bb->aux); |
9dca2ad5 JH |
1703 | bb->aux = NULL; |
1704 | } | |
1705 | find_many_sub_basic_blocks (blocks); | |
1706 | sbitmap_free (blocks); | |
3dec4024 JH |
1707 | } |
1708 | \f | |
1709 | /* Update the CFG for all queued instructions, taking special care of inserting | |
1710 | code on edges between call and storing its return value. */ | |
1711 | ||
1712 | void | |
d329e058 | 1713 | commit_edge_insertions_watch_calls (void) |
3dec4024 | 1714 | { |
3dec4024 | 1715 | basic_block bb; |
9809a362 JH |
1716 | sbitmap blocks; |
1717 | bool changed = false; | |
3dec4024 JH |
1718 | |
1719 | #ifdef ENABLE_CHECKING | |
1720 | verify_flow_info (); | |
1721 | #endif | |
1722 | ||
e0082a72 | 1723 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) |
3dec4024 | 1724 | { |
628f6a4e BE |
1725 | edge e; |
1726 | edge_iterator ei; | |
3dec4024 | 1727 | |
628f6a4e BE |
1728 | FOR_EACH_EDGE (e, ei, bb->succs) |
1729 | if (e->insns.r) | |
1730 | { | |
1731 | changed = true; | |
1732 | commit_one_edge_insertion (e, true); | |
1733 | } | |
ca6c03ca | 1734 | } |
9809a362 JH |
1735 | |
1736 | if (!changed) | |
1737 | return; | |
1738 | ||
1739 | blocks = sbitmap_alloc (last_basic_block); | |
1740 | sbitmap_zero (blocks); | |
1741 | FOR_EACH_BB (bb) | |
1742 | if (bb->aux) | |
1743 | { | |
1744 | SET_BIT (blocks, bb->index); | |
1745 | /* Check for forgotten bb->aux values before commit_edge_insertions | |
1746 | call. */ | |
341c100f | 1747 | gcc_assert (bb->aux == &bb->aux); |
9809a362 JH |
1748 | bb->aux = NULL; |
1749 | } | |
1750 | find_many_sub_basic_blocks (blocks); | |
1751 | sbitmap_free (blocks); | |
ca6c03ca JH |
1752 | } |
1753 | \f | |
f470c378 ZD |
1754 | /* Print out RTL-specific basic block information (live information |
1755 | at start and end). */ | |
ca6c03ca | 1756 | |
10e9fecc | 1757 | static void |
f470c378 | 1758 | rtl_dump_bb (basic_block bb, FILE *outf, int indent) |
ca6c03ca JH |
1759 | { |
1760 | rtx insn; | |
1761 | rtx last; | |
f470c378 | 1762 | char *s_indent; |
ca6c03ca | 1763 | |
400e39e3 KH |
1764 | s_indent = alloca ((size_t) indent + 1); |
1765 | memset (s_indent, ' ', (size_t) indent); | |
f470c378 ZD |
1766 | s_indent[indent] = '\0'; |
1767 | ||
1768 | fprintf (outf, ";;%s Registers live at start: ", s_indent); | |
ca6c03ca JH |
1769 | dump_regset (bb->global_live_at_start, outf); |
1770 | putc ('\n', outf); | |
1771 | ||
a813c111 | 1772 | for (insn = BB_HEAD (bb), last = NEXT_INSN (BB_END (bb)); insn != last; |
ca6c03ca JH |
1773 | insn = NEXT_INSN (insn)) |
1774 | print_rtl_single (outf, insn); | |
1775 | ||
f470c378 | 1776 | fprintf (outf, ";;%s Registers live at end: ", s_indent); |
ca6c03ca JH |
1777 | dump_regset (bb->global_live_at_end, outf); |
1778 | putc ('\n', outf); | |
ca6c03ca JH |
1779 | } |
1780 | \f | |
1781 | /* Like print_rtl, but also print out live information for the start of each | |
1782 | basic block. */ | |
1783 | ||
1784 | void | |
d329e058 | 1785 | print_rtl_with_bb (FILE *outf, rtx rtx_first) |
ca6c03ca | 1786 | { |
b3694847 | 1787 | rtx tmp_rtx; |
ca6c03ca JH |
1788 | |
1789 | if (rtx_first == 0) | |
1790 | fprintf (outf, "(nil)\n"); | |
1791 | else | |
1792 | { | |
ca6c03ca JH |
1793 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
1794 | int max_uid = get_max_uid (); | |
703ad42b KG |
1795 | basic_block *start = xcalloc (max_uid, sizeof (basic_block)); |
1796 | basic_block *end = xcalloc (max_uid, sizeof (basic_block)); | |
1797 | enum bb_state *in_bb_p = xcalloc (max_uid, sizeof (enum bb_state)); | |
ca6c03ca | 1798 | |
e0082a72 ZD |
1799 | basic_block bb; |
1800 | ||
1801 | FOR_EACH_BB_REVERSE (bb) | |
ca6c03ca | 1802 | { |
ca6c03ca JH |
1803 | rtx x; |
1804 | ||
a813c111 SB |
1805 | start[INSN_UID (BB_HEAD (bb))] = bb; |
1806 | end[INSN_UID (BB_END (bb))] = bb; | |
1807 | for (x = BB_HEAD (bb); x != NULL_RTX; x = NEXT_INSN (x)) | |
ca6c03ca JH |
1808 | { |
1809 | enum bb_state state = IN_MULTIPLE_BB; | |
5f0d2358 | 1810 | |
ca6c03ca JH |
1811 | if (in_bb_p[INSN_UID (x)] == NOT_IN_BB) |
1812 | state = IN_ONE_BB; | |
1813 | in_bb_p[INSN_UID (x)] = state; | |
1814 | ||
a813c111 | 1815 | if (x == BB_END (bb)) |
ca6c03ca JH |
1816 | break; |
1817 | } | |
1818 | } | |
1819 | ||
1820 | for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) | |
1821 | { | |
1822 | int did_output; | |
ca6c03ca JH |
1823 | |
1824 | if ((bb = start[INSN_UID (tmp_rtx)]) != NULL) | |
1825 | { | |
1826 | fprintf (outf, ";; Start of basic block %d, registers live:", | |
0b17ab2f | 1827 | bb->index); |
ca6c03ca JH |
1828 | dump_regset (bb->global_live_at_start, outf); |
1829 | putc ('\n', outf); | |
1830 | } | |
1831 | ||
1832 | if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB | |
4b4bf941 JQ |
1833 | && !NOTE_P (tmp_rtx) |
1834 | && !BARRIER_P (tmp_rtx)) | |
ca6c03ca JH |
1835 | fprintf (outf, ";; Insn is not within a basic block\n"); |
1836 | else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB) | |
1837 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); | |
1838 | ||
1839 | did_output = print_rtl_single (outf, tmp_rtx); | |
1840 | ||
1841 | if ((bb = end[INSN_UID (tmp_rtx)]) != NULL) | |
1842 | { | |
1843 | fprintf (outf, ";; End of basic block %d, registers live:\n", | |
0b17ab2f | 1844 | bb->index); |
ca6c03ca JH |
1845 | dump_regset (bb->global_live_at_end, outf); |
1846 | putc ('\n', outf); | |
1847 | } | |
1848 | ||
1849 | if (did_output) | |
1850 | putc ('\n', outf); | |
1851 | } | |
1852 | ||
1853 | free (start); | |
1854 | free (end); | |
1855 | free (in_bb_p); | |
1856 | } | |
1857 | ||
1858 | if (current_function_epilogue_delay_list != 0) | |
1859 | { | |
1860 | fprintf (outf, "\n;; Insns in epilogue delay list:\n\n"); | |
1861 | for (tmp_rtx = current_function_epilogue_delay_list; tmp_rtx != 0; | |
1862 | tmp_rtx = XEXP (tmp_rtx, 1)) | |
1863 | print_rtl_single (outf, XEXP (tmp_rtx, 0)); | |
1864 | } | |
1865 | } | |
1866 | \f | |
b446e5a2 | 1867 | void |
d329e058 | 1868 | update_br_prob_note (basic_block bb) |
b446e5a2 JH |
1869 | { |
1870 | rtx note; | |
4b4bf941 | 1871 | if (!JUMP_P (BB_END (bb))) |
b446e5a2 | 1872 | return; |
a813c111 | 1873 | note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX); |
b446e5a2 JH |
1874 | if (!note || INTVAL (XEXP (note, 0)) == BRANCH_EDGE (bb)->probability) |
1875 | return; | |
1876 | XEXP (note, 0) = GEN_INT (BRANCH_EDGE (bb)->probability); | |
1877 | } | |
1878 | \f | |
10e9fecc JH |
1879 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
1880 | cfglayout RTL. | |
ca6c03ca JH |
1881 | |
1882 | Currently it does following checks: | |
1883 | ||
1884 | - test head/end pointers | |
1885 | - overlapping of basic blocks | |
ca6c03ca | 1886 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) |
f63d1bf7 | 1887 | - tails of basic blocks (ensure that boundary is necessary) |
ca6c03ca JH |
1888 | - scans body of the basic block for JUMP_INSN, CODE_LABEL |
1889 | and NOTE_INSN_BASIC_BLOCK | |
750054a2 | 1890 | - verify that no fall_thru edge crosses hot/cold partition boundaries |
ca6c03ca JH |
1891 | |
1892 | In future it can be extended check a lot of other stuff as well | |
1893 | (reachability of basic blocks, life information, etc. etc.). */ | |
f470c378 | 1894 | |
10e9fecc | 1895 | static int |
d329e058 | 1896 | rtl_verify_flow_info_1 (void) |
ca6c03ca JH |
1897 | { |
1898 | const int max_uid = get_max_uid (); | |
ca6c03ca | 1899 | rtx last_head = get_last_insn (); |
10e9fecc | 1900 | basic_block *bb_info; |
ca6c03ca | 1901 | rtx x; |
10e9fecc | 1902 | int err = 0; |
94eb5ddb | 1903 | basic_block bb; |
ca6c03ca | 1904 | |
703ad42b | 1905 | bb_info = xcalloc (max_uid, sizeof (basic_block)); |
ca6c03ca | 1906 | |
e0082a72 | 1907 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1908 | { |
a813c111 SB |
1909 | rtx head = BB_HEAD (bb); |
1910 | rtx end = BB_END (bb); | |
ca6c03ca JH |
1911 | |
1912 | /* Verify the end of the basic block is in the INSN chain. */ | |
1913 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) | |
1914 | if (x == end) | |
1915 | break; | |
5f0d2358 | 1916 | |
ca6c03ca JH |
1917 | if (!x) |
1918 | { | |
1f978f5f | 1919 | error ("end insn %d for block %d not found in the insn stream", |
0b17ab2f | 1920 | INSN_UID (end), bb->index); |
ca6c03ca JH |
1921 | err = 1; |
1922 | } | |
1923 | ||
1924 | /* Work backwards from the end to the head of the basic block | |
1925 | to verify the head is in the RTL chain. */ | |
1926 | for (; x != NULL_RTX; x = PREV_INSN (x)) | |
1927 | { | |
1928 | /* While walking over the insn chain, verify insns appear | |
1929 | in only one basic block and initialize the BB_INFO array | |
1930 | used by other passes. */ | |
1931 | if (bb_info[INSN_UID (x)] != NULL) | |
1932 | { | |
1f978f5f | 1933 | error ("insn %d is in multiple basic blocks (%d and %d)", |
0b17ab2f | 1934 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); |
ca6c03ca JH |
1935 | err = 1; |
1936 | } | |
5f0d2358 | 1937 | |
ca6c03ca JH |
1938 | bb_info[INSN_UID (x)] = bb; |
1939 | ||
1940 | if (x == head) | |
1941 | break; | |
1942 | } | |
1943 | if (!x) | |
1944 | { | |
1f978f5f | 1945 | error ("head insn %d for block %d not found in the insn stream", |
0b17ab2f | 1946 | INSN_UID (head), bb->index); |
ca6c03ca JH |
1947 | err = 1; |
1948 | } | |
1949 | ||
1950 | last_head = x; | |
1951 | } | |
1952 | ||
1953 | /* Now check the basic blocks (boundaries etc.) */ | |
e0082a72 | 1954 | FOR_EACH_BB_REVERSE (bb) |
ca6c03ca | 1955 | { |
3dec4024 | 1956 | int n_fallthru = 0, n_eh = 0, n_call = 0, n_abnormal = 0, n_branch = 0; |
3cf54412 | 1957 | edge e, fallthru = NULL; |
5a1a3e5e | 1958 | rtx note; |
628f6a4e | 1959 | edge_iterator ei; |
ca6c03ca | 1960 | |
2085a21f | 1961 | if (JUMP_P (BB_END (bb)) |
a813c111 | 1962 | && (note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX)) |
628f6a4e | 1963 | && EDGE_COUNT (bb->succs) >= 2 |
a813c111 | 1964 | && any_condjump_p (BB_END (bb))) |
5a1a3e5e | 1965 | { |
e53de54d JH |
1966 | if (INTVAL (XEXP (note, 0)) != BRANCH_EDGE (bb)->probability |
1967 | && profile_status != PROFILE_ABSENT) | |
5a1a3e5e | 1968 | { |
0108ae51 | 1969 | error ("verify_flow_info: REG_BR_PROB does not match cfg %wi %i", |
5a1a3e5e JH |
1970 | INTVAL (XEXP (note, 0)), BRANCH_EDGE (bb)->probability); |
1971 | err = 1; | |
1972 | } | |
1973 | } | |
628f6a4e | 1974 | FOR_EACH_EDGE (e, ei, bb->succs) |
ca6c03ca | 1975 | { |
ca6c03ca | 1976 | if (e->flags & EDGE_FALLTHRU) |
750054a2 CT |
1977 | { |
1978 | n_fallthru++, fallthru = e; | |
bd454efd | 1979 | if ((e->flags & EDGE_CROSSING) |
076c7ab8 | 1980 | || (BB_PARTITION (e->src) != BB_PARTITION (e->dest) |
9fb32434 CT |
1981 | && e->src != ENTRY_BLOCK_PTR |
1982 | && e->dest != EXIT_BLOCK_PTR)) | |
1983 | { | |
750054a2 CT |
1984 | error ("Fallthru edge crosses section boundary (bb %i)", |
1985 | e->src->index); | |
1986 | err = 1; | |
1987 | } | |
1988 | } | |
3dec4024 | 1989 | |
65f43cdf ZD |
1990 | if ((e->flags & ~(EDGE_DFS_BACK |
1991 | | EDGE_CAN_FALLTHRU | |
1992 | | EDGE_IRREDUCIBLE_LOOP | |
9beb1c84 CT |
1993 | | EDGE_LOOP_EXIT |
1994 | | EDGE_CROSSING)) == 0) | |
3dec4024 JH |
1995 | n_branch++; |
1996 | ||
1997 | if (e->flags & EDGE_ABNORMAL_CALL) | |
1998 | n_call++; | |
1999 | ||
2000 | if (e->flags & EDGE_EH) | |
2001 | n_eh++; | |
2002 | else if (e->flags & EDGE_ABNORMAL) | |
2003 | n_abnormal++; | |
ca6c03ca | 2004 | } |
5f0d2358 | 2005 | |
a813c111 SB |
2006 | if (n_eh && GET_CODE (PATTERN (BB_END (bb))) != RESX |
2007 | && !find_reg_note (BB_END (bb), REG_EH_REGION, NULL_RTX)) | |
3dec4024 | 2008 | { |
0b17ab2f | 2009 | error ("Missing REG_EH_REGION note in the end of bb %i", bb->index); |
3dec4024 JH |
2010 | err = 1; |
2011 | } | |
2012 | if (n_branch | |
4b4bf941 | 2013 | && (!JUMP_P (BB_END (bb)) |
a813c111 SB |
2014 | || (n_branch > 1 && (any_uncondjump_p (BB_END (bb)) |
2015 | || any_condjump_p (BB_END (bb)))))) | |
3dec4024 | 2016 | { |
0b17ab2f | 2017 | error ("Too many outgoing branch edges from bb %i", bb->index); |
3dec4024 JH |
2018 | err = 1; |
2019 | } | |
a813c111 | 2020 | if (n_fallthru && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 2021 | { |
0b17ab2f | 2022 | error ("Fallthru edge after unconditional jump %i", bb->index); |
3dec4024 JH |
2023 | err = 1; |
2024 | } | |
a813c111 | 2025 | if (n_branch != 1 && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 2026 | { |
0b17ab2f | 2027 | error ("Wrong amount of branch edges after unconditional jump %i", bb->index); |
3dec4024 JH |
2028 | err = 1; |
2029 | } | |
a813c111 | 2030 | if (n_branch != 1 && any_condjump_p (BB_END (bb)) |
1cb7dfc3 | 2031 | && JUMP_LABEL (BB_END (bb)) == BB_HEAD (fallthru->dest)) |
3dec4024 | 2032 | { |
0b17ab2f | 2033 | error ("Wrong amount of branch edges after conditional jump %i", bb->index); |
3dec4024 JH |
2034 | err = 1; |
2035 | } | |
4b4bf941 | 2036 | if (n_call && !CALL_P (BB_END (bb))) |
3dec4024 | 2037 | { |
0b17ab2f | 2038 | error ("Call edges for non-call insn in bb %i", bb->index); |
3dec4024 JH |
2039 | err = 1; |
2040 | } | |
2041 | if (n_abnormal | |
4b4bf941 JQ |
2042 | && (!CALL_P (BB_END (bb)) && n_call != n_abnormal) |
2043 | && (!JUMP_P (BB_END (bb)) | |
a813c111 SB |
2044 | || any_condjump_p (BB_END (bb)) |
2045 | || any_uncondjump_p (BB_END (bb)))) | |
3dec4024 | 2046 | { |
0b17ab2f | 2047 | error ("Abnormal edges for no purpose in bb %i", bb->index); |
3dec4024 JH |
2048 | err = 1; |
2049 | } | |
f87c27b4 | 2050 | |
a813c111 | 2051 | for (x = BB_HEAD (bb); x != NEXT_INSN (BB_END (bb)); x = NEXT_INSN (x)) |
0ca541aa | 2052 | /* We may have a barrier inside a basic block before dead code |
9524880c HPN |
2053 | elimination. There is no BLOCK_FOR_INSN field in a barrier. */ |
2054 | if (!BARRIER_P (x) && BLOCK_FOR_INSN (x) != bb) | |
5f0d2358 RK |
2055 | { |
2056 | debug_rtx (x); | |
2057 | if (! BLOCK_FOR_INSN (x)) | |
2058 | error | |
2059 | ("insn %d inside basic block %d but block_for_insn is NULL", | |
0b17ab2f | 2060 | INSN_UID (x), bb->index); |
5f0d2358 RK |
2061 | else |
2062 | error | |
2063 | ("insn %d inside basic block %d but block_for_insn is %i", | |
0b17ab2f | 2064 | INSN_UID (x), bb->index, BLOCK_FOR_INSN (x)->index); |
5f0d2358 RK |
2065 | |
2066 | err = 1; | |
2067 | } | |
ca6c03ca JH |
2068 | |
2069 | /* OK pointers are correct. Now check the header of basic | |
2070 | block. It ought to contain optional CODE_LABEL followed | |
2071 | by NOTE_BASIC_BLOCK. */ | |
a813c111 | 2072 | x = BB_HEAD (bb); |
4b4bf941 | 2073 | if (LABEL_P (x)) |
ca6c03ca | 2074 | { |
a813c111 | 2075 | if (BB_END (bb) == x) |
ca6c03ca JH |
2076 | { |
2077 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 2078 | bb->index); |
ca6c03ca JH |
2079 | err = 1; |
2080 | } | |
5f0d2358 | 2081 | |
ca6c03ca JH |
2082 | x = NEXT_INSN (x); |
2083 | } | |
5f0d2358 | 2084 | |
ca6c03ca JH |
2085 | if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb) |
2086 | { | |
2087 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 2088 | bb->index); |
ca6c03ca JH |
2089 | err = 1; |
2090 | } | |
2091 | ||
a813c111 | 2092 | if (BB_END (bb) == x) |
49243025 | 2093 | /* Do checks for empty blocks here. */ |
5f0d2358 | 2094 | ; |
ca6c03ca | 2095 | else |
5f0d2358 RK |
2096 | for (x = NEXT_INSN (x); x; x = NEXT_INSN (x)) |
2097 | { | |
2098 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2099 | { | |
2100 | error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d", | |
0b17ab2f | 2101 | INSN_UID (x), bb->index); |
5f0d2358 RK |
2102 | err = 1; |
2103 | } | |
2104 | ||
a813c111 | 2105 | if (x == BB_END (bb)) |
5f0d2358 | 2106 | break; |
ca6c03ca | 2107 | |
83fd323c | 2108 | if (control_flow_insn_p (x)) |
5f0d2358 | 2109 | { |
0b17ab2f | 2110 | error ("in basic block %d:", bb->index); |
5f0d2358 RK |
2111 | fatal_insn ("flow control insn inside a basic block", x); |
2112 | } | |
2113 | } | |
ca6c03ca JH |
2114 | } |
2115 | ||
10e9fecc JH |
2116 | /* Clean up. */ |
2117 | free (bb_info); | |
2118 | return err; | |
2119 | } | |
5f0d2358 | 2120 | |
10e9fecc JH |
2121 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
2122 | cfglayout RTL. | |
5f0d2358 | 2123 | |
10e9fecc JH |
2124 | Currently it does following checks: |
2125 | - all checks of rtl_verify_flow_info_1 | |
2126 | - check that all insns are in the basic blocks | |
2127 | (except the switch handling code, barriers and notes) | |
2128 | - check that all returns are followed by barriers | |
2129 | - check that all fallthru edge points to the adjacent blocks. */ | |
2130 | static int | |
d329e058 | 2131 | rtl_verify_flow_info (void) |
10e9fecc JH |
2132 | { |
2133 | basic_block bb; | |
2134 | int err = rtl_verify_flow_info_1 (); | |
2135 | rtx x; | |
2136 | int num_bb_notes; | |
2137 | const rtx rtx_first = get_insns (); | |
2138 | basic_block last_bb_seen = ENTRY_BLOCK_PTR, curr_bb = NULL; | |
ca6c03ca | 2139 | |
10e9fecc JH |
2140 | FOR_EACH_BB_REVERSE (bb) |
2141 | { | |
2142 | edge e; | |
628f6a4e BE |
2143 | edge_iterator ei; |
2144 | ||
2145 | FOR_EACH_EDGE (e, ei, bb->succs) | |
10e9fecc JH |
2146 | if (e->flags & EDGE_FALLTHRU) |
2147 | break; | |
2148 | if (!e) | |
2149 | { | |
2150 | rtx insn; | |
2151 | ||
2152 | /* Ensure existence of barrier in BB with no fallthru edges. */ | |
4b4bf941 | 2153 | for (insn = BB_END (bb); !insn || !BARRIER_P (insn); |
10e9fecc JH |
2154 | insn = NEXT_INSN (insn)) |
2155 | if (!insn | |
4b4bf941 | 2156 | || (NOTE_P (insn) |
10e9fecc JH |
2157 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_BASIC_BLOCK)) |
2158 | { | |
2159 | error ("missing barrier after block %i", bb->index); | |
2160 | err = 1; | |
2161 | break; | |
2162 | } | |
2163 | } | |
2164 | else if (e->src != ENTRY_BLOCK_PTR | |
2165 | && e->dest != EXIT_BLOCK_PTR) | |
2166 | { | |
2167 | rtx insn; | |
2168 | ||
2169 | if (e->src->next_bb != e->dest) | |
2170 | { | |
2171 | error | |
2172 | ("verify_flow_info: Incorrect blocks for fallthru %i->%i", | |
2173 | e->src->index, e->dest->index); | |
2174 | err = 1; | |
2175 | } | |
2176 | else | |
a813c111 | 2177 | for (insn = NEXT_INSN (BB_END (e->src)); insn != BB_HEAD (e->dest); |
10e9fecc | 2178 | insn = NEXT_INSN (insn)) |
6be85b25 | 2179 | if (BARRIER_P (insn) || INSN_P (insn)) |
10e9fecc JH |
2180 | { |
2181 | error ("verify_flow_info: Incorrect fallthru %i->%i", | |
2182 | e->src->index, e->dest->index); | |
2183 | fatal_insn ("wrong insn in the fallthru edge", insn); | |
2184 | err = 1; | |
2185 | } | |
2186 | } | |
2187 | } | |
ca6c03ca | 2188 | |
ca6c03ca | 2189 | num_bb_notes = 0; |
e0082a72 ZD |
2190 | last_bb_seen = ENTRY_BLOCK_PTR; |
2191 | ||
5f0d2358 | 2192 | for (x = rtx_first; x; x = NEXT_INSN (x)) |
ca6c03ca JH |
2193 | { |
2194 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2195 | { | |
bf77398c | 2196 | bb = NOTE_BASIC_BLOCK (x); |
5f0d2358 | 2197 | |
ca6c03ca | 2198 | num_bb_notes++; |
e0082a72 | 2199 | if (bb != last_bb_seen->next_bb) |
10e9fecc | 2200 | internal_error ("basic blocks not laid down consecutively"); |
ca6c03ca | 2201 | |
10e9fecc | 2202 | curr_bb = last_bb_seen = bb; |
ca6c03ca JH |
2203 | } |
2204 | ||
10e9fecc | 2205 | if (!curr_bb) |
ca6c03ca JH |
2206 | { |
2207 | switch (GET_CODE (x)) | |
2208 | { | |
2209 | case BARRIER: | |
2210 | case NOTE: | |
2211 | break; | |
2212 | ||
2213 | case CODE_LABEL: | |
666c27b9 | 2214 | /* An addr_vec is placed outside any basic block. */ |
ca6c03ca | 2215 | if (NEXT_INSN (x) |
4b4bf941 | 2216 | && JUMP_P (NEXT_INSN (x)) |
ca6c03ca JH |
2217 | && (GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_DIFF_VEC |
2218 | || GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_VEC)) | |
5f0d2358 | 2219 | x = NEXT_INSN (x); |
ca6c03ca JH |
2220 | |
2221 | /* But in any case, non-deletable labels can appear anywhere. */ | |
2222 | break; | |
2223 | ||
2224 | default: | |
1f978f5f | 2225 | fatal_insn ("insn outside basic block", x); |
ca6c03ca JH |
2226 | } |
2227 | } | |
2228 | ||
26cae194 | 2229 | if (JUMP_P (x) |
ca6c03ca | 2230 | && returnjump_p (x) && ! condjump_p (x) |
4b4bf941 | 2231 | && ! (NEXT_INSN (x) && BARRIER_P (NEXT_INSN (x)))) |
1f978f5f | 2232 | fatal_insn ("return not followed by barrier", x); |
a813c111 | 2233 | if (curr_bb && x == BB_END (curr_bb)) |
10e9fecc | 2234 | curr_bb = NULL; |
ca6c03ca JH |
2235 | } |
2236 | ||
0b17ab2f | 2237 | if (num_bb_notes != n_basic_blocks) |
ca6c03ca | 2238 | internal_error |
0b17ab2f RH |
2239 | ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)", |
2240 | num_bb_notes, n_basic_blocks); | |
ca6c03ca | 2241 | |
10e9fecc | 2242 | return err; |
ca6c03ca JH |
2243 | } |
2244 | \f | |
eaec9b3d | 2245 | /* Assume that the preceding pass has possibly eliminated jump instructions |
ca6c03ca JH |
2246 | or converted the unconditional jumps. Eliminate the edges from CFG. |
2247 | Return true if any edges are eliminated. */ | |
2248 | ||
2249 | bool | |
d329e058 | 2250 | purge_dead_edges (basic_block bb) |
ca6c03ca | 2251 | { |
628f6a4e | 2252 | edge e; |
a813c111 | 2253 | rtx insn = BB_END (bb), note; |
ca6c03ca | 2254 | bool purged = false; |
628f6a4e BE |
2255 | bool found; |
2256 | edge_iterator ei; | |
ca6c03ca | 2257 | |
70da1d03 | 2258 | /* If this instruction cannot trap, remove REG_EH_REGION notes. */ |
4b4bf941 | 2259 | if (NONJUMP_INSN_P (insn) |
70da1d03 JH |
2260 | && (note = find_reg_note (insn, REG_EH_REGION, NULL))) |
2261 | { | |
2262 | rtx eqnote; | |
2263 | ||
2264 | if (! may_trap_p (PATTERN (insn)) | |
2265 | || ((eqnote = find_reg_equal_equiv_note (insn)) | |
2266 | && ! may_trap_p (XEXP (eqnote, 0)))) | |
2267 | remove_note (insn, note); | |
2268 | } | |
2269 | ||
546c093e | 2270 | /* Cleanup abnormal edges caused by exceptions or non-local gotos. */ |
628f6a4e | 2271 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
546c093e | 2272 | { |
546c093e RH |
2273 | if (e->flags & EDGE_EH) |
2274 | { | |
a813c111 | 2275 | if (can_throw_internal (BB_END (bb))) |
628f6a4e BE |
2276 | { |
2277 | ei_next (&ei); | |
2278 | continue; | |
2279 | } | |
546c093e RH |
2280 | } |
2281 | else if (e->flags & EDGE_ABNORMAL_CALL) | |
2282 | { | |
4b4bf941 | 2283 | if (CALL_P (BB_END (bb)) |
546c093e RH |
2284 | && (! (note = find_reg_note (insn, REG_EH_REGION, NULL)) |
2285 | || INTVAL (XEXP (note, 0)) >= 0)) | |
628f6a4e BE |
2286 | { |
2287 | ei_next (&ei); | |
2288 | continue; | |
2289 | } | |
546c093e RH |
2290 | } |
2291 | else | |
628f6a4e BE |
2292 | { |
2293 | ei_next (&ei); | |
2294 | continue; | |
2295 | } | |
546c093e RH |
2296 | |
2297 | remove_edge (e); | |
2298 | bb->flags |= BB_DIRTY; | |
2299 | purged = true; | |
2300 | } | |
5f0d2358 | 2301 | |
4b4bf941 | 2302 | if (JUMP_P (insn)) |
ca6c03ca JH |
2303 | { |
2304 | rtx note; | |
2305 | edge b,f; | |
628f6a4e | 2306 | edge_iterator ei; |
5f0d2358 | 2307 | |
ca6c03ca JH |
2308 | /* We do care only about conditional jumps and simplejumps. */ |
2309 | if (!any_condjump_p (insn) | |
2310 | && !returnjump_p (insn) | |
2311 | && !simplejump_p (insn)) | |
c51d95ec | 2312 | return purged; |
5f0d2358 | 2313 | |
5a1a3e5e JH |
2314 | /* Branch probability/prediction notes are defined only for |
2315 | condjumps. We've possibly turned condjump into simplejump. */ | |
2316 | if (simplejump_p (insn)) | |
2317 | { | |
2318 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2319 | if (note) | |
2320 | remove_note (insn, note); | |
2321 | while ((note = find_reg_note (insn, REG_BR_PRED, NULL))) | |
2322 | remove_note (insn, note); | |
2323 | } | |
2324 | ||
628f6a4e | 2325 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
ca6c03ca | 2326 | { |
7fcd7218 JH |
2327 | /* Avoid abnormal flags to leak from computed jumps turned |
2328 | into simplejumps. */ | |
f87c27b4 | 2329 | |
0e1638d4 | 2330 | e->flags &= ~EDGE_ABNORMAL; |
7fcd7218 | 2331 | |
5a566bed MM |
2332 | /* See if this edge is one we should keep. */ |
2333 | if ((e->flags & EDGE_FALLTHRU) && any_condjump_p (insn)) | |
2334 | /* A conditional jump can fall through into the next | |
2335 | block, so we should keep the edge. */ | |
628f6a4e BE |
2336 | { |
2337 | ei_next (&ei); | |
2338 | continue; | |
2339 | } | |
5f0d2358 | 2340 | else if (e->dest != EXIT_BLOCK_PTR |
a813c111 | 2341 | && BB_HEAD (e->dest) == JUMP_LABEL (insn)) |
5a566bed MM |
2342 | /* If the destination block is the target of the jump, |
2343 | keep the edge. */ | |
628f6a4e BE |
2344 | { |
2345 | ei_next (&ei); | |
2346 | continue; | |
2347 | } | |
5a566bed MM |
2348 | else if (e->dest == EXIT_BLOCK_PTR && returnjump_p (insn)) |
2349 | /* If the destination block is the exit block, and this | |
2350 | instruction is a return, then keep the edge. */ | |
628f6a4e BE |
2351 | { |
2352 | ei_next (&ei); | |
2353 | continue; | |
2354 | } | |
5a566bed MM |
2355 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) |
2356 | /* Keep the edges that correspond to exceptions thrown by | |
0b75beaa EB |
2357 | this instruction and rematerialize the EDGE_ABNORMAL |
2358 | flag we just cleared above. */ | |
2359 | { | |
2360 | e->flags |= EDGE_ABNORMAL; | |
628f6a4e | 2361 | ei_next (&ei); |
0b75beaa EB |
2362 | continue; |
2363 | } | |
5f0d2358 | 2364 | |
5a566bed | 2365 | /* We do not need this edge. */ |
c51d95ec | 2366 | bb->flags |= BB_DIRTY; |
ca6c03ca JH |
2367 | purged = true; |
2368 | remove_edge (e); | |
2369 | } | |
5f0d2358 | 2370 | |
628f6a4e | 2371 | if (EDGE_COUNT (bb->succs) == 0 || !purged) |
c51d95ec | 2372 | return purged; |
5f0d2358 | 2373 | |
c263766c RH |
2374 | if (dump_file) |
2375 | fprintf (dump_file, "Purged edges from bb %i\n", bb->index); | |
5f0d2358 | 2376 | |
ca6c03ca JH |
2377 | if (!optimize) |
2378 | return purged; | |
2379 | ||
2380 | /* Redistribute probabilities. */ | |
c5cbcccf | 2381 | if (single_succ_p (bb)) |
ca6c03ca | 2382 | { |
c5cbcccf ZD |
2383 | single_succ_edge (bb)->probability = REG_BR_PROB_BASE; |
2384 | single_succ_edge (bb)->count = bb->count; | |
f87c27b4 | 2385 | } |
ca6c03ca JH |
2386 | else |
2387 | { | |
2388 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
2389 | if (!note) | |
2390 | return purged; | |
5f0d2358 | 2391 | |
ca6c03ca JH |
2392 | b = BRANCH_EDGE (bb); |
2393 | f = FALLTHRU_EDGE (bb); | |
2394 | b->probability = INTVAL (XEXP (note, 0)); | |
2395 | f->probability = REG_BR_PROB_BASE - b->probability; | |
2396 | b->count = bb->count * b->probability / REG_BR_PROB_BASE; | |
2397 | f->count = bb->count * f->probability / REG_BR_PROB_BASE; | |
2398 | } | |
5f0d2358 | 2399 | |
ca6c03ca JH |
2400 | return purged; |
2401 | } | |
4b4bf941 | 2402 | else if (CALL_P (insn) && SIBLING_CALL_P (insn)) |
1722c2c8 RH |
2403 | { |
2404 | /* First, there should not be any EH or ABCALL edges resulting | |
2405 | from non-local gotos and the like. If there were, we shouldn't | |
2406 | have created the sibcall in the first place. Second, there | |
2407 | should of course never have been a fallthru edge. */ | |
c5cbcccf ZD |
2408 | gcc_assert (single_succ_p (bb)); |
2409 | gcc_assert (single_succ_edge (bb)->flags | |
2410 | == (EDGE_SIBCALL | EDGE_ABNORMAL)); | |
1722c2c8 RH |
2411 | |
2412 | return 0; | |
2413 | } | |
ca6c03ca | 2414 | |
ca6c03ca JH |
2415 | /* If we don't see a jump insn, we don't know exactly why the block would |
2416 | have been broken at this point. Look for a simple, non-fallthru edge, | |
2417 | as these are only created by conditional branches. If we find such an | |
2418 | edge we know that there used to be a jump here and can then safely | |
2419 | remove all non-fallthru edges. */ | |
628f6a4e BE |
2420 | found = false; |
2421 | FOR_EACH_EDGE (e, ei, bb->succs) | |
2422 | if (! (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU))) | |
2423 | { | |
2424 | found = true; | |
2425 | break; | |
2426 | } | |
5f0d2358 | 2427 | |
628f6a4e | 2428 | if (!found) |
ca6c03ca | 2429 | return purged; |
5f0d2358 | 2430 | |
628f6a4e | 2431 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
ca6c03ca | 2432 | { |
ca6c03ca | 2433 | if (!(e->flags & EDGE_FALLTHRU)) |
c51d95ec JH |
2434 | { |
2435 | bb->flags |= BB_DIRTY; | |
2436 | remove_edge (e); | |
2437 | purged = true; | |
2438 | } | |
628f6a4e BE |
2439 | else |
2440 | ei_next (&ei); | |
ca6c03ca | 2441 | } |
5f0d2358 | 2442 | |
c5cbcccf | 2443 | gcc_assert (single_succ_p (bb)); |
5f0d2358 | 2444 | |
c5cbcccf ZD |
2445 | single_succ_edge (bb)->probability = REG_BR_PROB_BASE; |
2446 | single_succ_edge (bb)->count = bb->count; | |
ca6c03ca | 2447 | |
c263766c RH |
2448 | if (dump_file) |
2449 | fprintf (dump_file, "Purged non-fallthru edges from bb %i\n", | |
0b17ab2f | 2450 | bb->index); |
ca6c03ca JH |
2451 | return purged; |
2452 | } | |
2453 | ||
5f0d2358 RK |
2454 | /* Search all basic blocks for potentially dead edges and purge them. Return |
2455 | true if some edge has been eliminated. */ | |
ca6c03ca JH |
2456 | |
2457 | bool | |
25cd19de | 2458 | purge_all_dead_edges (void) |
ca6c03ca | 2459 | { |
e0082a72 | 2460 | int purged = false; |
e0082a72 | 2461 | basic_block bb; |
473fb060 | 2462 | |
e0082a72 | 2463 | FOR_EACH_BB (bb) |
473fb060 | 2464 | { |
e0082a72 | 2465 | bool purged_here = purge_dead_edges (bb); |
5f0d2358 | 2466 | |
473fb060 | 2467 | purged |= purged_here; |
473fb060 | 2468 | } |
5f0d2358 | 2469 | |
ca6c03ca JH |
2470 | return purged; |
2471 | } | |
9ee634e3 JH |
2472 | |
2473 | /* Same as split_block but update cfg_layout structures. */ | |
f470c378 ZD |
2474 | |
2475 | static basic_block | |
d329e058 | 2476 | cfg_layout_split_block (basic_block bb, void *insnp) |
9ee634e3 JH |
2477 | { |
2478 | rtx insn = insnp; | |
f470c378 | 2479 | basic_block new_bb = rtl_split_block (bb, insn); |
9ee634e3 | 2480 | |
f470c378 ZD |
2481 | new_bb->rbi->footer = bb->rbi->footer; |
2482 | bb->rbi->footer = NULL; | |
9ee634e3 | 2483 | |
f470c378 | 2484 | return new_bb; |
9ee634e3 JH |
2485 | } |
2486 | ||
2487 | ||
2488 | /* Redirect Edge to DEST. */ | |
6de9cd9a | 2489 | static edge |
d329e058 | 2490 | cfg_layout_redirect_edge_and_branch (edge e, basic_block dest) |
9ee634e3 JH |
2491 | { |
2492 | basic_block src = e->src; | |
6de9cd9a | 2493 | edge ret; |
9ee634e3 | 2494 | |
bc35512f | 2495 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
6de9cd9a | 2496 | return NULL; |
bc35512f | 2497 | |
3348b696 | 2498 | if (e->dest == dest) |
6de9cd9a | 2499 | return e; |
bc35512f | 2500 | |
3348b696 | 2501 | if (e->src != ENTRY_BLOCK_PTR |
6de9cd9a | 2502 | && (ret = try_redirect_by_replacing_jump (e, dest, true))) |
f345f21a JH |
2503 | { |
2504 | src->flags |= BB_DIRTY; | |
6de9cd9a | 2505 | return ret; |
f345f21a | 2506 | } |
bc35512f JH |
2507 | |
2508 | if (e->src == ENTRY_BLOCK_PTR | |
2509 | && (e->flags & EDGE_FALLTHRU) && !(e->flags & EDGE_COMPLEX)) | |
2510 | { | |
c263766c RH |
2511 | if (dump_file) |
2512 | fprintf (dump_file, "Redirecting entry edge from bb %i to %i\n", | |
bc35512f JH |
2513 | e->src->index, dest->index); |
2514 | ||
f345f21a | 2515 | e->src->flags |= BB_DIRTY; |
bc35512f | 2516 | redirect_edge_succ (e, dest); |
6de9cd9a | 2517 | return e; |
bc35512f JH |
2518 | } |
2519 | ||
9ee634e3 JH |
2520 | /* Redirect_edge_and_branch may decide to turn branch into fallthru edge |
2521 | in the case the basic block appears to be in sequence. Avoid this | |
2522 | transformation. */ | |
2523 | ||
9ee634e3 JH |
2524 | if (e->flags & EDGE_FALLTHRU) |
2525 | { | |
2526 | /* Redirect any branch edges unified with the fallthru one. */ | |
4b4bf941 | 2527 | if (JUMP_P (BB_END (src)) |
432f982f JH |
2528 | && label_is_jump_target_p (BB_HEAD (e->dest), |
2529 | BB_END (src))) | |
9ee634e3 | 2530 | { |
341c100f NS |
2531 | edge redirected; |
2532 | ||
c263766c RH |
2533 | if (dump_file) |
2534 | fprintf (dump_file, "Fallthru edge unified with branch " | |
432f982f JH |
2535 | "%i->%i redirected to %i\n", |
2536 | e->src->index, e->dest->index, dest->index); | |
2537 | e->flags &= ~EDGE_FALLTHRU; | |
341c100f NS |
2538 | redirected = redirect_branch_edge (e, dest); |
2539 | gcc_assert (redirected); | |
432f982f | 2540 | e->flags |= EDGE_FALLTHRU; |
f345f21a | 2541 | e->src->flags |= BB_DIRTY; |
6de9cd9a | 2542 | return e; |
9ee634e3 JH |
2543 | } |
2544 | /* In case we are redirecting fallthru edge to the branch edge | |
2545 | of conditional jump, remove it. */ | |
628f6a4e | 2546 | if (EDGE_COUNT (src->succs) == 2) |
9ee634e3 | 2547 | { |
03101c6f KH |
2548 | /* Find the edge that is different from E. */ |
2549 | edge s = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e); | |
628f6a4e | 2550 | |
9ee634e3 | 2551 | if (s->dest == dest |
a813c111 SB |
2552 | && any_condjump_p (BB_END (src)) |
2553 | && onlyjump_p (BB_END (src))) | |
2554 | delete_insn (BB_END (src)); | |
9ee634e3 | 2555 | } |
6de9cd9a | 2556 | ret = redirect_edge_succ_nodup (e, dest); |
c263766c RH |
2557 | if (dump_file) |
2558 | fprintf (dump_file, "Fallthru edge %i->%i redirected to %i\n", | |
bc35512f | 2559 | e->src->index, e->dest->index, dest->index); |
9ee634e3 JH |
2560 | } |
2561 | else | |
bc35512f | 2562 | ret = redirect_branch_edge (e, dest); |
9ee634e3 JH |
2563 | |
2564 | /* We don't want simplejumps in the insn stream during cfglayout. */ | |
341c100f | 2565 | gcc_assert (!simplejump_p (BB_END (src))); |
9ee634e3 | 2566 | |
f345f21a | 2567 | src->flags |= BB_DIRTY; |
9ee634e3 JH |
2568 | return ret; |
2569 | } | |
2570 | ||
2571 | /* Simple wrapper as we always can redirect fallthru edges. */ | |
2572 | static basic_block | |
d329e058 | 2573 | cfg_layout_redirect_edge_and_branch_force (edge e, basic_block dest) |
9ee634e3 | 2574 | { |
341c100f NS |
2575 | edge redirected = cfg_layout_redirect_edge_and_branch (e, dest); |
2576 | ||
2577 | gcc_assert (redirected); | |
9ee634e3 JH |
2578 | return NULL; |
2579 | } | |
2580 | ||
f470c378 ZD |
2581 | /* Same as delete_basic_block but update cfg_layout structures. */ |
2582 | ||
9ee634e3 | 2583 | static void |
d329e058 | 2584 | cfg_layout_delete_block (basic_block bb) |
9ee634e3 | 2585 | { |
a813c111 | 2586 | rtx insn, next, prev = PREV_INSN (BB_HEAD (bb)), *to, remaints; |
9ee634e3 | 2587 | |
bc35512f | 2588 | if (bb->rbi->header) |
9ee634e3 | 2589 | { |
a813c111 | 2590 | next = BB_HEAD (bb); |
9ee634e3 | 2591 | if (prev) |
bc35512f | 2592 | NEXT_INSN (prev) = bb->rbi->header; |
9ee634e3 | 2593 | else |
bc35512f JH |
2594 | set_first_insn (bb->rbi->header); |
2595 | PREV_INSN (bb->rbi->header) = prev; | |
2596 | insn = bb->rbi->header; | |
9ee634e3 JH |
2597 | while (NEXT_INSN (insn)) |
2598 | insn = NEXT_INSN (insn); | |
2599 | NEXT_INSN (insn) = next; | |
2600 | PREV_INSN (next) = insn; | |
2601 | } | |
a813c111 | 2602 | next = NEXT_INSN (BB_END (bb)); |
bc35512f | 2603 | if (bb->rbi->footer) |
9ee634e3 | 2604 | { |
bc35512f JH |
2605 | insn = bb->rbi->footer; |
2606 | while (insn) | |
2607 | { | |
4b4bf941 | 2608 | if (BARRIER_P (insn)) |
bc35512f JH |
2609 | { |
2610 | if (PREV_INSN (insn)) | |
2611 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
2612 | else | |
2613 | bb->rbi->footer = NEXT_INSN (insn); | |
2614 | if (NEXT_INSN (insn)) | |
2615 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
2616 | } | |
4b4bf941 | 2617 | if (LABEL_P (insn)) |
bc35512f JH |
2618 | break; |
2619 | insn = NEXT_INSN (insn); | |
2620 | } | |
2621 | if (bb->rbi->footer) | |
2622 | { | |
a813c111 | 2623 | insn = BB_END (bb); |
bc35512f JH |
2624 | NEXT_INSN (insn) = bb->rbi->footer; |
2625 | PREV_INSN (bb->rbi->footer) = insn; | |
2626 | while (NEXT_INSN (insn)) | |
2627 | insn = NEXT_INSN (insn); | |
2628 | NEXT_INSN (insn) = next; | |
2629 | if (next) | |
2630 | PREV_INSN (next) = insn; | |
2631 | else | |
2632 | set_last_insn (insn); | |
2633 | } | |
9ee634e3 JH |
2634 | } |
2635 | if (bb->next_bb != EXIT_BLOCK_PTR) | |
bc35512f | 2636 | to = &bb->next_bb->rbi->header; |
9ee634e3 JH |
2637 | else |
2638 | to = &cfg_layout_function_footer; | |
997de8ed SB |
2639 | |
2640 | bb->rbi = NULL; | |
2641 | ||
9ee634e3 JH |
2642 | rtl_delete_block (bb); |
2643 | ||
2644 | if (prev) | |
2645 | prev = NEXT_INSN (prev); | |
d329e058 | 2646 | else |
9ee634e3 JH |
2647 | prev = get_insns (); |
2648 | if (next) | |
2649 | next = PREV_INSN (next); | |
d329e058 | 2650 | else |
9ee634e3 JH |
2651 | next = get_last_insn (); |
2652 | ||
2653 | if (next && NEXT_INSN (next) != prev) | |
2654 | { | |
2655 | remaints = unlink_insn_chain (prev, next); | |
2656 | insn = remaints; | |
2657 | while (NEXT_INSN (insn)) | |
2658 | insn = NEXT_INSN (insn); | |
2659 | NEXT_INSN (insn) = *to; | |
2660 | if (*to) | |
2661 | PREV_INSN (*to) = insn; | |
2662 | *to = remaints; | |
2663 | } | |
2664 | } | |
2665 | ||
beb235f8 | 2666 | /* Return true when blocks A and B can be safely merged. */ |
bc35512f JH |
2667 | static bool |
2668 | cfg_layout_can_merge_blocks_p (basic_block a, basic_block b) | |
2669 | { | |
750054a2 CT |
2670 | /* If we are partitioning hot/cold basic blocks, we don't want to |
2671 | mess up unconditional or indirect jumps that cross between hot | |
076c7ab8 ZW |
2672 | and cold sections. |
2673 | ||
8e8d5162 CT |
2674 | Basic block partitioning may result in some jumps that appear to |
2675 | be optimizable (or blocks that appear to be mergeable), but which really | |
2676 | must be left untouched (they are required to make it safely across | |
2677 | partition boundaries). See the comments at the top of | |
2678 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ | |
2679 | ||
87c8b4be | 2680 | if (BB_PARTITION (a) != BB_PARTITION (b)) |
076c7ab8 | 2681 | return false; |
750054a2 | 2682 | |
bc35512f | 2683 | /* There must be exactly one edge in between the blocks. */ |
c5cbcccf ZD |
2684 | return (single_succ_p (a) |
2685 | && single_succ (a) == b | |
2686 | && single_pred_p (b) == 1 | |
628f6a4e | 2687 | && a != b |
bc35512f | 2688 | /* Must be simple edge. */ |
c5cbcccf | 2689 | && !(single_succ_edge (a)->flags & EDGE_COMPLEX) |
bc35512f JH |
2690 | && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR |
2691 | /* If the jump insn has side effects, | |
2692 | we can't kill the edge. */ | |
4b4bf941 | 2693 | && (!JUMP_P (BB_END (a)) |
e24e7211 | 2694 | || (reload_completed |
a813c111 | 2695 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f JH |
2696 | } |
2697 | ||
2698 | /* Merge block A and B, abort when it is not possible. */ | |
2699 | static void | |
2700 | cfg_layout_merge_blocks (basic_block a, basic_block b) | |
2701 | { | |
2702 | #ifdef ENABLE_CHECKING | |
341c100f | 2703 | gcc_assert (cfg_layout_can_merge_blocks_p (a, b)); |
bc35512f JH |
2704 | #endif |
2705 | ||
2706 | /* If there was a CODE_LABEL beginning B, delete it. */ | |
4b4bf941 | 2707 | if (LABEL_P (BB_HEAD (b))) |
a813c111 | 2708 | delete_insn (BB_HEAD (b)); |
bc35512f JH |
2709 | |
2710 | /* We should have fallthru edge in a, or we can do dummy redirection to get | |
2711 | it cleaned up. */ | |
4b4bf941 | 2712 | if (JUMP_P (BB_END (a))) |
628f6a4e | 2713 | try_redirect_by_replacing_jump (EDGE_SUCC (a, 0), b, true); |
341c100f | 2714 | gcc_assert (!JUMP_P (BB_END (a))); |
bc35512f JH |
2715 | |
2716 | /* Possible line number notes should appear in between. */ | |
2717 | if (b->rbi->header) | |
2718 | { | |
a813c111 | 2719 | rtx first = BB_END (a), last; |
bc35512f | 2720 | |
a7102479 | 2721 | last = emit_insn_after_noloc (b->rbi->header, BB_END (a)); |
bc35512f JH |
2722 | delete_insn_chain (NEXT_INSN (first), last); |
2723 | b->rbi->header = NULL; | |
2724 | } | |
2725 | ||
2726 | /* In the case basic blocks are not adjacent, move them around. */ | |
a813c111 | 2727 | if (NEXT_INSN (BB_END (a)) != BB_HEAD (b)) |
bc35512f | 2728 | { |
a813c111 | 2729 | rtx first = unlink_insn_chain (BB_HEAD (b), BB_END (b)); |
bc35512f | 2730 | |
a7102479 | 2731 | emit_insn_after_noloc (first, BB_END (a)); |
bc35512f JH |
2732 | /* Skip possible DELETED_LABEL insn. */ |
2733 | if (!NOTE_INSN_BASIC_BLOCK_P (first)) | |
2734 | first = NEXT_INSN (first); | |
341c100f | 2735 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (first)); |
a813c111 | 2736 | BB_HEAD (b) = NULL; |
bc35512f JH |
2737 | delete_insn (first); |
2738 | } | |
2739 | /* Otherwise just re-associate the instructions. */ | |
2740 | else | |
2741 | { | |
2742 | rtx insn; | |
2743 | ||
a813c111 SB |
2744 | for (insn = BB_HEAD (b); |
2745 | insn != NEXT_INSN (BB_END (b)); | |
2746 | insn = NEXT_INSN (insn)) | |
bc35512f | 2747 | set_block_for_insn (insn, a); |
a813c111 | 2748 | insn = BB_HEAD (b); |
bc35512f JH |
2749 | /* Skip possible DELETED_LABEL insn. */ |
2750 | if (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
2751 | insn = NEXT_INSN (insn); | |
341c100f | 2752 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn)); |
a813c111 SB |
2753 | BB_HEAD (b) = NULL; |
2754 | BB_END (a) = BB_END (b); | |
bc35512f JH |
2755 | delete_insn (insn); |
2756 | } | |
2757 | ||
2758 | /* Possible tablejumps and barriers should appear after the block. */ | |
2759 | if (b->rbi->footer) | |
2760 | { | |
2761 | if (!a->rbi->footer) | |
2762 | a->rbi->footer = b->rbi->footer; | |
2763 | else | |
2764 | { | |
2765 | rtx last = a->rbi->footer; | |
2766 | ||
2767 | while (NEXT_INSN (last)) | |
2768 | last = NEXT_INSN (last); | |
2769 | NEXT_INSN (last) = b->rbi->footer; | |
2770 | PREV_INSN (b->rbi->footer) = last; | |
2771 | } | |
2772 | b->rbi->footer = NULL; | |
2773 | } | |
2774 | ||
c263766c RH |
2775 | if (dump_file) |
2776 | fprintf (dump_file, "Merged blocks %d and %d.\n", | |
bc35512f | 2777 | a->index, b->index); |
bc35512f JH |
2778 | } |
2779 | ||
2780 | /* Split edge E. */ | |
f470c378 | 2781 | |
bc35512f JH |
2782 | static basic_block |
2783 | cfg_layout_split_edge (edge e) | |
2784 | { | |
bc35512f JH |
2785 | basic_block new_bb = |
2786 | create_basic_block (e->src != ENTRY_BLOCK_PTR | |
a813c111 | 2787 | ? NEXT_INSN (BB_END (e->src)) : get_insns (), |
bc35512f JH |
2788 | NULL_RTX, e->src); |
2789 | ||
af874237 JW |
2790 | /* ??? This info is likely going to be out of date very soon, but we must |
2791 | create it to avoid getting an ICE later. */ | |
2792 | if (e->dest->global_live_at_start) | |
2793 | { | |
04389919 NS |
2794 | new_bb->global_live_at_start = ALLOC_REG_SET (®_obstack); |
2795 | new_bb->global_live_at_end = ALLOC_REG_SET (®_obstack); | |
af874237 JW |
2796 | COPY_REG_SET (new_bb->global_live_at_start, |
2797 | e->dest->global_live_at_start); | |
2798 | COPY_REG_SET (new_bb->global_live_at_end, | |
2799 | e->dest->global_live_at_start); | |
2800 | } | |
2801 | ||
a9b2ee88 | 2802 | make_edge (new_bb, e->dest, EDGE_FALLTHRU); |
bc35512f JH |
2803 | redirect_edge_and_branch_force (e, new_bb); |
2804 | ||
2805 | return new_bb; | |
2806 | } | |
2807 | ||
f470c378 ZD |
2808 | /* Do postprocessing after making a forwarder block joined by edge FALLTHRU. */ |
2809 | ||
2810 | static void | |
2811 | rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED) | |
2812 | { | |
2813 | } | |
2814 | ||
6de9cd9a DN |
2815 | /* Return 1 if BB ends with a call, possibly followed by some |
2816 | instructions that must stay with the call, 0 otherwise. */ | |
2817 | ||
2818 | static bool | |
2819 | rtl_block_ends_with_call_p (basic_block bb) | |
2820 | { | |
2821 | rtx insn = BB_END (bb); | |
2822 | ||
4b4bf941 | 2823 | while (!CALL_P (insn) |
6de9cd9a DN |
2824 | && insn != BB_HEAD (bb) |
2825 | && keep_with_call_p (insn)) | |
2826 | insn = PREV_INSN (insn); | |
4b4bf941 | 2827 | return (CALL_P (insn)); |
6de9cd9a DN |
2828 | } |
2829 | ||
2830 | /* Return 1 if BB ends with a conditional branch, 0 otherwise. */ | |
2831 | ||
2832 | static bool | |
2833 | rtl_block_ends_with_condjump_p (basic_block bb) | |
2834 | { | |
2835 | return any_condjump_p (BB_END (bb)); | |
2836 | } | |
2837 | ||
2838 | /* Return true if we need to add fake edge to exit. | |
2839 | Helper function for rtl_flow_call_edges_add. */ | |
2840 | ||
2841 | static bool | |
2842 | need_fake_edge_p (rtx insn) | |
2843 | { | |
2844 | if (!INSN_P (insn)) | |
2845 | return false; | |
2846 | ||
4b4bf941 | 2847 | if ((CALL_P (insn) |
6de9cd9a DN |
2848 | && !SIBLING_CALL_P (insn) |
2849 | && !find_reg_note (insn, REG_NORETURN, NULL) | |
6de9cd9a DN |
2850 | && !CONST_OR_PURE_CALL_P (insn))) |
2851 | return true; | |
2852 | ||
2853 | return ((GET_CODE (PATTERN (insn)) == ASM_OPERANDS | |
2854 | && MEM_VOLATILE_P (PATTERN (insn))) | |
2855 | || (GET_CODE (PATTERN (insn)) == PARALLEL | |
2856 | && asm_noperands (insn) != -1 | |
2857 | && MEM_VOLATILE_P (XVECEXP (PATTERN (insn), 0, 0))) | |
2858 | || GET_CODE (PATTERN (insn)) == ASM_INPUT); | |
2859 | } | |
2860 | ||
2861 | /* Add fake edges to the function exit for any non constant and non noreturn | |
2862 | calls, volatile inline assembly in the bitmap of blocks specified by | |
2863 | BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks | |
2864 | that were split. | |
2865 | ||
2866 | The goal is to expose cases in which entering a basic block does not imply | |
2867 | that all subsequent instructions must be executed. */ | |
2868 | ||
2869 | static int | |
2870 | rtl_flow_call_edges_add (sbitmap blocks) | |
2871 | { | |
2872 | int i; | |
2873 | int blocks_split = 0; | |
2874 | int last_bb = last_basic_block; | |
2875 | bool check_last_block = false; | |
2876 | ||
2877 | if (n_basic_blocks == 0) | |
2878 | return 0; | |
2879 | ||
2880 | if (! blocks) | |
2881 | check_last_block = true; | |
2882 | else | |
2883 | check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index); | |
2884 | ||
2885 | /* In the last basic block, before epilogue generation, there will be | |
2886 | a fallthru edge to EXIT. Special care is required if the last insn | |
2887 | of the last basic block is a call because make_edge folds duplicate | |
2888 | edges, which would result in the fallthru edge also being marked | |
2889 | fake, which would result in the fallthru edge being removed by | |
2890 | remove_fake_edges, which would result in an invalid CFG. | |
2891 | ||
2892 | Moreover, we can't elide the outgoing fake edge, since the block | |
2893 | profiler needs to take this into account in order to solve the minimal | |
2894 | spanning tree in the case that the call doesn't return. | |
2895 | ||
2896 | Handle this by adding a dummy instruction in a new last basic block. */ | |
2897 | if (check_last_block) | |
2898 | { | |
2899 | basic_block bb = EXIT_BLOCK_PTR->prev_bb; | |
2900 | rtx insn = BB_END (bb); | |
2901 | ||
2902 | /* Back up past insns that must be kept in the same block as a call. */ | |
2903 | while (insn != BB_HEAD (bb) | |
2904 | && keep_with_call_p (insn)) | |
2905 | insn = PREV_INSN (insn); | |
2906 | ||
2907 | if (need_fake_edge_p (insn)) | |
2908 | { | |
2909 | edge e; | |
2910 | ||
9ff3d2de JL |
2911 | e = find_edge (bb, EXIT_BLOCK_PTR); |
2912 | if (e) | |
2913 | { | |
2914 | insert_insn_on_edge (gen_rtx_USE (VOIDmode, const0_rtx), e); | |
2915 | commit_edge_insertions (); | |
2916 | } | |
6de9cd9a DN |
2917 | } |
2918 | } | |
2919 | ||
2920 | /* Now add fake edges to the function exit for any non constant | |
2921 | calls since there is no way that we can determine if they will | |
2922 | return or not... */ | |
2923 | ||
2924 | for (i = 0; i < last_bb; i++) | |
2925 | { | |
2926 | basic_block bb = BASIC_BLOCK (i); | |
2927 | rtx insn; | |
2928 | rtx prev_insn; | |
2929 | ||
2930 | if (!bb) | |
2931 | continue; | |
2932 | ||
2933 | if (blocks && !TEST_BIT (blocks, i)) | |
2934 | continue; | |
2935 | ||
2936 | for (insn = BB_END (bb); ; insn = prev_insn) | |
2937 | { | |
2938 | prev_insn = PREV_INSN (insn); | |
2939 | if (need_fake_edge_p (insn)) | |
2940 | { | |
2941 | edge e; | |
2942 | rtx split_at_insn = insn; | |
2943 | ||
2944 | /* Don't split the block between a call and an insn that should | |
2945 | remain in the same block as the call. */ | |
4b4bf941 | 2946 | if (CALL_P (insn)) |
6de9cd9a DN |
2947 | while (split_at_insn != BB_END (bb) |
2948 | && keep_with_call_p (NEXT_INSN (split_at_insn))) | |
2949 | split_at_insn = NEXT_INSN (split_at_insn); | |
2950 | ||
2951 | /* The handling above of the final block before the epilogue | |
2952 | should be enough to verify that there is no edge to the exit | |
2953 | block in CFG already. Calling make_edge in such case would | |
2954 | cause us to mark that edge as fake and remove it later. */ | |
2955 | ||
2956 | #ifdef ENABLE_CHECKING | |
2957 | if (split_at_insn == BB_END (bb)) | |
628f6a4e | 2958 | { |
9ff3d2de JL |
2959 | e = find_edge (bb, EXIT_BLOCK_PTR); |
2960 | gcc_assert (e == NULL); | |
628f6a4e | 2961 | } |
6de9cd9a DN |
2962 | #endif |
2963 | ||
2964 | /* Note that the following may create a new basic block | |
2965 | and renumber the existing basic blocks. */ | |
2966 | if (split_at_insn != BB_END (bb)) | |
2967 | { | |
2968 | e = split_block (bb, split_at_insn); | |
2969 | if (e) | |
2970 | blocks_split++; | |
2971 | } | |
2972 | ||
2973 | make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE); | |
2974 | } | |
2975 | ||
2976 | if (insn == BB_HEAD (bb)) | |
2977 | break; | |
2978 | } | |
2979 | } | |
2980 | ||
2981 | if (blocks_split) | |
2982 | verify_flow_info (); | |
2983 | ||
2984 | return blocks_split; | |
2985 | } | |
2986 | ||
1cb7dfc3 | 2987 | /* Add COMP_RTX as a condition at end of COND_BB. FIRST_HEAD is |
315682fb | 2988 | the conditional branch target, SECOND_HEAD should be the fall-thru |
1cb7dfc3 MH |
2989 | there is no need to handle this here the loop versioning code handles |
2990 | this. the reason for SECON_HEAD is that it is needed for condition | |
2991 | in trees, and this should be of the same type since it is a hook. */ | |
2992 | static void | |
2993 | rtl_lv_add_condition_to_bb (basic_block first_head , | |
2994 | basic_block second_head ATTRIBUTE_UNUSED, | |
2995 | basic_block cond_bb, void *comp_rtx) | |
2996 | { | |
2997 | rtx label, seq, jump; | |
2998 | rtx op0 = XEXP ((rtx)comp_rtx, 0); | |
2999 | rtx op1 = XEXP ((rtx)comp_rtx, 1); | |
3000 | enum rtx_code comp = GET_CODE ((rtx)comp_rtx); | |
3001 | enum machine_mode mode; | |
3002 | ||
3003 | ||
3004 | label = block_label (first_head); | |
3005 | mode = GET_MODE (op0); | |
3006 | if (mode == VOIDmode) | |
3007 | mode = GET_MODE (op1); | |
3008 | ||
3009 | start_sequence (); | |
3010 | op0 = force_operand (op0, NULL_RTX); | |
3011 | op1 = force_operand (op1, NULL_RTX); | |
3012 | do_compare_rtx_and_jump (op0, op1, comp, 0, | |
3013 | mode, NULL_RTX, NULL_RTX, label); | |
3014 | jump = get_last_insn (); | |
3015 | JUMP_LABEL (jump) = label; | |
3016 | LABEL_NUSES (label)++; | |
3017 | seq = get_insns (); | |
3018 | end_sequence (); | |
3019 | ||
3020 | /* Add the new cond , in the new head. */ | |
3021 | emit_insn_after(seq, BB_END(cond_bb)); | |
3022 | } | |
3023 | ||
3024 | ||
3025 | /* Given a block B with unconditional branch at its end, get the | |
3026 | store the return the branch edge and the fall-thru edge in | |
3027 | BRANCH_EDGE and FALLTHRU_EDGE respectively. */ | |
3028 | static void | |
3029 | rtl_extract_cond_bb_edges (basic_block b, edge *branch_edge, | |
3030 | edge *fallthru_edge) | |
3031 | { | |
3032 | edge e = EDGE_SUCC (b, 0); | |
3033 | ||
3034 | if (e->flags & EDGE_FALLTHRU) | |
3035 | { | |
3036 | *fallthru_edge = e; | |
3037 | *branch_edge = EDGE_SUCC (b, 1); | |
3038 | } | |
3039 | else | |
3040 | { | |
3041 | *branch_edge = e; | |
3042 | *fallthru_edge = EDGE_SUCC (b, 1); | |
3043 | } | |
3044 | } | |
3045 | ||
3046 | ||
9ee634e3 JH |
3047 | /* Implementation of CFG manipulation for linearized RTL. */ |
3048 | struct cfg_hooks rtl_cfg_hooks = { | |
f470c378 | 3049 | "rtl", |
9ee634e3 | 3050 | rtl_verify_flow_info, |
10e9fecc | 3051 | rtl_dump_bb, |
bc35512f | 3052 | rtl_create_basic_block, |
9ee634e3 JH |
3053 | rtl_redirect_edge_and_branch, |
3054 | rtl_redirect_edge_and_branch_force, | |
3055 | rtl_delete_block, | |
3056 | rtl_split_block, | |
f470c378 | 3057 | rtl_move_block_after, |
bc35512f JH |
3058 | rtl_can_merge_blocks, /* can_merge_blocks_p */ |
3059 | rtl_merge_blocks, | |
6de9cd9a DN |
3060 | rtl_predict_edge, |
3061 | rtl_predicted_by_p, | |
3062 | NULL, /* can_duplicate_block_p */ | |
3063 | NULL, /* duplicate_block */ | |
f470c378 ZD |
3064 | rtl_split_edge, |
3065 | rtl_make_forwarder_block, | |
6de9cd9a DN |
3066 | rtl_tidy_fallthru_edge, |
3067 | rtl_block_ends_with_call_p, | |
3068 | rtl_block_ends_with_condjump_p, | |
d9d4706f KH |
3069 | rtl_flow_call_edges_add, |
3070 | NULL, /* execute_on_growing_pred */ | |
1cb7dfc3 MH |
3071 | NULL, /* execute_on_shrinking_pred */ |
3072 | NULL, /* duplicate loop for trees */ | |
3073 | NULL, /* lv_add_condition_to_bb */ | |
3074 | NULL, /* lv_adjust_loop_header_phi*/ | |
3075 | NULL, /* extract_cond_bb_edges */ | |
3076 | NULL /* flush_pending_stmts */ | |
9ee634e3 JH |
3077 | }; |
3078 | ||
3079 | /* Implementation of CFG manipulation for cfg layout RTL, where | |
3080 | basic block connected via fallthru edges does not have to be adjacent. | |
3081 | This representation will hopefully become the default one in future | |
3082 | version of the compiler. */ | |
6de9cd9a DN |
3083 | |
3084 | /* We do not want to declare these functions in a header file, since they | |
3085 | should only be used through the cfghooks interface, and we do not want to | |
3086 | move them here since it would require also moving quite a lot of related | |
3087 | code. */ | |
3088 | extern bool cfg_layout_can_duplicate_bb_p (basic_block); | |
3089 | extern basic_block cfg_layout_duplicate_bb (basic_block); | |
3090 | ||
9ee634e3 | 3091 | struct cfg_hooks cfg_layout_rtl_cfg_hooks = { |
f470c378 | 3092 | "cfglayout mode", |
bc35512f | 3093 | rtl_verify_flow_info_1, |
10e9fecc | 3094 | rtl_dump_bb, |
bc35512f | 3095 | cfg_layout_create_basic_block, |
9ee634e3 JH |
3096 | cfg_layout_redirect_edge_and_branch, |
3097 | cfg_layout_redirect_edge_and_branch_force, | |
3098 | cfg_layout_delete_block, | |
3099 | cfg_layout_split_block, | |
f470c378 | 3100 | rtl_move_block_after, |
bc35512f JH |
3101 | cfg_layout_can_merge_blocks_p, |
3102 | cfg_layout_merge_blocks, | |
6de9cd9a DN |
3103 | rtl_predict_edge, |
3104 | rtl_predicted_by_p, | |
3105 | cfg_layout_can_duplicate_bb_p, | |
3106 | cfg_layout_duplicate_bb, | |
f470c378 ZD |
3107 | cfg_layout_split_edge, |
3108 | rtl_make_forwarder_block, | |
6de9cd9a DN |
3109 | NULL, |
3110 | rtl_block_ends_with_call_p, | |
3111 | rtl_block_ends_with_condjump_p, | |
d9d4706f KH |
3112 | rtl_flow_call_edges_add, |
3113 | NULL, /* execute_on_growing_pred */ | |
1cb7dfc3 MH |
3114 | NULL, /* execute_on_shrinking_pred */ |
3115 | duplicate_loop_to_header_edge, /* duplicate loop for trees */ | |
3116 | rtl_lv_add_condition_to_bb, /* lv_add_condition_to_bb */ | |
3117 | NULL, /* lv_adjust_loop_header_phi*/ | |
3118 | rtl_extract_cond_bb_edges, /* extract_cond_bb_edges */ | |
3119 | NULL /* flush_pending_stmts */ | |
9ee634e3 | 3120 | }; |
6de9cd9a | 3121 |