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ca6c03ca | 1 | /* Control flow graph manipulation code for GNU compiler. |
818ab71a | 2 | Copyright (C) 1987-2016 Free Software Foundation, Inc. |
ca6c03ca JH |
3 | |
4 | This file is part of GCC. | |
5 | ||
6 | GCC is free software; you can redistribute it and/or modify it under | |
7 | the terms of the GNU General Public License as published by the Free | |
9dcd6f09 | 8 | Software Foundation; either version 3, or (at your option) any later |
ca6c03ca JH |
9 | version. |
10 | ||
11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
14 | for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ | |
ca6c03ca | 19 | |
5f0d2358 RK |
20 | /* This file contains low level functions to manipulate the CFG and analyze it |
21 | that are aware of the RTL intermediate language. | |
ca6c03ca JH |
22 | |
23 | Available functionality: | |
bc35512f | 24 | - Basic CFG/RTL manipulation API documented in cfghooks.h |
5f0d2358 | 25 | - CFG-aware instruction chain manipulation |
ca6c03ca | 26 | delete_insn, delete_insn_chain |
bc35512f JH |
27 | - Edge splitting and committing to edges |
28 | insert_insn_on_edge, commit_edge_insertions | |
29 | - CFG updating after insn simplification | |
30 | purge_dead_edges, purge_all_dead_edges | |
ba5e9aca EB |
31 | - CFG fixing after coarse manipulation |
32 | fixup_abnormal_edges | |
bc35512f JH |
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 | 42 | #include "coretypes.h" |
c7131fb2 | 43 | #include "backend.h" |
957060b5 | 44 | #include "target.h" |
c7131fb2 | 45 | #include "rtl.h" |
957060b5 AM |
46 | #include "tree.h" |
47 | #include "cfghooks.h" | |
c7131fb2 | 48 | #include "df.h" |
957060b5 | 49 | #include "insn-config.h" |
4d0cdd0c | 50 | #include "memmodel.h" |
957060b5 | 51 | #include "emit-rtl.h" |
60393bbc AM |
52 | #include "cfgrtl.h" |
53 | #include "cfganal.h" | |
54 | #include "cfgbuild.h" | |
55 | #include "cfgcleanup.h" | |
60393bbc | 56 | #include "bb-reorder.h" |
0cbd9993 | 57 | #include "rtl-error.h" |
2a34bece | 58 | #include "insn-attr.h" |
36566b39 | 59 | #include "dojump.h" |
ff25ef99 | 60 | #include "expr.h" |
1cb7dfc3 | 61 | #include "cfgloop.h" |
ef330312 | 62 | #include "tree-pass.h" |
013a8899 | 63 | #include "print-rtl.h" |
ca6c03ca | 64 | |
78bde837 SB |
65 | /* Holds the interesting leading and trailing notes for the function. |
66 | Only applicable if the CFG is in cfglayout mode. */ | |
1130d5e3 | 67 | static GTY(()) rtx_insn *cfg_layout_function_footer; |
9152e0aa | 68 | static GTY(()) rtx_insn *cfg_layout_function_header; |
78bde837 | 69 | |
8879d71c | 70 | static rtx_insn *skip_insns_after_block (basic_block); |
78bde837 | 71 | static void record_effective_endpoints (void); |
78bde837 SB |
72 | static void fixup_reorder_chain (void); |
73 | ||
74 | void verify_insn_chain (void); | |
75 | static void fixup_fallthru_exit_predecessor (void); | |
8879d71c DM |
76 | static int can_delete_note_p (const rtx_note *); |
77 | static int can_delete_label_p (const rtx_code_label *); | |
d329e058 | 78 | static basic_block rtl_split_edge (edge); |
f470c378 | 79 | static bool rtl_move_block_after (basic_block, basic_block); |
d329e058 | 80 | static int rtl_verify_flow_info (void); |
f470c378 | 81 | static basic_block cfg_layout_split_block (basic_block, void *); |
6de9cd9a | 82 | static edge cfg_layout_redirect_edge_and_branch (edge, basic_block); |
d329e058 AJ |
83 | static basic_block cfg_layout_redirect_edge_and_branch_force (edge, basic_block); |
84 | static void cfg_layout_delete_block (basic_block); | |
85 | static void rtl_delete_block (basic_block); | |
86 | static basic_block rtl_redirect_edge_and_branch_force (edge, basic_block); | |
6de9cd9a | 87 | static edge rtl_redirect_edge_and_branch (edge, basic_block); |
f470c378 | 88 | static basic_block rtl_split_block (basic_block, void *); |
a315c44c | 89 | static void rtl_dump_bb (FILE *, basic_block, int, int); |
d329e058 | 90 | static int rtl_verify_flow_info_1 (void); |
f470c378 | 91 | static void rtl_make_forwarder_block (edge); |
ca6c03ca JH |
92 | \f |
93 | /* Return true if NOTE is not one of the ones that must be kept paired, | |
5f0d2358 | 94 | so that we may simply delete it. */ |
ca6c03ca JH |
95 | |
96 | static int | |
8879d71c | 97 | can_delete_note_p (const rtx_note *note) |
ca6c03ca | 98 | { |
cd9c1ca8 RH |
99 | switch (NOTE_KIND (note)) |
100 | { | |
101 | case NOTE_INSN_DELETED: | |
102 | case NOTE_INSN_BASIC_BLOCK: | |
103 | case NOTE_INSN_EPILOGUE_BEG: | |
104 | return true; | |
105 | ||
106 | default: | |
107 | return false; | |
108 | } | |
ca6c03ca JH |
109 | } |
110 | ||
111 | /* True if a given label can be deleted. */ | |
112 | ||
113 | static int | |
8879d71c | 114 | can_delete_label_p (const rtx_code_label *label) |
ca6c03ca | 115 | { |
5f0d2358 RK |
116 | return (!LABEL_PRESERVE_P (label) |
117 | /* User declared labels must be preserved. */ | |
118 | && LABEL_NAME (label) == 0 | |
6f7eba34 TS |
119 | && !vec_safe_contains<rtx_insn *> (forced_labels, |
120 | const_cast<rtx_code_label *> (label))); | |
ca6c03ca JH |
121 | } |
122 | ||
03fbe718 | 123 | /* Delete INSN by patching it out. */ |
ca6c03ca | 124 | |
03fbe718 | 125 | void |
1130d5e3 | 126 | delete_insn (rtx uncast_insn) |
ca6c03ca | 127 | { |
1130d5e3 | 128 | rtx_insn *insn = as_a <rtx_insn *> (uncast_insn); |
ca6c03ca JH |
129 | rtx note; |
130 | bool really_delete = true; | |
131 | ||
4b4bf941 | 132 | if (LABEL_P (insn)) |
ca6c03ca JH |
133 | { |
134 | /* Some labels can't be directly removed from the INSN chain, as they | |
c22cacf3 MS |
135 | might be references via variables, constant pool etc. |
136 | Convert them to the special NOTE_INSN_DELETED_LABEL note. */ | |
8879d71c | 137 | if (! can_delete_label_p (as_a <rtx_code_label *> (insn))) |
ca6c03ca JH |
138 | { |
139 | const char *name = LABEL_NAME (insn); | |
5e5df392 | 140 | basic_block bb = BLOCK_FOR_INSN (insn); |
8879d71c | 141 | rtx_insn *bb_note = NEXT_INSN (insn); |
ca6c03ca JH |
142 | |
143 | really_delete = false; | |
144 | PUT_CODE (insn, NOTE); | |
a38e7aa5 | 145 | NOTE_KIND (insn) = NOTE_INSN_DELETED_LABEL; |
6773e15f | 146 | NOTE_DELETED_LABEL_NAME (insn) = name; |
03fbe718 | 147 | |
0f33baa9 | 148 | /* If the note following the label starts a basic block, and the |
5e5df392 | 149 | label is a member of the same basic block, interchange the two. */ |
0f33baa9 TV |
150 | if (bb_note != NULL_RTX |
151 | && NOTE_INSN_BASIC_BLOCK_P (bb_note) | |
5e5df392 TV |
152 | && bb != NULL |
153 | && bb == BLOCK_FOR_INSN (bb_note)) | |
03fbe718 TV |
154 | { |
155 | reorder_insns_nobb (insn, insn, bb_note); | |
1130d5e3 | 156 | BB_HEAD (bb) = bb_note; |
03fbe718 | 157 | if (BB_END (bb) == bb_note) |
1130d5e3 | 158 | BB_END (bb) = insn; |
03fbe718 | 159 | } |
ca6c03ca | 160 | } |
5f0d2358 | 161 | |
b5241a5a | 162 | remove_node_from_insn_list (insn, &nonlocal_goto_handler_labels); |
ca6c03ca JH |
163 | } |
164 | ||
165 | if (really_delete) | |
166 | { | |
cda94cbb | 167 | /* If this insn has already been deleted, something is very wrong. */ |
4654c0cf | 168 | gcc_assert (!insn->deleted ()); |
1f397f45 SB |
169 | if (INSN_P (insn)) |
170 | df_insn_delete (insn); | |
ca6c03ca | 171 | remove_insn (insn); |
4654c0cf | 172 | insn->set_deleted (); |
ca6c03ca JH |
173 | } |
174 | ||
175 | /* If deleting a jump, decrement the use count of the label. Deleting | |
176 | the label itself should happen in the normal course of block merging. */ | |
cf7c4aa6 | 177 | if (JUMP_P (insn)) |
9295a326 | 178 | { |
cf7c4aa6 HPN |
179 | if (JUMP_LABEL (insn) |
180 | && LABEL_P (JUMP_LABEL (insn))) | |
181 | LABEL_NUSES (JUMP_LABEL (insn))--; | |
182 | ||
183 | /* If there are more targets, remove them too. */ | |
184 | while ((note | |
185 | = find_reg_note (insn, REG_LABEL_TARGET, NULL_RTX)) != NULL_RTX | |
4b4bf941 | 186 | && LABEL_P (XEXP (note, 0))) |
9295a326 JZ |
187 | { |
188 | LABEL_NUSES (XEXP (note, 0))--; | |
189 | remove_note (insn, note); | |
190 | } | |
191 | } | |
ca6c03ca | 192 | |
cf7c4aa6 HPN |
193 | /* Also if deleting any insn that references a label as an operand. */ |
194 | while ((note = find_reg_note (insn, REG_LABEL_OPERAND, NULL_RTX)) != NULL_RTX | |
195 | && LABEL_P (XEXP (note, 0))) | |
196 | { | |
197 | LABEL_NUSES (XEXP (note, 0))--; | |
198 | remove_note (insn, note); | |
199 | } | |
200 | ||
95c43227 | 201 | if (rtx_jump_table_data *table = dyn_cast <rtx_jump_table_data *> (insn)) |
ca6c03ca | 202 | { |
95c43227 DM |
203 | rtvec vec = table->get_labels (); |
204 | int len = GET_NUM_ELEM (vec); | |
ca6c03ca JH |
205 | int i; |
206 | ||
207 | for (i = 0; i < len; i++) | |
a124fcda | 208 | { |
95c43227 | 209 | rtx label = XEXP (RTVEC_ELT (vec, i), 0); |
a124fcda RH |
210 | |
211 | /* When deleting code in bulk (e.g. removing many unreachable | |
212 | blocks) we can delete a label that's a target of the vector | |
213 | before deleting the vector itself. */ | |
4b4bf941 | 214 | if (!NOTE_P (label)) |
a124fcda RH |
215 | LABEL_NUSES (label)--; |
216 | } | |
ca6c03ca | 217 | } |
ca6c03ca JH |
218 | } |
219 | ||
98ccd1d7 IE |
220 | /* Like delete_insn but also purge dead edges from BB. |
221 | Return true if any edges are eliminated. */ | |
9ed7b221 | 222 | |
98ccd1d7 | 223 | bool |
373fc786 | 224 | delete_insn_and_edges (rtx_insn *insn) |
3dec4024 | 225 | { |
3dec4024 JH |
226 | bool purge = false; |
227 | ||
ba4f7968 | 228 | if (INSN_P (insn) |
3dec4024 | 229 | && BLOCK_FOR_INSN (insn) |
a813c111 | 230 | && BB_END (BLOCK_FOR_INSN (insn)) == insn) |
3dec4024 | 231 | purge = true; |
03fbe718 | 232 | delete_insn (insn); |
3dec4024 | 233 | if (purge) |
98ccd1d7 IE |
234 | return purge_dead_edges (BLOCK_FOR_INSN (insn)); |
235 | return false; | |
3dec4024 JH |
236 | } |
237 | ||
ca6c03ca | 238 | /* Unlink a chain of insns between START and FINISH, leaving notes |
a7b87f73 ZD |
239 | that must be paired. If CLEAR_BB is true, we set bb field for |
240 | insns that cannot be removed to NULL. */ | |
ca6c03ca JH |
241 | |
242 | void | |
a7b87f73 | 243 | delete_insn_chain (rtx start, rtx finish, bool clear_bb) |
ca6c03ca | 244 | { |
8879d71c | 245 | rtx_insn *prev, *current; |
ca6c03ca | 246 | |
5f0d2358 RK |
247 | /* Unchain the insns one by one. It would be quicker to delete all of these |
248 | with a single unchaining, rather than one at a time, but we need to keep | |
249 | the NOTE's. */ | |
8879d71c | 250 | current = safe_as_a <rtx_insn *> (finish); |
ca6c03ca JH |
251 | while (1) |
252 | { | |
03fbe718 | 253 | prev = PREV_INSN (current); |
8879d71c | 254 | if (NOTE_P (current) && !can_delete_note_p (as_a <rtx_note *> (current))) |
ca6c03ca JH |
255 | ; |
256 | else | |
03fbe718 | 257 | delete_insn (current); |
ca6c03ca | 258 | |
4654c0cf | 259 | if (clear_bb && !current->deleted ()) |
03fbe718 | 260 | set_block_for_insn (current, NULL); |
a7b87f73 | 261 | |
03fbe718 | 262 | if (current == start) |
ca6c03ca | 263 | break; |
03fbe718 | 264 | current = prev; |
ca6c03ca JH |
265 | } |
266 | } | |
267 | \f | |
5f0d2358 RK |
268 | /* Create a new basic block consisting of the instructions between HEAD and END |
269 | inclusive. This function is designed to allow fast BB construction - reuses | |
270 | the note and basic block struct in BB_NOTE, if any and do not grow | |
271 | BASIC_BLOCK chain and should be used directly only by CFG construction code. | |
272 | END can be NULL in to create new empty basic block before HEAD. Both END | |
918ed612 ZD |
273 | and HEAD can be NULL to create basic block at the end of INSN chain. |
274 | AFTER is the basic block we should be put after. */ | |
ca6c03ca JH |
275 | |
276 | basic_block | |
e00022e9 | 277 | create_basic_block_structure (rtx_insn *head, rtx_insn *end, rtx_note *bb_note, |
66e8df53 | 278 | basic_block after) |
ca6c03ca JH |
279 | { |
280 | basic_block bb; | |
281 | ||
282 | if (bb_note | |
ca6c03ca JH |
283 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL |
284 | && bb->aux == NULL) | |
285 | { | |
286 | /* If we found an existing note, thread it back onto the chain. */ | |
287 | ||
fee3e72c | 288 | rtx_insn *after; |
ca6c03ca | 289 | |
4b4bf941 | 290 | if (LABEL_P (head)) |
ca6c03ca JH |
291 | after = head; |
292 | else | |
293 | { | |
294 | after = PREV_INSN (head); | |
295 | head = bb_note; | |
296 | } | |
297 | ||
298 | if (after != bb_note && NEXT_INSN (after) != bb_note) | |
ba4f7968 | 299 | reorder_insns_nobb (bb_note, bb_note, after); |
ca6c03ca JH |
300 | } |
301 | else | |
302 | { | |
303 | /* Otherwise we must create a note and a basic block structure. */ | |
304 | ||
305 | bb = alloc_block (); | |
306 | ||
5e2d947c | 307 | init_rtl_bb_info (bb); |
ca6c03ca | 308 | if (!head && !end) |
5f0d2358 RK |
309 | head = end = bb_note |
310 | = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); | |
4b4bf941 | 311 | else if (LABEL_P (head) && end) |
ca6c03ca JH |
312 | { |
313 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); | |
314 | if (head == end) | |
315 | end = bb_note; | |
316 | } | |
317 | else | |
318 | { | |
319 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); | |
320 | head = bb_note; | |
321 | if (!end) | |
322 | end = head; | |
323 | } | |
5f0d2358 | 324 | |
ca6c03ca JH |
325 | NOTE_BASIC_BLOCK (bb_note) = bb; |
326 | } | |
327 | ||
328 | /* Always include the bb note in the block. */ | |
329 | if (NEXT_INSN (end) == bb_note) | |
330 | end = bb_note; | |
331 | ||
1130d5e3 DM |
332 | BB_HEAD (bb) = head; |
333 | BB_END (bb) = end; | |
8b1c6fd7 | 334 | bb->index = last_basic_block_for_fn (cfun)++; |
5e2d947c | 335 | bb->flags = BB_NEW | BB_RTL; |
918ed612 | 336 | link_block (bb, after); |
557c4b49 | 337 | SET_BASIC_BLOCK_FOR_FN (cfun, bb->index, bb); |
6fb5fa3c | 338 | df_bb_refs_record (bb->index, false); |
ba4f7968 | 339 | update_bb_for_insn (bb); |
076c7ab8 | 340 | BB_SET_PARTITION (bb, BB_UNPARTITIONED); |
ca6c03ca JH |
341 | |
342 | /* Tag the block so that we know it has been used when considering | |
343 | other basic block notes. */ | |
344 | bb->aux = bb; | |
345 | ||
346 | return bb; | |
347 | } | |
348 | ||
5f0d2358 | 349 | /* Create new basic block consisting of instructions in between HEAD and END |
ffe14686 AM |
350 | and place it to the BB chain after block AFTER. END can be NULL to |
351 | create a new empty basic block before HEAD. Both END and HEAD can be | |
352 | NULL to create basic block at the end of INSN chain. */ | |
ca6c03ca | 353 | |
bc35512f JH |
354 | static basic_block |
355 | rtl_create_basic_block (void *headp, void *endp, basic_block after) | |
ca6c03ca | 356 | { |
e00022e9 DM |
357 | rtx_insn *head = (rtx_insn *) headp; |
358 | rtx_insn *end = (rtx_insn *) endp; | |
ca6c03ca | 359 | basic_block bb; |
0b17ab2f | 360 | |
7eca0767 | 361 | /* Grow the basic block array if needed. */ |
8b1c6fd7 DM |
362 | if ((size_t) last_basic_block_for_fn (cfun) |
363 | >= basic_block_info_for_fn (cfun)->length ()) | |
7eca0767 | 364 | { |
8b1c6fd7 DM |
365 | size_t new_size = |
366 | (last_basic_block_for_fn (cfun) | |
367 | + (last_basic_block_for_fn (cfun) + 3) / 4); | |
c5f05f68 | 368 | vec_safe_grow_cleared (basic_block_info_for_fn (cfun), new_size); |
7eca0767 | 369 | } |
0b17ab2f | 370 | |
0cae8d31 | 371 | n_basic_blocks_for_fn (cfun)++; |
ca6c03ca | 372 | |
852c6ec7 | 373 | bb = create_basic_block_structure (head, end, NULL, after); |
ca6c03ca JH |
374 | bb->aux = NULL; |
375 | return bb; | |
376 | } | |
bc35512f JH |
377 | |
378 | static basic_block | |
379 | cfg_layout_create_basic_block (void *head, void *end, basic_block after) | |
380 | { | |
381 | basic_block newbb = rtl_create_basic_block (head, end, after); | |
382 | ||
bc35512f JH |
383 | return newbb; |
384 | } | |
ca6c03ca JH |
385 | \f |
386 | /* Delete the insns in a (non-live) block. We physically delete every | |
387 | non-deleted-note insn, and update the flow graph appropriately. | |
388 | ||
389 | Return nonzero if we deleted an exception handler. */ | |
390 | ||
391 | /* ??? Preserving all such notes strikes me as wrong. It would be nice | |
392 | to post-process the stream to remove empty blocks, loops, ranges, etc. */ | |
393 | ||
f0fda11c | 394 | static void |
d329e058 | 395 | rtl_delete_block (basic_block b) |
ca6c03ca | 396 | { |
8879d71c | 397 | rtx_insn *insn, *end; |
ca6c03ca JH |
398 | |
399 | /* If the head of this block is a CODE_LABEL, then it might be the | |
f39e46ba SB |
400 | label for an exception handler which can't be reached. We need |
401 | to remove the label from the exception_handler_label list. */ | |
a813c111 | 402 | insn = BB_HEAD (b); |
ca6c03ca | 403 | |
96370780 | 404 | end = get_last_bb_insn (b); |
ca6c03ca JH |
405 | |
406 | /* Selectively delete the entire chain. */ | |
1130d5e3 | 407 | BB_HEAD (b) = NULL; |
a7b87f73 ZD |
408 | delete_insn_chain (insn, end, true); |
409 | ||
6fb5fa3c DB |
410 | |
411 | if (dump_file) | |
412 | fprintf (dump_file, "deleting block %d\n", b->index); | |
413 | df_bb_delete (b->index); | |
ca6c03ca JH |
414 | } |
415 | \f | |
852c6ec7 | 416 | /* Records the basic block struct in BLOCK_FOR_INSN for every insn. */ |
ca6c03ca JH |
417 | |
418 | void | |
d329e058 | 419 | compute_bb_for_insn (void) |
ca6c03ca | 420 | { |
e0082a72 | 421 | basic_block bb; |
ca6c03ca | 422 | |
11cd3bed | 423 | FOR_EACH_BB_FN (bb, cfun) |
ca6c03ca | 424 | { |
8879d71c DM |
425 | rtx_insn *end = BB_END (bb); |
426 | rtx_insn *insn; | |
ca6c03ca | 427 | |
a813c111 | 428 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
ca6c03ca | 429 | { |
ba4f7968 | 430 | BLOCK_FOR_INSN (insn) = bb; |
ca6c03ca JH |
431 | if (insn == end) |
432 | break; | |
ca6c03ca JH |
433 | } |
434 | } | |
435 | } | |
436 | ||
437 | /* Release the basic_block_for_insn array. */ | |
438 | ||
c2924966 | 439 | unsigned int |
d329e058 | 440 | free_bb_for_insn (void) |
ca6c03ca | 441 | { |
8879d71c | 442 | rtx_insn *insn; |
ba4f7968 | 443 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) |
4b4bf941 | 444 | if (!BARRIER_P (insn)) |
ba4f7968 | 445 | BLOCK_FOR_INSN (insn) = NULL; |
c2924966 | 446 | return 0; |
ca6c03ca JH |
447 | } |
448 | ||
27a4cd48 DM |
449 | namespace { |
450 | ||
451 | const pass_data pass_data_free_cfg = | |
452 | { | |
453 | RTL_PASS, /* type */ | |
454 | "*free_cfg", /* name */ | |
455 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
456 | TV_NONE, /* tv_id */ |
457 | 0, /* properties_required */ | |
458 | 0, /* properties_provided */ | |
459 | PROP_cfg, /* properties_destroyed */ | |
460 | 0, /* todo_flags_start */ | |
461 | 0, /* todo_flags_finish */ | |
ef330312 PB |
462 | }; |
463 | ||
27a4cd48 DM |
464 | class pass_free_cfg : public rtl_opt_pass |
465 | { | |
466 | public: | |
c3284718 RS |
467 | pass_free_cfg (gcc::context *ctxt) |
468 | : rtl_opt_pass (pass_data_free_cfg, ctxt) | |
27a4cd48 DM |
469 | {} |
470 | ||
471 | /* opt_pass methods: */ | |
be55bfe6 | 472 | virtual unsigned int execute (function *); |
27a4cd48 DM |
473 | |
474 | }; // class pass_free_cfg | |
475 | ||
be55bfe6 TS |
476 | unsigned int |
477 | pass_free_cfg::execute (function *) | |
478 | { | |
be55bfe6 TS |
479 | /* The resource.c machinery uses DF but the CFG isn't guaranteed to be |
480 | valid at that point so it would be too late to call df_analyze. */ | |
e90bedf5 | 481 | if (DELAY_SLOTS && optimize > 0 && flag_delayed_branch) |
be55bfe6 TS |
482 | { |
483 | df_note_add_problem (); | |
484 | df_analyze (); | |
485 | } | |
be55bfe6 TS |
486 | |
487 | if (crtl->has_bb_partition) | |
488 | insert_section_boundary_note (); | |
489 | ||
490 | free_bb_for_insn (); | |
491 | return 0; | |
492 | } | |
493 | ||
27a4cd48 DM |
494 | } // anon namespace |
495 | ||
496 | rtl_opt_pass * | |
497 | make_pass_free_cfg (gcc::context *ctxt) | |
498 | { | |
499 | return new pass_free_cfg (ctxt); | |
500 | } | |
501 | ||
91278841 | 502 | /* Return RTX to emit after when we want to emit code on the entry of function. */ |
8a2e8325 | 503 | rtx_insn * |
91278841 AP |
504 | entry_of_function (void) |
505 | { | |
0cae8d31 | 506 | return (n_basic_blocks_for_fn (cfun) > NUM_FIXED_BLOCKS ? |
fefa31b5 | 507 | BB_HEAD (ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb) : get_insns ()); |
91278841 AP |
508 | } |
509 | ||
11b904a1 BS |
510 | /* Emit INSN at the entry point of the function, ensuring that it is only |
511 | executed once per function. */ | |
512 | void | |
513 | emit_insn_at_entry (rtx insn) | |
514 | { | |
fefa31b5 | 515 | edge_iterator ei = ei_start (ENTRY_BLOCK_PTR_FOR_FN (cfun)->succs); |
11b904a1 | 516 | edge e = ei_safe_edge (ei); |
5419bc7f | 517 | gcc_assert (e->flags & EDGE_FALLTHRU); |
11b904a1 BS |
518 | |
519 | insert_insn_on_edge (insn, e); | |
520 | commit_edge_insertions (); | |
521 | } | |
522 | ||
6c3d0e31 | 523 | /* Update BLOCK_FOR_INSN of insns between BEGIN and END |
b8698a0f | 524 | (or BARRIER if found) and notify df of the bb change. |
6c3d0e31 SP |
525 | The insn chain range is inclusive |
526 | (i.e. both BEGIN and END will be updated. */ | |
ca6c03ca | 527 | |
6c3d0e31 | 528 | static void |
8879d71c | 529 | update_bb_for_insn_chain (rtx_insn *begin, rtx_insn *end, basic_block bb) |
ca6c03ca | 530 | { |
8879d71c | 531 | rtx_insn *insn; |
ca6c03ca | 532 | |
6c3d0e31 SP |
533 | end = NEXT_INSN (end); |
534 | for (insn = begin; insn != end; insn = NEXT_INSN (insn)) | |
63642d5a AO |
535 | if (!BARRIER_P (insn)) |
536 | df_insn_change_bb (insn, bb); | |
ca6c03ca | 537 | } |
6c3d0e31 SP |
538 | |
539 | /* Update BLOCK_FOR_INSN of insns in BB to BB, | |
540 | and notify df of the change. */ | |
541 | ||
542 | void | |
543 | update_bb_for_insn (basic_block bb) | |
544 | { | |
545 | update_bb_for_insn_chain (BB_HEAD (bb), BB_END (bb), bb); | |
546 | } | |
547 | ||
532aafad SB |
548 | \f |
549 | /* Like active_insn_p, except keep the return value clobber around | |
550 | even after reload. */ | |
551 | ||
552 | static bool | |
8879d71c | 553 | flow_active_insn_p (const rtx_insn *insn) |
532aafad SB |
554 | { |
555 | if (active_insn_p (insn)) | |
556 | return true; | |
557 | ||
558 | /* A clobber of the function return value exists for buggy | |
559 | programs that fail to return a value. Its effect is to | |
560 | keep the return value from being live across the entire | |
561 | function. If we allow it to be skipped, we introduce the | |
562 | possibility for register lifetime confusion. */ | |
563 | if (GET_CODE (PATTERN (insn)) == CLOBBER | |
564 | && REG_P (XEXP (PATTERN (insn), 0)) | |
565 | && REG_FUNCTION_VALUE_P (XEXP (PATTERN (insn), 0))) | |
566 | return true; | |
567 | ||
568 | return false; | |
569 | } | |
570 | ||
571 | /* Return true if the block has no effect and only forwards control flow to | |
572 | its single destination. */ | |
532aafad SB |
573 | |
574 | bool | |
2407343c | 575 | contains_no_active_insn_p (const_basic_block bb) |
532aafad | 576 | { |
8879d71c | 577 | rtx_insn *insn; |
532aafad | 578 | |
4833f561 JJ |
579 | if (bb == EXIT_BLOCK_PTR_FOR_FN (cfun) |
580 | || bb == ENTRY_BLOCK_PTR_FOR_FN (cfun) | |
581 | || !single_succ_p (bb) | |
582 | || (single_succ_edge (bb)->flags & EDGE_FAKE) != 0) | |
532aafad SB |
583 | return false; |
584 | ||
2407343c JR |
585 | for (insn = BB_HEAD (bb); insn != BB_END (bb); insn = NEXT_INSN (insn)) |
586 | if (INSN_P (insn) && flow_active_insn_p (insn)) | |
587 | return false; | |
588 | ||
589 | return (!INSN_P (insn) | |
590 | || (JUMP_P (insn) && simplejump_p (insn)) | |
591 | || !flow_active_insn_p (insn)); | |
592 | } | |
593 | ||
594 | /* Likewise, but protect loop latches, headers and preheaders. */ | |
595 | /* FIXME: Make this a cfg hook. */ | |
596 | ||
597 | bool | |
598 | forwarder_block_p (const_basic_block bb) | |
599 | { | |
600 | if (!contains_no_active_insn_p (bb)) | |
601 | return false; | |
602 | ||
532aafad SB |
603 | /* Protect loop latches, headers and preheaders. */ |
604 | if (current_loops) | |
605 | { | |
606 | basic_block dest; | |
607 | if (bb->loop_father->header == bb) | |
608 | return false; | |
609 | dest = EDGE_SUCC (bb, 0)->dest; | |
610 | if (dest->loop_father->header == dest) | |
611 | return false; | |
612 | } | |
613 | ||
2407343c | 614 | return true; |
532aafad SB |
615 | } |
616 | ||
617 | /* Return nonzero if we can reach target from src by falling through. */ | |
d7b6661b | 618 | /* FIXME: Make this a cfg hook, the result is only valid in cfgrtl mode. */ |
532aafad SB |
619 | |
620 | bool | |
621 | can_fallthru (basic_block src, basic_block target) | |
622 | { | |
8879d71c DM |
623 | rtx_insn *insn = BB_END (src); |
624 | rtx_insn *insn2; | |
532aafad SB |
625 | edge e; |
626 | edge_iterator ei; | |
627 | ||
fefa31b5 | 628 | if (target == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
532aafad SB |
629 | return true; |
630 | if (src->next_bb != target) | |
d7b6661b SB |
631 | return false; |
632 | ||
633 | /* ??? Later we may add code to move jump tables offline. */ | |
634 | if (tablejump_p (insn, NULL, NULL)) | |
635 | return false; | |
636 | ||
532aafad | 637 | FOR_EACH_EDGE (e, ei, src->succs) |
fefa31b5 | 638 | if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) |
532aafad | 639 | && e->flags & EDGE_FALLTHRU) |
d7b6661b | 640 | return false; |
532aafad SB |
641 | |
642 | insn2 = BB_HEAD (target); | |
d7b6661b | 643 | if (!active_insn_p (insn2)) |
532aafad SB |
644 | insn2 = next_active_insn (insn2); |
645 | ||
532aafad SB |
646 | return next_active_insn (insn) == insn2; |
647 | } | |
648 | ||
649 | /* Return nonzero if we could reach target from src by falling through, | |
650 | if the target was made adjacent. If we already have a fall-through | |
651 | edge to the exit block, we can't do that. */ | |
652 | static bool | |
653 | could_fall_through (basic_block src, basic_block target) | |
654 | { | |
655 | edge e; | |
656 | edge_iterator ei; | |
657 | ||
fefa31b5 | 658 | if (target == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
532aafad SB |
659 | return true; |
660 | FOR_EACH_EDGE (e, ei, src->succs) | |
fefa31b5 | 661 | if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) |
532aafad SB |
662 | && e->flags & EDGE_FALLTHRU) |
663 | return 0; | |
664 | return true; | |
665 | } | |
ca6c03ca | 666 | \f |
ef2be249 | 667 | /* Return the NOTE_INSN_BASIC_BLOCK of BB. */ |
ed270997 | 668 | rtx_note * |
ef2be249 RS |
669 | bb_note (basic_block bb) |
670 | { | |
8879d71c | 671 | rtx_insn *note; |
ef2be249 RS |
672 | |
673 | note = BB_HEAD (bb); | |
674 | if (LABEL_P (note)) | |
675 | note = NEXT_INSN (note); | |
676 | ||
677 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (note)); | |
ed270997 | 678 | return as_a <rtx_note *> (note); |
ef2be249 RS |
679 | } |
680 | ||
6fb5fa3c DB |
681 | /* Return the INSN immediately following the NOTE_INSN_BASIC_BLOCK |
682 | note associated with the BLOCK. */ | |
683 | ||
8879d71c | 684 | static rtx_insn * |
6fb5fa3c DB |
685 | first_insn_after_basic_block_note (basic_block block) |
686 | { | |
8879d71c | 687 | rtx_insn *insn; |
6fb5fa3c DB |
688 | |
689 | /* Get the first instruction in the block. */ | |
690 | insn = BB_HEAD (block); | |
691 | ||
692 | if (insn == NULL_RTX) | |
8879d71c | 693 | return NULL; |
6fb5fa3c DB |
694 | if (LABEL_P (insn)) |
695 | insn = NEXT_INSN (insn); | |
696 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn)); | |
697 | ||
698 | return NEXT_INSN (insn); | |
699 | } | |
700 | ||
2b9c63a2 FY |
701 | /* Creates a new basic block just after basic block BB by splitting |
702 | everything after specified instruction INSNP. */ | |
ca6c03ca | 703 | |
f470c378 | 704 | static basic_block |
d329e058 | 705 | rtl_split_block (basic_block bb, void *insnp) |
ca6c03ca JH |
706 | { |
707 | basic_block new_bb; | |
8879d71c | 708 | rtx_insn *insn = (rtx_insn *) insnp; |
f470c378 | 709 | edge e; |
628f6a4e | 710 | edge_iterator ei; |
ca6c03ca | 711 | |
f470c378 ZD |
712 | if (!insn) |
713 | { | |
714 | insn = first_insn_after_basic_block_note (bb); | |
715 | ||
716 | if (insn) | |
b5b8b0ac | 717 | { |
8879d71c | 718 | rtx_insn *next = insn; |
b5b8b0ac AO |
719 | |
720 | insn = PREV_INSN (insn); | |
721 | ||
722 | /* If the block contains only debug insns, insn would have | |
723 | been NULL in a non-debug compilation, and then we'd end | |
724 | up emitting a DELETED note. For -fcompare-debug | |
725 | stability, emit the note too. */ | |
726 | if (insn != BB_END (bb) | |
727 | && DEBUG_INSN_P (next) | |
728 | && DEBUG_INSN_P (BB_END (bb))) | |
729 | { | |
730 | while (next != BB_END (bb) && DEBUG_INSN_P (next)) | |
731 | next = NEXT_INSN (next); | |
732 | ||
733 | if (next == BB_END (bb)) | |
734 | emit_note_after (NOTE_INSN_DELETED, next); | |
735 | } | |
736 | } | |
f470c378 ZD |
737 | else |
738 | insn = get_last_insn (); | |
739 | } | |
740 | ||
741 | /* We probably should check type of the insn so that we do not create | |
742 | inconsistent cfg. It is checked in verify_flow_info anyway, so do not | |
743 | bother. */ | |
744 | if (insn == BB_END (bb)) | |
745 | emit_note_after (NOTE_INSN_DELETED, insn); | |
ca6c03ca JH |
746 | |
747 | /* Create the new basic block. */ | |
a813c111 | 748 | new_bb = create_basic_block (NEXT_INSN (insn), BB_END (bb), bb); |
076c7ab8 | 749 | BB_COPY_PARTITION (new_bb, bb); |
1130d5e3 | 750 | BB_END (bb) = insn; |
ca6c03ca JH |
751 | |
752 | /* Redirect the outgoing edges. */ | |
628f6a4e BE |
753 | new_bb->succs = bb->succs; |
754 | bb->succs = NULL; | |
755 | FOR_EACH_EDGE (e, ei, new_bb->succs) | |
ca6c03ca JH |
756 | e->src = new_bb; |
757 | ||
6fb5fa3c DB |
758 | /* The new block starts off being dirty. */ |
759 | df_set_bb_dirty (bb); | |
f470c378 | 760 | return new_bb; |
bc35512f JH |
761 | } |
762 | ||
9be94227 EB |
763 | /* Return true if the single edge between blocks A and B is the only place |
764 | in RTL which holds some unique locus. */ | |
765 | ||
766 | static bool | |
767 | unique_locus_on_edge_between_p (basic_block a, basic_block b) | |
768 | { | |
5368224f | 769 | const location_t goto_locus = EDGE_SUCC (a, 0)->goto_locus; |
8879d71c | 770 | rtx_insn *insn, *end; |
9be94227 | 771 | |
2f13f2de | 772 | if (LOCATION_LOCUS (goto_locus) == UNKNOWN_LOCATION) |
9be94227 EB |
773 | return false; |
774 | ||
775 | /* First scan block A backward. */ | |
776 | insn = BB_END (a); | |
777 | end = PREV_INSN (BB_HEAD (a)); | |
5368224f | 778 | while (insn != end && (!NONDEBUG_INSN_P (insn) || !INSN_HAS_LOCATION (insn))) |
9be94227 EB |
779 | insn = PREV_INSN (insn); |
780 | ||
5368224f | 781 | if (insn != end && INSN_LOCATION (insn) == goto_locus) |
9be94227 EB |
782 | return false; |
783 | ||
784 | /* Then scan block B forward. */ | |
785 | insn = BB_HEAD (b); | |
786 | if (insn) | |
787 | { | |
788 | end = NEXT_INSN (BB_END (b)); | |
789 | while (insn != end && !NONDEBUG_INSN_P (insn)) | |
790 | insn = NEXT_INSN (insn); | |
791 | ||
5368224f DC |
792 | if (insn != end && INSN_HAS_LOCATION (insn) |
793 | && INSN_LOCATION (insn) == goto_locus) | |
9be94227 EB |
794 | return false; |
795 | } | |
796 | ||
797 | return true; | |
798 | } | |
799 | ||
800 | /* If the single edge between blocks A and B is the only place in RTL which | |
801 | holds some unique locus, emit a nop with that locus between the blocks. */ | |
802 | ||
803 | static void | |
804 | emit_nop_for_unique_locus_between (basic_block a, basic_block b) | |
805 | { | |
806 | if (!unique_locus_on_edge_between_p (a, b)) | |
807 | return; | |
808 | ||
1130d5e3 | 809 | BB_END (a) = emit_insn_after_noloc (gen_nop (), BB_END (a), a); |
5368224f | 810 | INSN_LOCATION (BB_END (a)) = EDGE_SUCC (a, 0)->goto_locus; |
9be94227 EB |
811 | } |
812 | ||
ca6c03ca | 813 | /* Blocks A and B are to be merged into a single block A. The insns |
bc35512f | 814 | are already contiguous. */ |
ca6c03ca | 815 | |
bc35512f JH |
816 | static void |
817 | rtl_merge_blocks (basic_block a, basic_block b) | |
ca6c03ca | 818 | { |
8879d71c DM |
819 | rtx_insn *b_head = BB_HEAD (b), *b_end = BB_END (b), *a_end = BB_END (a); |
820 | rtx_insn *del_first = NULL, *del_last = NULL; | |
821 | rtx_insn *b_debug_start = b_end, *b_debug_end = b_end; | |
50a36e42 | 822 | bool forwarder_p = (b->flags & BB_FORWARDER_BLOCK) != 0; |
ca6c03ca JH |
823 | int b_empty = 0; |
824 | ||
6fb5fa3c | 825 | if (dump_file) |
50a36e42 EB |
826 | fprintf (dump_file, "Merging block %d into block %d...\n", b->index, |
827 | a->index); | |
6fb5fa3c | 828 | |
b5b8b0ac AO |
829 | while (DEBUG_INSN_P (b_end)) |
830 | b_end = PREV_INSN (b_debug_start = b_end); | |
831 | ||
ca6c03ca | 832 | /* If there was a CODE_LABEL beginning B, delete it. */ |
4b4bf941 | 833 | if (LABEL_P (b_head)) |
ca6c03ca JH |
834 | { |
835 | /* Detect basic blocks with nothing but a label. This can happen | |
836 | in particular at the end of a function. */ | |
837 | if (b_head == b_end) | |
838 | b_empty = 1; | |
5f0d2358 | 839 | |
ca6c03ca JH |
840 | del_first = del_last = b_head; |
841 | b_head = NEXT_INSN (b_head); | |
842 | } | |
843 | ||
5f0d2358 RK |
844 | /* Delete the basic block note and handle blocks containing just that |
845 | note. */ | |
ca6c03ca JH |
846 | if (NOTE_INSN_BASIC_BLOCK_P (b_head)) |
847 | { | |
848 | if (b_head == b_end) | |
849 | b_empty = 1; | |
850 | if (! del_last) | |
851 | del_first = b_head; | |
5f0d2358 | 852 | |
ca6c03ca JH |
853 | del_last = b_head; |
854 | b_head = NEXT_INSN (b_head); | |
855 | } | |
856 | ||
857 | /* If there was a jump out of A, delete it. */ | |
4b4bf941 | 858 | if (JUMP_P (a_end)) |
ca6c03ca | 859 | { |
8879d71c | 860 | rtx_insn *prev; |
ca6c03ca JH |
861 | |
862 | for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev)) | |
4b4bf941 | 863 | if (!NOTE_P (prev) |
a38e7aa5 | 864 | || NOTE_INSN_BASIC_BLOCK_P (prev) |
a813c111 | 865 | || prev == BB_HEAD (a)) |
ca6c03ca JH |
866 | break; |
867 | ||
868 | del_first = a_end; | |
869 | ||
ca6c03ca JH |
870 | /* If this was a conditional jump, we need to also delete |
871 | the insn that set cc0. */ | |
058eb3b0 | 872 | if (HAVE_cc0 && only_sets_cc0_p (prev)) |
ca6c03ca | 873 | { |
8879d71c | 874 | rtx_insn *tmp = prev; |
5f0d2358 | 875 | |
ca6c03ca JH |
876 | prev = prev_nonnote_insn (prev); |
877 | if (!prev) | |
a813c111 | 878 | prev = BB_HEAD (a); |
ca6c03ca JH |
879 | del_first = tmp; |
880 | } | |
ca6c03ca JH |
881 | |
882 | a_end = PREV_INSN (del_first); | |
883 | } | |
4b4bf941 | 884 | else if (BARRIER_P (NEXT_INSN (a_end))) |
ca6c03ca JH |
885 | del_first = NEXT_INSN (a_end); |
886 | ||
ca6c03ca JH |
887 | /* Delete everything marked above as well as crap that might be |
888 | hanging out between the two blocks. */ | |
1130d5e3 DM |
889 | BB_END (a) = a_end; |
890 | BB_HEAD (b) = b_empty ? NULL : b_head; | |
a7b87f73 | 891 | delete_insn_chain (del_first, del_last, true); |
ca6c03ca | 892 | |
8a829274 | 893 | /* When not optimizing and the edge is the only place in RTL which holds |
9be94227 EB |
894 | some unique locus, emit a nop with that locus in between. */ |
895 | if (!optimize) | |
896 | { | |
897 | emit_nop_for_unique_locus_between (a, b); | |
898 | a_end = BB_END (a); | |
899 | } | |
900 | ||
ca6c03ca JH |
901 | /* Reassociate the insns of B with A. */ |
902 | if (!b_empty) | |
903 | { | |
b5b8b0ac | 904 | update_bb_for_insn_chain (a_end, b_debug_end, a); |
5f0d2358 | 905 | |
1130d5e3 DM |
906 | BB_END (a) = b_debug_end; |
907 | BB_HEAD (b) = NULL; | |
b5b8b0ac AO |
908 | } |
909 | else if (b_end != b_debug_end) | |
910 | { | |
911 | /* Move any deleted labels and other notes between the end of A | |
912 | and the debug insns that make up B after the debug insns, | |
913 | bringing the debug insns into A while keeping the notes after | |
914 | the end of A. */ | |
915 | if (NEXT_INSN (a_end) != b_debug_start) | |
916 | reorder_insns_nobb (NEXT_INSN (a_end), PREV_INSN (b_debug_start), | |
917 | b_debug_end); | |
918 | update_bb_for_insn_chain (b_debug_start, b_debug_end, a); | |
1130d5e3 | 919 | BB_END (a) = b_debug_end; |
ca6c03ca | 920 | } |
5f0d2358 | 921 | |
6fb5fa3c | 922 | df_bb_delete (b->index); |
50a36e42 EB |
923 | |
924 | /* If B was a forwarder block, propagate the locus on the edge. */ | |
fbc68f2a DC |
925 | if (forwarder_p |
926 | && LOCATION_LOCUS (EDGE_SUCC (b, 0)->goto_locus) == UNKNOWN_LOCATION) | |
50a36e42 EB |
927 | EDGE_SUCC (b, 0)->goto_locus = EDGE_SUCC (a, 0)->goto_locus; |
928 | ||
929 | if (dump_file) | |
930 | fprintf (dump_file, "Merged blocks %d and %d.\n", a->index, b->index); | |
ca6c03ca | 931 | } |
bc35512f | 932 | |
6fb5fa3c | 933 | |
bc35512f | 934 | /* Return true when block A and B can be merged. */ |
9678086d | 935 | |
b48d0358 DN |
936 | static bool |
937 | rtl_can_merge_blocks (basic_block a, basic_block b) | |
bc35512f | 938 | { |
750054a2 CT |
939 | /* If we are partitioning hot/cold basic blocks, we don't want to |
940 | mess up unconditional or indirect jumps that cross between hot | |
076c7ab8 ZW |
941 | and cold sections. |
942 | ||
8e8d5162 | 943 | Basic block partitioning may result in some jumps that appear to |
c22cacf3 MS |
944 | be optimizable (or blocks that appear to be mergeable), but which really |
945 | must be left untouched (they are required to make it safely across | |
946 | partition boundaries). See the comments at the top of | |
8e8d5162 | 947 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
076c7ab8 | 948 | |
87c8b4be | 949 | if (BB_PARTITION (a) != BB_PARTITION (b)) |
076c7ab8 | 950 | return false; |
750054a2 | 951 | |
7d776ee2 RG |
952 | /* Protect the loop latches. */ |
953 | if (current_loops && b->loop_father->latch == b) | |
954 | return false; | |
955 | ||
bc35512f | 956 | /* There must be exactly one edge in between the blocks. */ |
c5cbcccf ZD |
957 | return (single_succ_p (a) |
958 | && single_succ (a) == b | |
959 | && single_pred_p (b) | |
628f6a4e | 960 | && a != b |
bc35512f | 961 | /* Must be simple edge. */ |
c5cbcccf | 962 | && !(single_succ_edge (a)->flags & EDGE_COMPLEX) |
bc35512f | 963 | && a->next_bb == b |
fefa31b5 DM |
964 | && a != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
965 | && b != EXIT_BLOCK_PTR_FOR_FN (cfun) | |
bc35512f JH |
966 | /* If the jump insn has side effects, |
967 | we can't kill the edge. */ | |
4b4bf941 | 968 | && (!JUMP_P (BB_END (a)) |
e24e7211 | 969 | || (reload_completed |
a813c111 | 970 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f | 971 | } |
ca6c03ca | 972 | \f |
5f0d2358 RK |
973 | /* Return the label in the head of basic block BLOCK. Create one if it doesn't |
974 | exist. */ | |
ca6c03ca | 975 | |
1476d1bd | 976 | rtx_code_label * |
d329e058 | 977 | block_label (basic_block block) |
ca6c03ca | 978 | { |
fefa31b5 | 979 | if (block == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
1476d1bd | 980 | return NULL; |
5f0d2358 | 981 | |
4b4bf941 | 982 | if (!LABEL_P (BB_HEAD (block))) |
ca6c03ca | 983 | { |
1130d5e3 | 984 | BB_HEAD (block) = emit_label_before (gen_label_rtx (), BB_HEAD (block)); |
ca6c03ca | 985 | } |
5f0d2358 | 986 | |
1476d1bd | 987 | return as_a <rtx_code_label *> (BB_HEAD (block)); |
ca6c03ca JH |
988 | } |
989 | ||
990 | /* Attempt to perform edge redirection by replacing possibly complex jump | |
5f0d2358 RK |
991 | instruction by unconditional jump or removing jump completely. This can |
992 | apply only if all edges now point to the same block. The parameters and | |
993 | return values are equivalent to redirect_edge_and_branch. */ | |
ca6c03ca | 994 | |
6de9cd9a | 995 | edge |
bc35512f | 996 | try_redirect_by_replacing_jump (edge e, basic_block target, bool in_cfglayout) |
ca6c03ca JH |
997 | { |
998 | basic_block src = e->src; | |
8879d71c | 999 | rtx_insn *insn = BB_END (src), *kill_from; |
e1233a7d | 1000 | rtx set; |
ca6c03ca | 1001 | int fallthru = 0; |
750054a2 CT |
1002 | |
1003 | /* If we are partitioning hot/cold basic blocks, we don't want to | |
1004 | mess up unconditional or indirect jumps that cross between hot | |
8e8d5162 CT |
1005 | and cold sections. |
1006 | ||
1007 | Basic block partitioning may result in some jumps that appear to | |
c22cacf3 MS |
1008 | be optimizable (or blocks that appear to be mergeable), but which really |
1009 | must be left untouched (they are required to make it safely across | |
1010 | partition boundaries). See the comments at the top of | |
8e8d5162 | 1011 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
c22cacf3 | 1012 | |
3371a64f | 1013 | if (BB_PARTITION (src) != BB_PARTITION (target)) |
9cf84a3c | 1014 | return NULL; |
750054a2 | 1015 | |
6a66a8a7 KH |
1016 | /* We can replace or remove a complex jump only when we have exactly |
1017 | two edges. Also, if we have exactly one outgoing edge, we can | |
1018 | redirect that. */ | |
1019 | if (EDGE_COUNT (src->succs) >= 3 | |
1020 | /* Verify that all targets will be TARGET. Specifically, the | |
1021 | edge that is not E must also go to TARGET. */ | |
1022 | || (EDGE_COUNT (src->succs) == 2 | |
1023 | && EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)) | |
1024 | return NULL; | |
5f0d2358 | 1025 | |
6a66a8a7 | 1026 | if (!onlyjump_p (insn)) |
6de9cd9a | 1027 | return NULL; |
3348b696 | 1028 | if ((!optimize || reload_completed) && tablejump_p (insn, NULL, NULL)) |
6de9cd9a | 1029 | return NULL; |
ca6c03ca JH |
1030 | |
1031 | /* Avoid removing branch with side effects. */ | |
1032 | set = single_set (insn); | |
1033 | if (!set || side_effects_p (set)) | |
6de9cd9a | 1034 | return NULL; |
ca6c03ca JH |
1035 | |
1036 | /* In case we zap a conditional jump, we'll need to kill | |
1037 | the cc0 setter too. */ | |
1038 | kill_from = insn; | |
058eb3b0 | 1039 | if (HAVE_cc0 && reg_mentioned_p (cc0_rtx, PATTERN (insn)) |
9caea4a7 | 1040 | && only_sets_cc0_p (PREV_INSN (insn))) |
ca6c03ca | 1041 | kill_from = PREV_INSN (insn); |
ca6c03ca JH |
1042 | |
1043 | /* See if we can create the fallthru edge. */ | |
bc35512f | 1044 | if (in_cfglayout || can_fallthru (src, target)) |
ca6c03ca | 1045 | { |
c263766c RH |
1046 | if (dump_file) |
1047 | fprintf (dump_file, "Removing jump %i.\n", INSN_UID (insn)); | |
ca6c03ca JH |
1048 | fallthru = 1; |
1049 | ||
eaec9b3d | 1050 | /* Selectively unlink whole insn chain. */ |
bc35512f JH |
1051 | if (in_cfglayout) |
1052 | { | |
8879d71c | 1053 | rtx_insn *insn = BB_FOOTER (src); |
bc35512f | 1054 | |
a7b87f73 | 1055 | delete_insn_chain (kill_from, BB_END (src), false); |
bc35512f JH |
1056 | |
1057 | /* Remove barriers but keep jumptables. */ | |
1058 | while (insn) | |
1059 | { | |
4b4bf941 | 1060 | if (BARRIER_P (insn)) |
bc35512f JH |
1061 | { |
1062 | if (PREV_INSN (insn)) | |
0f82e5c9 | 1063 | SET_NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); |
bc35512f | 1064 | else |
d8ce2eae | 1065 | BB_FOOTER (src) = NEXT_INSN (insn); |
bc35512f | 1066 | if (NEXT_INSN (insn)) |
0f82e5c9 | 1067 | SET_PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); |
bc35512f | 1068 | } |
4b4bf941 | 1069 | if (LABEL_P (insn)) |
bc35512f JH |
1070 | break; |
1071 | insn = NEXT_INSN (insn); | |
1072 | } | |
1073 | } | |
1074 | else | |
a7b87f73 ZD |
1075 | delete_insn_chain (kill_from, PREV_INSN (BB_HEAD (target)), |
1076 | false); | |
ca6c03ca | 1077 | } |
5f0d2358 | 1078 | |
ca6c03ca JH |
1079 | /* If this already is simplejump, redirect it. */ |
1080 | else if (simplejump_p (insn)) | |
1081 | { | |
1082 | if (e->dest == target) | |
6de9cd9a | 1083 | return NULL; |
c263766c RH |
1084 | if (dump_file) |
1085 | fprintf (dump_file, "Redirecting jump %i from %i to %i.\n", | |
0b17ab2f | 1086 | INSN_UID (insn), e->dest->index, target->index); |
1476d1bd MM |
1087 | if (!redirect_jump (as_a <rtx_jump_insn *> (insn), |
1088 | block_label (target), 0)) | |
6ee3c8e4 | 1089 | { |
fefa31b5 | 1090 | gcc_assert (target == EXIT_BLOCK_PTR_FOR_FN (cfun)); |
341c100f | 1091 | return NULL; |
6ee3c8e4 | 1092 | } |
ca6c03ca | 1093 | } |
5f0d2358 | 1094 | |
6ee3c8e4 | 1095 | /* Cannot do anything for target exit block. */ |
fefa31b5 | 1096 | else if (target == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
6de9cd9a | 1097 | return NULL; |
6ee3c8e4 | 1098 | |
ca6c03ca JH |
1099 | /* Or replace possibly complicated jump insn by simple jump insn. */ |
1100 | else | |
1101 | { | |
e67d1102 | 1102 | rtx_code_label *target_label = block_label (target); |
8879d71c DM |
1103 | rtx_insn *barrier; |
1104 | rtx label; | |
8942ee0f | 1105 | rtx_jump_table_data *table; |
ca6c03ca | 1106 | |
ec4a505f | 1107 | emit_jump_insn_after_noloc (targetm.gen_jump (target_label), insn); |
a813c111 | 1108 | JUMP_LABEL (BB_END (src)) = target_label; |
ca6c03ca | 1109 | LABEL_NUSES (target_label)++; |
c263766c RH |
1110 | if (dump_file) |
1111 | fprintf (dump_file, "Replacing insn %i by jump %i\n", | |
a813c111 | 1112 | INSN_UID (insn), INSN_UID (BB_END (src))); |
ca6c03ca | 1113 | |
4da2eb6b | 1114 | |
ba4807a0 LB |
1115 | delete_insn_chain (kill_from, insn, false); |
1116 | ||
4da2eb6b RH |
1117 | /* Recognize a tablejump that we are converting to a |
1118 | simple jump and remove its associated CODE_LABEL | |
1119 | and ADDR_VEC or ADDR_DIFF_VEC. */ | |
ba4807a0 LB |
1120 | if (tablejump_p (insn, &label, &table)) |
1121 | delete_insn_chain (label, table, false); | |
eb5b8ad4 | 1122 | |
a813c111 | 1123 | barrier = next_nonnote_insn (BB_END (src)); |
4b4bf941 | 1124 | if (!barrier || !BARRIER_P (barrier)) |
a813c111 | 1125 | emit_barrier_after (BB_END (src)); |
5d693491 JZ |
1126 | else |
1127 | { | |
a813c111 | 1128 | if (barrier != NEXT_INSN (BB_END (src))) |
5d693491 JZ |
1129 | { |
1130 | /* Move the jump before barrier so that the notes | |
1131 | which originally were or were created before jump table are | |
1132 | inside the basic block. */ | |
8879d71c | 1133 | rtx_insn *new_insn = BB_END (src); |
5d693491 | 1134 | |
6c3d0e31 SP |
1135 | update_bb_for_insn_chain (NEXT_INSN (BB_END (src)), |
1136 | PREV_INSN (barrier), src); | |
5d693491 | 1137 | |
0f82e5c9 DM |
1138 | SET_NEXT_INSN (PREV_INSN (new_insn)) = NEXT_INSN (new_insn); |
1139 | SET_PREV_INSN (NEXT_INSN (new_insn)) = PREV_INSN (new_insn); | |
5d693491 | 1140 | |
0f82e5c9 DM |
1141 | SET_NEXT_INSN (new_insn) = barrier; |
1142 | SET_NEXT_INSN (PREV_INSN (barrier)) = new_insn; | |
5d693491 | 1143 | |
0f82e5c9 DM |
1144 | SET_PREV_INSN (new_insn) = PREV_INSN (barrier); |
1145 | SET_PREV_INSN (barrier) = new_insn; | |
5d693491 JZ |
1146 | } |
1147 | } | |
ca6c03ca JH |
1148 | } |
1149 | ||
1150 | /* Keep only one edge out and set proper flags. */ | |
c5cbcccf | 1151 | if (!single_succ_p (src)) |
628f6a4e | 1152 | remove_edge (e); |
c5cbcccf | 1153 | gcc_assert (single_succ_p (src)); |
628f6a4e | 1154 | |
c5cbcccf | 1155 | e = single_succ_edge (src); |
ca6c03ca JH |
1156 | if (fallthru) |
1157 | e->flags = EDGE_FALLTHRU; | |
1158 | else | |
1159 | e->flags = 0; | |
5f0d2358 | 1160 | |
ca6c03ca JH |
1161 | e->probability = REG_BR_PROB_BASE; |
1162 | e->count = src->count; | |
1163 | ||
ca6c03ca JH |
1164 | if (e->dest != target) |
1165 | redirect_edge_succ (e, target); | |
6de9cd9a | 1166 | return e; |
ca6c03ca JH |
1167 | } |
1168 | ||
4e3825db MM |
1169 | /* Subroutine of redirect_branch_edge that tries to patch the jump |
1170 | instruction INSN so that it reaches block NEW. Do this | |
1171 | only when it originally reached block OLD. Return true if this | |
1172 | worked or the original target wasn't OLD, return false if redirection | |
1173 | doesn't work. */ | |
1174 | ||
1175 | static bool | |
8879d71c | 1176 | patch_jump_insn (rtx_insn *insn, rtx_insn *old_label, basic_block new_bb) |
ca6c03ca | 1177 | { |
8942ee0f | 1178 | rtx_jump_table_data *table; |
ca6c03ca | 1179 | rtx tmp; |
ca6c03ca | 1180 | /* Recognize a tablejump and adjust all matching cases. */ |
8942ee0f | 1181 | if (tablejump_p (insn, NULL, &table)) |
ca6c03ca JH |
1182 | { |
1183 | rtvec vec; | |
1184 | int j; | |
e67d1102 | 1185 | rtx_code_label *new_label = block_label (new_bb); |
ca6c03ca | 1186 | |
fefa31b5 | 1187 | if (new_bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
4e3825db | 1188 | return false; |
95c43227 | 1189 | vec = table->get_labels (); |
ca6c03ca JH |
1190 | |
1191 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
1192 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
1193 | { | |
1194 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (Pmode, new_label); | |
1195 | --LABEL_NUSES (old_label); | |
1196 | ++LABEL_NUSES (new_label); | |
1197 | } | |
1198 | ||
f9da5064 | 1199 | /* Handle casesi dispatch insns. */ |
ca6c03ca JH |
1200 | if ((tmp = single_set (insn)) != NULL |
1201 | && SET_DEST (tmp) == pc_rtx | |
1202 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
1203 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF | |
04a121a7 | 1204 | && label_ref_label (XEXP (SET_SRC (tmp), 2)) == old_label) |
ca6c03ca | 1205 | { |
4c33cb26 | 1206 | XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (Pmode, |
ca6c03ca JH |
1207 | new_label); |
1208 | --LABEL_NUSES (old_label); | |
1209 | ++LABEL_NUSES (new_label); | |
1210 | } | |
1211 | } | |
1c384bf1 RH |
1212 | else if ((tmp = extract_asm_operands (PATTERN (insn))) != NULL) |
1213 | { | |
1214 | int i, n = ASM_OPERANDS_LABEL_LENGTH (tmp); | |
e67d1102 | 1215 | rtx note; |
1c384bf1 | 1216 | |
fefa31b5 | 1217 | if (new_bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
1c384bf1 | 1218 | return false; |
e67d1102 | 1219 | rtx_code_label *new_label = block_label (new_bb); |
1c384bf1 RH |
1220 | |
1221 | for (i = 0; i < n; ++i) | |
1222 | { | |
1223 | rtx old_ref = ASM_OPERANDS_LABEL (tmp, i); | |
1224 | gcc_assert (GET_CODE (old_ref) == LABEL_REF); | |
1225 | if (XEXP (old_ref, 0) == old_label) | |
1226 | { | |
1227 | ASM_OPERANDS_LABEL (tmp, i) | |
1228 | = gen_rtx_LABEL_REF (Pmode, new_label); | |
1229 | --LABEL_NUSES (old_label); | |
1230 | ++LABEL_NUSES (new_label); | |
1231 | } | |
1232 | } | |
1233 | ||
1234 | if (JUMP_LABEL (insn) == old_label) | |
1235 | { | |
1236 | JUMP_LABEL (insn) = new_label; | |
1237 | note = find_reg_note (insn, REG_LABEL_TARGET, new_label); | |
1238 | if (note) | |
1239 | remove_note (insn, note); | |
1240 | } | |
1241 | else | |
1242 | { | |
1243 | note = find_reg_note (insn, REG_LABEL_TARGET, old_label); | |
1244 | if (note) | |
1245 | remove_note (insn, note); | |
1246 | if (JUMP_LABEL (insn) != new_label | |
1247 | && !find_reg_note (insn, REG_LABEL_TARGET, new_label)) | |
1248 | add_reg_note (insn, REG_LABEL_TARGET, new_label); | |
1249 | } | |
3b5fda81 JJ |
1250 | while ((note = find_reg_note (insn, REG_LABEL_OPERAND, old_label)) |
1251 | != NULL_RTX) | |
1252 | XEXP (note, 0) = new_label; | |
1c384bf1 | 1253 | } |
ca6c03ca JH |
1254 | else |
1255 | { | |
1256 | /* ?? We may play the games with moving the named labels from | |
1257 | one basic block to the other in case only one computed_jump is | |
1258 | available. */ | |
5f0d2358 RK |
1259 | if (computed_jump_p (insn) |
1260 | /* A return instruction can't be redirected. */ | |
1261 | || returnjump_p (insn)) | |
4e3825db | 1262 | return false; |
6ee3c8e4 | 1263 | |
4e3825db | 1264 | if (!currently_expanding_to_rtl || JUMP_LABEL (insn) == old_label) |
6ee3c8e4 | 1265 | { |
4e3825db MM |
1266 | /* If the insn doesn't go where we think, we're confused. */ |
1267 | gcc_assert (JUMP_LABEL (insn) == old_label); | |
1268 | ||
1269 | /* If the substitution doesn't succeed, die. This can happen | |
1270 | if the back end emitted unrecognizable instructions or if | |
1271 | target is exit block on some arches. */ | |
1476d1bd MM |
1272 | if (!redirect_jump (as_a <rtx_jump_insn *> (insn), |
1273 | block_label (new_bb), 0)) | |
4e3825db | 1274 | { |
fefa31b5 | 1275 | gcc_assert (new_bb == EXIT_BLOCK_PTR_FOR_FN (cfun)); |
4e3825db MM |
1276 | return false; |
1277 | } | |
6ee3c8e4 | 1278 | } |
ca6c03ca | 1279 | } |
4e3825db MM |
1280 | return true; |
1281 | } | |
1282 | ||
1283 | ||
1284 | /* Redirect edge representing branch of (un)conditional jump or tablejump, | |
1285 | NULL on failure */ | |
1286 | static edge | |
1287 | redirect_branch_edge (edge e, basic_block target) | |
1288 | { | |
8879d71c | 1289 | rtx_insn *old_label = BB_HEAD (e->dest); |
4e3825db | 1290 | basic_block src = e->src; |
8879d71c | 1291 | rtx_insn *insn = BB_END (src); |
4e3825db MM |
1292 | |
1293 | /* We can only redirect non-fallthru edges of jump insn. */ | |
1294 | if (e->flags & EDGE_FALLTHRU) | |
1295 | return NULL; | |
1296 | else if (!JUMP_P (insn) && !currently_expanding_to_rtl) | |
1297 | return NULL; | |
1298 | ||
1299 | if (!currently_expanding_to_rtl) | |
1300 | { | |
1476d1bd | 1301 | if (!patch_jump_insn (as_a <rtx_jump_insn *> (insn), old_label, target)) |
4e3825db MM |
1302 | return NULL; |
1303 | } | |
1304 | else | |
1305 | /* When expanding this BB might actually contain multiple | |
1306 | jumps (i.e. not yet split by find_many_sub_basic_blocks). | |
1307 | Redirect all of those that match our label. */ | |
0f346928 | 1308 | FOR_BB_INSNS (src, insn) |
1476d1bd MM |
1309 | if (JUMP_P (insn) && !patch_jump_insn (as_a <rtx_jump_insn *> (insn), |
1310 | old_label, target)) | |
4e3825db | 1311 | return NULL; |
ca6c03ca | 1312 | |
c263766c RH |
1313 | if (dump_file) |
1314 | fprintf (dump_file, "Edge %i->%i redirected to %i\n", | |
0b17ab2f | 1315 | e->src->index, e->dest->index, target->index); |
5f0d2358 | 1316 | |
ca6c03ca | 1317 | if (e->dest != target) |
6de9cd9a | 1318 | e = redirect_edge_succ_nodup (e, target); |
6fb5fa3c | 1319 | |
6de9cd9a | 1320 | return e; |
bc35512f JH |
1321 | } |
1322 | ||
3371a64f TJ |
1323 | /* Called when edge E has been redirected to a new destination, |
1324 | in order to update the region crossing flag on the edge and | |
1325 | jump. */ | |
1326 | ||
1327 | static void | |
1328 | fixup_partition_crossing (edge e) | |
1329 | { | |
fefa31b5 DM |
1330 | if (e->src == ENTRY_BLOCK_PTR_FOR_FN (cfun) || e->dest |
1331 | == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
3371a64f TJ |
1332 | return; |
1333 | /* If we redirected an existing edge, it may already be marked | |
1334 | crossing, even though the new src is missing a reg crossing note. | |
1335 | But make sure reg crossing note doesn't already exist before | |
1336 | inserting. */ | |
1337 | if (BB_PARTITION (e->src) != BB_PARTITION (e->dest)) | |
1338 | { | |
1339 | e->flags |= EDGE_CROSSING; | |
3371a64f | 1340 | if (JUMP_P (BB_END (e->src)) |
339ba33b RS |
1341 | && !CROSSING_JUMP_P (BB_END (e->src))) |
1342 | CROSSING_JUMP_P (BB_END (e->src)) = 1; | |
3371a64f TJ |
1343 | } |
1344 | else if (BB_PARTITION (e->src) == BB_PARTITION (e->dest)) | |
1345 | { | |
1346 | e->flags &= ~EDGE_CROSSING; | |
1347 | /* Remove the section crossing note from jump at end of | |
1348 | src if it exists, and if no other successors are | |
1349 | still crossing. */ | |
339ba33b | 1350 | if (JUMP_P (BB_END (e->src)) && CROSSING_JUMP_P (BB_END (e->src))) |
3371a64f TJ |
1351 | { |
1352 | bool has_crossing_succ = false; | |
1353 | edge e2; | |
1354 | edge_iterator ei; | |
1355 | FOR_EACH_EDGE (e2, ei, e->src->succs) | |
1356 | { | |
1357 | has_crossing_succ |= (e2->flags & EDGE_CROSSING); | |
1358 | if (has_crossing_succ) | |
1359 | break; | |
1360 | } | |
1361 | if (!has_crossing_succ) | |
339ba33b | 1362 | CROSSING_JUMP_P (BB_END (e->src)) = 0; |
3371a64f TJ |
1363 | } |
1364 | } | |
1365 | } | |
1366 | ||
600b5b1d TJ |
1367 | /* Called when block BB has been reassigned to the cold partition, |
1368 | because it is now dominated by another cold block, | |
1369 | to ensure that the region crossing attributes are updated. */ | |
1370 | ||
1371 | static void | |
1372 | fixup_new_cold_bb (basic_block bb) | |
1373 | { | |
1374 | edge e; | |
1375 | edge_iterator ei; | |
1376 | ||
1377 | /* This is called when a hot bb is found to now be dominated | |
1378 | by a cold bb and therefore needs to become cold. Therefore, | |
1379 | its preds will no longer be region crossing. Any non-dominating | |
1380 | preds that were previously hot would also have become cold | |
1381 | in the caller for the same region. Any preds that were previously | |
1382 | region-crossing will be adjusted in fixup_partition_crossing. */ | |
1383 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1384 | { | |
1385 | fixup_partition_crossing (e); | |
1386 | } | |
1387 | ||
1388 | /* Possibly need to make bb's successor edges region crossing, | |
1389 | or remove stale region crossing. */ | |
1390 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1391 | { | |
1392 | /* We can't have fall-through edges across partition boundaries. | |
1393 | Note that force_nonfallthru will do any necessary partition | |
1394 | boundary fixup by calling fixup_partition_crossing itself. */ | |
1395 | if ((e->flags & EDGE_FALLTHRU) | |
1396 | && BB_PARTITION (bb) != BB_PARTITION (e->dest) | |
fefa31b5 | 1397 | && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
600b5b1d TJ |
1398 | force_nonfallthru (e); |
1399 | else | |
1400 | fixup_partition_crossing (e); | |
1401 | } | |
1402 | } | |
1403 | ||
bc35512f JH |
1404 | /* Attempt to change code to redirect edge E to TARGET. Don't do that on |
1405 | expense of adding new instructions or reordering basic blocks. | |
1406 | ||
1407 | Function can be also called with edge destination equivalent to the TARGET. | |
1408 | Then it should try the simplifications and do nothing if none is possible. | |
1409 | ||
6de9cd9a DN |
1410 | Return edge representing the branch if transformation succeeded. Return NULL |
1411 | on failure. | |
1412 | We still return NULL in case E already destinated TARGET and we didn't | |
1413 | managed to simplify instruction stream. */ | |
bc35512f | 1414 | |
6de9cd9a | 1415 | static edge |
5671bf27 | 1416 | rtl_redirect_edge_and_branch (edge e, basic_block target) |
bc35512f | 1417 | { |
6de9cd9a | 1418 | edge ret; |
f345f21a | 1419 | basic_block src = e->src; |
3371a64f | 1420 | basic_block dest = e->dest; |
f345f21a | 1421 | |
bc35512f | 1422 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
6de9cd9a | 1423 | return NULL; |
bc35512f | 1424 | |
3371a64f | 1425 | if (dest == target) |
6de9cd9a | 1426 | return e; |
3348b696 | 1427 | |
6de9cd9a | 1428 | if ((ret = try_redirect_by_replacing_jump (e, target, false)) != NULL) |
f345f21a | 1429 | { |
6fb5fa3c | 1430 | df_set_bb_dirty (src); |
3371a64f | 1431 | fixup_partition_crossing (ret); |
6de9cd9a | 1432 | return ret; |
f345f21a | 1433 | } |
bc35512f | 1434 | |
6de9cd9a DN |
1435 | ret = redirect_branch_edge (e, target); |
1436 | if (!ret) | |
1437 | return NULL; | |
5f0d2358 | 1438 | |
6fb5fa3c | 1439 | df_set_bb_dirty (src); |
3371a64f | 1440 | fixup_partition_crossing (ret); |
6de9cd9a | 1441 | return ret; |
ca6c03ca JH |
1442 | } |
1443 | ||
3371a64f TJ |
1444 | /* Emit a barrier after BB, into the footer if we are in CFGLAYOUT mode. */ |
1445 | ||
1446 | void | |
1447 | emit_barrier_after_bb (basic_block bb) | |
1448 | { | |
cd459bf8 | 1449 | rtx_barrier *barrier = emit_barrier_after (BB_END (bb)); |
c3284718 | 1450 | gcc_assert (current_ir_type () == IR_RTL_CFGRTL |
3371a64f TJ |
1451 | || current_ir_type () == IR_RTL_CFGLAYOUT); |
1452 | if (current_ir_type () == IR_RTL_CFGLAYOUT) | |
0fb3402f RX |
1453 | { |
1454 | rtx_insn *insn = unlink_insn_chain (barrier, barrier); | |
1455 | ||
1456 | if (BB_FOOTER (bb)) | |
1457 | { | |
1458 | rtx_insn *footer_tail = BB_FOOTER (bb); | |
1459 | ||
1460 | while (NEXT_INSN (footer_tail)) | |
1461 | footer_tail = NEXT_INSN (footer_tail); | |
1462 | if (!BARRIER_P (footer_tail)) | |
1463 | { | |
1464 | SET_NEXT_INSN (footer_tail) = insn; | |
1465 | SET_PREV_INSN (insn) = footer_tail; | |
1466 | } | |
1467 | } | |
1468 | else | |
1469 | BB_FOOTER (bb) = insn; | |
1470 | } | |
3371a64f TJ |
1471 | } |
1472 | ||
4fe9b91c | 1473 | /* Like force_nonfallthru below, but additionally performs redirection |
26898771 BS |
1474 | Used by redirect_edge_and_branch_force. JUMP_LABEL is used only |
1475 | when redirecting to the EXIT_BLOCK, it is either ret_rtx or | |
1476 | simple_return_rtx, indicating which kind of returnjump to create. | |
1477 | It should be NULL otherwise. */ | |
ca6c03ca | 1478 | |
dc0ff1c8 | 1479 | basic_block |
26898771 | 1480 | force_nonfallthru_and_redirect (edge e, basic_block target, rtx jump_label) |
ca6c03ca | 1481 | { |
a3716585 | 1482 | basic_block jump_block, new_bb = NULL, src = e->src; |
ca6c03ca JH |
1483 | rtx note; |
1484 | edge new_edge; | |
a3716585 | 1485 | int abnormal_edge_flags = 0; |
a3e6a37b | 1486 | bool asm_goto_edge = false; |
7241571e | 1487 | int loc; |
ca6c03ca | 1488 | |
cb9a1d9b JH |
1489 | /* In the case the last instruction is conditional jump to the next |
1490 | instruction, first redirect the jump itself and then continue | |
b20b352b | 1491 | by creating a basic block afterwards to redirect fallthru edge. */ |
fefa31b5 DM |
1492 | if (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
1493 | && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) | |
a813c111 | 1494 | && any_condjump_p (BB_END (e->src)) |
a813c111 | 1495 | && JUMP_LABEL (BB_END (e->src)) == BB_HEAD (e->dest)) |
cb9a1d9b JH |
1496 | { |
1497 | rtx note; | |
58e6ae30 | 1498 | edge b = unchecked_make_edge (e->src, target, 0); |
341c100f | 1499 | bool redirected; |
cb9a1d9b | 1500 | |
1476d1bd MM |
1501 | redirected = redirect_jump (as_a <rtx_jump_insn *> (BB_END (e->src)), |
1502 | block_label (target), 0); | |
341c100f | 1503 | gcc_assert (redirected); |
c22cacf3 | 1504 | |
a813c111 | 1505 | note = find_reg_note (BB_END (e->src), REG_BR_PROB, NULL_RTX); |
cb9a1d9b JH |
1506 | if (note) |
1507 | { | |
e5af9ddd | 1508 | int prob = XINT (note, 0); |
cb9a1d9b JH |
1509 | |
1510 | b->probability = prob; | |
8ddb5a29 | 1511 | /* Update this to use GCOV_COMPUTE_SCALE. */ |
cb9a1d9b JH |
1512 | b->count = e->count * prob / REG_BR_PROB_BASE; |
1513 | e->probability -= e->probability; | |
1514 | e->count -= b->count; | |
1515 | if (e->probability < 0) | |
1516 | e->probability = 0; | |
1517 | if (e->count < 0) | |
1518 | e->count = 0; | |
1519 | } | |
1520 | } | |
1521 | ||
ca6c03ca | 1522 | if (e->flags & EDGE_ABNORMAL) |
a3716585 JH |
1523 | { |
1524 | /* Irritating special case - fallthru edge to the same block as abnormal | |
1525 | edge. | |
1526 | We can't redirect abnormal edge, but we still can split the fallthru | |
d329e058 | 1527 | one and create separate abnormal edge to original destination. |
a3716585 | 1528 | This allows bb-reorder to make such edge non-fallthru. */ |
341c100f | 1529 | gcc_assert (e->dest == target); |
ee44c28d SB |
1530 | abnormal_edge_flags = e->flags & ~EDGE_FALLTHRU; |
1531 | e->flags &= EDGE_FALLTHRU; | |
a3716585 | 1532 | } |
341c100f | 1533 | else |
24c545ff | 1534 | { |
341c100f | 1535 | gcc_assert (e->flags & EDGE_FALLTHRU); |
fefa31b5 | 1536 | if (e->src == ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
341c100f NS |
1537 | { |
1538 | /* We can't redirect the entry block. Create an empty block | |
628f6a4e BE |
1539 | at the start of the function which we use to add the new |
1540 | jump. */ | |
1541 | edge tmp; | |
1542 | edge_iterator ei; | |
1543 | bool found = false; | |
c22cacf3 | 1544 | |
fefa31b5 DM |
1545 | basic_block bb = create_basic_block (BB_HEAD (e->dest), NULL, |
1546 | ENTRY_BLOCK_PTR_FOR_FN (cfun)); | |
c22cacf3 | 1547 | |
341c100f NS |
1548 | /* Change the existing edge's source to be the new block, and add |
1549 | a new edge from the entry block to the new block. */ | |
1550 | e->src = bb; | |
fefa31b5 DM |
1551 | for (ei = ei_start (ENTRY_BLOCK_PTR_FOR_FN (cfun)->succs); |
1552 | (tmp = ei_safe_edge (ei)); ) | |
628f6a4e BE |
1553 | { |
1554 | if (tmp == e) | |
1555 | { | |
fefa31b5 | 1556 | ENTRY_BLOCK_PTR_FOR_FN (cfun)->succs->unordered_remove (ei.index); |
628f6a4e BE |
1557 | found = true; |
1558 | break; | |
1559 | } | |
1560 | else | |
1561 | ei_next (&ei); | |
1562 | } | |
c22cacf3 | 1563 | |
628f6a4e | 1564 | gcc_assert (found); |
c22cacf3 | 1565 | |
9771b263 | 1566 | vec_safe_push (bb->succs, e); |
fefa31b5 DM |
1567 | make_single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun), bb, |
1568 | EDGE_FALLTHRU); | |
341c100f | 1569 | } |
24c545ff BS |
1570 | } |
1571 | ||
a3e6a37b | 1572 | /* If e->src ends with asm goto, see if any of the ASM_OPERANDS_LABELs |
891ca07d | 1573 | don't point to the target or fallthru label. */ |
a3e6a37b | 1574 | if (JUMP_P (BB_END (e->src)) |
fefa31b5 | 1575 | && target != EXIT_BLOCK_PTR_FOR_FN (cfun) |
a3e6a37b JJ |
1576 | && (e->flags & EDGE_FALLTHRU) |
1577 | && (note = extract_asm_operands (PATTERN (BB_END (e->src))))) | |
ca6c03ca | 1578 | { |
a3e6a37b | 1579 | int i, n = ASM_OPERANDS_LABEL_LENGTH (note); |
5d68b7e6 | 1580 | bool adjust_jump_target = false; |
a3e6a37b JJ |
1581 | |
1582 | for (i = 0; i < n; ++i) | |
891ca07d JJ |
1583 | { |
1584 | if (XEXP (ASM_OPERANDS_LABEL (note, i), 0) == BB_HEAD (e->dest)) | |
5d68b7e6 JJ |
1585 | { |
1586 | LABEL_NUSES (XEXP (ASM_OPERANDS_LABEL (note, i), 0))--; | |
1587 | XEXP (ASM_OPERANDS_LABEL (note, i), 0) = block_label (target); | |
1588 | LABEL_NUSES (XEXP (ASM_OPERANDS_LABEL (note, i), 0))++; | |
1589 | adjust_jump_target = true; | |
1590 | } | |
891ca07d | 1591 | if (XEXP (ASM_OPERANDS_LABEL (note, i), 0) == BB_HEAD (target)) |
a3e6a37b | 1592 | asm_goto_edge = true; |
891ca07d | 1593 | } |
5d68b7e6 JJ |
1594 | if (adjust_jump_target) |
1595 | { | |
8879d71c DM |
1596 | rtx_insn *insn = BB_END (e->src); |
1597 | rtx note; | |
1598 | rtx_insn *old_label = BB_HEAD (e->dest); | |
1599 | rtx_insn *new_label = BB_HEAD (target); | |
5d68b7e6 JJ |
1600 | |
1601 | if (JUMP_LABEL (insn) == old_label) | |
1602 | { | |
1603 | JUMP_LABEL (insn) = new_label; | |
1604 | note = find_reg_note (insn, REG_LABEL_TARGET, new_label); | |
1605 | if (note) | |
1606 | remove_note (insn, note); | |
1607 | } | |
1608 | else | |
1609 | { | |
1610 | note = find_reg_note (insn, REG_LABEL_TARGET, old_label); | |
1611 | if (note) | |
1612 | remove_note (insn, note); | |
1613 | if (JUMP_LABEL (insn) != new_label | |
1614 | && !find_reg_note (insn, REG_LABEL_TARGET, new_label)) | |
1615 | add_reg_note (insn, REG_LABEL_TARGET, new_label); | |
1616 | } | |
1617 | while ((note = find_reg_note (insn, REG_LABEL_OPERAND, old_label)) | |
1618 | != NULL_RTX) | |
1619 | XEXP (note, 0) = new_label; | |
1620 | } | |
a3e6a37b JJ |
1621 | } |
1622 | ||
1623 | if (EDGE_COUNT (e->src->succs) >= 2 || abnormal_edge_flags || asm_goto_edge) | |
1624 | { | |
dc01c3d1 | 1625 | rtx_insn *new_head; |
a3e6a37b JJ |
1626 | gcov_type count = e->count; |
1627 | int probability = e->probability; | |
ca6c03ca | 1628 | /* Create the new structures. */ |
31a78298 | 1629 | |
79019985 RH |
1630 | /* If the old block ended with a tablejump, skip its table |
1631 | by searching forward from there. Otherwise start searching | |
1632 | forward from the last instruction of the old block. */ | |
8942ee0f DM |
1633 | rtx_jump_table_data *table; |
1634 | if (tablejump_p (BB_END (e->src), NULL, &table)) | |
dc01c3d1 | 1635 | new_head = table; |
8942ee0f | 1636 | else |
dc01c3d1 DM |
1637 | new_head = BB_END (e->src); |
1638 | new_head = NEXT_INSN (new_head); | |
31a78298 | 1639 | |
dc01c3d1 | 1640 | jump_block = create_basic_block (new_head, NULL, e->src); |
a3e6a37b | 1641 | jump_block->count = count; |
ca6c03ca | 1642 | jump_block->frequency = EDGE_FREQUENCY (e); |
ca6c03ca | 1643 | |
750054a2 CT |
1644 | /* Make sure new block ends up in correct hot/cold section. */ |
1645 | ||
076c7ab8 | 1646 | BB_COPY_PARTITION (jump_block, e->src); |
c22cacf3 | 1647 | |
ca6c03ca JH |
1648 | /* Wire edge in. */ |
1649 | new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU); | |
a3e6a37b JJ |
1650 | new_edge->probability = probability; |
1651 | new_edge->count = count; | |
ca6c03ca JH |
1652 | |
1653 | /* Redirect old edge. */ | |
1654 | redirect_edge_pred (e, jump_block); | |
1655 | e->probability = REG_BR_PROB_BASE; | |
1656 | ||
3371a64f TJ |
1657 | /* If e->src was previously region crossing, it no longer is |
1658 | and the reg crossing note should be removed. */ | |
1659 | fixup_partition_crossing (new_edge); | |
1660 | ||
a3e6a37b JJ |
1661 | /* If asm goto has any label refs to target's label, |
1662 | add also edge from asm goto bb to target. */ | |
1663 | if (asm_goto_edge) | |
1664 | { | |
1665 | new_edge->probability /= 2; | |
1666 | new_edge->count /= 2; | |
1667 | jump_block->count /= 2; | |
1668 | jump_block->frequency /= 2; | |
1669 | new_edge = make_edge (new_edge->src, target, | |
1670 | e->flags & ~EDGE_FALLTHRU); | |
1671 | new_edge->probability = probability - probability / 2; | |
1672 | new_edge->count = count - count / 2; | |
1673 | } | |
1674 | ||
ca6c03ca JH |
1675 | new_bb = jump_block; |
1676 | } | |
1677 | else | |
1678 | jump_block = e->src; | |
5f0d2358 | 1679 | |
2f13f2de | 1680 | loc = e->goto_locus; |
ca6c03ca | 1681 | e->flags &= ~EDGE_FALLTHRU; |
fefa31b5 | 1682 | if (target == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
ca6c03ca | 1683 | { |
26898771 | 1684 | if (jump_label == ret_rtx) |
4bccb39e RS |
1685 | emit_jump_insn_after_setloc (targetm.gen_return (), |
1686 | BB_END (jump_block), loc); | |
26898771 BS |
1687 | else |
1688 | { | |
1689 | gcc_assert (jump_label == simple_return_rtx); | |
4bccb39e | 1690 | emit_jump_insn_after_setloc (targetm.gen_simple_return (), |
26898771 | 1691 | BB_END (jump_block), loc); |
26898771 | 1692 | } |
387748de | 1693 | set_return_jump_label (BB_END (jump_block)); |
ca6c03ca JH |
1694 | } |
1695 | else | |
1696 | { | |
e67d1102 | 1697 | rtx_code_label *label = block_label (target); |
ec4a505f RS |
1698 | emit_jump_insn_after_setloc (targetm.gen_jump (label), |
1699 | BB_END (jump_block), loc); | |
a813c111 | 1700 | JUMP_LABEL (BB_END (jump_block)) = label; |
ca6c03ca JH |
1701 | LABEL_NUSES (label)++; |
1702 | } | |
5f0d2358 | 1703 | |
3371a64f TJ |
1704 | /* We might be in cfg layout mode, and if so, the following routine will |
1705 | insert the barrier correctly. */ | |
1706 | emit_barrier_after_bb (jump_block); | |
ca6c03ca JH |
1707 | redirect_edge_succ_nodup (e, target); |
1708 | ||
a3716585 JH |
1709 | if (abnormal_edge_flags) |
1710 | make_edge (src, target, abnormal_edge_flags); | |
1711 | ||
b8698a0f | 1712 | df_mark_solutions_dirty (); |
3371a64f | 1713 | fixup_partition_crossing (e); |
ca6c03ca JH |
1714 | return new_bb; |
1715 | } | |
1716 | ||
1717 | /* Edge E is assumed to be fallthru edge. Emit needed jump instruction | |
1718 | (and possibly create new basic block) to make edge non-fallthru. | |
1719 | Return newly created BB or NULL if none. */ | |
5f0d2358 | 1720 | |
cf103ca4 EB |
1721 | static basic_block |
1722 | rtl_force_nonfallthru (edge e) | |
ca6c03ca | 1723 | { |
26898771 | 1724 | return force_nonfallthru_and_redirect (e, e->dest, NULL_RTX); |
ca6c03ca JH |
1725 | } |
1726 | ||
1727 | /* Redirect edge even at the expense of creating new jump insn or | |
1728 | basic block. Return new basic block if created, NULL otherwise. | |
41806d92 | 1729 | Conversion must be possible. */ |
ca6c03ca | 1730 | |
9ee634e3 | 1731 | static basic_block |
d329e058 | 1732 | rtl_redirect_edge_and_branch_force (edge e, basic_block target) |
ca6c03ca | 1733 | { |
5f0d2358 RK |
1734 | if (redirect_edge_and_branch (e, target) |
1735 | || e->dest == target) | |
ca6c03ca JH |
1736 | return NULL; |
1737 | ||
1738 | /* In case the edge redirection failed, try to force it to be non-fallthru | |
1739 | and redirect newly created simplejump. */ | |
6fb5fa3c | 1740 | df_set_bb_dirty (e->src); |
26898771 | 1741 | return force_nonfallthru_and_redirect (e, target, NULL_RTX); |
ca6c03ca JH |
1742 | } |
1743 | ||
1744 | /* The given edge should potentially be a fallthru edge. If that is in | |
1745 | fact true, delete the jump and barriers that are in the way. */ | |
1746 | ||
f470c378 ZD |
1747 | static void |
1748 | rtl_tidy_fallthru_edge (edge e) | |
ca6c03ca | 1749 | { |
8879d71c | 1750 | rtx_insn *q; |
f470c378 ZD |
1751 | basic_block b = e->src, c = b->next_bb; |
1752 | ||
ca6c03ca JH |
1753 | /* ??? In a late-running flow pass, other folks may have deleted basic |
1754 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
0fa2e4df | 1755 | and the target label. They ought to be chastised and fixed. |
ca6c03ca JH |
1756 | |
1757 | We can also wind up with a sequence of undeletable labels between | |
1758 | one block and the next. | |
1759 | ||
1760 | So search through a sequence of barriers, labels, and notes for | |
1761 | the head of block C and assert that we really do fall through. */ | |
1762 | ||
a813c111 | 1763 | for (q = NEXT_INSN (BB_END (b)); q != BB_HEAD (c); q = NEXT_INSN (q)) |
9c0a0632 RH |
1764 | if (INSN_P (q)) |
1765 | return; | |
ca6c03ca JH |
1766 | |
1767 | /* Remove what will soon cease being the jump insn from the source block. | |
1768 | If block B consisted only of this single jump, turn it into a deleted | |
1769 | note. */ | |
a813c111 | 1770 | q = BB_END (b); |
4b4bf941 | 1771 | if (JUMP_P (q) |
ca6c03ca JH |
1772 | && onlyjump_p (q) |
1773 | && (any_uncondjump_p (q) | |
c5cbcccf | 1774 | || single_succ_p (b))) |
ca6c03ca | 1775 | { |
adfac8df JJ |
1776 | rtx label; |
1777 | rtx_jump_table_data *table; | |
1778 | ||
1779 | if (tablejump_p (q, &label, &table)) | |
1780 | { | |
1781 | /* The label is likely mentioned in some instruction before | |
1782 | the tablejump and might not be DCEd, so turn it into | |
1783 | a note instead and move before the tablejump that is going to | |
1784 | be deleted. */ | |
1785 | const char *name = LABEL_NAME (label); | |
1786 | PUT_CODE (label, NOTE); | |
1787 | NOTE_KIND (label) = NOTE_INSN_DELETED_LABEL; | |
1788 | NOTE_DELETED_LABEL_NAME (label) = name; | |
1789 | rtx_insn *lab = safe_as_a <rtx_insn *> (label); | |
1790 | reorder_insns (lab, lab, PREV_INSN (q)); | |
1791 | delete_insn (table); | |
1792 | } | |
1793 | ||
ca6c03ca JH |
1794 | /* If this was a conditional jump, we need to also delete |
1795 | the insn that set cc0. */ | |
058eb3b0 | 1796 | if (HAVE_cc0 && any_condjump_p (q) && only_sets_cc0_p (PREV_INSN (q))) |
ca6c03ca | 1797 | q = PREV_INSN (q); |
ca6c03ca JH |
1798 | |
1799 | q = PREV_INSN (q); | |
ca6c03ca JH |
1800 | } |
1801 | ||
1802 | /* Selectively unlink the sequence. */ | |
a813c111 | 1803 | if (q != PREV_INSN (BB_HEAD (c))) |
a7b87f73 | 1804 | delete_insn_chain (NEXT_INSN (q), PREV_INSN (BB_HEAD (c)), false); |
ca6c03ca JH |
1805 | |
1806 | e->flags |= EDGE_FALLTHRU; | |
1807 | } | |
ca6c03ca | 1808 | \f |
f470c378 ZD |
1809 | /* Should move basic block BB after basic block AFTER. NIY. */ |
1810 | ||
1811 | static bool | |
1812 | rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED, | |
1813 | basic_block after ATTRIBUTE_UNUSED) | |
1814 | { | |
1815 | return false; | |
1816 | } | |
1817 | ||
3371a64f TJ |
1818 | /* Locate the last bb in the same partition as START_BB. */ |
1819 | ||
1820 | static basic_block | |
1821 | last_bb_in_partition (basic_block start_bb) | |
1822 | { | |
1823 | basic_block bb; | |
fefa31b5 | 1824 | FOR_BB_BETWEEN (bb, start_bb, EXIT_BLOCK_PTR_FOR_FN (cfun), next_bb) |
3371a64f TJ |
1825 | { |
1826 | if (BB_PARTITION (start_bb) != BB_PARTITION (bb->next_bb)) | |
1827 | return bb; | |
1828 | } | |
6626665f | 1829 | /* Return bb before the exit block. */ |
3371a64f TJ |
1830 | return bb->prev_bb; |
1831 | } | |
1832 | ||
ca6c03ca | 1833 | /* Split a (typically critical) edge. Return the new block. |
41806d92 | 1834 | The edge must not be abnormal. |
ca6c03ca JH |
1835 | |
1836 | ??? The code generally expects to be called on critical edges. | |
1837 | The case of a block ending in an unconditional jump to a | |
1838 | block with multiple predecessors is not handled optimally. */ | |
1839 | ||
8ce33230 | 1840 | static basic_block |
d329e058 | 1841 | rtl_split_edge (edge edge_in) |
ca6c03ca | 1842 | { |
3371a64f | 1843 | basic_block bb, new_bb; |
8879d71c | 1844 | rtx_insn *before; |
ca6c03ca JH |
1845 | |
1846 | /* Abnormal edges cannot be split. */ | |
341c100f | 1847 | gcc_assert (!(edge_in->flags & EDGE_ABNORMAL)); |
ca6c03ca JH |
1848 | |
1849 | /* We are going to place the new block in front of edge destination. | |
eaec9b3d | 1850 | Avoid existence of fallthru predecessors. */ |
ca6c03ca JH |
1851 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) |
1852 | { | |
0fd4b31d | 1853 | edge e = find_fallthru_edge (edge_in->dest->preds); |
ca6c03ca JH |
1854 | |
1855 | if (e) | |
1856 | force_nonfallthru (e); | |
1857 | } | |
1858 | ||
96e82e0a | 1859 | /* Create the basic block note. */ |
fefa31b5 | 1860 | if (edge_in->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
a813c111 | 1861 | before = BB_HEAD (edge_in->dest); |
ca6c03ca | 1862 | else |
8879d71c | 1863 | before = NULL; |
ca6c03ca | 1864 | |
623a66fa | 1865 | /* If this is a fall through edge to the exit block, the blocks might be |
ffe14686 | 1866 | not adjacent, and the right place is after the source. */ |
fefa31b5 DM |
1867 | if ((edge_in->flags & EDGE_FALLTHRU) |
1868 | && edge_in->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
623a66fa R |
1869 | { |
1870 | before = NEXT_INSN (BB_END (edge_in->src)); | |
623a66fa | 1871 | bb = create_basic_block (before, NULL, edge_in->src); |
076c7ab8 | 1872 | BB_COPY_PARTITION (bb, edge_in->src); |
623a66fa R |
1873 | } |
1874 | else | |
9fb32434 | 1875 | { |
fefa31b5 | 1876 | if (edge_in->src == ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
3371a64f TJ |
1877 | { |
1878 | bb = create_basic_block (before, NULL, edge_in->dest->prev_bb); | |
1879 | BB_COPY_PARTITION (bb, edge_in->dest); | |
1880 | } | |
1881 | else | |
1882 | { | |
1883 | basic_block after = edge_in->dest->prev_bb; | |
1884 | /* If this is post-bb reordering, and the edge crosses a partition | |
1885 | boundary, the new block needs to be inserted in the bb chain | |
1886 | at the end of the src partition (since we put the new bb into | |
1887 | that partition, see below). Otherwise we may end up creating | |
1888 | an extra partition crossing in the chain, which is illegal. | |
1889 | It can't go after the src, because src may have a fall-through | |
1890 | to a different block. */ | |
1891 | if (crtl->bb_reorder_complete | |
1892 | && (edge_in->flags & EDGE_CROSSING)) | |
1893 | { | |
1894 | after = last_bb_in_partition (edge_in->src); | |
b3a3ae09 | 1895 | before = get_last_bb_insn (after); |
3371a64f TJ |
1896 | /* The instruction following the last bb in partition should |
1897 | be a barrier, since it cannot end in a fall-through. */ | |
1898 | gcc_checking_assert (BARRIER_P (before)); | |
1899 | before = NEXT_INSN (before); | |
1900 | } | |
1901 | bb = create_basic_block (before, NULL, after); | |
1902 | /* Put the split bb into the src partition, to avoid creating | |
1903 | a situation where a cold bb dominates a hot bb, in the case | |
1904 | where src is cold and dest is hot. The src will dominate | |
1905 | the new bb (whereas it might not have dominated dest). */ | |
1906 | BB_COPY_PARTITION (bb, edge_in->src); | |
1907 | } | |
9fb32434 | 1908 | } |
ca6c03ca | 1909 | |
4977bab6 | 1910 | make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU); |
ca6c03ca | 1911 | |
3371a64f TJ |
1912 | /* Can't allow a region crossing edge to be fallthrough. */ |
1913 | if (BB_PARTITION (bb) != BB_PARTITION (edge_in->dest) | |
fefa31b5 | 1914 | && edge_in->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
3371a64f TJ |
1915 | { |
1916 | new_bb = force_nonfallthru (single_succ_edge (bb)); | |
1917 | gcc_assert (!new_bb); | |
1918 | } | |
1919 | ||
4d6922ee | 1920 | /* For non-fallthru edges, we must adjust the predecessor's |
ca6c03ca JH |
1921 | jump instruction to target our new block. */ |
1922 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1923 | { | |
341c100f NS |
1924 | edge redirected = redirect_edge_and_branch (edge_in, bb); |
1925 | gcc_assert (redirected); | |
ca6c03ca JH |
1926 | } |
1927 | else | |
3b5fda81 | 1928 | { |
fefa31b5 | 1929 | if (edge_in->src != ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
3b5fda81 JJ |
1930 | { |
1931 | /* For asm goto even splitting of fallthru edge might | |
1932 | need insn patching, as other labels might point to the | |
1933 | old label. */ | |
8879d71c | 1934 | rtx_insn *last = BB_END (edge_in->src); |
3b5fda81 JJ |
1935 | if (last |
1936 | && JUMP_P (last) | |
fefa31b5 | 1937 | && edge_in->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) |
3b5fda81 JJ |
1938 | && extract_asm_operands (PATTERN (last)) != NULL_RTX |
1939 | && patch_jump_insn (last, before, bb)) | |
1940 | df_set_bb_dirty (edge_in->src); | |
1941 | } | |
1942 | redirect_edge_succ (edge_in, bb); | |
1943 | } | |
ca6c03ca JH |
1944 | |
1945 | return bb; | |
1946 | } | |
1947 | ||
1948 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1949 | The new instructions and basic blocks (if any) will not appear in the | |
1950 | CFG until commit_edge_insertions is called. */ | |
1951 | ||
1952 | void | |
d329e058 | 1953 | insert_insn_on_edge (rtx pattern, edge e) |
ca6c03ca JH |
1954 | { |
1955 | /* We cannot insert instructions on an abnormal critical edge. | |
1956 | It will be easier to find the culprit if we die now. */ | |
341c100f | 1957 | gcc_assert (!((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e))); |
ca6c03ca | 1958 | |
6de9cd9a | 1959 | if (e->insns.r == NULL_RTX) |
ca6c03ca JH |
1960 | start_sequence (); |
1961 | else | |
6de9cd9a | 1962 | push_to_sequence (e->insns.r); |
ca6c03ca JH |
1963 | |
1964 | emit_insn (pattern); | |
1965 | ||
6de9cd9a | 1966 | e->insns.r = get_insns (); |
ca6c03ca JH |
1967 | end_sequence (); |
1968 | } | |
1969 | ||
1970 | /* Update the CFG for the instructions queued on edge E. */ | |
1971 | ||
4e3825db | 1972 | void |
2ac66157 | 1973 | commit_one_edge_insertion (edge e) |
ca6c03ca | 1974 | { |
8879d71c | 1975 | rtx_insn *before = NULL, *after = NULL, *insns, *tmp, *last; |
898c90c0 | 1976 | basic_block bb; |
ca6c03ca JH |
1977 | |
1978 | /* Pull the insns off the edge now since the edge might go away. */ | |
3ffa95c2 DM |
1979 | insns = e->insns.r; |
1980 | e->insns.r = NULL; | |
ca6c03ca | 1981 | |
898c90c0 EB |
1982 | /* Figure out where to put these insns. If the destination has |
1983 | one predecessor, insert there. Except for the exit block. */ | |
fefa31b5 | 1984 | if (single_pred_p (e->dest) && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
ca6c03ca | 1985 | { |
898c90c0 EB |
1986 | bb = e->dest; |
1987 | ||
1988 | /* Get the location correct wrt a code label, and "nice" wrt | |
1989 | a basic block note, and before everything else. */ | |
1990 | tmp = BB_HEAD (bb); | |
1991 | if (LABEL_P (tmp)) | |
1992 | tmp = NEXT_INSN (tmp); | |
1993 | if (NOTE_INSN_BASIC_BLOCK_P (tmp)) | |
1994 | tmp = NEXT_INSN (tmp); | |
1995 | if (tmp == BB_HEAD (bb)) | |
1996 | before = tmp; | |
1997 | else if (tmp) | |
1998 | after = PREV_INSN (tmp); | |
1999 | else | |
2000 | after = get_last_insn (); | |
2001 | } | |
3dec4024 | 2002 | |
898c90c0 | 2003 | /* If the source has one successor and the edge is not abnormal, |
a1d50386 JJ |
2004 | insert there. Except for the entry block. |
2005 | Don't do this if the predecessor ends in a jump other than | |
2006 | unconditional simple jump. E.g. for asm goto that points all | |
2007 | its labels at the fallthru basic block, we can't insert instructions | |
2008 | before the asm goto, as the asm goto can have various of side effects, | |
2009 | and can't emit instructions after the asm goto, as it must end | |
2010 | the basic block. */ | |
898c90c0 EB |
2011 | else if ((e->flags & EDGE_ABNORMAL) == 0 |
2012 | && single_succ_p (e->src) | |
fefa31b5 | 2013 | && e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
a1d50386 JJ |
2014 | && (!JUMP_P (BB_END (e->src)) |
2015 | || simplejump_p (BB_END (e->src)))) | |
898c90c0 EB |
2016 | { |
2017 | bb = e->src; | |
3dec4024 | 2018 | |
898c90c0 EB |
2019 | /* It is possible to have a non-simple jump here. Consider a target |
2020 | where some forms of unconditional jumps clobber a register. This | |
2021 | happens on the fr30 for example. | |
ca6c03ca | 2022 | |
898c90c0 EB |
2023 | We know this block has a single successor, so we can just emit |
2024 | the queued insns before the jump. */ | |
2025 | if (JUMP_P (BB_END (bb))) | |
2026 | before = BB_END (bb); | |
3dec4024 JH |
2027 | else |
2028 | { | |
898c90c0 EB |
2029 | /* We'd better be fallthru, or we've lost track of what's what. */ |
2030 | gcc_assert (e->flags & EDGE_FALLTHRU); | |
750054a2 | 2031 | |
898c90c0 | 2032 | after = BB_END (bb); |
ca6c03ca JH |
2033 | } |
2034 | } | |
2035 | ||
898c90c0 EB |
2036 | /* Otherwise we must split the edge. */ |
2037 | else | |
2038 | { | |
2039 | bb = split_edge (e); | |
3371a64f TJ |
2040 | |
2041 | /* If E crossed a partition boundary, we needed to make bb end in | |
2042 | a region-crossing jump, even though it was originally fallthru. */ | |
2043 | if (JUMP_P (BB_END (bb))) | |
2044 | before = BB_END (bb); | |
2045 | else | |
2046 | after = BB_END (bb); | |
898c90c0 EB |
2047 | } |
2048 | ||
2049 | /* Now that we've found the spot, do the insertion. */ | |
ca6c03ca JH |
2050 | if (before) |
2051 | { | |
6fb5fa3c | 2052 | emit_insn_before_noloc (insns, before, bb); |
ca6c03ca JH |
2053 | last = prev_nonnote_insn (before); |
2054 | } | |
2055 | else | |
6fb5fa3c | 2056 | last = emit_insn_after_noloc (insns, after, bb); |
ca6c03ca JH |
2057 | |
2058 | if (returnjump_p (last)) | |
2059 | { | |
2060 | /* ??? Remove all outgoing edges from BB and add one for EXIT. | |
c22cacf3 MS |
2061 | This is not currently a problem because this only happens |
2062 | for the (single) epilogue, which already has a fallthru edge | |
2063 | to EXIT. */ | |
ca6c03ca | 2064 | |
c5cbcccf | 2065 | e = single_succ_edge (bb); |
fefa31b5 | 2066 | gcc_assert (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) |
c5cbcccf | 2067 | && single_succ_p (bb) && (e->flags & EDGE_FALLTHRU)); |
ca6c03ca | 2068 | |
5f0d2358 | 2069 | e->flags &= ~EDGE_FALLTHRU; |
ca6c03ca | 2070 | emit_barrier_after (last); |
0b17ab2f | 2071 | |
ca6c03ca JH |
2072 | if (before) |
2073 | delete_insn (before); | |
2074 | } | |
341c100f NS |
2075 | else |
2076 | gcc_assert (!JUMP_P (last)); | |
ca6c03ca JH |
2077 | } |
2078 | ||
2079 | /* Update the CFG for all queued instructions. */ | |
2080 | ||
2081 | void | |
d329e058 | 2082 | commit_edge_insertions (void) |
ca6c03ca | 2083 | { |
ca6c03ca JH |
2084 | basic_block bb; |
2085 | ||
600b5b1d TJ |
2086 | /* Optimization passes that invoke this routine can cause hot blocks |
2087 | previously reached by both hot and cold blocks to become dominated only | |
2088 | by cold blocks. This will cause the verification below to fail, | |
2089 | and lead to now cold code in the hot section. In some cases this | |
2090 | may only be visible after newly unreachable blocks are deleted, | |
2091 | which will be done by fixup_partitions. */ | |
2092 | fixup_partitions (); | |
2093 | ||
b2b29377 | 2094 | checking_verify_flow_info (); |
ca6c03ca | 2095 | |
fefa31b5 DM |
2096 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (cfun), |
2097 | EXIT_BLOCK_PTR_FOR_FN (cfun), next_bb) | |
ca6c03ca | 2098 | { |
628f6a4e BE |
2099 | edge e; |
2100 | edge_iterator ei; | |
ca6c03ca | 2101 | |
628f6a4e BE |
2102 | FOR_EACH_EDGE (e, ei, bb->succs) |
2103 | if (e->insns.r) | |
cf103ca4 | 2104 | commit_one_edge_insertion (e); |
3dec4024 | 2105 | } |
ca6c03ca JH |
2106 | } |
2107 | \f | |
6fb5fa3c | 2108 | |
f470c378 | 2109 | /* Print out RTL-specific basic block information (live information |
a315c44c SB |
2110 | at start and end with TDF_DETAILS). FLAGS are the TDF_* masks |
2111 | documented in dumpfile.h. */ | |
ca6c03ca | 2112 | |
10e9fecc | 2113 | static void |
a315c44c | 2114 | rtl_dump_bb (FILE *outf, basic_block bb, int indent, int flags) |
ca6c03ca | 2115 | { |
8879d71c DM |
2116 | rtx_insn *insn; |
2117 | rtx_insn *last; | |
f470c378 | 2118 | char *s_indent; |
ca6c03ca | 2119 | |
ae50c0cb | 2120 | s_indent = (char *) alloca ((size_t) indent + 1); |
400e39e3 | 2121 | memset (s_indent, ' ', (size_t) indent); |
f470c378 | 2122 | s_indent[indent] = '\0'; |
b8698a0f | 2123 | |
a315c44c | 2124 | if (df && (flags & TDF_DETAILS)) |
6fb5fa3c DB |
2125 | { |
2126 | df_dump_top (bb, outf); | |
2127 | putc ('\n', outf); | |
2128 | } | |
ca6c03ca | 2129 | |
68cc3174 EB |
2130 | if (bb->index != ENTRY_BLOCK && bb->index != EXIT_BLOCK) |
2131 | for (insn = BB_HEAD (bb), last = NEXT_INSN (BB_END (bb)); insn != last; | |
2132 | insn = NEXT_INSN (insn)) | |
a315c44c | 2133 | { |
7b19209f SB |
2134 | if (flags & TDF_DETAILS) |
2135 | df_dump_insn_top (insn, outf); | |
a315c44c SB |
2136 | if (! (flags & TDF_SLIM)) |
2137 | print_rtl_single (outf, insn); | |
2138 | else | |
2139 | dump_insn_slim (outf, insn); | |
7b19209f SB |
2140 | if (flags & TDF_DETAILS) |
2141 | df_dump_insn_bottom (insn, outf); | |
a315c44c SB |
2142 | } |
2143 | ||
2144 | if (df && (flags & TDF_DETAILS)) | |
6fb5fa3c DB |
2145 | { |
2146 | df_dump_bottom (bb, outf); | |
2147 | putc ('\n', outf); | |
2148 | } | |
2149 | ||
ca6c03ca JH |
2150 | } |
2151 | \f | |
c4669594 SB |
2152 | /* Like dump_function_to_file, but for RTL. Print out dataflow information |
2153 | for the start of each basic block. FLAGS are the TDF_* masks documented | |
2154 | in dumpfile.h. */ | |
ca6c03ca JH |
2155 | |
2156 | void | |
b2908ba6 | 2157 | print_rtl_with_bb (FILE *outf, const rtx_insn *rtx_first, int flags) |
ca6c03ca | 2158 | { |
b2908ba6 | 2159 | const rtx_insn *tmp_rtx; |
ca6c03ca JH |
2160 | if (rtx_first == 0) |
2161 | fprintf (outf, "(nil)\n"); | |
2162 | else | |
2163 | { | |
ca6c03ca JH |
2164 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
2165 | int max_uid = get_max_uid (); | |
5ed6ace5 MD |
2166 | basic_block *start = XCNEWVEC (basic_block, max_uid); |
2167 | basic_block *end = XCNEWVEC (basic_block, max_uid); | |
2168 | enum bb_state *in_bb_p = XCNEWVEC (enum bb_state, max_uid); | |
e0082a72 ZD |
2169 | basic_block bb; |
2170 | ||
c4669594 SB |
2171 | /* After freeing the CFG, we still have BLOCK_FOR_INSN set on most |
2172 | insns, but the CFG is not maintained so the basic block info | |
2173 | is not reliable. Therefore it's omitted from the dumps. */ | |
2174 | if (! (cfun->curr_properties & PROP_cfg)) | |
2175 | flags &= ~TDF_BLOCKS; | |
2176 | ||
6fb5fa3c DB |
2177 | if (df) |
2178 | df_dump_start (outf); | |
2179 | ||
c4669594 | 2180 | if (flags & TDF_BLOCKS) |
ca6c03ca | 2181 | { |
4f42035e | 2182 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
ca6c03ca | 2183 | { |
8879d71c | 2184 | rtx_insn *x; |
c4669594 SB |
2185 | |
2186 | start[INSN_UID (BB_HEAD (bb))] = bb; | |
2187 | end[INSN_UID (BB_END (bb))] = bb; | |
2188 | for (x = BB_HEAD (bb); x != NULL_RTX; x = NEXT_INSN (x)) | |
2189 | { | |
2190 | enum bb_state state = IN_MULTIPLE_BB; | |
5f0d2358 | 2191 | |
c4669594 SB |
2192 | if (in_bb_p[INSN_UID (x)] == NOT_IN_BB) |
2193 | state = IN_ONE_BB; | |
2194 | in_bb_p[INSN_UID (x)] = state; | |
ca6c03ca | 2195 | |
c4669594 SB |
2196 | if (x == BB_END (bb)) |
2197 | break; | |
2198 | } | |
ca6c03ca JH |
2199 | } |
2200 | } | |
2201 | ||
2202 | for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) | |
2203 | { | |
c4669594 SB |
2204 | if (flags & TDF_BLOCKS) |
2205 | { | |
2206 | bb = start[INSN_UID (tmp_rtx)]; | |
2207 | if (bb != NULL) | |
2208 | { | |
2209 | dump_bb_info (outf, bb, 0, dump_flags | TDF_COMMENT, true, false); | |
2210 | if (df && (flags & TDF_DETAILS)) | |
2211 | df_dump_top (bb, outf); | |
2212 | } | |
ca6c03ca | 2213 | |
c4669594 SB |
2214 | if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB |
2215 | && !NOTE_P (tmp_rtx) | |
2216 | && !BARRIER_P (tmp_rtx)) | |
2217 | fprintf (outf, ";; Insn is not within a basic block\n"); | |
2218 | else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB) | |
2219 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); | |
2220 | } | |
ca6c03ca | 2221 | |
7b19209f SB |
2222 | if (flags & TDF_DETAILS) |
2223 | df_dump_insn_top (tmp_rtx, outf); | |
a315c44c SB |
2224 | if (! (flags & TDF_SLIM)) |
2225 | print_rtl_single (outf, tmp_rtx); | |
2226 | else | |
2227 | dump_insn_slim (outf, tmp_rtx); | |
7b19209f SB |
2228 | if (flags & TDF_DETAILS) |
2229 | df_dump_insn_bottom (tmp_rtx, outf); | |
ca6c03ca | 2230 | |
c4669594 SB |
2231 | if (flags & TDF_BLOCKS) |
2232 | { | |
2233 | bb = end[INSN_UID (tmp_rtx)]; | |
2234 | if (bb != NULL) | |
2235 | { | |
2236 | dump_bb_info (outf, bb, 0, dump_flags | TDF_COMMENT, false, true); | |
2237 | if (df && (flags & TDF_DETAILS)) | |
2238 | df_dump_bottom (bb, outf); | |
1b03a96d | 2239 | putc ('\n', outf); |
c4669594 SB |
2240 | } |
2241 | } | |
ca6c03ca JH |
2242 | } |
2243 | ||
2244 | free (start); | |
2245 | free (end); | |
2246 | free (in_bb_p); | |
2247 | } | |
ca6c03ca JH |
2248 | } |
2249 | \f | |
532aafad SB |
2250 | /* Update the branch probability of BB if a REG_BR_PROB is present. */ |
2251 | ||
b446e5a2 | 2252 | void |
d329e058 | 2253 | update_br_prob_note (basic_block bb) |
b446e5a2 JH |
2254 | { |
2255 | rtx note; | |
4b4bf941 | 2256 | if (!JUMP_P (BB_END (bb))) |
b446e5a2 | 2257 | return; |
a813c111 | 2258 | note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX); |
e5af9ddd | 2259 | if (!note || XINT (note, 0) == BRANCH_EDGE (bb)->probability) |
b446e5a2 | 2260 | return; |
e5af9ddd | 2261 | XINT (note, 0) = BRANCH_EDGE (bb)->probability; |
b446e5a2 | 2262 | } |
96370780 MK |
2263 | |
2264 | /* Get the last insn associated with block BB (that includes barriers and | |
2265 | tablejumps after BB). */ | |
636eb204 | 2266 | rtx_insn * |
96370780 MK |
2267 | get_last_bb_insn (basic_block bb) |
2268 | { | |
8942ee0f | 2269 | rtx_jump_table_data *table; |
636eb204 DM |
2270 | rtx_insn *tmp; |
2271 | rtx_insn *end = BB_END (bb); | |
96370780 MK |
2272 | |
2273 | /* Include any jump table following the basic block. */ | |
8942ee0f DM |
2274 | if (tablejump_p (end, NULL, &table)) |
2275 | end = table; | |
96370780 MK |
2276 | |
2277 | /* Include any barriers that may follow the basic block. */ | |
1e211590 | 2278 | tmp = next_nonnote_insn_bb (end); |
96370780 MK |
2279 | while (tmp && BARRIER_P (tmp)) |
2280 | { | |
2281 | end = tmp; | |
1e211590 | 2282 | tmp = next_nonnote_insn_bb (end); |
96370780 MK |
2283 | } |
2284 | ||
2285 | return end; | |
2286 | } | |
af205f67 | 2287 | |
600b5b1d TJ |
2288 | /* Sanity check partition hotness to ensure that basic blocks in |
2289 | the cold partition don't dominate basic blocks in the hot partition. | |
2290 | If FLAG_ONLY is true, report violations as errors. Otherwise | |
2291 | re-mark the dominated blocks as cold, since this is run after | |
2292 | cfg optimizations that may make hot blocks previously reached | |
2293 | by both hot and cold blocks now only reachable along cold paths. */ | |
2294 | ||
2295 | static vec<basic_block> | |
2296 | find_partition_fixes (bool flag_only) | |
2297 | { | |
2298 | basic_block bb; | |
2299 | vec<basic_block> bbs_in_cold_partition = vNULL; | |
2300 | vec<basic_block> bbs_to_fix = vNULL; | |
2301 | ||
2302 | /* Callers check this. */ | |
2303 | gcc_checking_assert (crtl->has_bb_partition); | |
2304 | ||
11cd3bed | 2305 | FOR_EACH_BB_FN (bb, cfun) |
600b5b1d TJ |
2306 | if ((BB_PARTITION (bb) == BB_COLD_PARTITION)) |
2307 | bbs_in_cold_partition.safe_push (bb); | |
2308 | ||
2309 | if (bbs_in_cold_partition.is_empty ()) | |
2310 | return vNULL; | |
2311 | ||
2312 | bool dom_calculated_here = !dom_info_available_p (CDI_DOMINATORS); | |
2313 | ||
2314 | if (dom_calculated_here) | |
2315 | calculate_dominance_info (CDI_DOMINATORS); | |
2316 | ||
2317 | while (! bbs_in_cold_partition.is_empty ()) | |
2318 | { | |
2319 | bb = bbs_in_cold_partition.pop (); | |
2320 | /* Any blocks dominated by a block in the cold section | |
2321 | must also be cold. */ | |
2322 | basic_block son; | |
2323 | for (son = first_dom_son (CDI_DOMINATORS, bb); | |
2324 | son; | |
2325 | son = next_dom_son (CDI_DOMINATORS, son)) | |
2326 | { | |
2327 | /* If son is not yet cold, then mark it cold here and | |
2328 | enqueue it for further processing. */ | |
2329 | if ((BB_PARTITION (son) != BB_COLD_PARTITION)) | |
2330 | { | |
2331 | if (flag_only) | |
2332 | error ("non-cold basic block %d dominated " | |
2333 | "by a block in the cold partition (%d)", son->index, bb->index); | |
2334 | else | |
2335 | BB_SET_PARTITION (son, BB_COLD_PARTITION); | |
2336 | bbs_to_fix.safe_push (son); | |
2337 | bbs_in_cold_partition.safe_push (son); | |
2338 | } | |
2339 | } | |
2340 | } | |
2341 | ||
2342 | if (dom_calculated_here) | |
2343 | free_dominance_info (CDI_DOMINATORS); | |
2344 | ||
2345 | return bbs_to_fix; | |
2346 | } | |
2347 | ||
2348 | /* Perform cleanup on the hot/cold bb partitioning after optimization | |
2349 | passes that modify the cfg. */ | |
2350 | ||
2351 | void | |
2352 | fixup_partitions (void) | |
2353 | { | |
2354 | basic_block bb; | |
2355 | ||
2356 | if (!crtl->has_bb_partition) | |
2357 | return; | |
2358 | ||
2359 | /* Delete any blocks that became unreachable and weren't | |
2360 | already cleaned up, for example during edge forwarding | |
2361 | and convert_jumps_to_returns. This will expose more | |
2362 | opportunities for fixing the partition boundaries here. | |
2363 | Also, the calculation of the dominance graph during verification | |
2364 | will assert if there are unreachable nodes. */ | |
2365 | delete_unreachable_blocks (); | |
2366 | ||
2367 | /* If there are partitions, do a sanity check on them: A basic block in | |
2368 | a cold partition cannot dominate a basic block in a hot partition. | |
2369 | Fixup any that now violate this requirement, as a result of edge | |
2370 | forwarding and unreachable block deletion. */ | |
2371 | vec<basic_block> bbs_to_fix = find_partition_fixes (false); | |
2372 | ||
2373 | /* Do the partition fixup after all necessary blocks have been converted to | |
2374 | cold, so that we only update the region crossings the minimum number of | |
2375 | places, which can require forcing edges to be non fallthru. */ | |
2376 | while (! bbs_to_fix.is_empty ()) | |
2377 | { | |
2378 | bb = bbs_to_fix.pop (); | |
2379 | fixup_new_cold_bb (bb); | |
2380 | } | |
2381 | } | |
2382 | ||
af205f67 TJ |
2383 | /* Verify, in the basic block chain, that there is at most one switch |
2384 | between hot/cold partitions. This condition will not be true until | |
2385 | after reorder_basic_blocks is called. */ | |
2386 | ||
251a41b9 | 2387 | static int |
af205f67 TJ |
2388 | verify_hot_cold_block_grouping (void) |
2389 | { | |
2390 | basic_block bb; | |
2391 | int err = 0; | |
2392 | bool switched_sections = false; | |
2393 | int current_partition = BB_UNPARTITIONED; | |
2394 | ||
3371a64f TJ |
2395 | /* Even after bb reordering is complete, we go into cfglayout mode |
2396 | again (in compgoto). Ensure we don't call this before going back | |
2397 | into linearized RTL when any layout fixes would have been committed. */ | |
2398 | if (!crtl->bb_reorder_complete | |
c3284718 | 2399 | || current_ir_type () != IR_RTL_CFGRTL) |
251a41b9 | 2400 | return err; |
af205f67 | 2401 | |
11cd3bed | 2402 | FOR_EACH_BB_FN (bb, cfun) |
af205f67 TJ |
2403 | { |
2404 | if (current_partition != BB_UNPARTITIONED | |
2405 | && BB_PARTITION (bb) != current_partition) | |
2406 | { | |
2407 | if (switched_sections) | |
2408 | { | |
2409 | error ("multiple hot/cold transitions found (bb %i)", | |
2410 | bb->index); | |
2411 | err = 1; | |
2412 | } | |
2413 | else | |
2414 | switched_sections = true; | |
2415 | ||
2416 | if (!crtl->has_bb_partition) | |
2417 | error ("partition found but function partition flag not set"); | |
2418 | } | |
2419 | current_partition = BB_PARTITION (bb); | |
2420 | } | |
2421 | ||
251a41b9 | 2422 | return err; |
af205f67 | 2423 | } |
b446e5a2 | 2424 | \f |
ca6c03ca | 2425 | |
251a41b9 TJ |
2426 | /* Perform several checks on the edges out of each block, such as |
2427 | the consistency of the branch probabilities, the correctness | |
2428 | of hot/cold partition crossing edges, and the number of expected | |
600b5b1d TJ |
2429 | successor edges. Also verify that the dominance relationship |
2430 | between hot/cold blocks is sane. */ | |
f470c378 | 2431 | |
10e9fecc | 2432 | static int |
251a41b9 | 2433 | rtl_verify_edges (void) |
ca6c03ca | 2434 | { |
10e9fecc | 2435 | int err = 0; |
94eb5ddb | 2436 | basic_block bb; |
ca6c03ca | 2437 | |
4f42035e | 2438 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
ca6c03ca | 2439 | { |
f99ffaa3 EB |
2440 | int n_fallthru = 0, n_branch = 0, n_abnormal_call = 0, n_sibcall = 0; |
2441 | int n_eh = 0, n_abnormal = 0; | |
3cf54412 | 2442 | edge e, fallthru = NULL; |
628f6a4e | 2443 | edge_iterator ei; |
251a41b9 | 2444 | rtx note; |
3371a64f | 2445 | bool has_crossing_edge = false; |
ca6c03ca | 2446 | |
2085a21f | 2447 | if (JUMP_P (BB_END (bb)) |
a813c111 | 2448 | && (note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX)) |
628f6a4e | 2449 | && EDGE_COUNT (bb->succs) >= 2 |
a813c111 | 2450 | && any_condjump_p (BB_END (bb))) |
5a1a3e5e | 2451 | { |
e5af9ddd | 2452 | if (XINT (note, 0) != BRANCH_EDGE (bb)->probability |
0a6a6ac9 | 2453 | && profile_status_for_fn (cfun) != PROFILE_ABSENT) |
5a1a3e5e | 2454 | { |
e5af9ddd RS |
2455 | error ("verify_flow_info: REG_BR_PROB does not match cfg %i %i", |
2456 | XINT (note, 0), BRANCH_EDGE (bb)->probability); | |
5a1a3e5e JH |
2457 | err = 1; |
2458 | } | |
2459 | } | |
251a41b9 | 2460 | |
628f6a4e | 2461 | FOR_EACH_EDGE (e, ei, bb->succs) |
ca6c03ca | 2462 | { |
0be7e7a6 RH |
2463 | bool is_crossing; |
2464 | ||
ca6c03ca | 2465 | if (e->flags & EDGE_FALLTHRU) |
0be7e7a6 RH |
2466 | n_fallthru++, fallthru = e; |
2467 | ||
2468 | is_crossing = (BB_PARTITION (e->src) != BB_PARTITION (e->dest) | |
fefa31b5 DM |
2469 | && e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
2470 | && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)); | |
3371a64f | 2471 | has_crossing_edge |= is_crossing; |
0be7e7a6 | 2472 | if (e->flags & EDGE_CROSSING) |
750054a2 | 2473 | { |
0be7e7a6 RH |
2474 | if (!is_crossing) |
2475 | { | |
2476 | error ("EDGE_CROSSING incorrectly set across same section"); | |
2477 | err = 1; | |
2478 | } | |
2479 | if (e->flags & EDGE_FALLTHRU) | |
2480 | { | |
f99ffaa3 | 2481 | error ("fallthru edge crosses section boundary in bb %i", |
750054a2 CT |
2482 | e->src->index); |
2483 | err = 1; | |
2484 | } | |
0be7e7a6 RH |
2485 | if (e->flags & EDGE_EH) |
2486 | { | |
f99ffaa3 | 2487 | error ("EH edge crosses section boundary in bb %i", |
0be7e7a6 RH |
2488 | e->src->index); |
2489 | err = 1; | |
2490 | } | |
339ba33b | 2491 | if (JUMP_P (BB_END (bb)) && !CROSSING_JUMP_P (BB_END (bb))) |
3371a64f TJ |
2492 | { |
2493 | error ("No region crossing jump at section boundary in bb %i", | |
2494 | bb->index); | |
2495 | err = 1; | |
2496 | } | |
0be7e7a6 RH |
2497 | } |
2498 | else if (is_crossing) | |
2499 | { | |
2500 | error ("EDGE_CROSSING missing across section boundary"); | |
2501 | err = 1; | |
750054a2 | 2502 | } |
3dec4024 | 2503 | |
65f43cdf ZD |
2504 | if ((e->flags & ~(EDGE_DFS_BACK |
2505 | | EDGE_CAN_FALLTHRU | |
2506 | | EDGE_IRREDUCIBLE_LOOP | |
9beb1c84 | 2507 | | EDGE_LOOP_EXIT |
7e872b90 JJ |
2508 | | EDGE_CROSSING |
2509 | | EDGE_PRESERVE)) == 0) | |
3dec4024 JH |
2510 | n_branch++; |
2511 | ||
2512 | if (e->flags & EDGE_ABNORMAL_CALL) | |
f99ffaa3 EB |
2513 | n_abnormal_call++; |
2514 | ||
2515 | if (e->flags & EDGE_SIBCALL) | |
2516 | n_sibcall++; | |
3dec4024 JH |
2517 | |
2518 | if (e->flags & EDGE_EH) | |
2519 | n_eh++; | |
f99ffaa3 EB |
2520 | |
2521 | if (e->flags & EDGE_ABNORMAL) | |
3dec4024 | 2522 | n_abnormal++; |
ca6c03ca | 2523 | } |
5f0d2358 | 2524 | |
3371a64f | 2525 | if (!has_crossing_edge |
339ba33b RS |
2526 | && JUMP_P (BB_END (bb)) |
2527 | && CROSSING_JUMP_P (BB_END (bb))) | |
3371a64f TJ |
2528 | { |
2529 | print_rtl_with_bb (stderr, get_insns (), TDF_RTL | TDF_BLOCKS | TDF_DETAILS); | |
2530 | error ("Region crossing jump across same section in bb %i", | |
2531 | bb->index); | |
2532 | err = 1; | |
2533 | } | |
2534 | ||
1d65f45c | 2535 | if (n_eh && !find_reg_note (BB_END (bb), REG_EH_REGION, NULL_RTX)) |
3dec4024 | 2536 | { |
f99ffaa3 | 2537 | error ("missing REG_EH_REGION note at the end of bb %i", bb->index); |
3dec4024 JH |
2538 | err = 1; |
2539 | } | |
1d65f45c RH |
2540 | if (n_eh > 1) |
2541 | { | |
f99ffaa3 | 2542 | error ("too many exception handling edges in bb %i", bb->index); |
1d65f45c RH |
2543 | err = 1; |
2544 | } | |
3dec4024 | 2545 | if (n_branch |
4b4bf941 | 2546 | && (!JUMP_P (BB_END (bb)) |
a813c111 SB |
2547 | || (n_branch > 1 && (any_uncondjump_p (BB_END (bb)) |
2548 | || any_condjump_p (BB_END (bb)))))) | |
3dec4024 | 2549 | { |
ab532386 | 2550 | error ("too many outgoing branch edges from bb %i", bb->index); |
3dec4024 JH |
2551 | err = 1; |
2552 | } | |
a813c111 | 2553 | if (n_fallthru && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 2554 | { |
f99ffaa3 | 2555 | error ("fallthru edge after unconditional jump in bb %i", bb->index); |
3dec4024 JH |
2556 | err = 1; |
2557 | } | |
a813c111 | 2558 | if (n_branch != 1 && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 2559 | { |
f99ffaa3 EB |
2560 | error ("wrong number of branch edges after unconditional jump" |
2561 | " in bb %i", bb->index); | |
3dec4024 JH |
2562 | err = 1; |
2563 | } | |
a813c111 | 2564 | if (n_branch != 1 && any_condjump_p (BB_END (bb)) |
c11fd0b2 | 2565 | && JUMP_LABEL (BB_END (bb)) != BB_HEAD (fallthru->dest)) |
3dec4024 | 2566 | { |
f99ffaa3 EB |
2567 | error ("wrong amount of branch edges after conditional jump" |
2568 | " in bb %i", bb->index); | |
2569 | err = 1; | |
2570 | } | |
2571 | if (n_abnormal_call && !CALL_P (BB_END (bb))) | |
2572 | { | |
2573 | error ("abnormal call edges for non-call insn in bb %i", bb->index); | |
3dec4024 JH |
2574 | err = 1; |
2575 | } | |
f99ffaa3 | 2576 | if (n_sibcall && !CALL_P (BB_END (bb))) |
3dec4024 | 2577 | { |
f99ffaa3 | 2578 | error ("sibcall edges for non-call insn in bb %i", bb->index); |
3dec4024 JH |
2579 | err = 1; |
2580 | } | |
f99ffaa3 EB |
2581 | if (n_abnormal > n_eh |
2582 | && !(CALL_P (BB_END (bb)) | |
2583 | && n_abnormal == n_abnormal_call + n_sibcall) | |
4b4bf941 | 2584 | && (!JUMP_P (BB_END (bb)) |
a813c111 SB |
2585 | || any_condjump_p (BB_END (bb)) |
2586 | || any_uncondjump_p (BB_END (bb)))) | |
3dec4024 | 2587 | { |
ab532386 | 2588 | error ("abnormal edges for no purpose in bb %i", bb->index); |
3dec4024 JH |
2589 | err = 1; |
2590 | } | |
251a41b9 | 2591 | } |
f87c27b4 | 2592 | |
600b5b1d TJ |
2593 | /* If there are partitions, do a sanity check on them: A basic block in |
2594 | a cold partition cannot dominate a basic block in a hot partition. */ | |
2595 | if (crtl->has_bb_partition && !err) | |
2596 | { | |
2597 | vec<basic_block> bbs_to_fix = find_partition_fixes (true); | |
2598 | err = !bbs_to_fix.is_empty (); | |
2599 | } | |
2600 | ||
251a41b9 TJ |
2601 | /* Clean up. */ |
2602 | return err; | |
2603 | } | |
5f0d2358 | 2604 | |
251a41b9 TJ |
2605 | /* Checks on the instructions within blocks. Currently checks that each |
2606 | block starts with a basic block note, and that basic block notes and | |
2607 | control flow jumps are not found in the middle of the block. */ | |
ca6c03ca | 2608 | |
251a41b9 TJ |
2609 | static int |
2610 | rtl_verify_bb_insns (void) | |
2611 | { | |
8879d71c | 2612 | rtx_insn *x; |
251a41b9 TJ |
2613 | int err = 0; |
2614 | basic_block bb; | |
2615 | ||
4f42035e | 2616 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
251a41b9 TJ |
2617 | { |
2618 | /* Now check the header of basic | |
c22cacf3 | 2619 | block. It ought to contain optional CODE_LABEL followed |
ca6c03ca | 2620 | by NOTE_BASIC_BLOCK. */ |
a813c111 | 2621 | x = BB_HEAD (bb); |
4b4bf941 | 2622 | if (LABEL_P (x)) |
ca6c03ca | 2623 | { |
a813c111 | 2624 | if (BB_END (bb) == x) |
ca6c03ca JH |
2625 | { |
2626 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 2627 | bb->index); |
ca6c03ca JH |
2628 | err = 1; |
2629 | } | |
5f0d2358 | 2630 | |
ca6c03ca JH |
2631 | x = NEXT_INSN (x); |
2632 | } | |
5f0d2358 | 2633 | |
ca6c03ca JH |
2634 | if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb) |
2635 | { | |
2636 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 2637 | bb->index); |
ca6c03ca JH |
2638 | err = 1; |
2639 | } | |
2640 | ||
a813c111 | 2641 | if (BB_END (bb) == x) |
49243025 | 2642 | /* Do checks for empty blocks here. */ |
5f0d2358 | 2643 | ; |
ca6c03ca | 2644 | else |
5f0d2358 RK |
2645 | for (x = NEXT_INSN (x); x; x = NEXT_INSN (x)) |
2646 | { | |
2647 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2648 | { | |
2649 | error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d", | |
0b17ab2f | 2650 | INSN_UID (x), bb->index); |
5f0d2358 RK |
2651 | err = 1; |
2652 | } | |
2653 | ||
a813c111 | 2654 | if (x == BB_END (bb)) |
5f0d2358 | 2655 | break; |
ca6c03ca | 2656 | |
83fd323c | 2657 | if (control_flow_insn_p (x)) |
5f0d2358 | 2658 | { |
0b17ab2f | 2659 | error ("in basic block %d:", bb->index); |
5f0d2358 RK |
2660 | fatal_insn ("flow control insn inside a basic block", x); |
2661 | } | |
2662 | } | |
ca6c03ca JH |
2663 | } |
2664 | ||
251a41b9 TJ |
2665 | /* Clean up. */ |
2666 | return err; | |
2667 | } | |
2668 | ||
2669 | /* Verify that block pointers for instructions in basic blocks, headers and | |
2670 | footers are set appropriately. */ | |
2671 | ||
2672 | static int | |
2673 | rtl_verify_bb_pointers (void) | |
2674 | { | |
2675 | int err = 0; | |
2676 | basic_block bb; | |
2677 | ||
2678 | /* Check the general integrity of the basic blocks. */ | |
4f42035e | 2679 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
251a41b9 | 2680 | { |
8879d71c | 2681 | rtx_insn *insn; |
251a41b9 TJ |
2682 | |
2683 | if (!(bb->flags & BB_RTL)) | |
2684 | { | |
2685 | error ("BB_RTL flag not set for block %d", bb->index); | |
2686 | err = 1; | |
2687 | } | |
2688 | ||
2689 | FOR_BB_INSNS (bb, insn) | |
2690 | if (BLOCK_FOR_INSN (insn) != bb) | |
2691 | { | |
2692 | error ("insn %d basic block pointer is %d, should be %d", | |
2693 | INSN_UID (insn), | |
2694 | BLOCK_FOR_INSN (insn) ? BLOCK_FOR_INSN (insn)->index : 0, | |
2695 | bb->index); | |
2696 | err = 1; | |
2697 | } | |
2698 | ||
2699 | for (insn = BB_HEADER (bb); insn; insn = NEXT_INSN (insn)) | |
2700 | if (!BARRIER_P (insn) | |
2701 | && BLOCK_FOR_INSN (insn) != NULL) | |
2702 | { | |
2703 | error ("insn %d in header of bb %d has non-NULL basic block", | |
2704 | INSN_UID (insn), bb->index); | |
2705 | err = 1; | |
2706 | } | |
2707 | for (insn = BB_FOOTER (bb); insn; insn = NEXT_INSN (insn)) | |
2708 | if (!BARRIER_P (insn) | |
2709 | && BLOCK_FOR_INSN (insn) != NULL) | |
2710 | { | |
2711 | error ("insn %d in footer of bb %d has non-NULL basic block", | |
2712 | INSN_UID (insn), bb->index); | |
2713 | err = 1; | |
2714 | } | |
2715 | } | |
af205f67 | 2716 | |
10e9fecc | 2717 | /* Clean up. */ |
10e9fecc JH |
2718 | return err; |
2719 | } | |
5f0d2358 | 2720 | |
10e9fecc JH |
2721 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
2722 | cfglayout RTL. | |
5f0d2358 | 2723 | |
10e9fecc | 2724 | Currently it does following checks: |
251a41b9 TJ |
2725 | |
2726 | - overlapping of basic blocks | |
2727 | - insns with wrong BLOCK_FOR_INSN pointers | |
2728 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) | |
2729 | - tails of basic blocks (ensure that boundary is necessary) | |
2730 | - scans body of the basic block for JUMP_INSN, CODE_LABEL | |
2731 | and NOTE_INSN_BASIC_BLOCK | |
2732 | - verify that no fall_thru edge crosses hot/cold partition boundaries | |
2733 | - verify that there are no pending RTL branch predictions | |
600b5b1d | 2734 | - verify that hot blocks are not dominated by cold blocks |
251a41b9 TJ |
2735 | |
2736 | In future it can be extended check a lot of other stuff as well | |
2737 | (reachability of basic blocks, life information, etc. etc.). */ | |
9eab6785 | 2738 | |
10e9fecc | 2739 | static int |
251a41b9 TJ |
2740 | rtl_verify_flow_info_1 (void) |
2741 | { | |
2742 | int err = 0; | |
2743 | ||
2744 | err |= rtl_verify_bb_pointers (); | |
2745 | ||
2746 | err |= rtl_verify_bb_insns (); | |
2747 | ||
2748 | err |= rtl_verify_edges (); | |
2749 | ||
251a41b9 TJ |
2750 | return err; |
2751 | } | |
2752 | ||
2753 | /* Walk the instruction chain and verify that bb head/end pointers | |
2754 | are correct, and that instructions are in exactly one bb and have | |
2755 | correct block pointers. */ | |
2756 | ||
2757 | static int | |
2758 | rtl_verify_bb_insn_chain (void) | |
10e9fecc JH |
2759 | { |
2760 | basic_block bb; | |
251a41b9 | 2761 | int err = 0; |
8879d71c DM |
2762 | rtx_insn *x; |
2763 | rtx_insn *last_head = get_last_insn (); | |
9eab6785 | 2764 | basic_block *bb_info; |
9eab6785 SB |
2765 | const int max_uid = get_max_uid (); |
2766 | ||
2767 | bb_info = XCNEWVEC (basic_block, max_uid); | |
ca6c03ca | 2768 | |
4f42035e | 2769 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
10e9fecc | 2770 | { |
8879d71c DM |
2771 | rtx_insn *head = BB_HEAD (bb); |
2772 | rtx_insn *end = BB_END (bb); | |
628f6a4e | 2773 | |
9eab6785 | 2774 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) |
a7b87f73 ZD |
2775 | { |
2776 | /* Verify the end of the basic block is in the INSN chain. */ | |
2777 | if (x == end) | |
2778 | break; | |
2779 | ||
251a41b9 TJ |
2780 | /* And that the code outside of basic blocks has NULL bb field. */ |
2781 | if (!BARRIER_P (x) | |
2782 | && BLOCK_FOR_INSN (x) != NULL) | |
2783 | { | |
2784 | error ("insn %d outside of basic blocks has non-NULL bb field", | |
2785 | INSN_UID (x)); | |
2786 | err = 1; | |
2787 | } | |
a7b87f73 | 2788 | } |
9eab6785 SB |
2789 | |
2790 | if (!x) | |
2791 | { | |
2792 | error ("end insn %d for block %d not found in the insn stream", | |
2793 | INSN_UID (end), bb->index); | |
2794 | err = 1; | |
2795 | } | |
2796 | ||
2797 | /* Work backwards from the end to the head of the basic block | |
2798 | to verify the head is in the RTL chain. */ | |
2799 | for (; x != NULL_RTX; x = PREV_INSN (x)) | |
a00d11f0 | 2800 | { |
9eab6785 SB |
2801 | /* While walking over the insn chain, verify insns appear |
2802 | in only one basic block. */ | |
2803 | if (bb_info[INSN_UID (x)] != NULL) | |
2804 | { | |
2805 | error ("insn %d is in multiple basic blocks (%d and %d)", | |
2806 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); | |
2807 | err = 1; | |
2808 | } | |
2809 | ||
2810 | bb_info[INSN_UID (x)] = bb; | |
2811 | ||
2812 | if (x == head) | |
2813 | break; | |
2814 | } | |
2815 | if (!x) | |
2816 | { | |
2817 | error ("head insn %d for block %d not found in the insn stream", | |
2818 | INSN_UID (head), bb->index); | |
a00d11f0 JH |
2819 | err = 1; |
2820 | } | |
2821 | ||
a7b87f73 | 2822 | last_head = PREV_INSN (x); |
251a41b9 TJ |
2823 | } |
2824 | ||
2825 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) | |
2826 | { | |
2827 | /* Check that the code before the first basic block has NULL | |
2828 | bb field. */ | |
2829 | if (!BARRIER_P (x) | |
2830 | && BLOCK_FOR_INSN (x) != NULL) | |
2831 | { | |
2832 | error ("insn %d outside of basic blocks has non-NULL bb field", | |
2833 | INSN_UID (x)); | |
2834 | err = 1; | |
2835 | } | |
2836 | } | |
2837 | free (bb_info); | |
2838 | ||
2839 | return err; | |
2840 | } | |
2841 | ||
2842 | /* Verify that fallthru edges point to adjacent blocks in layout order and | |
2843 | that barriers exist after non-fallthru blocks. */ | |
2844 | ||
2845 | static int | |
2846 | rtl_verify_fallthru (void) | |
2847 | { | |
2848 | basic_block bb; | |
2849 | int err = 0; | |
2850 | ||
4f42035e | 2851 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
251a41b9 TJ |
2852 | { |
2853 | edge e; | |
9eab6785 | 2854 | |
0fd4b31d | 2855 | e = find_fallthru_edge (bb->succs); |
10e9fecc JH |
2856 | if (!e) |
2857 | { | |
8879d71c | 2858 | rtx_insn *insn; |
10e9fecc JH |
2859 | |
2860 | /* Ensure existence of barrier in BB with no fallthru edges. */ | |
468059bc DD |
2861 | for (insn = NEXT_INSN (BB_END (bb)); ; insn = NEXT_INSN (insn)) |
2862 | { | |
2863 | if (!insn || NOTE_INSN_BASIC_BLOCK_P (insn)) | |
10e9fecc JH |
2864 | { |
2865 | error ("missing barrier after block %i", bb->index); | |
2866 | err = 1; | |
2867 | break; | |
2868 | } | |
468059bc DD |
2869 | if (BARRIER_P (insn)) |
2870 | break; | |
2871 | } | |
10e9fecc | 2872 | } |
fefa31b5 DM |
2873 | else if (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
2874 | && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
c22cacf3 | 2875 | { |
8879d71c | 2876 | rtx_insn *insn; |
10e9fecc JH |
2877 | |
2878 | if (e->src->next_bb != e->dest) | |
2879 | { | |
2880 | error | |
2881 | ("verify_flow_info: Incorrect blocks for fallthru %i->%i", | |
2882 | e->src->index, e->dest->index); | |
2883 | err = 1; | |
2884 | } | |
2885 | else | |
a813c111 | 2886 | for (insn = NEXT_INSN (BB_END (e->src)); insn != BB_HEAD (e->dest); |
10e9fecc | 2887 | insn = NEXT_INSN (insn)) |
6be85b25 | 2888 | if (BARRIER_P (insn) || INSN_P (insn)) |
10e9fecc JH |
2889 | { |
2890 | error ("verify_flow_info: Incorrect fallthru %i->%i", | |
2891 | e->src->index, e->dest->index); | |
2892 | fatal_insn ("wrong insn in the fallthru edge", insn); | |
2893 | err = 1; | |
2894 | } | |
c22cacf3 | 2895 | } |
10e9fecc | 2896 | } |
ca6c03ca | 2897 | |
251a41b9 TJ |
2898 | return err; |
2899 | } | |
2900 | ||
2901 | /* Verify that blocks are laid out in consecutive order. While walking the | |
2902 | instructions, verify that all expected instructions are inside the basic | |
2903 | blocks, and that all returns are followed by barriers. */ | |
2904 | ||
2905 | static int | |
2906 | rtl_verify_bb_layout (void) | |
2907 | { | |
2908 | basic_block bb; | |
2909 | int err = 0; | |
8879d71c | 2910 | rtx_insn *x; |
251a41b9 | 2911 | int num_bb_notes; |
8879d71c | 2912 | rtx_insn * const rtx_first = get_insns (); |
fefa31b5 | 2913 | basic_block last_bb_seen = ENTRY_BLOCK_PTR_FOR_FN (cfun), curr_bb = NULL; |
9eab6785 | 2914 | |
ca6c03ca | 2915 | num_bb_notes = 0; |
fefa31b5 | 2916 | last_bb_seen = ENTRY_BLOCK_PTR_FOR_FN (cfun); |
e0082a72 | 2917 | |
5f0d2358 | 2918 | for (x = rtx_first; x; x = NEXT_INSN (x)) |
ca6c03ca JH |
2919 | { |
2920 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2921 | { | |
bf77398c | 2922 | bb = NOTE_BASIC_BLOCK (x); |
5f0d2358 | 2923 | |
ca6c03ca | 2924 | num_bb_notes++; |
e0082a72 | 2925 | if (bb != last_bb_seen->next_bb) |
10e9fecc | 2926 | internal_error ("basic blocks not laid down consecutively"); |
ca6c03ca | 2927 | |
10e9fecc | 2928 | curr_bb = last_bb_seen = bb; |
ca6c03ca JH |
2929 | } |
2930 | ||
10e9fecc | 2931 | if (!curr_bb) |
ca6c03ca JH |
2932 | { |
2933 | switch (GET_CODE (x)) | |
2934 | { | |
2935 | case BARRIER: | |
2936 | case NOTE: | |
2937 | break; | |
2938 | ||
2939 | case CODE_LABEL: | |
39718607 | 2940 | /* An ADDR_VEC is placed outside any basic block. */ |
ca6c03ca | 2941 | if (NEXT_INSN (x) |
481683e1 | 2942 | && JUMP_TABLE_DATA_P (NEXT_INSN (x))) |
5f0d2358 | 2943 | x = NEXT_INSN (x); |
ca6c03ca JH |
2944 | |
2945 | /* But in any case, non-deletable labels can appear anywhere. */ | |
2946 | break; | |
2947 | ||
2948 | default: | |
1f978f5f | 2949 | fatal_insn ("insn outside basic block", x); |
ca6c03ca JH |
2950 | } |
2951 | } | |
2952 | ||
26cae194 | 2953 | if (JUMP_P (x) |
ca6c03ca | 2954 | && returnjump_p (x) && ! condjump_p (x) |
15eb3a2e | 2955 | && ! (next_nonnote_insn (x) && BARRIER_P (next_nonnote_insn (x)))) |
1f978f5f | 2956 | fatal_insn ("return not followed by barrier", x); |
251a41b9 | 2957 | |
a813c111 | 2958 | if (curr_bb && x == BB_END (curr_bb)) |
10e9fecc | 2959 | curr_bb = NULL; |
ca6c03ca JH |
2960 | } |
2961 | ||
0cae8d31 | 2962 | if (num_bb_notes != n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS) |
ca6c03ca | 2963 | internal_error |
0b17ab2f | 2964 | ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)", |
0cae8d31 | 2965 | num_bb_notes, n_basic_blocks_for_fn (cfun)); |
ca6c03ca | 2966 | |
10e9fecc | 2967 | return err; |
ca6c03ca | 2968 | } |
251a41b9 TJ |
2969 | |
2970 | /* Verify the CFG and RTL consistency common for both underlying RTL and | |
2971 | cfglayout RTL, plus consistency checks specific to linearized RTL mode. | |
2972 | ||
2973 | Currently it does following checks: | |
2974 | - all checks of rtl_verify_flow_info_1 | |
2975 | - test head/end pointers | |
2976 | - check that blocks are laid out in consecutive order | |
2977 | - check that all insns are in the basic blocks | |
2978 | (except the switch handling code, barriers and notes) | |
2979 | - check that all returns are followed by barriers | |
600b5b1d TJ |
2980 | - check that all fallthru edge points to the adjacent blocks |
2981 | - verify that there is a single hot/cold partition boundary after bbro */ | |
251a41b9 TJ |
2982 | |
2983 | static int | |
2984 | rtl_verify_flow_info (void) | |
2985 | { | |
2986 | int err = 0; | |
2987 | ||
2988 | err |= rtl_verify_flow_info_1 (); | |
2989 | ||
2990 | err |= rtl_verify_bb_insn_chain (); | |
2991 | ||
2992 | err |= rtl_verify_fallthru (); | |
2993 | ||
2994 | err |= rtl_verify_bb_layout (); | |
2995 | ||
3371a64f TJ |
2996 | err |= verify_hot_cold_block_grouping (); |
2997 | ||
251a41b9 TJ |
2998 | return err; |
2999 | } | |
ca6c03ca | 3000 | \f |
eaec9b3d | 3001 | /* Assume that the preceding pass has possibly eliminated jump instructions |
ca6c03ca JH |
3002 | or converted the unconditional jumps. Eliminate the edges from CFG. |
3003 | Return true if any edges are eliminated. */ | |
3004 | ||
3005 | bool | |
d329e058 | 3006 | purge_dead_edges (basic_block bb) |
ca6c03ca | 3007 | { |
628f6a4e | 3008 | edge e; |
8879d71c DM |
3009 | rtx_insn *insn = BB_END (bb); |
3010 | rtx note; | |
ca6c03ca | 3011 | bool purged = false; |
628f6a4e BE |
3012 | bool found; |
3013 | edge_iterator ei; | |
ca6c03ca | 3014 | |
b5b8b0ac AO |
3015 | if (DEBUG_INSN_P (insn) && insn != BB_HEAD (bb)) |
3016 | do | |
3017 | insn = PREV_INSN (insn); | |
3018 | while ((DEBUG_INSN_P (insn) || NOTE_P (insn)) && insn != BB_HEAD (bb)); | |
3019 | ||
70da1d03 | 3020 | /* If this instruction cannot trap, remove REG_EH_REGION notes. */ |
4b4bf941 | 3021 | if (NONJUMP_INSN_P (insn) |
70da1d03 JH |
3022 | && (note = find_reg_note (insn, REG_EH_REGION, NULL))) |
3023 | { | |
3024 | rtx eqnote; | |
3025 | ||
3026 | if (! may_trap_p (PATTERN (insn)) | |
3027 | || ((eqnote = find_reg_equal_equiv_note (insn)) | |
3028 | && ! may_trap_p (XEXP (eqnote, 0)))) | |
3029 | remove_note (insn, note); | |
3030 | } | |
3031 | ||
546c093e | 3032 | /* Cleanup abnormal edges caused by exceptions or non-local gotos. */ |
628f6a4e | 3033 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
546c093e | 3034 | { |
1d65f45c RH |
3035 | bool remove = false; |
3036 | ||
e5f9a909 JW |
3037 | /* There are three types of edges we need to handle correctly here: EH |
3038 | edges, abnormal call EH edges, and abnormal call non-EH edges. The | |
3039 | latter can appear when nonlocal gotos are used. */ | |
1d65f45c | 3040 | if (e->flags & EDGE_ABNORMAL_CALL) |
546c093e | 3041 | { |
1d65f45c RH |
3042 | if (!CALL_P (insn)) |
3043 | remove = true; | |
3044 | else if (can_nonlocal_goto (insn)) | |
3045 | ; | |
3046 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) | |
3047 | ; | |
0a35513e AH |
3048 | else if (flag_tm && find_reg_note (insn, REG_TM, NULL)) |
3049 | ; | |
1d65f45c RH |
3050 | else |
3051 | remove = true; | |
546c093e | 3052 | } |
1d65f45c RH |
3053 | else if (e->flags & EDGE_EH) |
3054 | remove = !can_throw_internal (insn); | |
3055 | ||
3056 | if (remove) | |
546c093e | 3057 | { |
1d65f45c RH |
3058 | remove_edge (e); |
3059 | df_set_bb_dirty (bb); | |
3060 | purged = true; | |
546c093e RH |
3061 | } |
3062 | else | |
1d65f45c | 3063 | ei_next (&ei); |
546c093e | 3064 | } |
5f0d2358 | 3065 | |
4b4bf941 | 3066 | if (JUMP_P (insn)) |
ca6c03ca JH |
3067 | { |
3068 | rtx note; | |
3069 | edge b,f; | |
628f6a4e | 3070 | edge_iterator ei; |
5f0d2358 | 3071 | |
ca6c03ca JH |
3072 | /* We do care only about conditional jumps and simplejumps. */ |
3073 | if (!any_condjump_p (insn) | |
3074 | && !returnjump_p (insn) | |
3075 | && !simplejump_p (insn)) | |
c51d95ec | 3076 | return purged; |
5f0d2358 | 3077 | |
5a1a3e5e JH |
3078 | /* Branch probability/prediction notes are defined only for |
3079 | condjumps. We've possibly turned condjump into simplejump. */ | |
3080 | if (simplejump_p (insn)) | |
3081 | { | |
3082 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
3083 | if (note) | |
3084 | remove_note (insn, note); | |
3085 | while ((note = find_reg_note (insn, REG_BR_PRED, NULL))) | |
3086 | remove_note (insn, note); | |
3087 | } | |
3088 | ||
628f6a4e | 3089 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
ca6c03ca | 3090 | { |
7fcd7218 JH |
3091 | /* Avoid abnormal flags to leak from computed jumps turned |
3092 | into simplejumps. */ | |
f87c27b4 | 3093 | |
0e1638d4 | 3094 | e->flags &= ~EDGE_ABNORMAL; |
7fcd7218 | 3095 | |
5a566bed MM |
3096 | /* See if this edge is one we should keep. */ |
3097 | if ((e->flags & EDGE_FALLTHRU) && any_condjump_p (insn)) | |
3098 | /* A conditional jump can fall through into the next | |
3099 | block, so we should keep the edge. */ | |
628f6a4e BE |
3100 | { |
3101 | ei_next (&ei); | |
3102 | continue; | |
3103 | } | |
fefa31b5 | 3104 | else if (e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) |
a813c111 | 3105 | && BB_HEAD (e->dest) == JUMP_LABEL (insn)) |
5a566bed MM |
3106 | /* If the destination block is the target of the jump, |
3107 | keep the edge. */ | |
628f6a4e BE |
3108 | { |
3109 | ei_next (&ei); | |
3110 | continue; | |
3111 | } | |
fefa31b5 DM |
3112 | else if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) |
3113 | && returnjump_p (insn)) | |
5a566bed MM |
3114 | /* If the destination block is the exit block, and this |
3115 | instruction is a return, then keep the edge. */ | |
628f6a4e BE |
3116 | { |
3117 | ei_next (&ei); | |
3118 | continue; | |
3119 | } | |
5a566bed MM |
3120 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) |
3121 | /* Keep the edges that correspond to exceptions thrown by | |
0b75beaa EB |
3122 | this instruction and rematerialize the EDGE_ABNORMAL |
3123 | flag we just cleared above. */ | |
3124 | { | |
3125 | e->flags |= EDGE_ABNORMAL; | |
628f6a4e | 3126 | ei_next (&ei); |
0b75beaa EB |
3127 | continue; |
3128 | } | |
5f0d2358 | 3129 | |
5a566bed | 3130 | /* We do not need this edge. */ |
6fb5fa3c | 3131 | df_set_bb_dirty (bb); |
ca6c03ca JH |
3132 | purged = true; |
3133 | remove_edge (e); | |
3134 | } | |
5f0d2358 | 3135 | |
628f6a4e | 3136 | if (EDGE_COUNT (bb->succs) == 0 || !purged) |
c51d95ec | 3137 | return purged; |
5f0d2358 | 3138 | |
c263766c RH |
3139 | if (dump_file) |
3140 | fprintf (dump_file, "Purged edges from bb %i\n", bb->index); | |
5f0d2358 | 3141 | |
ca6c03ca JH |
3142 | if (!optimize) |
3143 | return purged; | |
3144 | ||
3145 | /* Redistribute probabilities. */ | |
c5cbcccf | 3146 | if (single_succ_p (bb)) |
ca6c03ca | 3147 | { |
c5cbcccf ZD |
3148 | single_succ_edge (bb)->probability = REG_BR_PROB_BASE; |
3149 | single_succ_edge (bb)->count = bb->count; | |
f87c27b4 | 3150 | } |
ca6c03ca JH |
3151 | else |
3152 | { | |
3153 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
3154 | if (!note) | |
3155 | return purged; | |
5f0d2358 | 3156 | |
ca6c03ca JH |
3157 | b = BRANCH_EDGE (bb); |
3158 | f = FALLTHRU_EDGE (bb); | |
e5af9ddd | 3159 | b->probability = XINT (note, 0); |
ca6c03ca | 3160 | f->probability = REG_BR_PROB_BASE - b->probability; |
8ddb5a29 | 3161 | /* Update these to use GCOV_COMPUTE_SCALE. */ |
ca6c03ca JH |
3162 | b->count = bb->count * b->probability / REG_BR_PROB_BASE; |
3163 | f->count = bb->count * f->probability / REG_BR_PROB_BASE; | |
3164 | } | |
5f0d2358 | 3165 | |
ca6c03ca JH |
3166 | return purged; |
3167 | } | |
4b4bf941 | 3168 | else if (CALL_P (insn) && SIBLING_CALL_P (insn)) |
1722c2c8 RH |
3169 | { |
3170 | /* First, there should not be any EH or ABCALL edges resulting | |
3171 | from non-local gotos and the like. If there were, we shouldn't | |
3172 | have created the sibcall in the first place. Second, there | |
3173 | should of course never have been a fallthru edge. */ | |
c5cbcccf ZD |
3174 | gcc_assert (single_succ_p (bb)); |
3175 | gcc_assert (single_succ_edge (bb)->flags | |
3176 | == (EDGE_SIBCALL | EDGE_ABNORMAL)); | |
1722c2c8 RH |
3177 | |
3178 | return 0; | |
3179 | } | |
ca6c03ca | 3180 | |
ca6c03ca JH |
3181 | /* If we don't see a jump insn, we don't know exactly why the block would |
3182 | have been broken at this point. Look for a simple, non-fallthru edge, | |
3183 | as these are only created by conditional branches. If we find such an | |
3184 | edge we know that there used to be a jump here and can then safely | |
3185 | remove all non-fallthru edges. */ | |
628f6a4e BE |
3186 | found = false; |
3187 | FOR_EACH_EDGE (e, ei, bb->succs) | |
3188 | if (! (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU))) | |
3189 | { | |
3190 | found = true; | |
3191 | break; | |
3192 | } | |
5f0d2358 | 3193 | |
628f6a4e | 3194 | if (!found) |
ca6c03ca | 3195 | return purged; |
5f0d2358 | 3196 | |
2afa8dce DB |
3197 | /* Remove all but the fake and fallthru edges. The fake edge may be |
3198 | the only successor for this block in the case of noreturn | |
3199 | calls. */ | |
628f6a4e | 3200 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
ca6c03ca | 3201 | { |
2afa8dce | 3202 | if (!(e->flags & (EDGE_FALLTHRU | EDGE_FAKE))) |
c51d95ec | 3203 | { |
6fb5fa3c | 3204 | df_set_bb_dirty (bb); |
c51d95ec JH |
3205 | remove_edge (e); |
3206 | purged = true; | |
3207 | } | |
628f6a4e BE |
3208 | else |
3209 | ei_next (&ei); | |
ca6c03ca | 3210 | } |
5f0d2358 | 3211 | |
c5cbcccf | 3212 | gcc_assert (single_succ_p (bb)); |
5f0d2358 | 3213 | |
c5cbcccf ZD |
3214 | single_succ_edge (bb)->probability = REG_BR_PROB_BASE; |
3215 | single_succ_edge (bb)->count = bb->count; | |
ca6c03ca | 3216 | |
c263766c RH |
3217 | if (dump_file) |
3218 | fprintf (dump_file, "Purged non-fallthru edges from bb %i\n", | |
0b17ab2f | 3219 | bb->index); |
ca6c03ca JH |
3220 | return purged; |
3221 | } | |
3222 | ||
5f0d2358 RK |
3223 | /* Search all basic blocks for potentially dead edges and purge them. Return |
3224 | true if some edge has been eliminated. */ | |
ca6c03ca JH |
3225 | |
3226 | bool | |
25cd19de | 3227 | purge_all_dead_edges (void) |
ca6c03ca | 3228 | { |
e0082a72 | 3229 | int purged = false; |
e0082a72 | 3230 | basic_block bb; |
473fb060 | 3231 | |
11cd3bed | 3232 | FOR_EACH_BB_FN (bb, cfun) |
473fb060 | 3233 | { |
e0082a72 | 3234 | bool purged_here = purge_dead_edges (bb); |
5f0d2358 | 3235 | |
473fb060 | 3236 | purged |= purged_here; |
473fb060 | 3237 | } |
5f0d2358 | 3238 | |
ca6c03ca JH |
3239 | return purged; |
3240 | } | |
9ee634e3 | 3241 | |
ba5e9aca EB |
3242 | /* This is used by a few passes that emit some instructions after abnormal |
3243 | calls, moving the basic block's end, while they in fact do want to emit | |
3244 | them on the fallthru edge. Look for abnormal call edges, find backward | |
3245 | the call in the block and insert the instructions on the edge instead. | |
3246 | ||
3247 | Similarly, handle instructions throwing exceptions internally. | |
3248 | ||
3249 | Return true when instructions have been found and inserted on edges. */ | |
3250 | ||
3251 | bool | |
3252 | fixup_abnormal_edges (void) | |
3253 | { | |
3254 | bool inserted = false; | |
3255 | basic_block bb; | |
3256 | ||
11cd3bed | 3257 | FOR_EACH_BB_FN (bb, cfun) |
ba5e9aca EB |
3258 | { |
3259 | edge e; | |
3260 | edge_iterator ei; | |
3261 | ||
3262 | /* Look for cases we are interested in - calls or instructions causing | |
3263 | exceptions. */ | |
3264 | FOR_EACH_EDGE (e, ei, bb->succs) | |
3265 | if ((e->flags & EDGE_ABNORMAL_CALL) | |
3266 | || ((e->flags & (EDGE_ABNORMAL | EDGE_EH)) | |
3267 | == (EDGE_ABNORMAL | EDGE_EH))) | |
3268 | break; | |
3269 | ||
3270 | if (e && !CALL_P (BB_END (bb)) && !can_throw_internal (BB_END (bb))) | |
3271 | { | |
8879d71c | 3272 | rtx_insn *insn; |
ba5e9aca EB |
3273 | |
3274 | /* Get past the new insns generated. Allow notes, as the insns | |
3275 | may be already deleted. */ | |
3276 | insn = BB_END (bb); | |
3277 | while ((NONJUMP_INSN_P (insn) || NOTE_P (insn)) | |
3278 | && !can_throw_internal (insn) | |
3279 | && insn != BB_HEAD (bb)) | |
3280 | insn = PREV_INSN (insn); | |
3281 | ||
3282 | if (CALL_P (insn) || can_throw_internal (insn)) | |
3283 | { | |
8879d71c | 3284 | rtx_insn *stop, *next; |
ba5e9aca EB |
3285 | |
3286 | e = find_fallthru_edge (bb->succs); | |
3287 | ||
3288 | stop = NEXT_INSN (BB_END (bb)); | |
1130d5e3 | 3289 | BB_END (bb) = insn; |
ba5e9aca EB |
3290 | |
3291 | for (insn = NEXT_INSN (insn); insn != stop; insn = next) | |
3292 | { | |
3293 | next = NEXT_INSN (insn); | |
3294 | if (INSN_P (insn)) | |
3295 | { | |
3296 | delete_insn (insn); | |
3297 | ||
3298 | /* Sometimes there's still the return value USE. | |
3299 | If it's placed after a trapping call (i.e. that | |
3300 | call is the last insn anyway), we have no fallthru | |
3301 | edge. Simply delete this use and don't try to insert | |
3302 | on the non-existent edge. */ | |
3303 | if (GET_CODE (PATTERN (insn)) != USE) | |
3304 | { | |
3305 | /* We're not deleting it, we're moving it. */ | |
4654c0cf | 3306 | insn->set_undeleted (); |
0f82e5c9 DM |
3307 | SET_PREV_INSN (insn) = NULL_RTX; |
3308 | SET_NEXT_INSN (insn) = NULL_RTX; | |
ba5e9aca EB |
3309 | |
3310 | insert_insn_on_edge (insn, e); | |
3311 | inserted = true; | |
3312 | } | |
3313 | } | |
3314 | else if (!BARRIER_P (insn)) | |
3315 | set_block_for_insn (insn, NULL); | |
3316 | } | |
3317 | } | |
3318 | ||
3319 | /* It may be that we don't find any trapping insn. In this | |
3320 | case we discovered quite late that the insn that had been | |
3321 | marked as can_throw_internal in fact couldn't trap at all. | |
3322 | So we should in fact delete the EH edges out of the block. */ | |
3323 | else | |
3324 | purge_dead_edges (bb); | |
3325 | } | |
3326 | } | |
3327 | ||
3328 | return inserted; | |
3329 | } | |
78bde837 SB |
3330 | \f |
3331 | /* Cut the insns from FIRST to LAST out of the insns stream. */ | |
3332 | ||
a90c614a | 3333 | rtx_insn * |
9152e0aa | 3334 | unlink_insn_chain (rtx_insn *first, rtx_insn *last) |
78bde837 | 3335 | { |
a90c614a DM |
3336 | rtx_insn *prevfirst = PREV_INSN (first); |
3337 | rtx_insn *nextlast = NEXT_INSN (last); | |
78bde837 | 3338 | |
0f82e5c9 DM |
3339 | SET_PREV_INSN (first) = NULL; |
3340 | SET_NEXT_INSN (last) = NULL; | |
78bde837 | 3341 | if (prevfirst) |
0f82e5c9 | 3342 | SET_NEXT_INSN (prevfirst) = nextlast; |
78bde837 | 3343 | if (nextlast) |
0f82e5c9 | 3344 | SET_PREV_INSN (nextlast) = prevfirst; |
78bde837 SB |
3345 | else |
3346 | set_last_insn (prevfirst); | |
3347 | if (!prevfirst) | |
3348 | set_first_insn (nextlast); | |
9152e0aa | 3349 | return first; |
78bde837 SB |
3350 | } |
3351 | \f | |
3352 | /* Skip over inter-block insns occurring after BB which are typically | |
3353 | associated with BB (e.g., barriers). If there are any such insns, | |
3354 | we return the last one. Otherwise, we return the end of BB. */ | |
3355 | ||
8879d71c | 3356 | static rtx_insn * |
78bde837 SB |
3357 | skip_insns_after_block (basic_block bb) |
3358 | { | |
8879d71c | 3359 | rtx_insn *insn, *last_insn, *next_head, *prev; |
78bde837 | 3360 | |
8879d71c | 3361 | next_head = NULL; |
fefa31b5 | 3362 | if (bb->next_bb != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
78bde837 SB |
3363 | next_head = BB_HEAD (bb->next_bb); |
3364 | ||
3365 | for (last_insn = insn = BB_END (bb); (insn = NEXT_INSN (insn)) != 0; ) | |
3366 | { | |
3367 | if (insn == next_head) | |
3368 | break; | |
3369 | ||
3370 | switch (GET_CODE (insn)) | |
3371 | { | |
3372 | case BARRIER: | |
3373 | last_insn = insn; | |
3374 | continue; | |
3375 | ||
3376 | case NOTE: | |
3377 | switch (NOTE_KIND (insn)) | |
3378 | { | |
3379 | case NOTE_INSN_BLOCK_END: | |
3380 | gcc_unreachable (); | |
3381 | continue; | |
3382 | default: | |
3383 | continue; | |
3384 | break; | |
3385 | } | |
3386 | break; | |
3387 | ||
3388 | case CODE_LABEL: | |
3389 | if (NEXT_INSN (insn) | |
3390 | && JUMP_TABLE_DATA_P (NEXT_INSN (insn))) | |
3391 | { | |
3392 | insn = NEXT_INSN (insn); | |
3393 | last_insn = insn; | |
3394 | continue; | |
3395 | } | |
3396 | break; | |
3397 | ||
3398 | default: | |
3399 | break; | |
3400 | } | |
3401 | ||
3402 | break; | |
3403 | } | |
3404 | ||
3405 | /* It is possible to hit contradictory sequence. For instance: | |
3406 | ||
3407 | jump_insn | |
3408 | NOTE_INSN_BLOCK_BEG | |
3409 | barrier | |
3410 | ||
3411 | Where barrier belongs to jump_insn, but the note does not. This can be | |
3412 | created by removing the basic block originally following | |
3413 | NOTE_INSN_BLOCK_BEG. In such case reorder the notes. */ | |
3414 | ||
3415 | for (insn = last_insn; insn != BB_END (bb); insn = prev) | |
3416 | { | |
3417 | prev = PREV_INSN (insn); | |
3418 | if (NOTE_P (insn)) | |
3419 | switch (NOTE_KIND (insn)) | |
3420 | { | |
3421 | case NOTE_INSN_BLOCK_END: | |
3422 | gcc_unreachable (); | |
3423 | break; | |
3424 | case NOTE_INSN_DELETED: | |
3425 | case NOTE_INSN_DELETED_LABEL: | |
3426 | case NOTE_INSN_DELETED_DEBUG_LABEL: | |
3427 | continue; | |
3428 | default: | |
3429 | reorder_insns (insn, insn, last_insn); | |
3430 | } | |
3431 | } | |
3432 | ||
3433 | return last_insn; | |
3434 | } | |
3435 | ||
3436 | /* Locate or create a label for a given basic block. */ | |
3437 | ||
e67d1102 | 3438 | static rtx_insn * |
78bde837 SB |
3439 | label_for_bb (basic_block bb) |
3440 | { | |
e67d1102 | 3441 | rtx_insn *label = BB_HEAD (bb); |
78bde837 SB |
3442 | |
3443 | if (!LABEL_P (label)) | |
3444 | { | |
3445 | if (dump_file) | |
3446 | fprintf (dump_file, "Emitting label for block %d\n", bb->index); | |
3447 | ||
3448 | label = block_label (bb); | |
3449 | } | |
3450 | ||
3451 | return label; | |
3452 | } | |
3453 | ||
3454 | /* Locate the effective beginning and end of the insn chain for each | |
3455 | block, as defined by skip_insns_after_block above. */ | |
3456 | ||
3457 | static void | |
3458 | record_effective_endpoints (void) | |
3459 | { | |
8879d71c | 3460 | rtx_insn *next_insn; |
78bde837 | 3461 | basic_block bb; |
8879d71c | 3462 | rtx_insn *insn; |
78bde837 SB |
3463 | |
3464 | for (insn = get_insns (); | |
3465 | insn | |
3466 | && NOTE_P (insn) | |
3467 | && NOTE_KIND (insn) != NOTE_INSN_BASIC_BLOCK; | |
3468 | insn = NEXT_INSN (insn)) | |
3469 | continue; | |
3470 | /* No basic blocks at all? */ | |
3471 | gcc_assert (insn); | |
3472 | ||
3473 | if (PREV_INSN (insn)) | |
3474 | cfg_layout_function_header = | |
3475 | unlink_insn_chain (get_insns (), PREV_INSN (insn)); | |
3476 | else | |
9152e0aa | 3477 | cfg_layout_function_header = NULL; |
78bde837 SB |
3478 | |
3479 | next_insn = get_insns (); | |
11cd3bed | 3480 | FOR_EACH_BB_FN (bb, cfun) |
78bde837 | 3481 | { |
8879d71c | 3482 | rtx_insn *end; |
78bde837 SB |
3483 | |
3484 | if (PREV_INSN (BB_HEAD (bb)) && next_insn != BB_HEAD (bb)) | |
1130d5e3 | 3485 | BB_HEADER (bb) = unlink_insn_chain (next_insn, |
190bea87 | 3486 | PREV_INSN (BB_HEAD (bb))); |
78bde837 SB |
3487 | end = skip_insns_after_block (bb); |
3488 | if (NEXT_INSN (BB_END (bb)) && BB_END (bb) != end) | |
d8ce2eae | 3489 | BB_FOOTER (bb) = unlink_insn_chain (NEXT_INSN (BB_END (bb)), end); |
78bde837 SB |
3490 | next_insn = NEXT_INSN (BB_END (bb)); |
3491 | } | |
3492 | ||
3493 | cfg_layout_function_footer = next_insn; | |
3494 | if (cfg_layout_function_footer) | |
3495 | cfg_layout_function_footer = unlink_insn_chain (cfg_layout_function_footer, get_last_insn ()); | |
3496 | } | |
3497 | \f | |
27a4cd48 DM |
3498 | namespace { |
3499 | ||
3500 | const pass_data pass_data_into_cfg_layout_mode = | |
3501 | { | |
3502 | RTL_PASS, /* type */ | |
3503 | "into_cfglayout", /* name */ | |
3504 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
3505 | TV_CFG, /* tv_id */ |
3506 | 0, /* properties_required */ | |
3507 | PROP_cfglayout, /* properties_provided */ | |
3508 | 0, /* properties_destroyed */ | |
3509 | 0, /* todo_flags_start */ | |
3510 | 0, /* todo_flags_finish */ | |
78bde837 SB |
3511 | }; |
3512 | ||
27a4cd48 DM |
3513 | class pass_into_cfg_layout_mode : public rtl_opt_pass |
3514 | { | |
3515 | public: | |
c3284718 RS |
3516 | pass_into_cfg_layout_mode (gcc::context *ctxt) |
3517 | : rtl_opt_pass (pass_data_into_cfg_layout_mode, ctxt) | |
27a4cd48 DM |
3518 | {} |
3519 | ||
3520 | /* opt_pass methods: */ | |
be55bfe6 TS |
3521 | virtual unsigned int execute (function *) |
3522 | { | |
3523 | cfg_layout_initialize (0); | |
3524 | return 0; | |
3525 | } | |
27a4cd48 DM |
3526 | |
3527 | }; // class pass_into_cfg_layout_mode | |
3528 | ||
3529 | } // anon namespace | |
3530 | ||
3531 | rtl_opt_pass * | |
3532 | make_pass_into_cfg_layout_mode (gcc::context *ctxt) | |
3533 | { | |
3534 | return new pass_into_cfg_layout_mode (ctxt); | |
3535 | } | |
3536 | ||
3537 | namespace { | |
3538 | ||
3539 | const pass_data pass_data_outof_cfg_layout_mode = | |
3540 | { | |
3541 | RTL_PASS, /* type */ | |
3542 | "outof_cfglayout", /* name */ | |
3543 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
3544 | TV_CFG, /* tv_id */ |
3545 | 0, /* properties_required */ | |
3546 | 0, /* properties_provided */ | |
3547 | PROP_cfglayout, /* properties_destroyed */ | |
3548 | 0, /* todo_flags_start */ | |
3549 | 0, /* todo_flags_finish */ | |
78bde837 | 3550 | }; |
27a4cd48 DM |
3551 | |
3552 | class pass_outof_cfg_layout_mode : public rtl_opt_pass | |
3553 | { | |
3554 | public: | |
c3284718 RS |
3555 | pass_outof_cfg_layout_mode (gcc::context *ctxt) |
3556 | : rtl_opt_pass (pass_data_outof_cfg_layout_mode, ctxt) | |
27a4cd48 DM |
3557 | {} |
3558 | ||
3559 | /* opt_pass methods: */ | |
be55bfe6 | 3560 | virtual unsigned int execute (function *); |
27a4cd48 DM |
3561 | |
3562 | }; // class pass_outof_cfg_layout_mode | |
3563 | ||
be55bfe6 TS |
3564 | unsigned int |
3565 | pass_outof_cfg_layout_mode::execute (function *fun) | |
3566 | { | |
3567 | basic_block bb; | |
3568 | ||
3569 | FOR_EACH_BB_FN (bb, fun) | |
3570 | if (bb->next_bb != EXIT_BLOCK_PTR_FOR_FN (fun)) | |
3571 | bb->aux = bb->next_bb; | |
3572 | ||
3573 | cfg_layout_finalize (); | |
3574 | ||
3575 | return 0; | |
3576 | } | |
3577 | ||
27a4cd48 DM |
3578 | } // anon namespace |
3579 | ||
3580 | rtl_opt_pass * | |
3581 | make_pass_outof_cfg_layout_mode (gcc::context *ctxt) | |
3582 | { | |
3583 | return new pass_outof_cfg_layout_mode (ctxt); | |
3584 | } | |
78bde837 SB |
3585 | \f |
3586 | ||
3587 | /* Link the basic blocks in the correct order, compacting the basic | |
3588 | block queue while at it. If STAY_IN_CFGLAYOUT_MODE is false, this | |
3589 | function also clears the basic block header and footer fields. | |
3590 | ||
3591 | This function is usually called after a pass (e.g. tracer) finishes | |
3592 | some transformations while in cfglayout mode. The required sequence | |
3593 | of the basic blocks is in a linked list along the bb->aux field. | |
3594 | This functions re-links the basic block prev_bb and next_bb pointers | |
532aafad SB |
3595 | accordingly, and it compacts and renumbers the blocks. |
3596 | ||
3597 | FIXME: This currently works only for RTL, but the only RTL-specific | |
3598 | bits are the STAY_IN_CFGLAYOUT_MODE bits. The tracer pass was moved | |
3599 | to GIMPLE a long time ago, but it doesn't relink the basic block | |
3600 | chain. It could do that (to give better initial RTL) if this function | |
3601 | is made IR-agnostic (and moved to cfganal.c or cfg.c while at it). */ | |
78bde837 SB |
3602 | |
3603 | void | |
3604 | relink_block_chain (bool stay_in_cfglayout_mode) | |
3605 | { | |
3606 | basic_block bb, prev_bb; | |
3607 | int index; | |
3608 | ||
3609 | /* Maybe dump the re-ordered sequence. */ | |
3610 | if (dump_file) | |
3611 | { | |
3612 | fprintf (dump_file, "Reordered sequence:\n"); | |
fefa31b5 DM |
3613 | for (bb = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb, index = |
3614 | NUM_FIXED_BLOCKS; | |
78bde837 SB |
3615 | bb; |
3616 | bb = (basic_block) bb->aux, index++) | |
3617 | { | |
3618 | fprintf (dump_file, " %i ", index); | |
3619 | if (get_bb_original (bb)) | |
3620 | fprintf (dump_file, "duplicate of %i ", | |
3621 | get_bb_original (bb)->index); | |
3622 | else if (forwarder_block_p (bb) | |
3623 | && !LABEL_P (BB_HEAD (bb))) | |
3624 | fprintf (dump_file, "compensation "); | |
3625 | else | |
3626 | fprintf (dump_file, "bb %i ", bb->index); | |
3627 | fprintf (dump_file, " [%i]\n", bb->frequency); | |
3628 | } | |
3629 | } | |
3630 | ||
3631 | /* Now reorder the blocks. */ | |
fefa31b5 DM |
3632 | prev_bb = ENTRY_BLOCK_PTR_FOR_FN (cfun); |
3633 | bb = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb; | |
78bde837 SB |
3634 | for (; bb; prev_bb = bb, bb = (basic_block) bb->aux) |
3635 | { | |
3636 | bb->prev_bb = prev_bb; | |
3637 | prev_bb->next_bb = bb; | |
3638 | } | |
fefa31b5 DM |
3639 | prev_bb->next_bb = EXIT_BLOCK_PTR_FOR_FN (cfun); |
3640 | EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb = prev_bb; | |
78bde837 SB |
3641 | |
3642 | /* Then, clean up the aux fields. */ | |
04a90bec | 3643 | FOR_ALL_BB_FN (bb, cfun) |
78bde837 SB |
3644 | { |
3645 | bb->aux = NULL; | |
3646 | if (!stay_in_cfglayout_mode) | |
1130d5e3 | 3647 | BB_HEADER (bb) = BB_FOOTER (bb) = NULL; |
78bde837 SB |
3648 | } |
3649 | ||
3650 | /* Maybe reset the original copy tables, they are not valid anymore | |
3651 | when we renumber the basic blocks in compact_blocks. If we are | |
3652 | are going out of cfglayout mode, don't re-allocate the tables. */ | |
3653 | free_original_copy_tables (); | |
3654 | if (stay_in_cfglayout_mode) | |
3655 | initialize_original_copy_tables (); | |
3656 | ||
3657 | /* Finally, put basic_block_info in the new order. */ | |
3658 | compact_blocks (); | |
3659 | } | |
3660 | \f | |
3661 | ||
3662 | /* Given a reorder chain, rearrange the code to match. */ | |
3663 | ||
3664 | static void | |
3665 | fixup_reorder_chain (void) | |
3666 | { | |
3667 | basic_block bb; | |
9152e0aa | 3668 | rtx_insn *insn = NULL; |
78bde837 SB |
3669 | |
3670 | if (cfg_layout_function_header) | |
3671 | { | |
3672 | set_first_insn (cfg_layout_function_header); | |
3673 | insn = cfg_layout_function_header; | |
3674 | while (NEXT_INSN (insn)) | |
3675 | insn = NEXT_INSN (insn); | |
3676 | } | |
3677 | ||
3678 | /* First do the bulk reordering -- rechain the blocks without regard to | |
3679 | the needed changes to jumps and labels. */ | |
3680 | ||
fefa31b5 DM |
3681 | for (bb = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb; bb; bb = (basic_block) |
3682 | bb->aux) | |
78bde837 SB |
3683 | { |
3684 | if (BB_HEADER (bb)) | |
3685 | { | |
3686 | if (insn) | |
0f82e5c9 | 3687 | SET_NEXT_INSN (insn) = BB_HEADER (bb); |
78bde837 SB |
3688 | else |
3689 | set_first_insn (BB_HEADER (bb)); | |
0f82e5c9 | 3690 | SET_PREV_INSN (BB_HEADER (bb)) = insn; |
78bde837 SB |
3691 | insn = BB_HEADER (bb); |
3692 | while (NEXT_INSN (insn)) | |
3693 | insn = NEXT_INSN (insn); | |
3694 | } | |
3695 | if (insn) | |
0f82e5c9 | 3696 | SET_NEXT_INSN (insn) = BB_HEAD (bb); |
78bde837 SB |
3697 | else |
3698 | set_first_insn (BB_HEAD (bb)); | |
0f82e5c9 | 3699 | SET_PREV_INSN (BB_HEAD (bb)) = insn; |
78bde837 SB |
3700 | insn = BB_END (bb); |
3701 | if (BB_FOOTER (bb)) | |
3702 | { | |
0f82e5c9 DM |
3703 | SET_NEXT_INSN (insn) = BB_FOOTER (bb); |
3704 | SET_PREV_INSN (BB_FOOTER (bb)) = insn; | |
78bde837 SB |
3705 | while (NEXT_INSN (insn)) |
3706 | insn = NEXT_INSN (insn); | |
3707 | } | |
3708 | } | |
3709 | ||
0f82e5c9 | 3710 | SET_NEXT_INSN (insn) = cfg_layout_function_footer; |
78bde837 | 3711 | if (cfg_layout_function_footer) |
0f82e5c9 | 3712 | SET_PREV_INSN (cfg_layout_function_footer) = insn; |
78bde837 SB |
3713 | |
3714 | while (NEXT_INSN (insn)) | |
3715 | insn = NEXT_INSN (insn); | |
3716 | ||
3717 | set_last_insn (insn); | |
b2b29377 MM |
3718 | if (flag_checking) |
3719 | verify_insn_chain (); | |
78bde837 SB |
3720 | |
3721 | /* Now add jumps and labels as needed to match the blocks new | |
29f3fd5b | 3722 | outgoing edges. */ |
78bde837 | 3723 | |
29f3fd5b SB |
3724 | for (bb = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb; bb ; bb = (basic_block) |
3725 | bb->aux) | |
78bde837 SB |
3726 | { |
3727 | edge e_fall, e_taken, e; | |
8879d71c | 3728 | rtx_insn *bb_end_insn; |
78bde837 | 3729 | rtx ret_label = NULL_RTX; |
3371a64f | 3730 | basic_block nb; |
78bde837 SB |
3731 | edge_iterator ei; |
3732 | ||
3733 | if (EDGE_COUNT (bb->succs) == 0) | |
3734 | continue; | |
3735 | ||
3736 | /* Find the old fallthru edge, and another non-EH edge for | |
3737 | a taken jump. */ | |
3738 | e_taken = e_fall = NULL; | |
3739 | ||
3740 | FOR_EACH_EDGE (e, ei, bb->succs) | |
3741 | if (e->flags & EDGE_FALLTHRU) | |
3742 | e_fall = e; | |
3743 | else if (! (e->flags & EDGE_EH)) | |
3744 | e_taken = e; | |
3745 | ||
3746 | bb_end_insn = BB_END (bb); | |
1476d1bd | 3747 | if (rtx_jump_insn *bb_end_jump = dyn_cast <rtx_jump_insn *> (bb_end_insn)) |
78bde837 | 3748 | { |
1476d1bd MM |
3749 | ret_label = JUMP_LABEL (bb_end_jump); |
3750 | if (any_condjump_p (bb_end_jump)) | |
78bde837 SB |
3751 | { |
3752 | /* This might happen if the conditional jump has side | |
3753 | effects and could therefore not be optimized away. | |
3754 | Make the basic block to end with a barrier in order | |
3755 | to prevent rtl_verify_flow_info from complaining. */ | |
3756 | if (!e_fall) | |
3757 | { | |
1476d1bd MM |
3758 | gcc_assert (!onlyjump_p (bb_end_jump) |
3759 | || returnjump_p (bb_end_jump) | |
91af97c3 | 3760 | || (e_taken->flags & EDGE_CROSSING)); |
1476d1bd | 3761 | emit_barrier_after (bb_end_jump); |
78bde837 SB |
3762 | continue; |
3763 | } | |
3764 | ||
3765 | /* If the old fallthru is still next, nothing to do. */ | |
3766 | if (bb->aux == e_fall->dest | |
fefa31b5 | 3767 | || e_fall->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
78bde837 SB |
3768 | continue; |
3769 | ||
3770 | /* The degenerated case of conditional jump jumping to the next | |
3771 | instruction can happen for jumps with side effects. We need | |
3772 | to construct a forwarder block and this will be done just | |
3773 | fine by force_nonfallthru below. */ | |
3774 | if (!e_taken) | |
3775 | ; | |
3776 | ||
3777 | /* There is another special case: if *neither* block is next, | |
3778 | such as happens at the very end of a function, then we'll | |
3779 | need to add a new unconditional jump. Choose the taken | |
3780 | edge based on known or assumed probability. */ | |
3781 | else if (bb->aux != e_taken->dest) | |
3782 | { | |
1476d1bd | 3783 | rtx note = find_reg_note (bb_end_jump, REG_BR_PROB, 0); |
78bde837 SB |
3784 | |
3785 | if (note | |
e5af9ddd | 3786 | && XINT (note, 0) < REG_BR_PROB_BASE / 2 |
1476d1bd | 3787 | && invert_jump (bb_end_jump, |
fefa31b5 DM |
3788 | (e_fall->dest |
3789 | == EXIT_BLOCK_PTR_FOR_FN (cfun) | |
78bde837 SB |
3790 | ? NULL_RTX |
3791 | : label_for_bb (e_fall->dest)), 0)) | |
3792 | { | |
3793 | e_fall->flags &= ~EDGE_FALLTHRU; | |
3794 | gcc_checking_assert (could_fall_through | |
3795 | (e_taken->src, e_taken->dest)); | |
3796 | e_taken->flags |= EDGE_FALLTHRU; | |
3797 | update_br_prob_note (bb); | |
3798 | e = e_fall, e_fall = e_taken, e_taken = e; | |
3799 | } | |
3800 | } | |
3801 | ||
3802 | /* If the "jumping" edge is a crossing edge, and the fall | |
3803 | through edge is non-crossing, leave things as they are. */ | |
3804 | else if ((e_taken->flags & EDGE_CROSSING) | |
3805 | && !(e_fall->flags & EDGE_CROSSING)) | |
3806 | continue; | |
3807 | ||
3808 | /* Otherwise we can try to invert the jump. This will | |
3809 | basically never fail, however, keep up the pretense. */ | |
1476d1bd | 3810 | else if (invert_jump (bb_end_jump, |
fefa31b5 DM |
3811 | (e_fall->dest |
3812 | == EXIT_BLOCK_PTR_FOR_FN (cfun) | |
78bde837 SB |
3813 | ? NULL_RTX |
3814 | : label_for_bb (e_fall->dest)), 0)) | |
3815 | { | |
3816 | e_fall->flags &= ~EDGE_FALLTHRU; | |
3817 | gcc_checking_assert (could_fall_through | |
3818 | (e_taken->src, e_taken->dest)); | |
3819 | e_taken->flags |= EDGE_FALLTHRU; | |
3820 | update_br_prob_note (bb); | |
3821 | if (LABEL_NUSES (ret_label) == 0 | |
3822 | && single_pred_p (e_taken->dest)) | |
3823 | delete_insn (ret_label); | |
3824 | continue; | |
3825 | } | |
3826 | } | |
3827 | else if (extract_asm_operands (PATTERN (bb_end_insn)) != NULL) | |
3828 | { | |
3829 | /* If the old fallthru is still next or if | |
3830 | asm goto doesn't have a fallthru (e.g. when followed by | |
3831 | __builtin_unreachable ()), nothing to do. */ | |
3832 | if (! e_fall | |
3833 | || bb->aux == e_fall->dest | |
fefa31b5 | 3834 | || e_fall->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
78bde837 SB |
3835 | continue; |
3836 | ||
3837 | /* Otherwise we'll have to use the fallthru fixup below. */ | |
3838 | } | |
3839 | else | |
3840 | { | |
3841 | /* Otherwise we have some return, switch or computed | |
3842 | jump. In the 99% case, there should not have been a | |
3843 | fallthru edge. */ | |
3844 | gcc_assert (returnjump_p (bb_end_insn) || !e_fall); | |
3845 | continue; | |
3846 | } | |
3847 | } | |
3848 | else | |
3849 | { | |
3850 | /* No fallthru implies a noreturn function with EH edges, or | |
3851 | something similarly bizarre. In any case, we don't need to | |
3852 | do anything. */ | |
3853 | if (! e_fall) | |
3854 | continue; | |
3855 | ||
3856 | /* If the fallthru block is still next, nothing to do. */ | |
3857 | if (bb->aux == e_fall->dest) | |
3858 | continue; | |
3859 | ||
3860 | /* A fallthru to exit block. */ | |
fefa31b5 | 3861 | if (e_fall->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
78bde837 SB |
3862 | continue; |
3863 | } | |
3864 | ||
3865 | /* We got here if we need to add a new jump insn. | |
3866 | Note force_nonfallthru can delete E_FALL and thus we have to | |
3867 | save E_FALL->src prior to the call to force_nonfallthru. */ | |
78bde837 SB |
3868 | nb = force_nonfallthru_and_redirect (e_fall, e_fall->dest, ret_label); |
3869 | if (nb) | |
3870 | { | |
3871 | nb->aux = bb->aux; | |
3872 | bb->aux = nb; | |
3873 | /* Don't process this new block. */ | |
3874 | bb = nb; | |
78bde837 SB |
3875 | } |
3876 | } | |
3877 | ||
3878 | relink_block_chain (/*stay_in_cfglayout_mode=*/false); | |
3879 | ||
29f3fd5b | 3880 | /* Annoying special case - jump around dead jumptables left in the code. */ |
11cd3bed | 3881 | FOR_EACH_BB_FN (bb, cfun) |
78bde837 SB |
3882 | { |
3883 | edge e = find_fallthru_edge (bb->succs); | |
3884 | ||
29f3fd5b SB |
3885 | if (e && !can_fallthru (e->src, e->dest)) |
3886 | force_nonfallthru (e); | |
78bde837 SB |
3887 | } |
3888 | ||
3889 | /* Ensure goto_locus from edges has some instructions with that locus | |
3890 | in RTL. */ | |
3891 | if (!optimize) | |
11cd3bed | 3892 | FOR_EACH_BB_FN (bb, cfun) |
78bde837 SB |
3893 | { |
3894 | edge e; | |
3895 | edge_iterator ei; | |
3896 | ||
3897 | FOR_EACH_EDGE (e, ei, bb->succs) | |
2f13f2de | 3898 | if (LOCATION_LOCUS (e->goto_locus) != UNKNOWN_LOCATION |
5368224f | 3899 | && !(e->flags & EDGE_ABNORMAL)) |
78bde837 SB |
3900 | { |
3901 | edge e2; | |
3902 | edge_iterator ei2; | |
3903 | basic_block dest, nb; | |
8879d71c | 3904 | rtx_insn *end; |
78bde837 SB |
3905 | |
3906 | insn = BB_END (e->src); | |
3907 | end = PREV_INSN (BB_HEAD (e->src)); | |
3908 | while (insn != end | |
5368224f | 3909 | && (!NONDEBUG_INSN_P (insn) || !INSN_HAS_LOCATION (insn))) |
78bde837 SB |
3910 | insn = PREV_INSN (insn); |
3911 | if (insn != end | |
5368224f | 3912 | && INSN_LOCATION (insn) == e->goto_locus) |
78bde837 SB |
3913 | continue; |
3914 | if (simplejump_p (BB_END (e->src)) | |
5368224f | 3915 | && !INSN_HAS_LOCATION (BB_END (e->src))) |
78bde837 | 3916 | { |
5368224f | 3917 | INSN_LOCATION (BB_END (e->src)) = e->goto_locus; |
78bde837 SB |
3918 | continue; |
3919 | } | |
3920 | dest = e->dest; | |
fefa31b5 | 3921 | if (dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
78bde837 SB |
3922 | { |
3923 | /* Non-fallthru edges to the exit block cannot be split. */ | |
3924 | if (!(e->flags & EDGE_FALLTHRU)) | |
3925 | continue; | |
3926 | } | |
3927 | else | |
3928 | { | |
3929 | insn = BB_HEAD (dest); | |
3930 | end = NEXT_INSN (BB_END (dest)); | |
3931 | while (insn != end && !NONDEBUG_INSN_P (insn)) | |
3932 | insn = NEXT_INSN (insn); | |
5368224f DC |
3933 | if (insn != end && INSN_HAS_LOCATION (insn) |
3934 | && INSN_LOCATION (insn) == e->goto_locus) | |
78bde837 SB |
3935 | continue; |
3936 | } | |
3937 | nb = split_edge (e); | |
3938 | if (!INSN_P (BB_END (nb))) | |
1130d5e3 | 3939 | BB_END (nb) = emit_insn_after_noloc (gen_nop (), BB_END (nb), |
190bea87 | 3940 | nb); |
5368224f | 3941 | INSN_LOCATION (BB_END (nb)) = e->goto_locus; |
78bde837 SB |
3942 | |
3943 | /* If there are other incoming edges to the destination block | |
3944 | with the same goto locus, redirect them to the new block as | |
3945 | well, this can prevent other such blocks from being created | |
3946 | in subsequent iterations of the loop. */ | |
3947 | for (ei2 = ei_start (dest->preds); (e2 = ei_safe_edge (ei2)); ) | |
2f13f2de | 3948 | if (LOCATION_LOCUS (e2->goto_locus) != UNKNOWN_LOCATION |
78bde837 | 3949 | && !(e2->flags & (EDGE_ABNORMAL | EDGE_FALLTHRU)) |
5368224f | 3950 | && e->goto_locus == e2->goto_locus) |
78bde837 SB |
3951 | redirect_edge_and_branch (e2, nb); |
3952 | else | |
3953 | ei_next (&ei2); | |
3954 | } | |
3955 | } | |
3956 | } | |
3957 | \f | |
3958 | /* Perform sanity checks on the insn chain. | |
3959 | 1. Check that next/prev pointers are consistent in both the forward and | |
3960 | reverse direction. | |
3961 | 2. Count insns in chain, going both directions, and check if equal. | |
3962 | 3. Check that get_last_insn () returns the actual end of chain. */ | |
3963 | ||
3964 | DEBUG_FUNCTION void | |
3965 | verify_insn_chain (void) | |
3966 | { | |
8879d71c | 3967 | rtx_insn *x, *prevx, *nextx; |
78bde837 SB |
3968 | int insn_cnt1, insn_cnt2; |
3969 | ||
3970 | for (prevx = NULL, insn_cnt1 = 1, x = get_insns (); | |
3971 | x != 0; | |
3972 | prevx = x, insn_cnt1++, x = NEXT_INSN (x)) | |
3973 | gcc_assert (PREV_INSN (x) == prevx); | |
3974 | ||
3975 | gcc_assert (prevx == get_last_insn ()); | |
3976 | ||
3977 | for (nextx = NULL, insn_cnt2 = 1, x = get_last_insn (); | |
3978 | x != 0; | |
3979 | nextx = x, insn_cnt2++, x = PREV_INSN (x)) | |
3980 | gcc_assert (NEXT_INSN (x) == nextx); | |
3981 | ||
3982 | gcc_assert (insn_cnt1 == insn_cnt2); | |
3983 | } | |
3984 | \f | |
3985 | /* If we have assembler epilogues, the block falling through to exit must | |
3986 | be the last one in the reordered chain when we reach final. Ensure | |
3987 | that this condition is met. */ | |
3988 | static void | |
3989 | fixup_fallthru_exit_predecessor (void) | |
3990 | { | |
3991 | edge e; | |
3992 | basic_block bb = NULL; | |
3993 | ||
3994 | /* This transformation is not valid before reload, because we might | |
3995 | separate a call from the instruction that copies the return | |
3996 | value. */ | |
3997 | gcc_assert (reload_completed); | |
3998 | ||
fefa31b5 | 3999 | e = find_fallthru_edge (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds); |
78bde837 SB |
4000 | if (e) |
4001 | bb = e->src; | |
4002 | ||
4003 | if (bb && bb->aux) | |
4004 | { | |
fefa31b5 | 4005 | basic_block c = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb; |
78bde837 SB |
4006 | |
4007 | /* If the very first block is the one with the fall-through exit | |
4008 | edge, we have to split that block. */ | |
4009 | if (c == bb) | |
4010 | { | |
c4d281b2 | 4011 | bb = split_block_after_labels (bb)->dest; |
78bde837 SB |
4012 | bb->aux = c->aux; |
4013 | c->aux = bb; | |
d8ce2eae DM |
4014 | BB_FOOTER (bb) = BB_FOOTER (c); |
4015 | BB_FOOTER (c) = NULL; | |
78bde837 SB |
4016 | } |
4017 | ||
4018 | while (c->aux != bb) | |
4019 | c = (basic_block) c->aux; | |
4020 | ||
4021 | c->aux = bb->aux; | |
4022 | while (c->aux) | |
4023 | c = (basic_block) c->aux; | |
4024 | ||
4025 | c->aux = bb; | |
4026 | bb->aux = NULL; | |
4027 | } | |
4028 | } | |
4029 | ||
4030 | /* In case there are more than one fallthru predecessors of exit, force that | |
4031 | there is only one. */ | |
4032 | ||
4033 | static void | |
4034 | force_one_exit_fallthru (void) | |
4035 | { | |
4036 | edge e, predecessor = NULL; | |
4037 | bool more = false; | |
4038 | edge_iterator ei; | |
4039 | basic_block forwarder, bb; | |
4040 | ||
fefa31b5 | 4041 | FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds) |
78bde837 SB |
4042 | if (e->flags & EDGE_FALLTHRU) |
4043 | { | |
4044 | if (predecessor == NULL) | |
4045 | predecessor = e; | |
4046 | else | |
4047 | { | |
4048 | more = true; | |
4049 | break; | |
4050 | } | |
4051 | } | |
4052 | ||
4053 | if (!more) | |
4054 | return; | |
4055 | ||
4056 | /* Exit has several fallthru predecessors. Create a forwarder block for | |
4057 | them. */ | |
4058 | forwarder = split_edge (predecessor); | |
fefa31b5 DM |
4059 | for (ei = ei_start (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds); |
4060 | (e = ei_safe_edge (ei)); ) | |
78bde837 SB |
4061 | { |
4062 | if (e->src == forwarder | |
4063 | || !(e->flags & EDGE_FALLTHRU)) | |
4064 | ei_next (&ei); | |
4065 | else | |
4066 | redirect_edge_and_branch_force (e, forwarder); | |
4067 | } | |
4068 | ||
4069 | /* Fix up the chain of blocks -- make FORWARDER immediately precede the | |
4070 | exit block. */ | |
11cd3bed | 4071 | FOR_EACH_BB_FN (bb, cfun) |
78bde837 SB |
4072 | { |
4073 | if (bb->aux == NULL && bb != forwarder) | |
4074 | { | |
4075 | bb->aux = forwarder; | |
4076 | break; | |
4077 | } | |
4078 | } | |
4079 | } | |
4080 | \f | |
4081 | /* Return true in case it is possible to duplicate the basic block BB. */ | |
4082 | ||
4083 | static bool | |
4084 | cfg_layout_can_duplicate_bb_p (const_basic_block bb) | |
4085 | { | |
4086 | /* Do not attempt to duplicate tablejumps, as we need to unshare | |
4087 | the dispatch table. This is difficult to do, as the instructions | |
4088 | computing jump destination may be hoisted outside the basic block. */ | |
4089 | if (tablejump_p (BB_END (bb), NULL, NULL)) | |
4090 | return false; | |
4091 | ||
4092 | /* Do not duplicate blocks containing insns that can't be copied. */ | |
4093 | if (targetm.cannot_copy_insn_p) | |
4094 | { | |
8879d71c | 4095 | rtx_insn *insn = BB_HEAD (bb); |
78bde837 SB |
4096 | while (1) |
4097 | { | |
4098 | if (INSN_P (insn) && targetm.cannot_copy_insn_p (insn)) | |
4099 | return false; | |
4100 | if (insn == BB_END (bb)) | |
4101 | break; | |
4102 | insn = NEXT_INSN (insn); | |
4103 | } | |
4104 | } | |
4105 | ||
4106 | return true; | |
4107 | } | |
4108 | ||
a90c614a | 4109 | rtx_insn * |
5d34b050 | 4110 | duplicate_insn_chain (rtx_insn *from, rtx_insn *to) |
78bde837 | 4111 | { |
5d34b050 | 4112 | rtx_insn *insn, *next, *copy; |
66e8df53 | 4113 | rtx_note *last; |
78bde837 SB |
4114 | |
4115 | /* Avoid updating of boundaries of previous basic block. The | |
4116 | note will get removed from insn stream in fixup. */ | |
4117 | last = emit_note (NOTE_INSN_DELETED); | |
4118 | ||
4119 | /* Create copy at the end of INSN chain. The chain will | |
4120 | be reordered later. */ | |
4121 | for (insn = from; insn != NEXT_INSN (to); insn = NEXT_INSN (insn)) | |
4122 | { | |
4123 | switch (GET_CODE (insn)) | |
4124 | { | |
4125 | case DEBUG_INSN: | |
4126 | /* Don't duplicate label debug insns. */ | |
4127 | if (TREE_CODE (INSN_VAR_LOCATION_DECL (insn)) == LABEL_DECL) | |
4128 | break; | |
4129 | /* FALLTHRU */ | |
4130 | case INSN: | |
4131 | case CALL_INSN: | |
4132 | case JUMP_INSN: | |
78bde837 SB |
4133 | copy = emit_copy_of_insn_after (insn, get_last_insn ()); |
4134 | if (JUMP_P (insn) && JUMP_LABEL (insn) != NULL_RTX | |
4135 | && ANY_RETURN_P (JUMP_LABEL (insn))) | |
4136 | JUMP_LABEL (copy) = JUMP_LABEL (insn); | |
4137 | maybe_copy_prologue_epilogue_insn (insn, copy); | |
4138 | break; | |
4139 | ||
39718607 SB |
4140 | case JUMP_TABLE_DATA: |
4141 | /* Avoid copying of dispatch tables. We never duplicate | |
4142 | tablejumps, so this can hit only in case the table got | |
4143 | moved far from original jump. | |
4144 | Avoid copying following barrier as well if any | |
4145 | (and debug insns in between). */ | |
4146 | for (next = NEXT_INSN (insn); | |
4147 | next != NEXT_INSN (to); | |
4148 | next = NEXT_INSN (next)) | |
4149 | if (!DEBUG_INSN_P (next)) | |
4150 | break; | |
4151 | if (next != NEXT_INSN (to) && BARRIER_P (next)) | |
4152 | insn = next; | |
4153 | break; | |
4154 | ||
78bde837 SB |
4155 | case CODE_LABEL: |
4156 | break; | |
4157 | ||
4158 | case BARRIER: | |
4159 | emit_barrier (); | |
4160 | break; | |
4161 | ||
4162 | case NOTE: | |
4163 | switch (NOTE_KIND (insn)) | |
4164 | { | |
4165 | /* In case prologue is empty and function contain label | |
4166 | in first BB, we may want to copy the block. */ | |
4167 | case NOTE_INSN_PROLOGUE_END: | |
4168 | ||
4169 | case NOTE_INSN_DELETED: | |
4170 | case NOTE_INSN_DELETED_LABEL: | |
4171 | case NOTE_INSN_DELETED_DEBUG_LABEL: | |
4172 | /* No problem to strip these. */ | |
4173 | case NOTE_INSN_FUNCTION_BEG: | |
4174 | /* There is always just single entry to function. */ | |
4175 | case NOTE_INSN_BASIC_BLOCK: | |
3371a64f TJ |
4176 | /* We should only switch text sections once. */ |
4177 | case NOTE_INSN_SWITCH_TEXT_SECTIONS: | |
78bde837 SB |
4178 | break; |
4179 | ||
4180 | case NOTE_INSN_EPILOGUE_BEG: | |
d33606c3 | 4181 | case NOTE_INSN_UPDATE_SJLJ_CONTEXT: |
66e8df53 | 4182 | emit_note_copy (as_a <rtx_note *> (insn)); |
78bde837 SB |
4183 | break; |
4184 | ||
4185 | default: | |
4186 | /* All other notes should have already been eliminated. */ | |
4187 | gcc_unreachable (); | |
4188 | } | |
4189 | break; | |
4190 | default: | |
4191 | gcc_unreachable (); | |
4192 | } | |
4193 | } | |
4194 | insn = NEXT_INSN (last); | |
4195 | delete_insn (last); | |
5d34b050 | 4196 | return insn; |
78bde837 SB |
4197 | } |
4198 | ||
4199 | /* Create a duplicate of the basic block BB. */ | |
4200 | ||
4201 | static basic_block | |
4202 | cfg_layout_duplicate_bb (basic_block bb) | |
4203 | { | |
8879d71c | 4204 | rtx_insn *insn; |
78bde837 SB |
4205 | basic_block new_bb; |
4206 | ||
4207 | insn = duplicate_insn_chain (BB_HEAD (bb), BB_END (bb)); | |
4208 | new_bb = create_basic_block (insn, | |
4209 | insn ? get_last_insn () : NULL, | |
fefa31b5 | 4210 | EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb); |
78bde837 SB |
4211 | |
4212 | BB_COPY_PARTITION (new_bb, bb); | |
4213 | if (BB_HEADER (bb)) | |
4214 | { | |
4215 | insn = BB_HEADER (bb); | |
4216 | while (NEXT_INSN (insn)) | |
4217 | insn = NEXT_INSN (insn); | |
4218 | insn = duplicate_insn_chain (BB_HEADER (bb), insn); | |
4219 | if (insn) | |
1130d5e3 | 4220 | BB_HEADER (new_bb) = unlink_insn_chain (insn, get_last_insn ()); |
78bde837 SB |
4221 | } |
4222 | ||
4223 | if (BB_FOOTER (bb)) | |
4224 | { | |
4225 | insn = BB_FOOTER (bb); | |
4226 | while (NEXT_INSN (insn)) | |
4227 | insn = NEXT_INSN (insn); | |
4228 | insn = duplicate_insn_chain (BB_FOOTER (bb), insn); | |
4229 | if (insn) | |
d8ce2eae | 4230 | BB_FOOTER (new_bb) = unlink_insn_chain (insn, get_last_insn ()); |
78bde837 SB |
4231 | } |
4232 | ||
4233 | return new_bb; | |
4234 | } | |
4235 | ||
4236 | \f | |
4237 | /* Main entry point to this module - initialize the datastructures for | |
4238 | CFG layout changes. It keeps LOOPS up-to-date if not null. | |
4239 | ||
4240 | FLAGS is a set of additional flags to pass to cleanup_cfg(). */ | |
4241 | ||
4242 | void | |
4243 | cfg_layout_initialize (unsigned int flags) | |
4244 | { | |
b5241a5a | 4245 | rtx_insn_list *x; |
78bde837 SB |
4246 | basic_block bb; |
4247 | ||
8a9e6b45 BS |
4248 | /* Once bb partitioning is complete, cfg layout mode should not be |
4249 | re-entered. Entering cfg layout mode may require fixups. As an | |
4250 | example, if edge forwarding performed when optimizing the cfg | |
4251 | layout required moving a block from the hot to the cold | |
4252 | section. This would create an illegal partitioning unless some | |
4253 | manual fixup was performed. */ | |
4254 | gcc_assert (!(crtl->bb_reorder_complete | |
4255 | && flag_reorder_blocks_and_partition)); | |
4ca19309 | 4256 | |
78bde837 SB |
4257 | initialize_original_copy_tables (); |
4258 | ||
4259 | cfg_layout_rtl_register_cfg_hooks (); | |
4260 | ||
4261 | record_effective_endpoints (); | |
4262 | ||
4263 | /* Make sure that the targets of non local gotos are marked. */ | |
2382940b | 4264 | for (x = nonlocal_goto_handler_labels; x; x = x->next ()) |
78bde837 | 4265 | { |
b5241a5a | 4266 | bb = BLOCK_FOR_INSN (x->insn ()); |
78bde837 SB |
4267 | bb->flags |= BB_NON_LOCAL_GOTO_TARGET; |
4268 | } | |
4269 | ||
4270 | cleanup_cfg (CLEANUP_CFGLAYOUT | flags); | |
4271 | } | |
4272 | ||
4273 | /* Splits superblocks. */ | |
4274 | void | |
4275 | break_superblocks (void) | |
4276 | { | |
78bde837 SB |
4277 | bool need = false; |
4278 | basic_block bb; | |
4279 | ||
7ba9e72d | 4280 | auto_sbitmap superblocks (last_basic_block_for_fn (cfun)); |
f61e445a | 4281 | bitmap_clear (superblocks); |
78bde837 | 4282 | |
11cd3bed | 4283 | FOR_EACH_BB_FN (bb, cfun) |
78bde837 SB |
4284 | if (bb->flags & BB_SUPERBLOCK) |
4285 | { | |
4286 | bb->flags &= ~BB_SUPERBLOCK; | |
d7c028c0 | 4287 | bitmap_set_bit (superblocks, bb->index); |
78bde837 SB |
4288 | need = true; |
4289 | } | |
4290 | ||
4291 | if (need) | |
4292 | { | |
4293 | rebuild_jump_labels (get_insns ()); | |
4294 | find_many_sub_basic_blocks (superblocks); | |
4295 | } | |
78bde837 SB |
4296 | } |
4297 | ||
4298 | /* Finalize the changes: reorder insn list according to the sequence specified | |
29f3fd5b | 4299 | by aux pointers, enter compensation code, rebuild scope forest. */ |
78bde837 SB |
4300 | |
4301 | void | |
4302 | cfg_layout_finalize (void) | |
4303 | { | |
b2b29377 | 4304 | checking_verify_flow_info (); |
63da5ff6 | 4305 | free_dominance_info (CDI_DOMINATORS); |
78bde837 SB |
4306 | force_one_exit_fallthru (); |
4307 | rtl_register_cfg_hooks (); | |
e86a9946 | 4308 | if (reload_completed && !targetm.have_epilogue ()) |
78bde837 SB |
4309 | fixup_fallthru_exit_predecessor (); |
4310 | fixup_reorder_chain (); | |
4311 | ||
29f3fd5b SB |
4312 | rebuild_jump_labels (get_insns ()); |
4313 | delete_dead_jumptables (); | |
4314 | ||
b2b29377 MM |
4315 | if (flag_checking) |
4316 | verify_insn_chain (); | |
4317 | checking_verify_flow_info (); | |
78bde837 SB |
4318 | } |
4319 | ||
ba5e9aca | 4320 | |
9ee634e3 | 4321 | /* Same as split_block but update cfg_layout structures. */ |
f470c378 ZD |
4322 | |
4323 | static basic_block | |
d329e058 | 4324 | cfg_layout_split_block (basic_block bb, void *insnp) |
9ee634e3 | 4325 | { |
ae50c0cb | 4326 | rtx insn = (rtx) insnp; |
f470c378 | 4327 | basic_block new_bb = rtl_split_block (bb, insn); |
9ee634e3 | 4328 | |
d8ce2eae DM |
4329 | BB_FOOTER (new_bb) = BB_FOOTER (bb); |
4330 | BB_FOOTER (bb) = NULL; | |
9ee634e3 | 4331 | |
f470c378 | 4332 | return new_bb; |
9ee634e3 JH |
4333 | } |
4334 | ||
9ee634e3 | 4335 | /* Redirect Edge to DEST. */ |
6de9cd9a | 4336 | static edge |
d329e058 | 4337 | cfg_layout_redirect_edge_and_branch (edge e, basic_block dest) |
9ee634e3 JH |
4338 | { |
4339 | basic_block src = e->src; | |
6de9cd9a | 4340 | edge ret; |
9ee634e3 | 4341 | |
bc35512f | 4342 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
6de9cd9a | 4343 | return NULL; |
bc35512f | 4344 | |
3348b696 | 4345 | if (e->dest == dest) |
6de9cd9a | 4346 | return e; |
bc35512f | 4347 | |
fefa31b5 | 4348 | if (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
6de9cd9a | 4349 | && (ret = try_redirect_by_replacing_jump (e, dest, true))) |
f345f21a | 4350 | { |
6fb5fa3c | 4351 | df_set_bb_dirty (src); |
6de9cd9a | 4352 | return ret; |
f345f21a | 4353 | } |
bc35512f | 4354 | |
fefa31b5 | 4355 | if (e->src == ENTRY_BLOCK_PTR_FOR_FN (cfun) |
bc35512f JH |
4356 | && (e->flags & EDGE_FALLTHRU) && !(e->flags & EDGE_COMPLEX)) |
4357 | { | |
c263766c RH |
4358 | if (dump_file) |
4359 | fprintf (dump_file, "Redirecting entry edge from bb %i to %i\n", | |
bc35512f JH |
4360 | e->src->index, dest->index); |
4361 | ||
6fb5fa3c | 4362 | df_set_bb_dirty (e->src); |
bc35512f | 4363 | redirect_edge_succ (e, dest); |
6de9cd9a | 4364 | return e; |
bc35512f JH |
4365 | } |
4366 | ||
9ee634e3 JH |
4367 | /* Redirect_edge_and_branch may decide to turn branch into fallthru edge |
4368 | in the case the basic block appears to be in sequence. Avoid this | |
4369 | transformation. */ | |
4370 | ||
9ee634e3 JH |
4371 | if (e->flags & EDGE_FALLTHRU) |
4372 | { | |
4373 | /* Redirect any branch edges unified with the fallthru one. */ | |
4b4bf941 | 4374 | if (JUMP_P (BB_END (src)) |
432f982f JH |
4375 | && label_is_jump_target_p (BB_HEAD (e->dest), |
4376 | BB_END (src))) | |
9ee634e3 | 4377 | { |
341c100f | 4378 | edge redirected; |
c22cacf3 | 4379 | |
c263766c RH |
4380 | if (dump_file) |
4381 | fprintf (dump_file, "Fallthru edge unified with branch " | |
432f982f JH |
4382 | "%i->%i redirected to %i\n", |
4383 | e->src->index, e->dest->index, dest->index); | |
4384 | e->flags &= ~EDGE_FALLTHRU; | |
341c100f NS |
4385 | redirected = redirect_branch_edge (e, dest); |
4386 | gcc_assert (redirected); | |
0c617be4 JL |
4387 | redirected->flags |= EDGE_FALLTHRU; |
4388 | df_set_bb_dirty (redirected->src); | |
4389 | return redirected; | |
9ee634e3 JH |
4390 | } |
4391 | /* In case we are redirecting fallthru edge to the branch edge | |
c22cacf3 | 4392 | of conditional jump, remove it. */ |
628f6a4e | 4393 | if (EDGE_COUNT (src->succs) == 2) |
9ee634e3 | 4394 | { |
03101c6f KH |
4395 | /* Find the edge that is different from E. */ |
4396 | edge s = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e); | |
628f6a4e | 4397 | |
9ee634e3 | 4398 | if (s->dest == dest |
a813c111 SB |
4399 | && any_condjump_p (BB_END (src)) |
4400 | && onlyjump_p (BB_END (src))) | |
4401 | delete_insn (BB_END (src)); | |
9ee634e3 | 4402 | } |
c263766c | 4403 | if (dump_file) |
dc764d10 | 4404 | fprintf (dump_file, "Redirecting fallthru edge %i->%i to %i\n", |
bc35512f | 4405 | e->src->index, e->dest->index, dest->index); |
0c617be4 | 4406 | ret = redirect_edge_succ_nodup (e, dest); |
9ee634e3 JH |
4407 | } |
4408 | else | |
bc35512f | 4409 | ret = redirect_branch_edge (e, dest); |
9ee634e3 JH |
4410 | |
4411 | /* We don't want simplejumps in the insn stream during cfglayout. */ | |
341c100f | 4412 | gcc_assert (!simplejump_p (BB_END (src))); |
9ee634e3 | 4413 | |
6fb5fa3c | 4414 | df_set_bb_dirty (src); |
9ee634e3 JH |
4415 | return ret; |
4416 | } | |
4417 | ||
4418 | /* Simple wrapper as we always can redirect fallthru edges. */ | |
4419 | static basic_block | |
d329e058 | 4420 | cfg_layout_redirect_edge_and_branch_force (edge e, basic_block dest) |
9ee634e3 | 4421 | { |
341c100f NS |
4422 | edge redirected = cfg_layout_redirect_edge_and_branch (e, dest); |
4423 | ||
4424 | gcc_assert (redirected); | |
9ee634e3 JH |
4425 | return NULL; |
4426 | } | |
4427 | ||
f470c378 ZD |
4428 | /* Same as delete_basic_block but update cfg_layout structures. */ |
4429 | ||
9ee634e3 | 4430 | static void |
d329e058 | 4431 | cfg_layout_delete_block (basic_block bb) |
9ee634e3 | 4432 | { |
8879d71c | 4433 | rtx_insn *insn, *next, *prev = PREV_INSN (BB_HEAD (bb)), *remaints; |
1130d5e3 | 4434 | rtx_insn **to; |
9ee634e3 | 4435 | |
bcc708fc | 4436 | if (BB_HEADER (bb)) |
9ee634e3 | 4437 | { |
a813c111 | 4438 | next = BB_HEAD (bb); |
9ee634e3 | 4439 | if (prev) |
0f82e5c9 | 4440 | SET_NEXT_INSN (prev) = BB_HEADER (bb); |
9ee634e3 | 4441 | else |
bcc708fc | 4442 | set_first_insn (BB_HEADER (bb)); |
0f82e5c9 | 4443 | SET_PREV_INSN (BB_HEADER (bb)) = prev; |
bcc708fc | 4444 | insn = BB_HEADER (bb); |
9ee634e3 JH |
4445 | while (NEXT_INSN (insn)) |
4446 | insn = NEXT_INSN (insn); | |
0f82e5c9 DM |
4447 | SET_NEXT_INSN (insn) = next; |
4448 | SET_PREV_INSN (next) = insn; | |
9ee634e3 | 4449 | } |
a813c111 | 4450 | next = NEXT_INSN (BB_END (bb)); |
bcc708fc | 4451 | if (BB_FOOTER (bb)) |
9ee634e3 | 4452 | { |
bcc708fc | 4453 | insn = BB_FOOTER (bb); |
bc35512f JH |
4454 | while (insn) |
4455 | { | |
4b4bf941 | 4456 | if (BARRIER_P (insn)) |
bc35512f JH |
4457 | { |
4458 | if (PREV_INSN (insn)) | |
0f82e5c9 | 4459 | SET_NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); |
bc35512f | 4460 | else |
d8ce2eae | 4461 | BB_FOOTER (bb) = NEXT_INSN (insn); |
bc35512f | 4462 | if (NEXT_INSN (insn)) |
0f82e5c9 | 4463 | SET_PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); |
bc35512f | 4464 | } |
4b4bf941 | 4465 | if (LABEL_P (insn)) |
bc35512f JH |
4466 | break; |
4467 | insn = NEXT_INSN (insn); | |
4468 | } | |
bcc708fc | 4469 | if (BB_FOOTER (bb)) |
bc35512f | 4470 | { |
a813c111 | 4471 | insn = BB_END (bb); |
0f82e5c9 DM |
4472 | SET_NEXT_INSN (insn) = BB_FOOTER (bb); |
4473 | SET_PREV_INSN (BB_FOOTER (bb)) = insn; | |
bc35512f JH |
4474 | while (NEXT_INSN (insn)) |
4475 | insn = NEXT_INSN (insn); | |
0f82e5c9 | 4476 | SET_NEXT_INSN (insn) = next; |
bc35512f | 4477 | if (next) |
0f82e5c9 | 4478 | SET_PREV_INSN (next) = insn; |
bc35512f JH |
4479 | else |
4480 | set_last_insn (insn); | |
4481 | } | |
9ee634e3 | 4482 | } |
fefa31b5 | 4483 | if (bb->next_bb != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
1130d5e3 | 4484 | to = &BB_HEADER (bb->next_bb); |
9ee634e3 JH |
4485 | else |
4486 | to = &cfg_layout_function_footer; | |
997de8ed | 4487 | |
9ee634e3 JH |
4488 | rtl_delete_block (bb); |
4489 | ||
4490 | if (prev) | |
4491 | prev = NEXT_INSN (prev); | |
d329e058 | 4492 | else |
9ee634e3 JH |
4493 | prev = get_insns (); |
4494 | if (next) | |
4495 | next = PREV_INSN (next); | |
d329e058 | 4496 | else |
9ee634e3 JH |
4497 | next = get_last_insn (); |
4498 | ||
4499 | if (next && NEXT_INSN (next) != prev) | |
4500 | { | |
4501 | remaints = unlink_insn_chain (prev, next); | |
4502 | insn = remaints; | |
4503 | while (NEXT_INSN (insn)) | |
4504 | insn = NEXT_INSN (insn); | |
0f82e5c9 | 4505 | SET_NEXT_INSN (insn) = *to; |
9ee634e3 | 4506 | if (*to) |
0f82e5c9 | 4507 | SET_PREV_INSN (*to) = insn; |
9ee634e3 JH |
4508 | *to = remaints; |
4509 | } | |
4510 | } | |
4511 | ||
beb235f8 | 4512 | /* Return true when blocks A and B can be safely merged. */ |
b48d0358 | 4513 | |
bc35512f | 4514 | static bool |
b48d0358 | 4515 | cfg_layout_can_merge_blocks_p (basic_block a, basic_block b) |
bc35512f | 4516 | { |
750054a2 CT |
4517 | /* If we are partitioning hot/cold basic blocks, we don't want to |
4518 | mess up unconditional or indirect jumps that cross between hot | |
076c7ab8 ZW |
4519 | and cold sections. |
4520 | ||
8e8d5162 | 4521 | Basic block partitioning may result in some jumps that appear to |
c22cacf3 MS |
4522 | be optimizable (or blocks that appear to be mergeable), but which really |
4523 | must be left untouched (they are required to make it safely across | |
4524 | partition boundaries). See the comments at the top of | |
8e8d5162 CT |
4525 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
4526 | ||
87c8b4be | 4527 | if (BB_PARTITION (a) != BB_PARTITION (b)) |
076c7ab8 | 4528 | return false; |
750054a2 | 4529 | |
7d776ee2 RG |
4530 | /* Protect the loop latches. */ |
4531 | if (current_loops && b->loop_father->latch == b) | |
4532 | return false; | |
4533 | ||
894a84b5 BS |
4534 | /* If we would end up moving B's instructions, make sure it doesn't fall |
4535 | through into the exit block, since we cannot recover from a fallthrough | |
4536 | edge into the exit block occurring in the middle of a function. */ | |
4537 | if (NEXT_INSN (BB_END (a)) != BB_HEAD (b)) | |
4538 | { | |
4539 | edge e = find_fallthru_edge (b->succs); | |
fefa31b5 | 4540 | if (e && e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
894a84b5 BS |
4541 | return false; |
4542 | } | |
4543 | ||
bc35512f | 4544 | /* There must be exactly one edge in between the blocks. */ |
c5cbcccf ZD |
4545 | return (single_succ_p (a) |
4546 | && single_succ (a) == b | |
4547 | && single_pred_p (b) == 1 | |
628f6a4e | 4548 | && a != b |
bc35512f | 4549 | /* Must be simple edge. */ |
c5cbcccf | 4550 | && !(single_succ_edge (a)->flags & EDGE_COMPLEX) |
fefa31b5 DM |
4551 | && a != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
4552 | && b != EXIT_BLOCK_PTR_FOR_FN (cfun) | |
49ea3702 SB |
4553 | /* If the jump insn has side effects, we can't kill the edge. |
4554 | When not optimizing, try_redirect_by_replacing_jump will | |
4555 | not allow us to redirect an edge by replacing a table jump. */ | |
4b4bf941 | 4556 | && (!JUMP_P (BB_END (a)) |
49ea3702 | 4557 | || ((!optimize || reload_completed) |
a813c111 | 4558 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f JH |
4559 | } |
4560 | ||
41806d92 NS |
4561 | /* Merge block A and B. The blocks must be mergeable. */ |
4562 | ||
bc35512f JH |
4563 | static void |
4564 | cfg_layout_merge_blocks (basic_block a, basic_block b) | |
4565 | { | |
50a36e42 | 4566 | bool forwarder_p = (b->flags & BB_FORWARDER_BLOCK) != 0; |
8879d71c | 4567 | rtx_insn *insn; |
50a36e42 | 4568 | |
77a74ed7 | 4569 | gcc_checking_assert (cfg_layout_can_merge_blocks_p (a, b)); |
bc35512f | 4570 | |
6fb5fa3c | 4571 | if (dump_file) |
50a36e42 EB |
4572 | fprintf (dump_file, "Merging block %d into block %d...\n", b->index, |
4573 | a->index); | |
6fb5fa3c | 4574 | |
bc35512f | 4575 | /* If there was a CODE_LABEL beginning B, delete it. */ |
4b4bf941 | 4576 | if (LABEL_P (BB_HEAD (b))) |
2c97f8e4 | 4577 | { |
2c97f8e4 RH |
4578 | delete_insn (BB_HEAD (b)); |
4579 | } | |
bc35512f JH |
4580 | |
4581 | /* We should have fallthru edge in a, or we can do dummy redirection to get | |
4582 | it cleaned up. */ | |
4b4bf941 | 4583 | if (JUMP_P (BB_END (a))) |
628f6a4e | 4584 | try_redirect_by_replacing_jump (EDGE_SUCC (a, 0), b, true); |
341c100f | 4585 | gcc_assert (!JUMP_P (BB_END (a))); |
bc35512f | 4586 | |
8a829274 | 4587 | /* When not optimizing and the edge is the only place in RTL which holds |
7241571e | 4588 | some unique locus, emit a nop with that locus in between. */ |
9be94227 EB |
4589 | if (!optimize) |
4590 | emit_nop_for_unique_locus_between (a, b); | |
7241571e | 4591 | |
4c8af858 SB |
4592 | /* Move things from b->footer after a->footer. */ |
4593 | if (BB_FOOTER (b)) | |
bc35512f | 4594 | { |
4c8af858 | 4595 | if (!BB_FOOTER (a)) |
d8ce2eae | 4596 | BB_FOOTER (a) = BB_FOOTER (b); |
4c8af858 SB |
4597 | else |
4598 | { | |
8879d71c | 4599 | rtx_insn *last = BB_FOOTER (a); |
4c8af858 SB |
4600 | |
4601 | while (NEXT_INSN (last)) | |
4602 | last = NEXT_INSN (last); | |
0f82e5c9 DM |
4603 | SET_NEXT_INSN (last) = BB_FOOTER (b); |
4604 | SET_PREV_INSN (BB_FOOTER (b)) = last; | |
4c8af858 | 4605 | } |
d8ce2eae | 4606 | BB_FOOTER (b) = NULL; |
4c8af858 SB |
4607 | } |
4608 | ||
4609 | /* Move things from b->header before a->footer. | |
4610 | Note that this may include dead tablejump data, but we don't clean | |
4611 | those up until we go out of cfglayout mode. */ | |
4612 | if (BB_HEADER (b)) | |
4613 | { | |
4614 | if (! BB_FOOTER (a)) | |
d8ce2eae | 4615 | BB_FOOTER (a) = BB_HEADER (b); |
4c8af858 SB |
4616 | else |
4617 | { | |
8879d71c | 4618 | rtx_insn *last = BB_HEADER (b); |
4c8af858 SB |
4619 | |
4620 | while (NEXT_INSN (last)) | |
4621 | last = NEXT_INSN (last); | |
0f82e5c9 DM |
4622 | SET_NEXT_INSN (last) = BB_FOOTER (a); |
4623 | SET_PREV_INSN (BB_FOOTER (a)) = last; | |
d8ce2eae | 4624 | BB_FOOTER (a) = BB_HEADER (b); |
4c8af858 | 4625 | } |
1130d5e3 | 4626 | BB_HEADER (b) = NULL; |
bc35512f JH |
4627 | } |
4628 | ||
4629 | /* In the case basic blocks are not adjacent, move them around. */ | |
a813c111 | 4630 | if (NEXT_INSN (BB_END (a)) != BB_HEAD (b)) |
bc35512f | 4631 | { |
f9df6f16 | 4632 | insn = unlink_insn_chain (BB_HEAD (b), BB_END (b)); |
6c3d0e31 | 4633 | |
f9df6f16 | 4634 | emit_insn_after_noloc (insn, BB_END (a), a); |
bc35512f JH |
4635 | } |
4636 | /* Otherwise just re-associate the instructions. */ | |
4637 | else | |
4638 | { | |
a813c111 | 4639 | insn = BB_HEAD (b); |
1130d5e3 | 4640 | BB_END (a) = BB_END (b); |
bc35512f JH |
4641 | } |
4642 | ||
f9df6f16 JJ |
4643 | /* emit_insn_after_noloc doesn't call df_insn_change_bb. |
4644 | We need to explicitly call. */ | |
4645 | update_bb_for_insn_chain (insn, BB_END (b), a); | |
4646 | ||
4647 | /* Skip possible DELETED_LABEL insn. */ | |
4648 | if (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
4649 | insn = NEXT_INSN (insn); | |
4650 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn)); | |
1130d5e3 | 4651 | BB_HEAD (b) = BB_END (b) = NULL; |
f9df6f16 JJ |
4652 | delete_insn (insn); |
4653 | ||
6fb5fa3c DB |
4654 | df_bb_delete (b->index); |
4655 | ||
50a36e42 | 4656 | /* If B was a forwarder block, propagate the locus on the edge. */ |
2f13f2de | 4657 | if (forwarder_p |
fbc68f2a | 4658 | && LOCATION_LOCUS (EDGE_SUCC (b, 0)->goto_locus) == UNKNOWN_LOCATION) |
50a36e42 EB |
4659 | EDGE_SUCC (b, 0)->goto_locus = EDGE_SUCC (a, 0)->goto_locus; |
4660 | ||
c263766c | 4661 | if (dump_file) |
50a36e42 | 4662 | fprintf (dump_file, "Merged blocks %d and %d.\n", a->index, b->index); |
bc35512f JH |
4663 | } |
4664 | ||
4665 | /* Split edge E. */ | |
f470c378 | 4666 | |
bc35512f JH |
4667 | static basic_block |
4668 | cfg_layout_split_edge (edge e) | |
4669 | { | |
bc35512f | 4670 | basic_block new_bb = |
fefa31b5 | 4671 | create_basic_block (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
a813c111 | 4672 | ? NEXT_INSN (BB_END (e->src)) : get_insns (), |
bc35512f JH |
4673 | NULL_RTX, e->src); |
4674 | ||
fefa31b5 | 4675 | if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
3e7eb734 JJ |
4676 | BB_COPY_PARTITION (new_bb, e->src); |
4677 | else | |
4678 | BB_COPY_PARTITION (new_bb, e->dest); | |
a9b2ee88 | 4679 | make_edge (new_bb, e->dest, EDGE_FALLTHRU); |
bc35512f JH |
4680 | redirect_edge_and_branch_force (e, new_bb); |
4681 | ||
4682 | return new_bb; | |
4683 | } | |
4684 | ||
f470c378 ZD |
4685 | /* Do postprocessing after making a forwarder block joined by edge FALLTHRU. */ |
4686 | ||
4687 | static void | |
4688 | rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED) | |
4689 | { | |
4690 | } | |
4691 | ||
df92c640 SB |
4692 | /* Return true if BB contains only labels or non-executable |
4693 | instructions. */ | |
4694 | ||
4695 | static bool | |
4696 | rtl_block_empty_p (basic_block bb) | |
4697 | { | |
8879d71c | 4698 | rtx_insn *insn; |
df92c640 | 4699 | |
fefa31b5 DM |
4700 | if (bb == ENTRY_BLOCK_PTR_FOR_FN (cfun) |
4701 | || bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
df92c640 SB |
4702 | return true; |
4703 | ||
4704 | FOR_BB_INSNS (bb, insn) | |
4705 | if (NONDEBUG_INSN_P (insn) && !any_uncondjump_p (insn)) | |
4706 | return false; | |
4707 | ||
4708 | return true; | |
4709 | } | |
4710 | ||
4711 | /* Split a basic block if it ends with a conditional branch and if | |
4712 | the other part of the block is not empty. */ | |
4713 | ||
4714 | static basic_block | |
4715 | rtl_split_block_before_cond_jump (basic_block bb) | |
4716 | { | |
8879d71c DM |
4717 | rtx_insn *insn; |
4718 | rtx_insn *split_point = NULL; | |
4719 | rtx_insn *last = NULL; | |
df92c640 SB |
4720 | bool found_code = false; |
4721 | ||
4722 | FOR_BB_INSNS (bb, insn) | |
4723 | { | |
4724 | if (any_condjump_p (insn)) | |
4725 | split_point = last; | |
4726 | else if (NONDEBUG_INSN_P (insn)) | |
4727 | found_code = true; | |
4728 | last = insn; | |
4729 | } | |
4730 | ||
4731 | /* Did not find everything. */ | |
4732 | if (found_code && split_point) | |
4733 | return split_block (bb, split_point)->dest; | |
4734 | else | |
4735 | return NULL; | |
4736 | } | |
4737 | ||
6de9cd9a DN |
4738 | /* Return 1 if BB ends with a call, possibly followed by some |
4739 | instructions that must stay with the call, 0 otherwise. */ | |
4740 | ||
4741 | static bool | |
b48d0358 | 4742 | rtl_block_ends_with_call_p (basic_block bb) |
6de9cd9a | 4743 | { |
8879d71c | 4744 | rtx_insn *insn = BB_END (bb); |
6de9cd9a | 4745 | |
4b4bf941 | 4746 | while (!CALL_P (insn) |
6de9cd9a | 4747 | && insn != BB_HEAD (bb) |
92ddef69 | 4748 | && (keep_with_call_p (insn) |
b5b8b0ac AO |
4749 | || NOTE_P (insn) |
4750 | || DEBUG_INSN_P (insn))) | |
6de9cd9a | 4751 | insn = PREV_INSN (insn); |
4b4bf941 | 4752 | return (CALL_P (insn)); |
6de9cd9a DN |
4753 | } |
4754 | ||
4755 | /* Return 1 if BB ends with a conditional branch, 0 otherwise. */ | |
4756 | ||
4757 | static bool | |
9678086d | 4758 | rtl_block_ends_with_condjump_p (const_basic_block bb) |
6de9cd9a DN |
4759 | { |
4760 | return any_condjump_p (BB_END (bb)); | |
4761 | } | |
4762 | ||
4763 | /* Return true if we need to add fake edge to exit. | |
4764 | Helper function for rtl_flow_call_edges_add. */ | |
4765 | ||
4766 | static bool | |
8879d71c | 4767 | need_fake_edge_p (const rtx_insn *insn) |
6de9cd9a DN |
4768 | { |
4769 | if (!INSN_P (insn)) | |
4770 | return false; | |
4771 | ||
4b4bf941 | 4772 | if ((CALL_P (insn) |
6de9cd9a DN |
4773 | && !SIBLING_CALL_P (insn) |
4774 | && !find_reg_note (insn, REG_NORETURN, NULL) | |
becfd6e5 | 4775 | && !(RTL_CONST_OR_PURE_CALL_P (insn)))) |
6de9cd9a DN |
4776 | return true; |
4777 | ||
4778 | return ((GET_CODE (PATTERN (insn)) == ASM_OPERANDS | |
4779 | && MEM_VOLATILE_P (PATTERN (insn))) | |
4780 | || (GET_CODE (PATTERN (insn)) == PARALLEL | |
4781 | && asm_noperands (insn) != -1 | |
4782 | && MEM_VOLATILE_P (XVECEXP (PATTERN (insn), 0, 0))) | |
4783 | || GET_CODE (PATTERN (insn)) == ASM_INPUT); | |
4784 | } | |
4785 | ||
4786 | /* Add fake edges to the function exit for any non constant and non noreturn | |
4787 | calls, volatile inline assembly in the bitmap of blocks specified by | |
4788 | BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks | |
4789 | that were split. | |
4790 | ||
4791 | The goal is to expose cases in which entering a basic block does not imply | |
4792 | that all subsequent instructions must be executed. */ | |
4793 | ||
4794 | static int | |
4795 | rtl_flow_call_edges_add (sbitmap blocks) | |
4796 | { | |
4797 | int i; | |
4798 | int blocks_split = 0; | |
8b1c6fd7 | 4799 | int last_bb = last_basic_block_for_fn (cfun); |
6de9cd9a DN |
4800 | bool check_last_block = false; |
4801 | ||
0cae8d31 | 4802 | if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS) |
6de9cd9a DN |
4803 | return 0; |
4804 | ||
4805 | if (! blocks) | |
4806 | check_last_block = true; | |
4807 | else | |
fefa31b5 DM |
4808 | check_last_block = bitmap_bit_p (blocks, |
4809 | EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb->index); | |
6de9cd9a DN |
4810 | |
4811 | /* In the last basic block, before epilogue generation, there will be | |
4812 | a fallthru edge to EXIT. Special care is required if the last insn | |
4813 | of the last basic block is a call because make_edge folds duplicate | |
4814 | edges, which would result in the fallthru edge also being marked | |
4815 | fake, which would result in the fallthru edge being removed by | |
4816 | remove_fake_edges, which would result in an invalid CFG. | |
4817 | ||
4818 | Moreover, we can't elide the outgoing fake edge, since the block | |
4819 | profiler needs to take this into account in order to solve the minimal | |
4820 | spanning tree in the case that the call doesn't return. | |
4821 | ||
4822 | Handle this by adding a dummy instruction in a new last basic block. */ | |
4823 | if (check_last_block) | |
4824 | { | |
fefa31b5 | 4825 | basic_block bb = EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb; |
8879d71c | 4826 | rtx_insn *insn = BB_END (bb); |
6de9cd9a DN |
4827 | |
4828 | /* Back up past insns that must be kept in the same block as a call. */ | |
4829 | while (insn != BB_HEAD (bb) | |
4830 | && keep_with_call_p (insn)) | |
4831 | insn = PREV_INSN (insn); | |
4832 | ||
4833 | if (need_fake_edge_p (insn)) | |
4834 | { | |
4835 | edge e; | |
4836 | ||
fefa31b5 | 4837 | e = find_edge (bb, EXIT_BLOCK_PTR_FOR_FN (cfun)); |
9ff3d2de JL |
4838 | if (e) |
4839 | { | |
c41c1387 | 4840 | insert_insn_on_edge (gen_use (const0_rtx), e); |
9ff3d2de JL |
4841 | commit_edge_insertions (); |
4842 | } | |
6de9cd9a DN |
4843 | } |
4844 | } | |
4845 | ||
4846 | /* Now add fake edges to the function exit for any non constant | |
4847 | calls since there is no way that we can determine if they will | |
4848 | return or not... */ | |
4849 | ||
24bd1a0b | 4850 | for (i = NUM_FIXED_BLOCKS; i < last_bb; i++) |
6de9cd9a | 4851 | { |
06e28de2 | 4852 | basic_block bb = BASIC_BLOCK_FOR_FN (cfun, i); |
8879d71c DM |
4853 | rtx_insn *insn; |
4854 | rtx_insn *prev_insn; | |
6de9cd9a DN |
4855 | |
4856 | if (!bb) | |
4857 | continue; | |
4858 | ||
d7c028c0 | 4859 | if (blocks && !bitmap_bit_p (blocks, i)) |
6de9cd9a DN |
4860 | continue; |
4861 | ||
4862 | for (insn = BB_END (bb); ; insn = prev_insn) | |
4863 | { | |
4864 | prev_insn = PREV_INSN (insn); | |
4865 | if (need_fake_edge_p (insn)) | |
4866 | { | |
4867 | edge e; | |
8879d71c | 4868 | rtx_insn *split_at_insn = insn; |
6de9cd9a DN |
4869 | |
4870 | /* Don't split the block between a call and an insn that should | |
c22cacf3 | 4871 | remain in the same block as the call. */ |
4b4bf941 | 4872 | if (CALL_P (insn)) |
6de9cd9a DN |
4873 | while (split_at_insn != BB_END (bb) |
4874 | && keep_with_call_p (NEXT_INSN (split_at_insn))) | |
4875 | split_at_insn = NEXT_INSN (split_at_insn); | |
4876 | ||
4877 | /* The handling above of the final block before the epilogue | |
c22cacf3 | 4878 | should be enough to verify that there is no edge to the exit |
6de9cd9a DN |
4879 | block in CFG already. Calling make_edge in such case would |
4880 | cause us to mark that edge as fake and remove it later. */ | |
4881 | ||
b2b29377 | 4882 | if (flag_checking && split_at_insn == BB_END (bb)) |
628f6a4e | 4883 | { |
fefa31b5 | 4884 | e = find_edge (bb, EXIT_BLOCK_PTR_FOR_FN (cfun)); |
9ff3d2de | 4885 | gcc_assert (e == NULL); |
628f6a4e | 4886 | } |
6de9cd9a DN |
4887 | |
4888 | /* Note that the following may create a new basic block | |
4889 | and renumber the existing basic blocks. */ | |
4890 | if (split_at_insn != BB_END (bb)) | |
4891 | { | |
4892 | e = split_block (bb, split_at_insn); | |
4893 | if (e) | |
4894 | blocks_split++; | |
4895 | } | |
4896 | ||
fefa31b5 | 4897 | make_edge (bb, EXIT_BLOCK_PTR_FOR_FN (cfun), EDGE_FAKE); |
6de9cd9a DN |
4898 | } |
4899 | ||
4900 | if (insn == BB_HEAD (bb)) | |
4901 | break; | |
4902 | } | |
4903 | } | |
4904 | ||
4905 | if (blocks_split) | |
4906 | verify_flow_info (); | |
4907 | ||
4908 | return blocks_split; | |
4909 | } | |
4910 | ||
1cb7dfc3 | 4911 | /* Add COMP_RTX as a condition at end of COND_BB. FIRST_HEAD is |
315682fb | 4912 | the conditional branch target, SECOND_HEAD should be the fall-thru |
1cb7dfc3 MH |
4913 | there is no need to handle this here the loop versioning code handles |
4914 | this. the reason for SECON_HEAD is that it is needed for condition | |
4915 | in trees, and this should be of the same type since it is a hook. */ | |
4916 | static void | |
4917 | rtl_lv_add_condition_to_bb (basic_block first_head , | |
c22cacf3 MS |
4918 | basic_block second_head ATTRIBUTE_UNUSED, |
4919 | basic_block cond_bb, void *comp_rtx) | |
1cb7dfc3 | 4920 | { |
1476d1bd | 4921 | rtx_code_label *label; |
8879d71c | 4922 | rtx_insn *seq, *jump; |
1cb7dfc3 MH |
4923 | rtx op0 = XEXP ((rtx)comp_rtx, 0); |
4924 | rtx op1 = XEXP ((rtx)comp_rtx, 1); | |
4925 | enum rtx_code comp = GET_CODE ((rtx)comp_rtx); | |
ef4bddc2 | 4926 | machine_mode mode; |
1cb7dfc3 MH |
4927 | |
4928 | ||
4929 | label = block_label (first_head); | |
4930 | mode = GET_MODE (op0); | |
4931 | if (mode == VOIDmode) | |
4932 | mode = GET_MODE (op1); | |
4933 | ||
4934 | start_sequence (); | |
4935 | op0 = force_operand (op0, NULL_RTX); | |
4936 | op1 = force_operand (op1, NULL_RTX); | |
1476d1bd | 4937 | do_compare_rtx_and_jump (op0, op1, comp, 0, mode, NULL_RTX, NULL, label, -1); |
1cb7dfc3 MH |
4938 | jump = get_last_insn (); |
4939 | JUMP_LABEL (jump) = label; | |
4940 | LABEL_NUSES (label)++; | |
4941 | seq = get_insns (); | |
4942 | end_sequence (); | |
4943 | ||
2b9c63a2 | 4944 | /* Add the new cond, in the new head. */ |
c3284718 | 4945 | emit_insn_after (seq, BB_END (cond_bb)); |
1cb7dfc3 MH |
4946 | } |
4947 | ||
4948 | ||
4949 | /* Given a block B with unconditional branch at its end, get the | |
4950 | store the return the branch edge and the fall-thru edge in | |
4951 | BRANCH_EDGE and FALLTHRU_EDGE respectively. */ | |
4952 | static void | |
4953 | rtl_extract_cond_bb_edges (basic_block b, edge *branch_edge, | |
4954 | edge *fallthru_edge) | |
4955 | { | |
4956 | edge e = EDGE_SUCC (b, 0); | |
4957 | ||
4958 | if (e->flags & EDGE_FALLTHRU) | |
4959 | { | |
4960 | *fallthru_edge = e; | |
4961 | *branch_edge = EDGE_SUCC (b, 1); | |
4962 | } | |
4963 | else | |
4964 | { | |
4965 | *branch_edge = e; | |
4966 | *fallthru_edge = EDGE_SUCC (b, 1); | |
4967 | } | |
4968 | } | |
4969 | ||
5e2d947c JH |
4970 | void |
4971 | init_rtl_bb_info (basic_block bb) | |
4972 | { | |
bcc708fc MM |
4973 | gcc_assert (!bb->il.x.rtl); |
4974 | bb->il.x.head_ = NULL; | |
766090c2 | 4975 | bb->il.x.rtl = ggc_cleared_alloc<rtl_bb_info> (); |
5e2d947c JH |
4976 | } |
4977 | ||
14fa2cc0 ZD |
4978 | /* Returns true if it is possible to remove edge E by redirecting |
4979 | it to the destination of the other edge from E->src. */ | |
4980 | ||
4981 | static bool | |
9678086d | 4982 | rtl_can_remove_branch_p (const_edge e) |
14fa2cc0 | 4983 | { |
9678086d KG |
4984 | const_basic_block src = e->src; |
4985 | const_basic_block target = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest; | |
8879d71c DM |
4986 | const rtx_insn *insn = BB_END (src); |
4987 | rtx set; | |
14fa2cc0 ZD |
4988 | |
4989 | /* The conditions are taken from try_redirect_by_replacing_jump. */ | |
fefa31b5 | 4990 | if (target == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
14fa2cc0 ZD |
4991 | return false; |
4992 | ||
4993 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) | |
4994 | return false; | |
4995 | ||
3371a64f | 4996 | if (BB_PARTITION (src) != BB_PARTITION (target)) |
14fa2cc0 ZD |
4997 | return false; |
4998 | ||
4999 | if (!onlyjump_p (insn) | |
5000 | || tablejump_p (insn, NULL, NULL)) | |
5001 | return false; | |
5002 | ||
5003 | set = single_set (insn); | |
5004 | if (!set || side_effects_p (set)) | |
5005 | return false; | |
5006 | ||
5007 | return true; | |
5008 | } | |
5009 | ||
ffe14686 AM |
5010 | static basic_block |
5011 | rtl_duplicate_bb (basic_block bb) | |
5012 | { | |
5013 | bb = cfg_layout_duplicate_bb (bb); | |
5014 | bb->aux = NULL; | |
5015 | return bb; | |
5016 | } | |
5017 | ||
aa4723d7 SB |
5018 | /* Do book-keeping of basic block BB for the profile consistency checker. |
5019 | If AFTER_PASS is 0, do pre-pass accounting, or if AFTER_PASS is 1 | |
5020 | then do post-pass accounting. Store the counting in RECORD. */ | |
5021 | static void | |
5022 | rtl_account_profile_record (basic_block bb, int after_pass, | |
5023 | struct profile_record *record) | |
5024 | { | |
8879d71c | 5025 | rtx_insn *insn; |
aa4723d7 SB |
5026 | FOR_BB_INSNS (bb, insn) |
5027 | if (INSN_P (insn)) | |
5028 | { | |
5029 | record->size[after_pass] | |
5030 | += insn_rtx_cost (PATTERN (insn), false); | |
0a6a6ac9 | 5031 | if (profile_status_for_fn (cfun) == PROFILE_READ) |
aa4723d7 SB |
5032 | record->time[after_pass] |
5033 | += insn_rtx_cost (PATTERN (insn), true) * bb->count; | |
0a6a6ac9 | 5034 | else if (profile_status_for_fn (cfun) == PROFILE_GUESSED) |
aa4723d7 SB |
5035 | record->time[after_pass] |
5036 | += insn_rtx_cost (PATTERN (insn), true) * bb->frequency; | |
5037 | } | |
5038 | } | |
5039 | ||
9ee634e3 JH |
5040 | /* Implementation of CFG manipulation for linearized RTL. */ |
5041 | struct cfg_hooks rtl_cfg_hooks = { | |
f470c378 | 5042 | "rtl", |
9ee634e3 | 5043 | rtl_verify_flow_info, |
10e9fecc | 5044 | rtl_dump_bb, |
2c895bd1 | 5045 | rtl_dump_bb_for_graph, |
bc35512f | 5046 | rtl_create_basic_block, |
9ee634e3 JH |
5047 | rtl_redirect_edge_and_branch, |
5048 | rtl_redirect_edge_and_branch_force, | |
14fa2cc0 | 5049 | rtl_can_remove_branch_p, |
9ee634e3 JH |
5050 | rtl_delete_block, |
5051 | rtl_split_block, | |
f470c378 | 5052 | rtl_move_block_after, |
bc35512f JH |
5053 | rtl_can_merge_blocks, /* can_merge_blocks_p */ |
5054 | rtl_merge_blocks, | |
6de9cd9a DN |
5055 | rtl_predict_edge, |
5056 | rtl_predicted_by_p, | |
ffe14686 AM |
5057 | cfg_layout_can_duplicate_bb_p, |
5058 | rtl_duplicate_bb, | |
f470c378 ZD |
5059 | rtl_split_edge, |
5060 | rtl_make_forwarder_block, | |
6de9cd9a | 5061 | rtl_tidy_fallthru_edge, |
cf103ca4 | 5062 | rtl_force_nonfallthru, |
6de9cd9a DN |
5063 | rtl_block_ends_with_call_p, |
5064 | rtl_block_ends_with_condjump_p, | |
d9d4706f KH |
5065 | rtl_flow_call_edges_add, |
5066 | NULL, /* execute_on_growing_pred */ | |
1cb7dfc3 MH |
5067 | NULL, /* execute_on_shrinking_pred */ |
5068 | NULL, /* duplicate loop for trees */ | |
5069 | NULL, /* lv_add_condition_to_bb */ | |
5070 | NULL, /* lv_adjust_loop_header_phi*/ | |
5071 | NULL, /* extract_cond_bb_edges */ | |
df92c640 SB |
5072 | NULL, /* flush_pending_stmts */ |
5073 | rtl_block_empty_p, /* block_empty_p */ | |
5074 | rtl_split_block_before_cond_jump, /* split_block_before_cond_jump */ | |
aa4723d7 | 5075 | rtl_account_profile_record, |
9ee634e3 JH |
5076 | }; |
5077 | ||
5078 | /* Implementation of CFG manipulation for cfg layout RTL, where | |
5079 | basic block connected via fallthru edges does not have to be adjacent. | |
5080 | This representation will hopefully become the default one in future | |
5081 | version of the compiler. */ | |
6de9cd9a | 5082 | |
9ee634e3 | 5083 | struct cfg_hooks cfg_layout_rtl_cfg_hooks = { |
f470c378 | 5084 | "cfglayout mode", |
bc35512f | 5085 | rtl_verify_flow_info_1, |
10e9fecc | 5086 | rtl_dump_bb, |
2c895bd1 | 5087 | rtl_dump_bb_for_graph, |
bc35512f | 5088 | cfg_layout_create_basic_block, |
9ee634e3 JH |
5089 | cfg_layout_redirect_edge_and_branch, |
5090 | cfg_layout_redirect_edge_and_branch_force, | |
14fa2cc0 | 5091 | rtl_can_remove_branch_p, |
9ee634e3 JH |
5092 | cfg_layout_delete_block, |
5093 | cfg_layout_split_block, | |
f470c378 | 5094 | rtl_move_block_after, |
bc35512f JH |
5095 | cfg_layout_can_merge_blocks_p, |
5096 | cfg_layout_merge_blocks, | |
6de9cd9a DN |
5097 | rtl_predict_edge, |
5098 | rtl_predicted_by_p, | |
5099 | cfg_layout_can_duplicate_bb_p, | |
5100 | cfg_layout_duplicate_bb, | |
f470c378 ZD |
5101 | cfg_layout_split_edge, |
5102 | rtl_make_forwarder_block, | |
cf103ca4 EB |
5103 | NULL, /* tidy_fallthru_edge */ |
5104 | rtl_force_nonfallthru, | |
6de9cd9a DN |
5105 | rtl_block_ends_with_call_p, |
5106 | rtl_block_ends_with_condjump_p, | |
d9d4706f KH |
5107 | rtl_flow_call_edges_add, |
5108 | NULL, /* execute_on_growing_pred */ | |
1cb7dfc3 MH |
5109 | NULL, /* execute_on_shrinking_pred */ |
5110 | duplicate_loop_to_header_edge, /* duplicate loop for trees */ | |
5111 | rtl_lv_add_condition_to_bb, /* lv_add_condition_to_bb */ | |
5112 | NULL, /* lv_adjust_loop_header_phi*/ | |
5113 | rtl_extract_cond_bb_edges, /* extract_cond_bb_edges */ | |
df92c640 SB |
5114 | NULL, /* flush_pending_stmts */ |
5115 | rtl_block_empty_p, /* block_empty_p */ | |
5116 | rtl_split_block_before_cond_jump, /* split_block_before_cond_jump */ | |
aa4723d7 | 5117 | rtl_account_profile_record, |
9ee634e3 | 5118 | }; |
78bde837 SB |
5119 | |
5120 | #include "gt-cfgrtl.h" |