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ca6c03ca | 1 | /* Control flow graph manipulation code for GNU compiler. |
85ec4feb | 2 | Copyright (C) 1987-2018 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 *); |
1a817418 | 89 | static void rtl_dump_bb (FILE *, basic_block, int, dump_flags_t); |
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 |
a29f6a2b | 126 | delete_insn (rtx_insn *insn) |
ca6c03ca | 127 | { |
ca6c03ca JH |
128 | rtx note; |
129 | bool really_delete = true; | |
130 | ||
4b4bf941 | 131 | if (LABEL_P (insn)) |
ca6c03ca JH |
132 | { |
133 | /* Some labels can't be directly removed from the INSN chain, as they | |
c22cacf3 MS |
134 | might be references via variables, constant pool etc. |
135 | Convert them to the special NOTE_INSN_DELETED_LABEL note. */ | |
8879d71c | 136 | if (! can_delete_label_p (as_a <rtx_code_label *> (insn))) |
ca6c03ca JH |
137 | { |
138 | const char *name = LABEL_NAME (insn); | |
5e5df392 | 139 | basic_block bb = BLOCK_FOR_INSN (insn); |
8879d71c | 140 | rtx_insn *bb_note = NEXT_INSN (insn); |
ca6c03ca JH |
141 | |
142 | really_delete = false; | |
143 | PUT_CODE (insn, NOTE); | |
a38e7aa5 | 144 | NOTE_KIND (insn) = NOTE_INSN_DELETED_LABEL; |
6773e15f | 145 | NOTE_DELETED_LABEL_NAME (insn) = name; |
03fbe718 | 146 | |
0f33baa9 | 147 | /* If the note following the label starts a basic block, and the |
5e5df392 | 148 | label is a member of the same basic block, interchange the two. */ |
0f33baa9 TV |
149 | if (bb_note != NULL_RTX |
150 | && NOTE_INSN_BASIC_BLOCK_P (bb_note) | |
5e5df392 TV |
151 | && bb != NULL |
152 | && bb == BLOCK_FOR_INSN (bb_note)) | |
03fbe718 TV |
153 | { |
154 | reorder_insns_nobb (insn, insn, bb_note); | |
1130d5e3 | 155 | BB_HEAD (bb) = bb_note; |
03fbe718 | 156 | if (BB_END (bb) == bb_note) |
1130d5e3 | 157 | BB_END (bb) = insn; |
03fbe718 | 158 | } |
ca6c03ca | 159 | } |
5f0d2358 | 160 | |
b5241a5a | 161 | remove_node_from_insn_list (insn, &nonlocal_goto_handler_labels); |
ca6c03ca JH |
162 | } |
163 | ||
164 | if (really_delete) | |
165 | { | |
cda94cbb | 166 | /* If this insn has already been deleted, something is very wrong. */ |
4654c0cf | 167 | gcc_assert (!insn->deleted ()); |
1f397f45 SB |
168 | if (INSN_P (insn)) |
169 | df_insn_delete (insn); | |
ca6c03ca | 170 | remove_insn (insn); |
4654c0cf | 171 | insn->set_deleted (); |
ca6c03ca JH |
172 | } |
173 | ||
174 | /* If deleting a jump, decrement the use count of the label. Deleting | |
175 | the label itself should happen in the normal course of block merging. */ | |
cf7c4aa6 | 176 | if (JUMP_P (insn)) |
9295a326 | 177 | { |
cf7c4aa6 HPN |
178 | if (JUMP_LABEL (insn) |
179 | && LABEL_P (JUMP_LABEL (insn))) | |
180 | LABEL_NUSES (JUMP_LABEL (insn))--; | |
181 | ||
182 | /* If there are more targets, remove them too. */ | |
183 | while ((note | |
184 | = find_reg_note (insn, REG_LABEL_TARGET, NULL_RTX)) != NULL_RTX | |
4b4bf941 | 185 | && LABEL_P (XEXP (note, 0))) |
9295a326 JZ |
186 | { |
187 | LABEL_NUSES (XEXP (note, 0))--; | |
188 | remove_note (insn, note); | |
189 | } | |
190 | } | |
ca6c03ca | 191 | |
cf7c4aa6 HPN |
192 | /* Also if deleting any insn that references a label as an operand. */ |
193 | while ((note = find_reg_note (insn, REG_LABEL_OPERAND, NULL_RTX)) != NULL_RTX | |
194 | && LABEL_P (XEXP (note, 0))) | |
195 | { | |
196 | LABEL_NUSES (XEXP (note, 0))--; | |
197 | remove_note (insn, note); | |
198 | } | |
199 | ||
95c43227 | 200 | if (rtx_jump_table_data *table = dyn_cast <rtx_jump_table_data *> (insn)) |
ca6c03ca | 201 | { |
95c43227 DM |
202 | rtvec vec = table->get_labels (); |
203 | int len = GET_NUM_ELEM (vec); | |
ca6c03ca JH |
204 | int i; |
205 | ||
206 | for (i = 0; i < len; i++) | |
a124fcda | 207 | { |
95c43227 | 208 | rtx label = XEXP (RTVEC_ELT (vec, i), 0); |
a124fcda RH |
209 | |
210 | /* When deleting code in bulk (e.g. removing many unreachable | |
211 | blocks) we can delete a label that's a target of the vector | |
212 | before deleting the vector itself. */ | |
4b4bf941 | 213 | if (!NOTE_P (label)) |
a124fcda RH |
214 | LABEL_NUSES (label)--; |
215 | } | |
ca6c03ca | 216 | } |
ca6c03ca JH |
217 | } |
218 | ||
98ccd1d7 IE |
219 | /* Like delete_insn but also purge dead edges from BB. |
220 | Return true if any edges are eliminated. */ | |
9ed7b221 | 221 | |
98ccd1d7 | 222 | bool |
373fc786 | 223 | delete_insn_and_edges (rtx_insn *insn) |
3dec4024 | 224 | { |
3dec4024 JH |
225 | bool purge = false; |
226 | ||
ba4f7968 | 227 | if (INSN_P (insn) |
3dec4024 | 228 | && BLOCK_FOR_INSN (insn) |
a813c111 | 229 | && BB_END (BLOCK_FOR_INSN (insn)) == insn) |
3dec4024 | 230 | purge = true; |
03fbe718 | 231 | delete_insn (insn); |
3dec4024 | 232 | if (purge) |
98ccd1d7 IE |
233 | return purge_dead_edges (BLOCK_FOR_INSN (insn)); |
234 | return false; | |
3dec4024 JH |
235 | } |
236 | ||
ca6c03ca | 237 | /* Unlink a chain of insns between START and FINISH, leaving notes |
a7b87f73 ZD |
238 | that must be paired. If CLEAR_BB is true, we set bb field for |
239 | insns that cannot be removed to NULL. */ | |
ca6c03ca JH |
240 | |
241 | void | |
2d93cd20 | 242 | delete_insn_chain (rtx start, rtx_insn *finish, bool clear_bb) |
ca6c03ca | 243 | { |
5f0d2358 RK |
244 | /* Unchain the insns one by one. It would be quicker to delete all of these |
245 | with a single unchaining, rather than one at a time, but we need to keep | |
246 | the NOTE's. */ | |
2d93cd20 | 247 | rtx_insn *current = finish; |
ca6c03ca JH |
248 | while (1) |
249 | { | |
2d93cd20 | 250 | rtx_insn *prev = PREV_INSN (current); |
8879d71c | 251 | if (NOTE_P (current) && !can_delete_note_p (as_a <rtx_note *> (current))) |
ca6c03ca JH |
252 | ; |
253 | else | |
03fbe718 | 254 | delete_insn (current); |
ca6c03ca | 255 | |
4654c0cf | 256 | if (clear_bb && !current->deleted ()) |
03fbe718 | 257 | set_block_for_insn (current, NULL); |
a7b87f73 | 258 | |
03fbe718 | 259 | if (current == start) |
ca6c03ca | 260 | break; |
03fbe718 | 261 | current = prev; |
ca6c03ca JH |
262 | } |
263 | } | |
264 | \f | |
5f0d2358 RK |
265 | /* Create a new basic block consisting of the instructions between HEAD and END |
266 | inclusive. This function is designed to allow fast BB construction - reuses | |
267 | the note and basic block struct in BB_NOTE, if any and do not grow | |
268 | BASIC_BLOCK chain and should be used directly only by CFG construction code. | |
269 | END can be NULL in to create new empty basic block before HEAD. Both END | |
918ed612 ZD |
270 | and HEAD can be NULL to create basic block at the end of INSN chain. |
271 | AFTER is the basic block we should be put after. */ | |
ca6c03ca JH |
272 | |
273 | basic_block | |
e00022e9 | 274 | create_basic_block_structure (rtx_insn *head, rtx_insn *end, rtx_note *bb_note, |
66e8df53 | 275 | basic_block after) |
ca6c03ca JH |
276 | { |
277 | basic_block bb; | |
278 | ||
279 | if (bb_note | |
ca6c03ca JH |
280 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL |
281 | && bb->aux == NULL) | |
282 | { | |
283 | /* If we found an existing note, thread it back onto the chain. */ | |
284 | ||
fee3e72c | 285 | rtx_insn *after; |
ca6c03ca | 286 | |
4b4bf941 | 287 | if (LABEL_P (head)) |
ca6c03ca JH |
288 | after = head; |
289 | else | |
290 | { | |
291 | after = PREV_INSN (head); | |
292 | head = bb_note; | |
293 | } | |
294 | ||
295 | if (after != bb_note && NEXT_INSN (after) != bb_note) | |
ba4f7968 | 296 | reorder_insns_nobb (bb_note, bb_note, after); |
ca6c03ca JH |
297 | } |
298 | else | |
299 | { | |
300 | /* Otherwise we must create a note and a basic block structure. */ | |
301 | ||
302 | bb = alloc_block (); | |
303 | ||
5e2d947c | 304 | init_rtl_bb_info (bb); |
ca6c03ca | 305 | if (!head && !end) |
5f0d2358 RK |
306 | head = end = bb_note |
307 | = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); | |
4b4bf941 | 308 | else if (LABEL_P (head) && end) |
ca6c03ca JH |
309 | { |
310 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); | |
311 | if (head == end) | |
312 | end = bb_note; | |
313 | } | |
314 | else | |
315 | { | |
316 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); | |
317 | head = bb_note; | |
318 | if (!end) | |
319 | end = head; | |
320 | } | |
5f0d2358 | 321 | |
ca6c03ca JH |
322 | NOTE_BASIC_BLOCK (bb_note) = bb; |
323 | } | |
324 | ||
325 | /* Always include the bb note in the block. */ | |
326 | if (NEXT_INSN (end) == bb_note) | |
327 | end = bb_note; | |
328 | ||
1130d5e3 DM |
329 | BB_HEAD (bb) = head; |
330 | BB_END (bb) = end; | |
8b1c6fd7 | 331 | bb->index = last_basic_block_for_fn (cfun)++; |
5e2d947c | 332 | bb->flags = BB_NEW | BB_RTL; |
918ed612 | 333 | link_block (bb, after); |
557c4b49 | 334 | SET_BASIC_BLOCK_FOR_FN (cfun, bb->index, bb); |
6fb5fa3c | 335 | df_bb_refs_record (bb->index, false); |
ba4f7968 | 336 | update_bb_for_insn (bb); |
076c7ab8 | 337 | BB_SET_PARTITION (bb, BB_UNPARTITIONED); |
ca6c03ca JH |
338 | |
339 | /* Tag the block so that we know it has been used when considering | |
340 | other basic block notes. */ | |
341 | bb->aux = bb; | |
342 | ||
343 | return bb; | |
344 | } | |
345 | ||
5f0d2358 | 346 | /* Create new basic block consisting of instructions in between HEAD and END |
ffe14686 AM |
347 | and place it to the BB chain after block AFTER. END can be NULL to |
348 | create a new empty basic block before HEAD. Both END and HEAD can be | |
349 | NULL to create basic block at the end of INSN chain. */ | |
ca6c03ca | 350 | |
bc35512f JH |
351 | static basic_block |
352 | rtl_create_basic_block (void *headp, void *endp, basic_block after) | |
ca6c03ca | 353 | { |
e00022e9 DM |
354 | rtx_insn *head = (rtx_insn *) headp; |
355 | rtx_insn *end = (rtx_insn *) endp; | |
ca6c03ca | 356 | basic_block bb; |
0b17ab2f | 357 | |
7eca0767 | 358 | /* Grow the basic block array if needed. */ |
8b1c6fd7 DM |
359 | if ((size_t) last_basic_block_for_fn (cfun) |
360 | >= basic_block_info_for_fn (cfun)->length ()) | |
7eca0767 | 361 | { |
8b1c6fd7 DM |
362 | size_t new_size = |
363 | (last_basic_block_for_fn (cfun) | |
364 | + (last_basic_block_for_fn (cfun) + 3) / 4); | |
c5f05f68 | 365 | vec_safe_grow_cleared (basic_block_info_for_fn (cfun), new_size); |
7eca0767 | 366 | } |
0b17ab2f | 367 | |
0cae8d31 | 368 | n_basic_blocks_for_fn (cfun)++; |
ca6c03ca | 369 | |
852c6ec7 | 370 | bb = create_basic_block_structure (head, end, NULL, after); |
ca6c03ca JH |
371 | bb->aux = NULL; |
372 | return bb; | |
373 | } | |
bc35512f JH |
374 | |
375 | static basic_block | |
376 | cfg_layout_create_basic_block (void *head, void *end, basic_block after) | |
377 | { | |
378 | basic_block newbb = rtl_create_basic_block (head, end, after); | |
379 | ||
bc35512f JH |
380 | return newbb; |
381 | } | |
ca6c03ca JH |
382 | \f |
383 | /* Delete the insns in a (non-live) block. We physically delete every | |
384 | non-deleted-note insn, and update the flow graph appropriately. | |
385 | ||
386 | Return nonzero if we deleted an exception handler. */ | |
387 | ||
388 | /* ??? Preserving all such notes strikes me as wrong. It would be nice | |
389 | to post-process the stream to remove empty blocks, loops, ranges, etc. */ | |
390 | ||
f0fda11c | 391 | static void |
d329e058 | 392 | rtl_delete_block (basic_block b) |
ca6c03ca | 393 | { |
8879d71c | 394 | rtx_insn *insn, *end; |
ca6c03ca JH |
395 | |
396 | /* If the head of this block is a CODE_LABEL, then it might be the | |
f39e46ba SB |
397 | label for an exception handler which can't be reached. We need |
398 | to remove the label from the exception_handler_label list. */ | |
a813c111 | 399 | insn = BB_HEAD (b); |
ca6c03ca | 400 | |
96370780 | 401 | end = get_last_bb_insn (b); |
ca6c03ca JH |
402 | |
403 | /* Selectively delete the entire chain. */ | |
1130d5e3 | 404 | BB_HEAD (b) = NULL; |
a7b87f73 ZD |
405 | delete_insn_chain (insn, end, true); |
406 | ||
6fb5fa3c DB |
407 | |
408 | if (dump_file) | |
409 | fprintf (dump_file, "deleting block %d\n", b->index); | |
410 | df_bb_delete (b->index); | |
ca6c03ca JH |
411 | } |
412 | \f | |
852c6ec7 | 413 | /* Records the basic block struct in BLOCK_FOR_INSN for every insn. */ |
ca6c03ca JH |
414 | |
415 | void | |
d329e058 | 416 | compute_bb_for_insn (void) |
ca6c03ca | 417 | { |
e0082a72 | 418 | basic_block bb; |
ca6c03ca | 419 | |
11cd3bed | 420 | FOR_EACH_BB_FN (bb, cfun) |
ca6c03ca | 421 | { |
8879d71c DM |
422 | rtx_insn *end = BB_END (bb); |
423 | rtx_insn *insn; | |
ca6c03ca | 424 | |
a813c111 | 425 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
ca6c03ca | 426 | { |
ba4f7968 | 427 | BLOCK_FOR_INSN (insn) = bb; |
ca6c03ca JH |
428 | if (insn == end) |
429 | break; | |
ca6c03ca JH |
430 | } |
431 | } | |
432 | } | |
433 | ||
434 | /* Release the basic_block_for_insn array. */ | |
435 | ||
c2924966 | 436 | unsigned int |
d329e058 | 437 | free_bb_for_insn (void) |
ca6c03ca | 438 | { |
8879d71c | 439 | rtx_insn *insn; |
ba4f7968 | 440 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) |
4b4bf941 | 441 | if (!BARRIER_P (insn)) |
ba4f7968 | 442 | BLOCK_FOR_INSN (insn) = NULL; |
c2924966 | 443 | return 0; |
ca6c03ca JH |
444 | } |
445 | ||
27a4cd48 DM |
446 | namespace { |
447 | ||
448 | const pass_data pass_data_free_cfg = | |
449 | { | |
450 | RTL_PASS, /* type */ | |
451 | "*free_cfg", /* name */ | |
452 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
453 | TV_NONE, /* tv_id */ |
454 | 0, /* properties_required */ | |
455 | 0, /* properties_provided */ | |
456 | PROP_cfg, /* properties_destroyed */ | |
457 | 0, /* todo_flags_start */ | |
458 | 0, /* todo_flags_finish */ | |
ef330312 PB |
459 | }; |
460 | ||
27a4cd48 DM |
461 | class pass_free_cfg : public rtl_opt_pass |
462 | { | |
463 | public: | |
c3284718 RS |
464 | pass_free_cfg (gcc::context *ctxt) |
465 | : rtl_opt_pass (pass_data_free_cfg, ctxt) | |
27a4cd48 DM |
466 | {} |
467 | ||
468 | /* opt_pass methods: */ | |
be55bfe6 | 469 | virtual unsigned int execute (function *); |
27a4cd48 DM |
470 | |
471 | }; // class pass_free_cfg | |
472 | ||
be55bfe6 TS |
473 | unsigned int |
474 | pass_free_cfg::execute (function *) | |
475 | { | |
be55bfe6 TS |
476 | /* The resource.c machinery uses DF but the CFG isn't guaranteed to be |
477 | valid at that point so it would be too late to call df_analyze. */ | |
e90bedf5 | 478 | if (DELAY_SLOTS && optimize > 0 && flag_delayed_branch) |
be55bfe6 TS |
479 | { |
480 | df_note_add_problem (); | |
481 | df_analyze (); | |
482 | } | |
be55bfe6 TS |
483 | |
484 | if (crtl->has_bb_partition) | |
485 | insert_section_boundary_note (); | |
486 | ||
487 | free_bb_for_insn (); | |
488 | return 0; | |
489 | } | |
490 | ||
27a4cd48 DM |
491 | } // anon namespace |
492 | ||
493 | rtl_opt_pass * | |
494 | make_pass_free_cfg (gcc::context *ctxt) | |
495 | { | |
496 | return new pass_free_cfg (ctxt); | |
497 | } | |
498 | ||
91278841 | 499 | /* Return RTX to emit after when we want to emit code on the entry of function. */ |
8a2e8325 | 500 | rtx_insn * |
91278841 AP |
501 | entry_of_function (void) |
502 | { | |
0cae8d31 | 503 | return (n_basic_blocks_for_fn (cfun) > NUM_FIXED_BLOCKS ? |
fefa31b5 | 504 | BB_HEAD (ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb) : get_insns ()); |
91278841 AP |
505 | } |
506 | ||
11b904a1 BS |
507 | /* Emit INSN at the entry point of the function, ensuring that it is only |
508 | executed once per function. */ | |
509 | void | |
510 | emit_insn_at_entry (rtx insn) | |
511 | { | |
fefa31b5 | 512 | edge_iterator ei = ei_start (ENTRY_BLOCK_PTR_FOR_FN (cfun)->succs); |
11b904a1 | 513 | edge e = ei_safe_edge (ei); |
5419bc7f | 514 | gcc_assert (e->flags & EDGE_FALLTHRU); |
11b904a1 BS |
515 | |
516 | insert_insn_on_edge (insn, e); | |
517 | commit_edge_insertions (); | |
518 | } | |
519 | ||
6c3d0e31 | 520 | /* Update BLOCK_FOR_INSN of insns between BEGIN and END |
b8698a0f | 521 | (or BARRIER if found) and notify df of the bb change. |
6c3d0e31 SP |
522 | The insn chain range is inclusive |
523 | (i.e. both BEGIN and END will be updated. */ | |
ca6c03ca | 524 | |
6c3d0e31 | 525 | static void |
8879d71c | 526 | update_bb_for_insn_chain (rtx_insn *begin, rtx_insn *end, basic_block bb) |
ca6c03ca | 527 | { |
8879d71c | 528 | rtx_insn *insn; |
ca6c03ca | 529 | |
6c3d0e31 SP |
530 | end = NEXT_INSN (end); |
531 | for (insn = begin; insn != end; insn = NEXT_INSN (insn)) | |
63642d5a AO |
532 | if (!BARRIER_P (insn)) |
533 | df_insn_change_bb (insn, bb); | |
ca6c03ca | 534 | } |
6c3d0e31 SP |
535 | |
536 | /* Update BLOCK_FOR_INSN of insns in BB to BB, | |
537 | and notify df of the change. */ | |
538 | ||
539 | void | |
540 | update_bb_for_insn (basic_block bb) | |
541 | { | |
542 | update_bb_for_insn_chain (BB_HEAD (bb), BB_END (bb), bb); | |
543 | } | |
544 | ||
532aafad SB |
545 | \f |
546 | /* Like active_insn_p, except keep the return value clobber around | |
547 | even after reload. */ | |
548 | ||
549 | static bool | |
8879d71c | 550 | flow_active_insn_p (const rtx_insn *insn) |
532aafad SB |
551 | { |
552 | if (active_insn_p (insn)) | |
553 | return true; | |
554 | ||
555 | /* A clobber of the function return value exists for buggy | |
556 | programs that fail to return a value. Its effect is to | |
557 | keep the return value from being live across the entire | |
558 | function. If we allow it to be skipped, we introduce the | |
559 | possibility for register lifetime confusion. */ | |
560 | if (GET_CODE (PATTERN (insn)) == CLOBBER | |
561 | && REG_P (XEXP (PATTERN (insn), 0)) | |
562 | && REG_FUNCTION_VALUE_P (XEXP (PATTERN (insn), 0))) | |
563 | return true; | |
564 | ||
565 | return false; | |
566 | } | |
567 | ||
568 | /* Return true if the block has no effect and only forwards control flow to | |
569 | its single destination. */ | |
532aafad SB |
570 | |
571 | bool | |
2407343c | 572 | contains_no_active_insn_p (const_basic_block bb) |
532aafad | 573 | { |
8879d71c | 574 | rtx_insn *insn; |
532aafad | 575 | |
4833f561 JJ |
576 | if (bb == EXIT_BLOCK_PTR_FOR_FN (cfun) |
577 | || bb == ENTRY_BLOCK_PTR_FOR_FN (cfun) | |
578 | || !single_succ_p (bb) | |
579 | || (single_succ_edge (bb)->flags & EDGE_FAKE) != 0) | |
532aafad SB |
580 | return false; |
581 | ||
2407343c JR |
582 | for (insn = BB_HEAD (bb); insn != BB_END (bb); insn = NEXT_INSN (insn)) |
583 | if (INSN_P (insn) && flow_active_insn_p (insn)) | |
584 | return false; | |
585 | ||
586 | return (!INSN_P (insn) | |
587 | || (JUMP_P (insn) && simplejump_p (insn)) | |
588 | || !flow_active_insn_p (insn)); | |
589 | } | |
590 | ||
591 | /* Likewise, but protect loop latches, headers and preheaders. */ | |
592 | /* FIXME: Make this a cfg hook. */ | |
593 | ||
594 | bool | |
595 | forwarder_block_p (const_basic_block bb) | |
596 | { | |
597 | if (!contains_no_active_insn_p (bb)) | |
598 | return false; | |
599 | ||
532aafad SB |
600 | /* Protect loop latches, headers and preheaders. */ |
601 | if (current_loops) | |
602 | { | |
603 | basic_block dest; | |
604 | if (bb->loop_father->header == bb) | |
605 | return false; | |
606 | dest = EDGE_SUCC (bb, 0)->dest; | |
607 | if (dest->loop_father->header == dest) | |
608 | return false; | |
609 | } | |
610 | ||
2407343c | 611 | return true; |
532aafad SB |
612 | } |
613 | ||
614 | /* Return nonzero if we can reach target from src by falling through. */ | |
d7b6661b | 615 | /* FIXME: Make this a cfg hook, the result is only valid in cfgrtl mode. */ |
532aafad SB |
616 | |
617 | bool | |
618 | can_fallthru (basic_block src, basic_block target) | |
619 | { | |
8879d71c DM |
620 | rtx_insn *insn = BB_END (src); |
621 | rtx_insn *insn2; | |
532aafad SB |
622 | edge e; |
623 | edge_iterator ei; | |
624 | ||
fefa31b5 | 625 | if (target == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
532aafad SB |
626 | return true; |
627 | if (src->next_bb != target) | |
d7b6661b SB |
628 | return false; |
629 | ||
630 | /* ??? Later we may add code to move jump tables offline. */ | |
631 | if (tablejump_p (insn, NULL, NULL)) | |
632 | return false; | |
633 | ||
532aafad | 634 | FOR_EACH_EDGE (e, ei, src->succs) |
fefa31b5 | 635 | if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) |
532aafad | 636 | && e->flags & EDGE_FALLTHRU) |
d7b6661b | 637 | return false; |
532aafad SB |
638 | |
639 | insn2 = BB_HEAD (target); | |
d7b6661b | 640 | if (!active_insn_p (insn2)) |
532aafad SB |
641 | insn2 = next_active_insn (insn2); |
642 | ||
532aafad SB |
643 | return next_active_insn (insn) == insn2; |
644 | } | |
645 | ||
646 | /* Return nonzero if we could reach target from src by falling through, | |
647 | if the target was made adjacent. If we already have a fall-through | |
648 | edge to the exit block, we can't do that. */ | |
649 | static bool | |
650 | could_fall_through (basic_block src, basic_block target) | |
651 | { | |
652 | edge e; | |
653 | edge_iterator ei; | |
654 | ||
fefa31b5 | 655 | if (target == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
532aafad SB |
656 | return true; |
657 | FOR_EACH_EDGE (e, ei, src->succs) | |
fefa31b5 | 658 | if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) |
532aafad SB |
659 | && e->flags & EDGE_FALLTHRU) |
660 | return 0; | |
661 | return true; | |
662 | } | |
ca6c03ca | 663 | \f |
ef2be249 | 664 | /* Return the NOTE_INSN_BASIC_BLOCK of BB. */ |
ed270997 | 665 | rtx_note * |
ef2be249 RS |
666 | bb_note (basic_block bb) |
667 | { | |
8879d71c | 668 | rtx_insn *note; |
ef2be249 RS |
669 | |
670 | note = BB_HEAD (bb); | |
671 | if (LABEL_P (note)) | |
672 | note = NEXT_INSN (note); | |
673 | ||
674 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (note)); | |
ed270997 | 675 | return as_a <rtx_note *> (note); |
ef2be249 RS |
676 | } |
677 | ||
6fb5fa3c DB |
678 | /* Return the INSN immediately following the NOTE_INSN_BASIC_BLOCK |
679 | note associated with the BLOCK. */ | |
680 | ||
8879d71c | 681 | static rtx_insn * |
6fb5fa3c DB |
682 | first_insn_after_basic_block_note (basic_block block) |
683 | { | |
8879d71c | 684 | rtx_insn *insn; |
6fb5fa3c DB |
685 | |
686 | /* Get the first instruction in the block. */ | |
687 | insn = BB_HEAD (block); | |
688 | ||
689 | if (insn == NULL_RTX) | |
8879d71c | 690 | return NULL; |
6fb5fa3c DB |
691 | if (LABEL_P (insn)) |
692 | insn = NEXT_INSN (insn); | |
693 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn)); | |
694 | ||
695 | return NEXT_INSN (insn); | |
696 | } | |
697 | ||
2b9c63a2 FY |
698 | /* Creates a new basic block just after basic block BB by splitting |
699 | everything after specified instruction INSNP. */ | |
ca6c03ca | 700 | |
f470c378 | 701 | static basic_block |
d329e058 | 702 | rtl_split_block (basic_block bb, void *insnp) |
ca6c03ca JH |
703 | { |
704 | basic_block new_bb; | |
8879d71c | 705 | rtx_insn *insn = (rtx_insn *) insnp; |
f470c378 | 706 | edge e; |
628f6a4e | 707 | edge_iterator ei; |
ca6c03ca | 708 | |
f470c378 ZD |
709 | if (!insn) |
710 | { | |
711 | insn = first_insn_after_basic_block_note (bb); | |
712 | ||
713 | if (insn) | |
b5b8b0ac | 714 | { |
8879d71c | 715 | rtx_insn *next = insn; |
b5b8b0ac AO |
716 | |
717 | insn = PREV_INSN (insn); | |
718 | ||
719 | /* If the block contains only debug insns, insn would have | |
720 | been NULL in a non-debug compilation, and then we'd end | |
721 | up emitting a DELETED note. For -fcompare-debug | |
722 | stability, emit the note too. */ | |
723 | if (insn != BB_END (bb) | |
724 | && DEBUG_INSN_P (next) | |
725 | && DEBUG_INSN_P (BB_END (bb))) | |
726 | { | |
727 | while (next != BB_END (bb) && DEBUG_INSN_P (next)) | |
728 | next = NEXT_INSN (next); | |
729 | ||
730 | if (next == BB_END (bb)) | |
731 | emit_note_after (NOTE_INSN_DELETED, next); | |
732 | } | |
733 | } | |
f470c378 ZD |
734 | else |
735 | insn = get_last_insn (); | |
736 | } | |
737 | ||
738 | /* We probably should check type of the insn so that we do not create | |
739 | inconsistent cfg. It is checked in verify_flow_info anyway, so do not | |
740 | bother. */ | |
741 | if (insn == BB_END (bb)) | |
742 | emit_note_after (NOTE_INSN_DELETED, insn); | |
ca6c03ca JH |
743 | |
744 | /* Create the new basic block. */ | |
a813c111 | 745 | new_bb = create_basic_block (NEXT_INSN (insn), BB_END (bb), bb); |
076c7ab8 | 746 | BB_COPY_PARTITION (new_bb, bb); |
1130d5e3 | 747 | BB_END (bb) = insn; |
ca6c03ca JH |
748 | |
749 | /* Redirect the outgoing edges. */ | |
628f6a4e BE |
750 | new_bb->succs = bb->succs; |
751 | bb->succs = NULL; | |
752 | FOR_EACH_EDGE (e, ei, new_bb->succs) | |
ca6c03ca JH |
753 | e->src = new_bb; |
754 | ||
6fb5fa3c DB |
755 | /* The new block starts off being dirty. */ |
756 | df_set_bb_dirty (bb); | |
f470c378 | 757 | return new_bb; |
bc35512f JH |
758 | } |
759 | ||
9be94227 EB |
760 | /* Return true if the single edge between blocks A and B is the only place |
761 | in RTL which holds some unique locus. */ | |
762 | ||
763 | static bool | |
764 | unique_locus_on_edge_between_p (basic_block a, basic_block b) | |
765 | { | |
5368224f | 766 | const location_t goto_locus = EDGE_SUCC (a, 0)->goto_locus; |
8879d71c | 767 | rtx_insn *insn, *end; |
9be94227 | 768 | |
2f13f2de | 769 | if (LOCATION_LOCUS (goto_locus) == UNKNOWN_LOCATION) |
9be94227 EB |
770 | return false; |
771 | ||
772 | /* First scan block A backward. */ | |
773 | insn = BB_END (a); | |
774 | end = PREV_INSN (BB_HEAD (a)); | |
5368224f | 775 | while (insn != end && (!NONDEBUG_INSN_P (insn) || !INSN_HAS_LOCATION (insn))) |
9be94227 EB |
776 | insn = PREV_INSN (insn); |
777 | ||
5368224f | 778 | if (insn != end && INSN_LOCATION (insn) == goto_locus) |
9be94227 EB |
779 | return false; |
780 | ||
781 | /* Then scan block B forward. */ | |
782 | insn = BB_HEAD (b); | |
783 | if (insn) | |
784 | { | |
785 | end = NEXT_INSN (BB_END (b)); | |
786 | while (insn != end && !NONDEBUG_INSN_P (insn)) | |
787 | insn = NEXT_INSN (insn); | |
788 | ||
5368224f DC |
789 | if (insn != end && INSN_HAS_LOCATION (insn) |
790 | && INSN_LOCATION (insn) == goto_locus) | |
9be94227 EB |
791 | return false; |
792 | } | |
793 | ||
794 | return true; | |
795 | } | |
796 | ||
797 | /* If the single edge between blocks A and B is the only place in RTL which | |
798 | holds some unique locus, emit a nop with that locus between the blocks. */ | |
799 | ||
800 | static void | |
801 | emit_nop_for_unique_locus_between (basic_block a, basic_block b) | |
802 | { | |
803 | if (!unique_locus_on_edge_between_p (a, b)) | |
804 | return; | |
805 | ||
1130d5e3 | 806 | BB_END (a) = emit_insn_after_noloc (gen_nop (), BB_END (a), a); |
5368224f | 807 | INSN_LOCATION (BB_END (a)) = EDGE_SUCC (a, 0)->goto_locus; |
9be94227 EB |
808 | } |
809 | ||
ca6c03ca | 810 | /* Blocks A and B are to be merged into a single block A. The insns |
bc35512f | 811 | are already contiguous. */ |
ca6c03ca | 812 | |
bc35512f JH |
813 | static void |
814 | rtl_merge_blocks (basic_block a, basic_block b) | |
ca6c03ca | 815 | { |
8879d71c DM |
816 | rtx_insn *b_head = BB_HEAD (b), *b_end = BB_END (b), *a_end = BB_END (a); |
817 | rtx_insn *del_first = NULL, *del_last = NULL; | |
818 | rtx_insn *b_debug_start = b_end, *b_debug_end = b_end; | |
50a36e42 | 819 | bool forwarder_p = (b->flags & BB_FORWARDER_BLOCK) != 0; |
ca6c03ca JH |
820 | int b_empty = 0; |
821 | ||
6fb5fa3c | 822 | if (dump_file) |
50a36e42 EB |
823 | fprintf (dump_file, "Merging block %d into block %d...\n", b->index, |
824 | a->index); | |
6fb5fa3c | 825 | |
b5b8b0ac AO |
826 | while (DEBUG_INSN_P (b_end)) |
827 | b_end = PREV_INSN (b_debug_start = b_end); | |
828 | ||
ca6c03ca | 829 | /* If there was a CODE_LABEL beginning B, delete it. */ |
4b4bf941 | 830 | if (LABEL_P (b_head)) |
ca6c03ca JH |
831 | { |
832 | /* Detect basic blocks with nothing but a label. This can happen | |
833 | in particular at the end of a function. */ | |
834 | if (b_head == b_end) | |
835 | b_empty = 1; | |
5f0d2358 | 836 | |
ca6c03ca JH |
837 | del_first = del_last = b_head; |
838 | b_head = NEXT_INSN (b_head); | |
839 | } | |
840 | ||
5f0d2358 RK |
841 | /* Delete the basic block note and handle blocks containing just that |
842 | note. */ | |
ca6c03ca JH |
843 | if (NOTE_INSN_BASIC_BLOCK_P (b_head)) |
844 | { | |
845 | if (b_head == b_end) | |
846 | b_empty = 1; | |
847 | if (! del_last) | |
848 | del_first = b_head; | |
5f0d2358 | 849 | |
ca6c03ca JH |
850 | del_last = b_head; |
851 | b_head = NEXT_INSN (b_head); | |
852 | } | |
853 | ||
854 | /* If there was a jump out of A, delete it. */ | |
4b4bf941 | 855 | if (JUMP_P (a_end)) |
ca6c03ca | 856 | { |
8879d71c | 857 | rtx_insn *prev; |
ca6c03ca JH |
858 | |
859 | for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev)) | |
4b4bf941 | 860 | if (!NOTE_P (prev) |
a38e7aa5 | 861 | || NOTE_INSN_BASIC_BLOCK_P (prev) |
a813c111 | 862 | || prev == BB_HEAD (a)) |
ca6c03ca JH |
863 | break; |
864 | ||
865 | del_first = a_end; | |
866 | ||
ca6c03ca JH |
867 | /* If this was a conditional jump, we need to also delete |
868 | the insn that set cc0. */ | |
058eb3b0 | 869 | if (HAVE_cc0 && only_sets_cc0_p (prev)) |
ca6c03ca | 870 | { |
8879d71c | 871 | rtx_insn *tmp = prev; |
5f0d2358 | 872 | |
ca6c03ca JH |
873 | prev = prev_nonnote_insn (prev); |
874 | if (!prev) | |
a813c111 | 875 | prev = BB_HEAD (a); |
ca6c03ca JH |
876 | del_first = tmp; |
877 | } | |
ca6c03ca JH |
878 | |
879 | a_end = PREV_INSN (del_first); | |
880 | } | |
4b4bf941 | 881 | else if (BARRIER_P (NEXT_INSN (a_end))) |
ca6c03ca JH |
882 | del_first = NEXT_INSN (a_end); |
883 | ||
ca6c03ca JH |
884 | /* Delete everything marked above as well as crap that might be |
885 | hanging out between the two blocks. */ | |
1130d5e3 DM |
886 | BB_END (a) = a_end; |
887 | BB_HEAD (b) = b_empty ? NULL : b_head; | |
a7b87f73 | 888 | delete_insn_chain (del_first, del_last, true); |
ca6c03ca | 889 | |
8a829274 | 890 | /* When not optimizing and the edge is the only place in RTL which holds |
9be94227 EB |
891 | some unique locus, emit a nop with that locus in between. */ |
892 | if (!optimize) | |
893 | { | |
894 | emit_nop_for_unique_locus_between (a, b); | |
895 | a_end = BB_END (a); | |
896 | } | |
897 | ||
ca6c03ca JH |
898 | /* Reassociate the insns of B with A. */ |
899 | if (!b_empty) | |
900 | { | |
b5b8b0ac | 901 | update_bb_for_insn_chain (a_end, b_debug_end, a); |
5f0d2358 | 902 | |
1130d5e3 DM |
903 | BB_END (a) = b_debug_end; |
904 | BB_HEAD (b) = NULL; | |
b5b8b0ac AO |
905 | } |
906 | else if (b_end != b_debug_end) | |
907 | { | |
908 | /* Move any deleted labels and other notes between the end of A | |
909 | and the debug insns that make up B after the debug insns, | |
910 | bringing the debug insns into A while keeping the notes after | |
911 | the end of A. */ | |
912 | if (NEXT_INSN (a_end) != b_debug_start) | |
913 | reorder_insns_nobb (NEXT_INSN (a_end), PREV_INSN (b_debug_start), | |
914 | b_debug_end); | |
915 | update_bb_for_insn_chain (b_debug_start, b_debug_end, a); | |
1130d5e3 | 916 | BB_END (a) = b_debug_end; |
ca6c03ca | 917 | } |
5f0d2358 | 918 | |
6fb5fa3c | 919 | df_bb_delete (b->index); |
50a36e42 EB |
920 | |
921 | /* If B was a forwarder block, propagate the locus on the edge. */ | |
fbc68f2a DC |
922 | if (forwarder_p |
923 | && LOCATION_LOCUS (EDGE_SUCC (b, 0)->goto_locus) == UNKNOWN_LOCATION) | |
50a36e42 EB |
924 | EDGE_SUCC (b, 0)->goto_locus = EDGE_SUCC (a, 0)->goto_locus; |
925 | ||
926 | if (dump_file) | |
927 | fprintf (dump_file, "Merged blocks %d and %d.\n", a->index, b->index); | |
ca6c03ca | 928 | } |
bc35512f | 929 | |
6fb5fa3c | 930 | |
bc35512f | 931 | /* Return true when block A and B can be merged. */ |
9678086d | 932 | |
b48d0358 DN |
933 | static bool |
934 | rtl_can_merge_blocks (basic_block a, basic_block b) | |
bc35512f | 935 | { |
750054a2 CT |
936 | /* If we are partitioning hot/cold basic blocks, we don't want to |
937 | mess up unconditional or indirect jumps that cross between hot | |
076c7ab8 ZW |
938 | and cold sections. |
939 | ||
8e8d5162 | 940 | Basic block partitioning may result in some jumps that appear to |
c22cacf3 MS |
941 | be optimizable (or blocks that appear to be mergeable), but which really |
942 | must be left untouched (they are required to make it safely across | |
943 | partition boundaries). See the comments at the top of | |
8e8d5162 | 944 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
076c7ab8 | 945 | |
87c8b4be | 946 | if (BB_PARTITION (a) != BB_PARTITION (b)) |
076c7ab8 | 947 | return false; |
750054a2 | 948 | |
7d776ee2 RG |
949 | /* Protect the loop latches. */ |
950 | if (current_loops && b->loop_father->latch == b) | |
951 | return false; | |
952 | ||
bc35512f | 953 | /* There must be exactly one edge in between the blocks. */ |
c5cbcccf ZD |
954 | return (single_succ_p (a) |
955 | && single_succ (a) == b | |
956 | && single_pred_p (b) | |
628f6a4e | 957 | && a != b |
bc35512f | 958 | /* Must be simple edge. */ |
c5cbcccf | 959 | && !(single_succ_edge (a)->flags & EDGE_COMPLEX) |
bc35512f | 960 | && a->next_bb == b |
fefa31b5 DM |
961 | && a != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
962 | && b != EXIT_BLOCK_PTR_FOR_FN (cfun) | |
bc35512f JH |
963 | /* If the jump insn has side effects, |
964 | we can't kill the edge. */ | |
4b4bf941 | 965 | && (!JUMP_P (BB_END (a)) |
e24e7211 | 966 | || (reload_completed |
a813c111 | 967 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f | 968 | } |
ca6c03ca | 969 | \f |
5f0d2358 RK |
970 | /* Return the label in the head of basic block BLOCK. Create one if it doesn't |
971 | exist. */ | |
ca6c03ca | 972 | |
1476d1bd | 973 | rtx_code_label * |
d329e058 | 974 | block_label (basic_block block) |
ca6c03ca | 975 | { |
fefa31b5 | 976 | if (block == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
1476d1bd | 977 | return NULL; |
5f0d2358 | 978 | |
4b4bf941 | 979 | if (!LABEL_P (BB_HEAD (block))) |
ca6c03ca | 980 | { |
1130d5e3 | 981 | BB_HEAD (block) = emit_label_before (gen_label_rtx (), BB_HEAD (block)); |
ca6c03ca | 982 | } |
5f0d2358 | 983 | |
1476d1bd | 984 | return as_a <rtx_code_label *> (BB_HEAD (block)); |
ca6c03ca JH |
985 | } |
986 | ||
987 | /* Attempt to perform edge redirection by replacing possibly complex jump | |
5f0d2358 RK |
988 | instruction by unconditional jump or removing jump completely. This can |
989 | apply only if all edges now point to the same block. The parameters and | |
990 | return values are equivalent to redirect_edge_and_branch. */ | |
ca6c03ca | 991 | |
6de9cd9a | 992 | edge |
bc35512f | 993 | try_redirect_by_replacing_jump (edge e, basic_block target, bool in_cfglayout) |
ca6c03ca JH |
994 | { |
995 | basic_block src = e->src; | |
8879d71c | 996 | rtx_insn *insn = BB_END (src), *kill_from; |
e1233a7d | 997 | rtx set; |
ca6c03ca | 998 | int fallthru = 0; |
750054a2 CT |
999 | |
1000 | /* If we are partitioning hot/cold basic blocks, we don't want to | |
1001 | mess up unconditional or indirect jumps that cross between hot | |
8e8d5162 CT |
1002 | and cold sections. |
1003 | ||
1004 | Basic block partitioning may result in some jumps that appear to | |
c22cacf3 MS |
1005 | be optimizable (or blocks that appear to be mergeable), but which really |
1006 | must be left untouched (they are required to make it safely across | |
1007 | partition boundaries). See the comments at the top of | |
8e8d5162 | 1008 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
c22cacf3 | 1009 | |
3371a64f | 1010 | if (BB_PARTITION (src) != BB_PARTITION (target)) |
9cf84a3c | 1011 | return NULL; |
750054a2 | 1012 | |
6a66a8a7 KH |
1013 | /* We can replace or remove a complex jump only when we have exactly |
1014 | two edges. Also, if we have exactly one outgoing edge, we can | |
1015 | redirect that. */ | |
1016 | if (EDGE_COUNT (src->succs) >= 3 | |
1017 | /* Verify that all targets will be TARGET. Specifically, the | |
1018 | edge that is not E must also go to TARGET. */ | |
1019 | || (EDGE_COUNT (src->succs) == 2 | |
1020 | && EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)) | |
1021 | return NULL; | |
5f0d2358 | 1022 | |
6a66a8a7 | 1023 | if (!onlyjump_p (insn)) |
6de9cd9a | 1024 | return NULL; |
3348b696 | 1025 | if ((!optimize || reload_completed) && tablejump_p (insn, NULL, NULL)) |
6de9cd9a | 1026 | return NULL; |
ca6c03ca JH |
1027 | |
1028 | /* Avoid removing branch with side effects. */ | |
1029 | set = single_set (insn); | |
1030 | if (!set || side_effects_p (set)) | |
6de9cd9a | 1031 | return NULL; |
ca6c03ca JH |
1032 | |
1033 | /* In case we zap a conditional jump, we'll need to kill | |
1034 | the cc0 setter too. */ | |
1035 | kill_from = insn; | |
058eb3b0 | 1036 | if (HAVE_cc0 && reg_mentioned_p (cc0_rtx, PATTERN (insn)) |
9caea4a7 | 1037 | && only_sets_cc0_p (PREV_INSN (insn))) |
ca6c03ca | 1038 | kill_from = PREV_INSN (insn); |
ca6c03ca JH |
1039 | |
1040 | /* See if we can create the fallthru edge. */ | |
bc35512f | 1041 | if (in_cfglayout || can_fallthru (src, target)) |
ca6c03ca | 1042 | { |
c263766c RH |
1043 | if (dump_file) |
1044 | fprintf (dump_file, "Removing jump %i.\n", INSN_UID (insn)); | |
ca6c03ca JH |
1045 | fallthru = 1; |
1046 | ||
eaec9b3d | 1047 | /* Selectively unlink whole insn chain. */ |
bc35512f JH |
1048 | if (in_cfglayout) |
1049 | { | |
8879d71c | 1050 | rtx_insn *insn = BB_FOOTER (src); |
bc35512f | 1051 | |
a7b87f73 | 1052 | delete_insn_chain (kill_from, BB_END (src), false); |
bc35512f JH |
1053 | |
1054 | /* Remove barriers but keep jumptables. */ | |
1055 | while (insn) | |
1056 | { | |
4b4bf941 | 1057 | if (BARRIER_P (insn)) |
bc35512f JH |
1058 | { |
1059 | if (PREV_INSN (insn)) | |
0f82e5c9 | 1060 | SET_NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); |
bc35512f | 1061 | else |
d8ce2eae | 1062 | BB_FOOTER (src) = NEXT_INSN (insn); |
bc35512f | 1063 | if (NEXT_INSN (insn)) |
0f82e5c9 | 1064 | SET_PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); |
bc35512f | 1065 | } |
4b4bf941 | 1066 | if (LABEL_P (insn)) |
bc35512f JH |
1067 | break; |
1068 | insn = NEXT_INSN (insn); | |
1069 | } | |
1070 | } | |
1071 | else | |
a7b87f73 ZD |
1072 | delete_insn_chain (kill_from, PREV_INSN (BB_HEAD (target)), |
1073 | false); | |
ca6c03ca | 1074 | } |
5f0d2358 | 1075 | |
ca6c03ca JH |
1076 | /* If this already is simplejump, redirect it. */ |
1077 | else if (simplejump_p (insn)) | |
1078 | { | |
1079 | if (e->dest == target) | |
6de9cd9a | 1080 | return NULL; |
c263766c RH |
1081 | if (dump_file) |
1082 | fprintf (dump_file, "Redirecting jump %i from %i to %i.\n", | |
0b17ab2f | 1083 | INSN_UID (insn), e->dest->index, target->index); |
1476d1bd MM |
1084 | if (!redirect_jump (as_a <rtx_jump_insn *> (insn), |
1085 | block_label (target), 0)) | |
6ee3c8e4 | 1086 | { |
fefa31b5 | 1087 | gcc_assert (target == EXIT_BLOCK_PTR_FOR_FN (cfun)); |
341c100f | 1088 | return NULL; |
6ee3c8e4 | 1089 | } |
ca6c03ca | 1090 | } |
5f0d2358 | 1091 | |
6ee3c8e4 | 1092 | /* Cannot do anything for target exit block. */ |
fefa31b5 | 1093 | else if (target == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
6de9cd9a | 1094 | return NULL; |
6ee3c8e4 | 1095 | |
ca6c03ca JH |
1096 | /* Or replace possibly complicated jump insn by simple jump insn. */ |
1097 | else | |
1098 | { | |
e67d1102 | 1099 | rtx_code_label *target_label = block_label (target); |
8879d71c | 1100 | rtx_insn *barrier; |
dfe08bc4 | 1101 | rtx_insn *label; |
8942ee0f | 1102 | rtx_jump_table_data *table; |
ca6c03ca | 1103 | |
ec4a505f | 1104 | emit_jump_insn_after_noloc (targetm.gen_jump (target_label), insn); |
a813c111 | 1105 | JUMP_LABEL (BB_END (src)) = target_label; |
ca6c03ca | 1106 | LABEL_NUSES (target_label)++; |
c263766c RH |
1107 | if (dump_file) |
1108 | fprintf (dump_file, "Replacing insn %i by jump %i\n", | |
a813c111 | 1109 | INSN_UID (insn), INSN_UID (BB_END (src))); |
ca6c03ca | 1110 | |
4da2eb6b | 1111 | |
ba4807a0 LB |
1112 | delete_insn_chain (kill_from, insn, false); |
1113 | ||
4da2eb6b RH |
1114 | /* Recognize a tablejump that we are converting to a |
1115 | simple jump and remove its associated CODE_LABEL | |
1116 | and ADDR_VEC or ADDR_DIFF_VEC. */ | |
ba4807a0 LB |
1117 | if (tablejump_p (insn, &label, &table)) |
1118 | delete_insn_chain (label, table, false); | |
eb5b8ad4 | 1119 | |
65f4b875 | 1120 | barrier = next_nonnote_nondebug_insn (BB_END (src)); |
4b4bf941 | 1121 | if (!barrier || !BARRIER_P (barrier)) |
a813c111 | 1122 | emit_barrier_after (BB_END (src)); |
5d693491 JZ |
1123 | else |
1124 | { | |
a813c111 | 1125 | if (barrier != NEXT_INSN (BB_END (src))) |
5d693491 JZ |
1126 | { |
1127 | /* Move the jump before barrier so that the notes | |
1128 | which originally were or were created before jump table are | |
1129 | inside the basic block. */ | |
8879d71c | 1130 | rtx_insn *new_insn = BB_END (src); |
5d693491 | 1131 | |
6c3d0e31 SP |
1132 | update_bb_for_insn_chain (NEXT_INSN (BB_END (src)), |
1133 | PREV_INSN (barrier), src); | |
5d693491 | 1134 | |
0f82e5c9 DM |
1135 | SET_NEXT_INSN (PREV_INSN (new_insn)) = NEXT_INSN (new_insn); |
1136 | SET_PREV_INSN (NEXT_INSN (new_insn)) = PREV_INSN (new_insn); | |
5d693491 | 1137 | |
0f82e5c9 DM |
1138 | SET_NEXT_INSN (new_insn) = barrier; |
1139 | SET_NEXT_INSN (PREV_INSN (barrier)) = new_insn; | |
5d693491 | 1140 | |
0f82e5c9 DM |
1141 | SET_PREV_INSN (new_insn) = PREV_INSN (barrier); |
1142 | SET_PREV_INSN (barrier) = new_insn; | |
5d693491 JZ |
1143 | } |
1144 | } | |
ca6c03ca JH |
1145 | } |
1146 | ||
1147 | /* Keep only one edge out and set proper flags. */ | |
c5cbcccf | 1148 | if (!single_succ_p (src)) |
628f6a4e | 1149 | remove_edge (e); |
c5cbcccf | 1150 | gcc_assert (single_succ_p (src)); |
628f6a4e | 1151 | |
c5cbcccf | 1152 | e = single_succ_edge (src); |
ca6c03ca JH |
1153 | if (fallthru) |
1154 | e->flags = EDGE_FALLTHRU; | |
1155 | else | |
1156 | e->flags = 0; | |
5f0d2358 | 1157 | |
357067f2 | 1158 | e->probability = profile_probability::always (); |
ca6c03ca | 1159 | |
ca6c03ca JH |
1160 | if (e->dest != target) |
1161 | redirect_edge_succ (e, target); | |
6de9cd9a | 1162 | return e; |
ca6c03ca JH |
1163 | } |
1164 | ||
4e3825db MM |
1165 | /* Subroutine of redirect_branch_edge that tries to patch the jump |
1166 | instruction INSN so that it reaches block NEW. Do this | |
1167 | only when it originally reached block OLD. Return true if this | |
1168 | worked or the original target wasn't OLD, return false if redirection | |
1169 | doesn't work. */ | |
1170 | ||
1171 | static bool | |
8879d71c | 1172 | patch_jump_insn (rtx_insn *insn, rtx_insn *old_label, basic_block new_bb) |
ca6c03ca | 1173 | { |
8942ee0f | 1174 | rtx_jump_table_data *table; |
ca6c03ca | 1175 | rtx tmp; |
ca6c03ca | 1176 | /* Recognize a tablejump and adjust all matching cases. */ |
8942ee0f | 1177 | if (tablejump_p (insn, NULL, &table)) |
ca6c03ca JH |
1178 | { |
1179 | rtvec vec; | |
1180 | int j; | |
e67d1102 | 1181 | rtx_code_label *new_label = block_label (new_bb); |
ca6c03ca | 1182 | |
fefa31b5 | 1183 | if (new_bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
4e3825db | 1184 | return false; |
95c43227 | 1185 | vec = table->get_labels (); |
ca6c03ca JH |
1186 | |
1187 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
1188 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
1189 | { | |
1190 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (Pmode, new_label); | |
1191 | --LABEL_NUSES (old_label); | |
1192 | ++LABEL_NUSES (new_label); | |
1193 | } | |
1194 | ||
f9da5064 | 1195 | /* Handle casesi dispatch insns. */ |
ca6c03ca JH |
1196 | if ((tmp = single_set (insn)) != NULL |
1197 | && SET_DEST (tmp) == pc_rtx | |
1198 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
1199 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF | |
04a121a7 | 1200 | && label_ref_label (XEXP (SET_SRC (tmp), 2)) == old_label) |
ca6c03ca | 1201 | { |
4c33cb26 | 1202 | XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (Pmode, |
ca6c03ca JH |
1203 | new_label); |
1204 | --LABEL_NUSES (old_label); | |
1205 | ++LABEL_NUSES (new_label); | |
1206 | } | |
1207 | } | |
1c384bf1 RH |
1208 | else if ((tmp = extract_asm_operands (PATTERN (insn))) != NULL) |
1209 | { | |
1210 | int i, n = ASM_OPERANDS_LABEL_LENGTH (tmp); | |
e67d1102 | 1211 | rtx note; |
1c384bf1 | 1212 | |
fefa31b5 | 1213 | if (new_bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
1c384bf1 | 1214 | return false; |
e67d1102 | 1215 | rtx_code_label *new_label = block_label (new_bb); |
1c384bf1 RH |
1216 | |
1217 | for (i = 0; i < n; ++i) | |
1218 | { | |
1219 | rtx old_ref = ASM_OPERANDS_LABEL (tmp, i); | |
1220 | gcc_assert (GET_CODE (old_ref) == LABEL_REF); | |
1221 | if (XEXP (old_ref, 0) == old_label) | |
1222 | { | |
1223 | ASM_OPERANDS_LABEL (tmp, i) | |
1224 | = gen_rtx_LABEL_REF (Pmode, new_label); | |
1225 | --LABEL_NUSES (old_label); | |
1226 | ++LABEL_NUSES (new_label); | |
1227 | } | |
1228 | } | |
1229 | ||
1230 | if (JUMP_LABEL (insn) == old_label) | |
1231 | { | |
1232 | JUMP_LABEL (insn) = new_label; | |
1233 | note = find_reg_note (insn, REG_LABEL_TARGET, new_label); | |
1234 | if (note) | |
1235 | remove_note (insn, note); | |
1236 | } | |
1237 | else | |
1238 | { | |
1239 | note = find_reg_note (insn, REG_LABEL_TARGET, old_label); | |
1240 | if (note) | |
1241 | remove_note (insn, note); | |
1242 | if (JUMP_LABEL (insn) != new_label | |
1243 | && !find_reg_note (insn, REG_LABEL_TARGET, new_label)) | |
1244 | add_reg_note (insn, REG_LABEL_TARGET, new_label); | |
1245 | } | |
3b5fda81 JJ |
1246 | while ((note = find_reg_note (insn, REG_LABEL_OPERAND, old_label)) |
1247 | != NULL_RTX) | |
1248 | XEXP (note, 0) = new_label; | |
1c384bf1 | 1249 | } |
ca6c03ca JH |
1250 | else |
1251 | { | |
1252 | /* ?? We may play the games with moving the named labels from | |
1253 | one basic block to the other in case only one computed_jump is | |
1254 | available. */ | |
5f0d2358 RK |
1255 | if (computed_jump_p (insn) |
1256 | /* A return instruction can't be redirected. */ | |
1257 | || returnjump_p (insn)) | |
4e3825db | 1258 | return false; |
6ee3c8e4 | 1259 | |
4e3825db | 1260 | if (!currently_expanding_to_rtl || JUMP_LABEL (insn) == old_label) |
6ee3c8e4 | 1261 | { |
4e3825db MM |
1262 | /* If the insn doesn't go where we think, we're confused. */ |
1263 | gcc_assert (JUMP_LABEL (insn) == old_label); | |
1264 | ||
1265 | /* If the substitution doesn't succeed, die. This can happen | |
1266 | if the back end emitted unrecognizable instructions or if | |
1267 | target is exit block on some arches. */ | |
1476d1bd MM |
1268 | if (!redirect_jump (as_a <rtx_jump_insn *> (insn), |
1269 | block_label (new_bb), 0)) | |
4e3825db | 1270 | { |
fefa31b5 | 1271 | gcc_assert (new_bb == EXIT_BLOCK_PTR_FOR_FN (cfun)); |
4e3825db MM |
1272 | return false; |
1273 | } | |
6ee3c8e4 | 1274 | } |
ca6c03ca | 1275 | } |
4e3825db MM |
1276 | return true; |
1277 | } | |
1278 | ||
1279 | ||
1280 | /* Redirect edge representing branch of (un)conditional jump or tablejump, | |
1281 | NULL on failure */ | |
1282 | static edge | |
1283 | redirect_branch_edge (edge e, basic_block target) | |
1284 | { | |
8879d71c | 1285 | rtx_insn *old_label = BB_HEAD (e->dest); |
4e3825db | 1286 | basic_block src = e->src; |
8879d71c | 1287 | rtx_insn *insn = BB_END (src); |
4e3825db MM |
1288 | |
1289 | /* We can only redirect non-fallthru edges of jump insn. */ | |
1290 | if (e->flags & EDGE_FALLTHRU) | |
1291 | return NULL; | |
1292 | else if (!JUMP_P (insn) && !currently_expanding_to_rtl) | |
1293 | return NULL; | |
1294 | ||
1295 | if (!currently_expanding_to_rtl) | |
1296 | { | |
1476d1bd | 1297 | if (!patch_jump_insn (as_a <rtx_jump_insn *> (insn), old_label, target)) |
4e3825db MM |
1298 | return NULL; |
1299 | } | |
1300 | else | |
1301 | /* When expanding this BB might actually contain multiple | |
1302 | jumps (i.e. not yet split by find_many_sub_basic_blocks). | |
1303 | Redirect all of those that match our label. */ | |
0f346928 | 1304 | FOR_BB_INSNS (src, insn) |
1476d1bd MM |
1305 | if (JUMP_P (insn) && !patch_jump_insn (as_a <rtx_jump_insn *> (insn), |
1306 | old_label, target)) | |
4e3825db | 1307 | return NULL; |
ca6c03ca | 1308 | |
c263766c RH |
1309 | if (dump_file) |
1310 | fprintf (dump_file, "Edge %i->%i redirected to %i\n", | |
0b17ab2f | 1311 | e->src->index, e->dest->index, target->index); |
5f0d2358 | 1312 | |
ca6c03ca | 1313 | if (e->dest != target) |
6de9cd9a | 1314 | e = redirect_edge_succ_nodup (e, target); |
6fb5fa3c | 1315 | |
6de9cd9a | 1316 | return e; |
bc35512f JH |
1317 | } |
1318 | ||
3371a64f TJ |
1319 | /* Called when edge E has been redirected to a new destination, |
1320 | in order to update the region crossing flag on the edge and | |
1321 | jump. */ | |
1322 | ||
1323 | static void | |
1324 | fixup_partition_crossing (edge e) | |
1325 | { | |
fefa31b5 DM |
1326 | if (e->src == ENTRY_BLOCK_PTR_FOR_FN (cfun) || e->dest |
1327 | == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
3371a64f TJ |
1328 | return; |
1329 | /* If we redirected an existing edge, it may already be marked | |
1330 | crossing, even though the new src is missing a reg crossing note. | |
1331 | But make sure reg crossing note doesn't already exist before | |
1332 | inserting. */ | |
1333 | if (BB_PARTITION (e->src) != BB_PARTITION (e->dest)) | |
1334 | { | |
1335 | e->flags |= EDGE_CROSSING; | |
52af3804 | 1336 | if (JUMP_P (BB_END (e->src))) |
339ba33b | 1337 | CROSSING_JUMP_P (BB_END (e->src)) = 1; |
3371a64f TJ |
1338 | } |
1339 | else if (BB_PARTITION (e->src) == BB_PARTITION (e->dest)) | |
1340 | { | |
1341 | e->flags &= ~EDGE_CROSSING; | |
1342 | /* Remove the section crossing note from jump at end of | |
1343 | src if it exists, and if no other successors are | |
1344 | still crossing. */ | |
339ba33b | 1345 | if (JUMP_P (BB_END (e->src)) && CROSSING_JUMP_P (BB_END (e->src))) |
3371a64f TJ |
1346 | { |
1347 | bool has_crossing_succ = false; | |
1348 | edge e2; | |
1349 | edge_iterator ei; | |
1350 | FOR_EACH_EDGE (e2, ei, e->src->succs) | |
1351 | { | |
1352 | has_crossing_succ |= (e2->flags & EDGE_CROSSING); | |
1353 | if (has_crossing_succ) | |
1354 | break; | |
1355 | } | |
1356 | if (!has_crossing_succ) | |
339ba33b | 1357 | CROSSING_JUMP_P (BB_END (e->src)) = 0; |
3371a64f TJ |
1358 | } |
1359 | } | |
1360 | } | |
1361 | ||
600b5b1d TJ |
1362 | /* Called when block BB has been reassigned to the cold partition, |
1363 | because it is now dominated by another cold block, | |
1364 | to ensure that the region crossing attributes are updated. */ | |
1365 | ||
1366 | static void | |
1367 | fixup_new_cold_bb (basic_block bb) | |
1368 | { | |
1369 | edge e; | |
1370 | edge_iterator ei; | |
1371 | ||
1372 | /* This is called when a hot bb is found to now be dominated | |
1373 | by a cold bb and therefore needs to become cold. Therefore, | |
1374 | its preds will no longer be region crossing. Any non-dominating | |
1375 | preds that were previously hot would also have become cold | |
1376 | in the caller for the same region. Any preds that were previously | |
1377 | region-crossing will be adjusted in fixup_partition_crossing. */ | |
1378 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1379 | { | |
1380 | fixup_partition_crossing (e); | |
1381 | } | |
1382 | ||
1383 | /* Possibly need to make bb's successor edges region crossing, | |
1384 | or remove stale region crossing. */ | |
1385 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1386 | { | |
1387 | /* We can't have fall-through edges across partition boundaries. | |
1388 | Note that force_nonfallthru will do any necessary partition | |
1389 | boundary fixup by calling fixup_partition_crossing itself. */ | |
1390 | if ((e->flags & EDGE_FALLTHRU) | |
1391 | && BB_PARTITION (bb) != BB_PARTITION (e->dest) | |
fefa31b5 | 1392 | && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
600b5b1d TJ |
1393 | force_nonfallthru (e); |
1394 | else | |
1395 | fixup_partition_crossing (e); | |
1396 | } | |
1397 | } | |
1398 | ||
bc35512f JH |
1399 | /* Attempt to change code to redirect edge E to TARGET. Don't do that on |
1400 | expense of adding new instructions or reordering basic blocks. | |
1401 | ||
1402 | Function can be also called with edge destination equivalent to the TARGET. | |
1403 | Then it should try the simplifications and do nothing if none is possible. | |
1404 | ||
6de9cd9a DN |
1405 | Return edge representing the branch if transformation succeeded. Return NULL |
1406 | on failure. | |
1407 | We still return NULL in case E already destinated TARGET and we didn't | |
1408 | managed to simplify instruction stream. */ | |
bc35512f | 1409 | |
6de9cd9a | 1410 | static edge |
5671bf27 | 1411 | rtl_redirect_edge_and_branch (edge e, basic_block target) |
bc35512f | 1412 | { |
6de9cd9a | 1413 | edge ret; |
f345f21a | 1414 | basic_block src = e->src; |
3371a64f | 1415 | basic_block dest = e->dest; |
f345f21a | 1416 | |
bc35512f | 1417 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
6de9cd9a | 1418 | return NULL; |
bc35512f | 1419 | |
3371a64f | 1420 | if (dest == target) |
6de9cd9a | 1421 | return e; |
3348b696 | 1422 | |
6de9cd9a | 1423 | if ((ret = try_redirect_by_replacing_jump (e, target, false)) != NULL) |
f345f21a | 1424 | { |
6fb5fa3c | 1425 | df_set_bb_dirty (src); |
3371a64f | 1426 | fixup_partition_crossing (ret); |
6de9cd9a | 1427 | return ret; |
f345f21a | 1428 | } |
bc35512f | 1429 | |
6de9cd9a DN |
1430 | ret = redirect_branch_edge (e, target); |
1431 | if (!ret) | |
1432 | return NULL; | |
5f0d2358 | 1433 | |
6fb5fa3c | 1434 | df_set_bb_dirty (src); |
3371a64f | 1435 | fixup_partition_crossing (ret); |
6de9cd9a | 1436 | return ret; |
ca6c03ca JH |
1437 | } |
1438 | ||
3371a64f TJ |
1439 | /* Emit a barrier after BB, into the footer if we are in CFGLAYOUT mode. */ |
1440 | ||
1441 | void | |
1442 | emit_barrier_after_bb (basic_block bb) | |
1443 | { | |
cd459bf8 | 1444 | rtx_barrier *barrier = emit_barrier_after (BB_END (bb)); |
c3284718 | 1445 | gcc_assert (current_ir_type () == IR_RTL_CFGRTL |
3371a64f TJ |
1446 | || current_ir_type () == IR_RTL_CFGLAYOUT); |
1447 | if (current_ir_type () == IR_RTL_CFGLAYOUT) | |
0fb3402f RX |
1448 | { |
1449 | rtx_insn *insn = unlink_insn_chain (barrier, barrier); | |
1450 | ||
1451 | if (BB_FOOTER (bb)) | |
1452 | { | |
1453 | rtx_insn *footer_tail = BB_FOOTER (bb); | |
1454 | ||
1455 | while (NEXT_INSN (footer_tail)) | |
1456 | footer_tail = NEXT_INSN (footer_tail); | |
1457 | if (!BARRIER_P (footer_tail)) | |
1458 | { | |
1459 | SET_NEXT_INSN (footer_tail) = insn; | |
1460 | SET_PREV_INSN (insn) = footer_tail; | |
1461 | } | |
1462 | } | |
1463 | else | |
1464 | BB_FOOTER (bb) = insn; | |
1465 | } | |
3371a64f TJ |
1466 | } |
1467 | ||
4fe9b91c | 1468 | /* Like force_nonfallthru below, but additionally performs redirection |
26898771 BS |
1469 | Used by redirect_edge_and_branch_force. JUMP_LABEL is used only |
1470 | when redirecting to the EXIT_BLOCK, it is either ret_rtx or | |
1471 | simple_return_rtx, indicating which kind of returnjump to create. | |
1472 | It should be NULL otherwise. */ | |
ca6c03ca | 1473 | |
dc0ff1c8 | 1474 | basic_block |
26898771 | 1475 | force_nonfallthru_and_redirect (edge e, basic_block target, rtx jump_label) |
ca6c03ca | 1476 | { |
a3716585 | 1477 | basic_block jump_block, new_bb = NULL, src = e->src; |
ca6c03ca JH |
1478 | rtx note; |
1479 | edge new_edge; | |
a3716585 | 1480 | int abnormal_edge_flags = 0; |
a3e6a37b | 1481 | bool asm_goto_edge = false; |
7241571e | 1482 | int loc; |
ca6c03ca | 1483 | |
cb9a1d9b JH |
1484 | /* In the case the last instruction is conditional jump to the next |
1485 | instruction, first redirect the jump itself and then continue | |
b20b352b | 1486 | by creating a basic block afterwards to redirect fallthru edge. */ |
fefa31b5 DM |
1487 | if (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
1488 | && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) | |
a813c111 | 1489 | && any_condjump_p (BB_END (e->src)) |
a813c111 | 1490 | && JUMP_LABEL (BB_END (e->src)) == BB_HEAD (e->dest)) |
cb9a1d9b JH |
1491 | { |
1492 | rtx note; | |
58e6ae30 | 1493 | edge b = unchecked_make_edge (e->src, target, 0); |
341c100f | 1494 | bool redirected; |
cb9a1d9b | 1495 | |
1476d1bd MM |
1496 | redirected = redirect_jump (as_a <rtx_jump_insn *> (BB_END (e->src)), |
1497 | block_label (target), 0); | |
341c100f | 1498 | gcc_assert (redirected); |
c22cacf3 | 1499 | |
a813c111 | 1500 | note = find_reg_note (BB_END (e->src), REG_BR_PROB, NULL_RTX); |
cb9a1d9b JH |
1501 | if (note) |
1502 | { | |
e5af9ddd | 1503 | int prob = XINT (note, 0); |
cb9a1d9b | 1504 | |
5fa396ad | 1505 | b->probability = profile_probability::from_reg_br_prob_note (prob); |
cb9a1d9b | 1506 | e->probability -= e->probability; |
cb9a1d9b JH |
1507 | } |
1508 | } | |
1509 | ||
ca6c03ca | 1510 | if (e->flags & EDGE_ABNORMAL) |
a3716585 JH |
1511 | { |
1512 | /* Irritating special case - fallthru edge to the same block as abnormal | |
1513 | edge. | |
1514 | We can't redirect abnormal edge, but we still can split the fallthru | |
d329e058 | 1515 | one and create separate abnormal edge to original destination. |
a3716585 | 1516 | This allows bb-reorder to make such edge non-fallthru. */ |
341c100f | 1517 | gcc_assert (e->dest == target); |
ee44c28d SB |
1518 | abnormal_edge_flags = e->flags & ~EDGE_FALLTHRU; |
1519 | e->flags &= EDGE_FALLTHRU; | |
a3716585 | 1520 | } |
341c100f | 1521 | else |
24c545ff | 1522 | { |
341c100f | 1523 | gcc_assert (e->flags & EDGE_FALLTHRU); |
fefa31b5 | 1524 | if (e->src == ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
341c100f NS |
1525 | { |
1526 | /* We can't redirect the entry block. Create an empty block | |
628f6a4e BE |
1527 | at the start of the function which we use to add the new |
1528 | jump. */ | |
1529 | edge tmp; | |
1530 | edge_iterator ei; | |
1531 | bool found = false; | |
c22cacf3 | 1532 | |
fefa31b5 DM |
1533 | basic_block bb = create_basic_block (BB_HEAD (e->dest), NULL, |
1534 | ENTRY_BLOCK_PTR_FOR_FN (cfun)); | |
e7a74006 | 1535 | bb->count = ENTRY_BLOCK_PTR_FOR_FN (cfun)->count; |
c22cacf3 | 1536 | |
63e1159c JJ |
1537 | /* Make sure new block ends up in correct hot/cold section. */ |
1538 | BB_COPY_PARTITION (bb, e->dest); | |
1539 | ||
341c100f NS |
1540 | /* Change the existing edge's source to be the new block, and add |
1541 | a new edge from the entry block to the new block. */ | |
1542 | e->src = bb; | |
fefa31b5 DM |
1543 | for (ei = ei_start (ENTRY_BLOCK_PTR_FOR_FN (cfun)->succs); |
1544 | (tmp = ei_safe_edge (ei)); ) | |
628f6a4e BE |
1545 | { |
1546 | if (tmp == e) | |
1547 | { | |
fefa31b5 | 1548 | ENTRY_BLOCK_PTR_FOR_FN (cfun)->succs->unordered_remove (ei.index); |
628f6a4e BE |
1549 | found = true; |
1550 | break; | |
1551 | } | |
1552 | else | |
1553 | ei_next (&ei); | |
1554 | } | |
c22cacf3 | 1555 | |
628f6a4e | 1556 | gcc_assert (found); |
c22cacf3 | 1557 | |
9771b263 | 1558 | vec_safe_push (bb->succs, e); |
fefa31b5 DM |
1559 | make_single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun), bb, |
1560 | EDGE_FALLTHRU); | |
341c100f | 1561 | } |
24c545ff BS |
1562 | } |
1563 | ||
a3e6a37b | 1564 | /* If e->src ends with asm goto, see if any of the ASM_OPERANDS_LABELs |
891ca07d | 1565 | don't point to the target or fallthru label. */ |
a3e6a37b | 1566 | if (JUMP_P (BB_END (e->src)) |
fefa31b5 | 1567 | && target != EXIT_BLOCK_PTR_FOR_FN (cfun) |
a3e6a37b JJ |
1568 | && (e->flags & EDGE_FALLTHRU) |
1569 | && (note = extract_asm_operands (PATTERN (BB_END (e->src))))) | |
ca6c03ca | 1570 | { |
a3e6a37b | 1571 | int i, n = ASM_OPERANDS_LABEL_LENGTH (note); |
5d68b7e6 | 1572 | bool adjust_jump_target = false; |
a3e6a37b JJ |
1573 | |
1574 | for (i = 0; i < n; ++i) | |
891ca07d JJ |
1575 | { |
1576 | if (XEXP (ASM_OPERANDS_LABEL (note, i), 0) == BB_HEAD (e->dest)) | |
5d68b7e6 JJ |
1577 | { |
1578 | LABEL_NUSES (XEXP (ASM_OPERANDS_LABEL (note, i), 0))--; | |
1579 | XEXP (ASM_OPERANDS_LABEL (note, i), 0) = block_label (target); | |
1580 | LABEL_NUSES (XEXP (ASM_OPERANDS_LABEL (note, i), 0))++; | |
1581 | adjust_jump_target = true; | |
1582 | } | |
891ca07d | 1583 | if (XEXP (ASM_OPERANDS_LABEL (note, i), 0) == BB_HEAD (target)) |
a3e6a37b | 1584 | asm_goto_edge = true; |
891ca07d | 1585 | } |
5d68b7e6 JJ |
1586 | if (adjust_jump_target) |
1587 | { | |
8879d71c DM |
1588 | rtx_insn *insn = BB_END (e->src); |
1589 | rtx note; | |
1590 | rtx_insn *old_label = BB_HEAD (e->dest); | |
1591 | rtx_insn *new_label = BB_HEAD (target); | |
5d68b7e6 JJ |
1592 | |
1593 | if (JUMP_LABEL (insn) == old_label) | |
1594 | { | |
1595 | JUMP_LABEL (insn) = new_label; | |
1596 | note = find_reg_note (insn, REG_LABEL_TARGET, new_label); | |
1597 | if (note) | |
1598 | remove_note (insn, note); | |
1599 | } | |
1600 | else | |
1601 | { | |
1602 | note = find_reg_note (insn, REG_LABEL_TARGET, old_label); | |
1603 | if (note) | |
1604 | remove_note (insn, note); | |
1605 | if (JUMP_LABEL (insn) != new_label | |
1606 | && !find_reg_note (insn, REG_LABEL_TARGET, new_label)) | |
1607 | add_reg_note (insn, REG_LABEL_TARGET, new_label); | |
1608 | } | |
1609 | while ((note = find_reg_note (insn, REG_LABEL_OPERAND, old_label)) | |
1610 | != NULL_RTX) | |
1611 | XEXP (note, 0) = new_label; | |
1612 | } | |
a3e6a37b JJ |
1613 | } |
1614 | ||
1615 | if (EDGE_COUNT (e->src->succs) >= 2 || abnormal_edge_flags || asm_goto_edge) | |
1616 | { | |
dc01c3d1 | 1617 | rtx_insn *new_head; |
ef30ab83 | 1618 | profile_count count = e->count (); |
357067f2 | 1619 | profile_probability probability = e->probability; |
ca6c03ca | 1620 | /* Create the new structures. */ |
31a78298 | 1621 | |
79019985 RH |
1622 | /* If the old block ended with a tablejump, skip its table |
1623 | by searching forward from there. Otherwise start searching | |
1624 | forward from the last instruction of the old block. */ | |
8942ee0f DM |
1625 | rtx_jump_table_data *table; |
1626 | if (tablejump_p (BB_END (e->src), NULL, &table)) | |
dc01c3d1 | 1627 | new_head = table; |
8942ee0f | 1628 | else |
dc01c3d1 DM |
1629 | new_head = BB_END (e->src); |
1630 | new_head = NEXT_INSN (new_head); | |
13f5d5e0 CZ |
1631 | /* Make sure we don't split a call and its corresponding |
1632 | CALL_ARG_LOCATION note. */ | |
1633 | if (new_head && NOTE_P (new_head) | |
1634 | && NOTE_KIND (new_head) == NOTE_INSN_CALL_ARG_LOCATION) | |
1635 | new_head = NEXT_INSN (new_head); | |
31a78298 | 1636 | |
dc01c3d1 | 1637 | jump_block = create_basic_block (new_head, NULL, e->src); |
a3e6a37b | 1638 | jump_block->count = count; |
ca6c03ca | 1639 | |
750054a2 CT |
1640 | /* Make sure new block ends up in correct hot/cold section. */ |
1641 | ||
076c7ab8 | 1642 | BB_COPY_PARTITION (jump_block, e->src); |
c22cacf3 | 1643 | |
ca6c03ca JH |
1644 | /* Wire edge in. */ |
1645 | new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU); | |
a3e6a37b | 1646 | new_edge->probability = probability; |
ca6c03ca JH |
1647 | |
1648 | /* Redirect old edge. */ | |
1649 | redirect_edge_pred (e, jump_block); | |
357067f2 | 1650 | e->probability = profile_probability::always (); |
ca6c03ca | 1651 | |
3371a64f TJ |
1652 | /* If e->src was previously region crossing, it no longer is |
1653 | and the reg crossing note should be removed. */ | |
1654 | fixup_partition_crossing (new_edge); | |
1655 | ||
a3e6a37b JJ |
1656 | /* If asm goto has any label refs to target's label, |
1657 | add also edge from asm goto bb to target. */ | |
1658 | if (asm_goto_edge) | |
1659 | { | |
357067f2 | 1660 | new_edge->probability = new_edge->probability.apply_scale (1, 2); |
3995f3a2 | 1661 | jump_block->count = jump_block->count.apply_scale (1, 2); |
3995f3a2 JH |
1662 | edge new_edge2 = make_edge (new_edge->src, target, |
1663 | e->flags & ~EDGE_FALLTHRU); | |
1664 | new_edge2->probability = probability - new_edge->probability; | |
a3e6a37b JJ |
1665 | } |
1666 | ||
ca6c03ca JH |
1667 | new_bb = jump_block; |
1668 | } | |
1669 | else | |
1670 | jump_block = e->src; | |
5f0d2358 | 1671 | |
2f13f2de | 1672 | loc = e->goto_locus; |
ca6c03ca | 1673 | e->flags &= ~EDGE_FALLTHRU; |
fefa31b5 | 1674 | if (target == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
ca6c03ca | 1675 | { |
26898771 | 1676 | if (jump_label == ret_rtx) |
4bccb39e RS |
1677 | emit_jump_insn_after_setloc (targetm.gen_return (), |
1678 | BB_END (jump_block), loc); | |
26898771 BS |
1679 | else |
1680 | { | |
1681 | gcc_assert (jump_label == simple_return_rtx); | |
4bccb39e | 1682 | emit_jump_insn_after_setloc (targetm.gen_simple_return (), |
26898771 | 1683 | BB_END (jump_block), loc); |
26898771 | 1684 | } |
387748de | 1685 | set_return_jump_label (BB_END (jump_block)); |
ca6c03ca JH |
1686 | } |
1687 | else | |
1688 | { | |
e67d1102 | 1689 | rtx_code_label *label = block_label (target); |
ec4a505f RS |
1690 | emit_jump_insn_after_setloc (targetm.gen_jump (label), |
1691 | BB_END (jump_block), loc); | |
a813c111 | 1692 | JUMP_LABEL (BB_END (jump_block)) = label; |
ca6c03ca JH |
1693 | LABEL_NUSES (label)++; |
1694 | } | |
5f0d2358 | 1695 | |
3371a64f TJ |
1696 | /* We might be in cfg layout mode, and if so, the following routine will |
1697 | insert the barrier correctly. */ | |
1698 | emit_barrier_after_bb (jump_block); | |
ca6c03ca JH |
1699 | redirect_edge_succ_nodup (e, target); |
1700 | ||
a3716585 JH |
1701 | if (abnormal_edge_flags) |
1702 | make_edge (src, target, abnormal_edge_flags); | |
1703 | ||
b8698a0f | 1704 | df_mark_solutions_dirty (); |
3371a64f | 1705 | fixup_partition_crossing (e); |
ca6c03ca JH |
1706 | return new_bb; |
1707 | } | |
1708 | ||
1709 | /* Edge E is assumed to be fallthru edge. Emit needed jump instruction | |
1710 | (and possibly create new basic block) to make edge non-fallthru. | |
1711 | Return newly created BB or NULL if none. */ | |
5f0d2358 | 1712 | |
cf103ca4 EB |
1713 | static basic_block |
1714 | rtl_force_nonfallthru (edge e) | |
ca6c03ca | 1715 | { |
26898771 | 1716 | return force_nonfallthru_and_redirect (e, e->dest, NULL_RTX); |
ca6c03ca JH |
1717 | } |
1718 | ||
1719 | /* Redirect edge even at the expense of creating new jump insn or | |
1720 | basic block. Return new basic block if created, NULL otherwise. | |
41806d92 | 1721 | Conversion must be possible. */ |
ca6c03ca | 1722 | |
9ee634e3 | 1723 | static basic_block |
d329e058 | 1724 | rtl_redirect_edge_and_branch_force (edge e, basic_block target) |
ca6c03ca | 1725 | { |
5f0d2358 RK |
1726 | if (redirect_edge_and_branch (e, target) |
1727 | || e->dest == target) | |
ca6c03ca JH |
1728 | return NULL; |
1729 | ||
1730 | /* In case the edge redirection failed, try to force it to be non-fallthru | |
1731 | and redirect newly created simplejump. */ | |
6fb5fa3c | 1732 | df_set_bb_dirty (e->src); |
26898771 | 1733 | return force_nonfallthru_and_redirect (e, target, NULL_RTX); |
ca6c03ca JH |
1734 | } |
1735 | ||
1736 | /* The given edge should potentially be a fallthru edge. If that is in | |
1737 | fact true, delete the jump and barriers that are in the way. */ | |
1738 | ||
f470c378 ZD |
1739 | static void |
1740 | rtl_tidy_fallthru_edge (edge e) | |
ca6c03ca | 1741 | { |
8879d71c | 1742 | rtx_insn *q; |
f470c378 ZD |
1743 | basic_block b = e->src, c = b->next_bb; |
1744 | ||
ca6c03ca JH |
1745 | /* ??? In a late-running flow pass, other folks may have deleted basic |
1746 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
0fa2e4df | 1747 | and the target label. They ought to be chastised and fixed. |
ca6c03ca JH |
1748 | |
1749 | We can also wind up with a sequence of undeletable labels between | |
1750 | one block and the next. | |
1751 | ||
1752 | So search through a sequence of barriers, labels, and notes for | |
1753 | the head of block C and assert that we really do fall through. */ | |
1754 | ||
a813c111 | 1755 | for (q = NEXT_INSN (BB_END (b)); q != BB_HEAD (c); q = NEXT_INSN (q)) |
65f4b875 | 1756 | if (NONDEBUG_INSN_P (q)) |
9c0a0632 | 1757 | return; |
ca6c03ca JH |
1758 | |
1759 | /* Remove what will soon cease being the jump insn from the source block. | |
1760 | If block B consisted only of this single jump, turn it into a deleted | |
1761 | note. */ | |
a813c111 | 1762 | q = BB_END (b); |
4b4bf941 | 1763 | if (JUMP_P (q) |
ca6c03ca JH |
1764 | && onlyjump_p (q) |
1765 | && (any_uncondjump_p (q) | |
c5cbcccf | 1766 | || single_succ_p (b))) |
ca6c03ca | 1767 | { |
dfe08bc4 | 1768 | rtx_insn *label; |
adfac8df JJ |
1769 | rtx_jump_table_data *table; |
1770 | ||
1771 | if (tablejump_p (q, &label, &table)) | |
1772 | { | |
1773 | /* The label is likely mentioned in some instruction before | |
1774 | the tablejump and might not be DCEd, so turn it into | |
1775 | a note instead and move before the tablejump that is going to | |
1776 | be deleted. */ | |
1777 | const char *name = LABEL_NAME (label); | |
1778 | PUT_CODE (label, NOTE); | |
1779 | NOTE_KIND (label) = NOTE_INSN_DELETED_LABEL; | |
1780 | NOTE_DELETED_LABEL_NAME (label) = name; | |
dfe08bc4 | 1781 | reorder_insns (label, label, PREV_INSN (q)); |
adfac8df JJ |
1782 | delete_insn (table); |
1783 | } | |
1784 | ||
ca6c03ca JH |
1785 | /* If this was a conditional jump, we need to also delete |
1786 | the insn that set cc0. */ | |
058eb3b0 | 1787 | if (HAVE_cc0 && any_condjump_p (q) && only_sets_cc0_p (PREV_INSN (q))) |
ca6c03ca | 1788 | q = PREV_INSN (q); |
ca6c03ca JH |
1789 | |
1790 | q = PREV_INSN (q); | |
ca6c03ca | 1791 | } |
b34f29a1 JJ |
1792 | /* Unconditional jumps with side-effects (i.e. which we can't just delete |
1793 | together with the barrier) should never have a fallthru edge. */ | |
1794 | else if (JUMP_P (q) && any_uncondjump_p (q)) | |
1795 | return; | |
ca6c03ca JH |
1796 | |
1797 | /* Selectively unlink the sequence. */ | |
a813c111 | 1798 | if (q != PREV_INSN (BB_HEAD (c))) |
a7b87f73 | 1799 | delete_insn_chain (NEXT_INSN (q), PREV_INSN (BB_HEAD (c)), false); |
ca6c03ca JH |
1800 | |
1801 | e->flags |= EDGE_FALLTHRU; | |
1802 | } | |
ca6c03ca | 1803 | \f |
f470c378 ZD |
1804 | /* Should move basic block BB after basic block AFTER. NIY. */ |
1805 | ||
1806 | static bool | |
1807 | rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED, | |
1808 | basic_block after ATTRIBUTE_UNUSED) | |
1809 | { | |
1810 | return false; | |
1811 | } | |
1812 | ||
3371a64f TJ |
1813 | /* Locate the last bb in the same partition as START_BB. */ |
1814 | ||
1815 | static basic_block | |
1816 | last_bb_in_partition (basic_block start_bb) | |
1817 | { | |
1818 | basic_block bb; | |
fefa31b5 | 1819 | FOR_BB_BETWEEN (bb, start_bb, EXIT_BLOCK_PTR_FOR_FN (cfun), next_bb) |
3371a64f TJ |
1820 | { |
1821 | if (BB_PARTITION (start_bb) != BB_PARTITION (bb->next_bb)) | |
1822 | return bb; | |
1823 | } | |
6626665f | 1824 | /* Return bb before the exit block. */ |
3371a64f TJ |
1825 | return bb->prev_bb; |
1826 | } | |
1827 | ||
ca6c03ca | 1828 | /* Split a (typically critical) edge. Return the new block. |
41806d92 | 1829 | The edge must not be abnormal. |
ca6c03ca JH |
1830 | |
1831 | ??? The code generally expects to be called on critical edges. | |
1832 | The case of a block ending in an unconditional jump to a | |
1833 | block with multiple predecessors is not handled optimally. */ | |
1834 | ||
8ce33230 | 1835 | static basic_block |
d329e058 | 1836 | rtl_split_edge (edge edge_in) |
ca6c03ca | 1837 | { |
3371a64f | 1838 | basic_block bb, new_bb; |
8879d71c | 1839 | rtx_insn *before; |
ca6c03ca JH |
1840 | |
1841 | /* Abnormal edges cannot be split. */ | |
341c100f | 1842 | gcc_assert (!(edge_in->flags & EDGE_ABNORMAL)); |
ca6c03ca JH |
1843 | |
1844 | /* We are going to place the new block in front of edge destination. | |
eaec9b3d | 1845 | Avoid existence of fallthru predecessors. */ |
ca6c03ca JH |
1846 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) |
1847 | { | |
0fd4b31d | 1848 | edge e = find_fallthru_edge (edge_in->dest->preds); |
ca6c03ca JH |
1849 | |
1850 | if (e) | |
1851 | force_nonfallthru (e); | |
1852 | } | |
1853 | ||
96e82e0a | 1854 | /* Create the basic block note. */ |
fefa31b5 | 1855 | if (edge_in->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
a813c111 | 1856 | before = BB_HEAD (edge_in->dest); |
ca6c03ca | 1857 | else |
8879d71c | 1858 | before = NULL; |
ca6c03ca | 1859 | |
623a66fa | 1860 | /* If this is a fall through edge to the exit block, the blocks might be |
ffe14686 | 1861 | not adjacent, and the right place is after the source. */ |
fefa31b5 DM |
1862 | if ((edge_in->flags & EDGE_FALLTHRU) |
1863 | && edge_in->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
623a66fa R |
1864 | { |
1865 | before = NEXT_INSN (BB_END (edge_in->src)); | |
623a66fa | 1866 | bb = create_basic_block (before, NULL, edge_in->src); |
076c7ab8 | 1867 | BB_COPY_PARTITION (bb, edge_in->src); |
623a66fa R |
1868 | } |
1869 | else | |
9fb32434 | 1870 | { |
fefa31b5 | 1871 | if (edge_in->src == ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
3371a64f TJ |
1872 | { |
1873 | bb = create_basic_block (before, NULL, edge_in->dest->prev_bb); | |
1874 | BB_COPY_PARTITION (bb, edge_in->dest); | |
1875 | } | |
1876 | else | |
1877 | { | |
1878 | basic_block after = edge_in->dest->prev_bb; | |
1879 | /* If this is post-bb reordering, and the edge crosses a partition | |
1880 | boundary, the new block needs to be inserted in the bb chain | |
1881 | at the end of the src partition (since we put the new bb into | |
1882 | that partition, see below). Otherwise we may end up creating | |
1883 | an extra partition crossing in the chain, which is illegal. | |
1884 | It can't go after the src, because src may have a fall-through | |
1885 | to a different block. */ | |
1886 | if (crtl->bb_reorder_complete | |
1887 | && (edge_in->flags & EDGE_CROSSING)) | |
1888 | { | |
1889 | after = last_bb_in_partition (edge_in->src); | |
b3a3ae09 | 1890 | before = get_last_bb_insn (after); |
3371a64f TJ |
1891 | /* The instruction following the last bb in partition should |
1892 | be a barrier, since it cannot end in a fall-through. */ | |
1893 | gcc_checking_assert (BARRIER_P (before)); | |
1894 | before = NEXT_INSN (before); | |
1895 | } | |
1896 | bb = create_basic_block (before, NULL, after); | |
1897 | /* Put the split bb into the src partition, to avoid creating | |
1898 | a situation where a cold bb dominates a hot bb, in the case | |
1899 | where src is cold and dest is hot. The src will dominate | |
1900 | the new bb (whereas it might not have dominated dest). */ | |
1901 | BB_COPY_PARTITION (bb, edge_in->src); | |
1902 | } | |
9fb32434 | 1903 | } |
ca6c03ca | 1904 | |
4977bab6 | 1905 | make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU); |
ca6c03ca | 1906 | |
3371a64f TJ |
1907 | /* Can't allow a region crossing edge to be fallthrough. */ |
1908 | if (BB_PARTITION (bb) != BB_PARTITION (edge_in->dest) | |
fefa31b5 | 1909 | && edge_in->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
3371a64f TJ |
1910 | { |
1911 | new_bb = force_nonfallthru (single_succ_edge (bb)); | |
1912 | gcc_assert (!new_bb); | |
1913 | } | |
1914 | ||
4d6922ee | 1915 | /* For non-fallthru edges, we must adjust the predecessor's |
ca6c03ca JH |
1916 | jump instruction to target our new block. */ |
1917 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1918 | { | |
341c100f NS |
1919 | edge redirected = redirect_edge_and_branch (edge_in, bb); |
1920 | gcc_assert (redirected); | |
ca6c03ca JH |
1921 | } |
1922 | else | |
3b5fda81 | 1923 | { |
fefa31b5 | 1924 | if (edge_in->src != ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
3b5fda81 JJ |
1925 | { |
1926 | /* For asm goto even splitting of fallthru edge might | |
1927 | need insn patching, as other labels might point to the | |
1928 | old label. */ | |
8879d71c | 1929 | rtx_insn *last = BB_END (edge_in->src); |
3b5fda81 JJ |
1930 | if (last |
1931 | && JUMP_P (last) | |
fefa31b5 | 1932 | && edge_in->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) |
81e63b63 SB |
1933 | && (extract_asm_operands (PATTERN (last)) |
1934 | || JUMP_LABEL (last) == before) | |
3b5fda81 JJ |
1935 | && patch_jump_insn (last, before, bb)) |
1936 | df_set_bb_dirty (edge_in->src); | |
1937 | } | |
1938 | redirect_edge_succ (edge_in, bb); | |
1939 | } | |
ca6c03ca JH |
1940 | |
1941 | return bb; | |
1942 | } | |
1943 | ||
1944 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1945 | The new instructions and basic blocks (if any) will not appear in the | |
1946 | CFG until commit_edge_insertions is called. */ | |
1947 | ||
1948 | void | |
d329e058 | 1949 | insert_insn_on_edge (rtx pattern, edge e) |
ca6c03ca JH |
1950 | { |
1951 | /* We cannot insert instructions on an abnormal critical edge. | |
1952 | It will be easier to find the culprit if we die now. */ | |
341c100f | 1953 | gcc_assert (!((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e))); |
ca6c03ca | 1954 | |
6de9cd9a | 1955 | if (e->insns.r == NULL_RTX) |
ca6c03ca JH |
1956 | start_sequence (); |
1957 | else | |
6de9cd9a | 1958 | push_to_sequence (e->insns.r); |
ca6c03ca JH |
1959 | |
1960 | emit_insn (pattern); | |
1961 | ||
6de9cd9a | 1962 | e->insns.r = get_insns (); |
ca6c03ca JH |
1963 | end_sequence (); |
1964 | } | |
1965 | ||
1966 | /* Update the CFG for the instructions queued on edge E. */ | |
1967 | ||
4e3825db | 1968 | void |
2ac66157 | 1969 | commit_one_edge_insertion (edge e) |
ca6c03ca | 1970 | { |
8879d71c | 1971 | rtx_insn *before = NULL, *after = NULL, *insns, *tmp, *last; |
898c90c0 | 1972 | basic_block bb; |
ca6c03ca JH |
1973 | |
1974 | /* Pull the insns off the edge now since the edge might go away. */ | |
3ffa95c2 DM |
1975 | insns = e->insns.r; |
1976 | e->insns.r = NULL; | |
ca6c03ca | 1977 | |
898c90c0 EB |
1978 | /* Figure out where to put these insns. If the destination has |
1979 | one predecessor, insert there. Except for the exit block. */ | |
fefa31b5 | 1980 | if (single_pred_p (e->dest) && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
ca6c03ca | 1981 | { |
898c90c0 EB |
1982 | bb = e->dest; |
1983 | ||
1984 | /* Get the location correct wrt a code label, and "nice" wrt | |
1985 | a basic block note, and before everything else. */ | |
1986 | tmp = BB_HEAD (bb); | |
1987 | if (LABEL_P (tmp)) | |
1988 | tmp = NEXT_INSN (tmp); | |
1989 | if (NOTE_INSN_BASIC_BLOCK_P (tmp)) | |
1990 | tmp = NEXT_INSN (tmp); | |
1991 | if (tmp == BB_HEAD (bb)) | |
1992 | before = tmp; | |
1993 | else if (tmp) | |
1994 | after = PREV_INSN (tmp); | |
1995 | else | |
1996 | after = get_last_insn (); | |
1997 | } | |
3dec4024 | 1998 | |
898c90c0 | 1999 | /* If the source has one successor and the edge is not abnormal, |
a1d50386 JJ |
2000 | insert there. Except for the entry block. |
2001 | Don't do this if the predecessor ends in a jump other than | |
2002 | unconditional simple jump. E.g. for asm goto that points all | |
2003 | its labels at the fallthru basic block, we can't insert instructions | |
2004 | before the asm goto, as the asm goto can have various of side effects, | |
2005 | and can't emit instructions after the asm goto, as it must end | |
2006 | the basic block. */ | |
898c90c0 EB |
2007 | else if ((e->flags & EDGE_ABNORMAL) == 0 |
2008 | && single_succ_p (e->src) | |
fefa31b5 | 2009 | && e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
a1d50386 JJ |
2010 | && (!JUMP_P (BB_END (e->src)) |
2011 | || simplejump_p (BB_END (e->src)))) | |
898c90c0 EB |
2012 | { |
2013 | bb = e->src; | |
3dec4024 | 2014 | |
898c90c0 EB |
2015 | /* It is possible to have a non-simple jump here. Consider a target |
2016 | where some forms of unconditional jumps clobber a register. This | |
2017 | happens on the fr30 for example. | |
ca6c03ca | 2018 | |
898c90c0 EB |
2019 | We know this block has a single successor, so we can just emit |
2020 | the queued insns before the jump. */ | |
2021 | if (JUMP_P (BB_END (bb))) | |
2022 | before = BB_END (bb); | |
3dec4024 JH |
2023 | else |
2024 | { | |
898c90c0 EB |
2025 | /* We'd better be fallthru, or we've lost track of what's what. */ |
2026 | gcc_assert (e->flags & EDGE_FALLTHRU); | |
750054a2 | 2027 | |
898c90c0 | 2028 | after = BB_END (bb); |
ca6c03ca JH |
2029 | } |
2030 | } | |
2031 | ||
898c90c0 EB |
2032 | /* Otherwise we must split the edge. */ |
2033 | else | |
2034 | { | |
2035 | bb = split_edge (e); | |
3371a64f TJ |
2036 | |
2037 | /* If E crossed a partition boundary, we needed to make bb end in | |
2038 | a region-crossing jump, even though it was originally fallthru. */ | |
2039 | if (JUMP_P (BB_END (bb))) | |
2040 | before = BB_END (bb); | |
2041 | else | |
2042 | after = BB_END (bb); | |
898c90c0 EB |
2043 | } |
2044 | ||
2045 | /* Now that we've found the spot, do the insertion. */ | |
ca6c03ca JH |
2046 | if (before) |
2047 | { | |
6fb5fa3c | 2048 | emit_insn_before_noloc (insns, before, bb); |
ca6c03ca JH |
2049 | last = prev_nonnote_insn (before); |
2050 | } | |
2051 | else | |
6fb5fa3c | 2052 | last = emit_insn_after_noloc (insns, after, bb); |
ca6c03ca JH |
2053 | |
2054 | if (returnjump_p (last)) | |
2055 | { | |
2056 | /* ??? Remove all outgoing edges from BB and add one for EXIT. | |
c22cacf3 MS |
2057 | This is not currently a problem because this only happens |
2058 | for the (single) epilogue, which already has a fallthru edge | |
2059 | to EXIT. */ | |
ca6c03ca | 2060 | |
c5cbcccf | 2061 | e = single_succ_edge (bb); |
fefa31b5 | 2062 | gcc_assert (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) |
c5cbcccf | 2063 | && single_succ_p (bb) && (e->flags & EDGE_FALLTHRU)); |
ca6c03ca | 2064 | |
5f0d2358 | 2065 | e->flags &= ~EDGE_FALLTHRU; |
ca6c03ca | 2066 | emit_barrier_after (last); |
0b17ab2f | 2067 | |
ca6c03ca JH |
2068 | if (before) |
2069 | delete_insn (before); | |
2070 | } | |
341c100f NS |
2071 | else |
2072 | gcc_assert (!JUMP_P (last)); | |
ca6c03ca JH |
2073 | } |
2074 | ||
2075 | /* Update the CFG for all queued instructions. */ | |
2076 | ||
2077 | void | |
d329e058 | 2078 | commit_edge_insertions (void) |
ca6c03ca | 2079 | { |
ca6c03ca JH |
2080 | basic_block bb; |
2081 | ||
600b5b1d TJ |
2082 | /* Optimization passes that invoke this routine can cause hot blocks |
2083 | previously reached by both hot and cold blocks to become dominated only | |
2084 | by cold blocks. This will cause the verification below to fail, | |
2085 | and lead to now cold code in the hot section. In some cases this | |
2086 | may only be visible after newly unreachable blocks are deleted, | |
2087 | which will be done by fixup_partitions. */ | |
2088 | fixup_partitions (); | |
2089 | ||
b2b29377 | 2090 | checking_verify_flow_info (); |
ca6c03ca | 2091 | |
fefa31b5 DM |
2092 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (cfun), |
2093 | EXIT_BLOCK_PTR_FOR_FN (cfun), next_bb) | |
ca6c03ca | 2094 | { |
628f6a4e BE |
2095 | edge e; |
2096 | edge_iterator ei; | |
ca6c03ca | 2097 | |
628f6a4e BE |
2098 | FOR_EACH_EDGE (e, ei, bb->succs) |
2099 | if (e->insns.r) | |
cf103ca4 | 2100 | commit_one_edge_insertion (e); |
3dec4024 | 2101 | } |
ca6c03ca JH |
2102 | } |
2103 | \f | |
6fb5fa3c | 2104 | |
f470c378 | 2105 | /* Print out RTL-specific basic block information (live information |
a315c44c SB |
2106 | at start and end with TDF_DETAILS). FLAGS are the TDF_* masks |
2107 | documented in dumpfile.h. */ | |
ca6c03ca | 2108 | |
10e9fecc | 2109 | static void |
1a817418 | 2110 | rtl_dump_bb (FILE *outf, basic_block bb, int indent, dump_flags_t flags) |
ca6c03ca | 2111 | { |
f470c378 | 2112 | char *s_indent; |
ca6c03ca | 2113 | |
ae50c0cb | 2114 | s_indent = (char *) alloca ((size_t) indent + 1); |
400e39e3 | 2115 | memset (s_indent, ' ', (size_t) indent); |
f470c378 | 2116 | s_indent[indent] = '\0'; |
b8698a0f | 2117 | |
a315c44c | 2118 | if (df && (flags & TDF_DETAILS)) |
6fb5fa3c DB |
2119 | { |
2120 | df_dump_top (bb, outf); | |
2121 | putc ('\n', outf); | |
2122 | } | |
ca6c03ca | 2123 | |
68cc3174 | 2124 | if (bb->index != ENTRY_BLOCK && bb->index != EXIT_BLOCK) |
9fcaf059 SB |
2125 | { |
2126 | rtx_insn *last = BB_END (bb); | |
2127 | if (last) | |
2128 | last = NEXT_INSN (last); | |
2129 | for (rtx_insn *insn = BB_HEAD (bb); insn != last; insn = NEXT_INSN (insn)) | |
2130 | { | |
2131 | if (flags & TDF_DETAILS) | |
2132 | df_dump_insn_top (insn, outf); | |
2133 | if (! (flags & TDF_SLIM)) | |
2134 | print_rtl_single (outf, insn); | |
2135 | else | |
2136 | dump_insn_slim (outf, insn); | |
2137 | if (flags & TDF_DETAILS) | |
2138 | df_dump_insn_bottom (insn, outf); | |
2139 | } | |
2140 | } | |
a315c44c SB |
2141 | |
2142 | if (df && (flags & TDF_DETAILS)) | |
6fb5fa3c DB |
2143 | { |
2144 | df_dump_bottom (bb, outf); | |
2145 | putc ('\n', outf); | |
2146 | } | |
2147 | ||
ca6c03ca JH |
2148 | } |
2149 | \f | |
c4669594 SB |
2150 | /* Like dump_function_to_file, but for RTL. Print out dataflow information |
2151 | for the start of each basic block. FLAGS are the TDF_* masks documented | |
2152 | in dumpfile.h. */ | |
ca6c03ca JH |
2153 | |
2154 | void | |
1a817418 | 2155 | print_rtl_with_bb (FILE *outf, const rtx_insn *rtx_first, dump_flags_t flags) |
ca6c03ca | 2156 | { |
b2908ba6 | 2157 | const rtx_insn *tmp_rtx; |
ca6c03ca JH |
2158 | if (rtx_first == 0) |
2159 | fprintf (outf, "(nil)\n"); | |
2160 | else | |
2161 | { | |
ca6c03ca JH |
2162 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
2163 | int max_uid = get_max_uid (); | |
5ed6ace5 MD |
2164 | basic_block *start = XCNEWVEC (basic_block, max_uid); |
2165 | basic_block *end = XCNEWVEC (basic_block, max_uid); | |
2166 | enum bb_state *in_bb_p = XCNEWVEC (enum bb_state, max_uid); | |
e0082a72 ZD |
2167 | basic_block bb; |
2168 | ||
c4669594 SB |
2169 | /* After freeing the CFG, we still have BLOCK_FOR_INSN set on most |
2170 | insns, but the CFG is not maintained so the basic block info | |
2171 | is not reliable. Therefore it's omitted from the dumps. */ | |
2172 | if (! (cfun->curr_properties & PROP_cfg)) | |
2173 | flags &= ~TDF_BLOCKS; | |
2174 | ||
6fb5fa3c DB |
2175 | if (df) |
2176 | df_dump_start (outf); | |
2177 | ||
c4669594 | 2178 | if (flags & TDF_BLOCKS) |
ca6c03ca | 2179 | { |
4f42035e | 2180 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
ca6c03ca | 2181 | { |
8879d71c | 2182 | rtx_insn *x; |
c4669594 SB |
2183 | |
2184 | start[INSN_UID (BB_HEAD (bb))] = bb; | |
2185 | end[INSN_UID (BB_END (bb))] = bb; | |
2186 | for (x = BB_HEAD (bb); x != NULL_RTX; x = NEXT_INSN (x)) | |
2187 | { | |
2188 | enum bb_state state = IN_MULTIPLE_BB; | |
5f0d2358 | 2189 | |
c4669594 SB |
2190 | if (in_bb_p[INSN_UID (x)] == NOT_IN_BB) |
2191 | state = IN_ONE_BB; | |
2192 | in_bb_p[INSN_UID (x)] = state; | |
ca6c03ca | 2193 | |
c4669594 SB |
2194 | if (x == BB_END (bb)) |
2195 | break; | |
2196 | } | |
ca6c03ca JH |
2197 | } |
2198 | } | |
2199 | ||
01512446 | 2200 | for (tmp_rtx = rtx_first; tmp_rtx != NULL; tmp_rtx = NEXT_INSN (tmp_rtx)) |
ca6c03ca | 2201 | { |
c4669594 SB |
2202 | if (flags & TDF_BLOCKS) |
2203 | { | |
2204 | bb = start[INSN_UID (tmp_rtx)]; | |
2205 | if (bb != NULL) | |
2206 | { | |
9d9573d5 | 2207 | dump_bb_info (outf, bb, 0, dump_flags, true, false); |
c4669594 SB |
2208 | if (df && (flags & TDF_DETAILS)) |
2209 | df_dump_top (bb, outf); | |
2210 | } | |
ca6c03ca | 2211 | |
c4669594 SB |
2212 | if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB |
2213 | && !NOTE_P (tmp_rtx) | |
2214 | && !BARRIER_P (tmp_rtx)) | |
2215 | fprintf (outf, ";; Insn is not within a basic block\n"); | |
2216 | else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB) | |
2217 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); | |
2218 | } | |
ca6c03ca | 2219 | |
7b19209f SB |
2220 | if (flags & TDF_DETAILS) |
2221 | df_dump_insn_top (tmp_rtx, outf); | |
a315c44c SB |
2222 | if (! (flags & TDF_SLIM)) |
2223 | print_rtl_single (outf, tmp_rtx); | |
2224 | else | |
2225 | dump_insn_slim (outf, tmp_rtx); | |
7b19209f SB |
2226 | if (flags & TDF_DETAILS) |
2227 | df_dump_insn_bottom (tmp_rtx, outf); | |
ca6c03ca | 2228 | |
c4669594 SB |
2229 | if (flags & TDF_BLOCKS) |
2230 | { | |
2231 | bb = end[INSN_UID (tmp_rtx)]; | |
2232 | if (bb != NULL) | |
2233 | { | |
9d9573d5 | 2234 | dump_bb_info (outf, bb, 0, dump_flags, false, true); |
c4669594 SB |
2235 | if (df && (flags & TDF_DETAILS)) |
2236 | df_dump_bottom (bb, outf); | |
1b03a96d | 2237 | putc ('\n', outf); |
c4669594 SB |
2238 | } |
2239 | } | |
ca6c03ca JH |
2240 | } |
2241 | ||
2242 | free (start); | |
2243 | free (end); | |
2244 | free (in_bb_p); | |
2245 | } | |
ca6c03ca JH |
2246 | } |
2247 | \f | |
532aafad SB |
2248 | /* Update the branch probability of BB if a REG_BR_PROB is present. */ |
2249 | ||
b446e5a2 | 2250 | void |
d329e058 | 2251 | update_br_prob_note (basic_block bb) |
b446e5a2 JH |
2252 | { |
2253 | rtx note; | |
a813c111 | 2254 | note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX); |
e7a74006 JH |
2255 | if (!JUMP_P (BB_END (bb)) || !BRANCH_EDGE (bb)->probability.initialized_p ()) |
2256 | { | |
2257 | if (note) | |
2258 | { | |
2259 | rtx *note_link, this_rtx; | |
2260 | ||
2261 | note_link = ®_NOTES (BB_END (bb)); | |
2262 | for (this_rtx = *note_link; this_rtx; this_rtx = XEXP (this_rtx, 1)) | |
2263 | if (this_rtx == note) | |
2264 | { | |
2265 | *note_link = XEXP (this_rtx, 1); | |
2266 | break; | |
2267 | } | |
2268 | } | |
2269 | return; | |
2270 | } | |
357067f2 | 2271 | if (!note |
5fa396ad | 2272 | || XINT (note, 0) == BRANCH_EDGE (bb)->probability.to_reg_br_prob_note ()) |
b446e5a2 | 2273 | return; |
5fa396ad | 2274 | XINT (note, 0) = BRANCH_EDGE (bb)->probability.to_reg_br_prob_note (); |
b446e5a2 | 2275 | } |
96370780 MK |
2276 | |
2277 | /* Get the last insn associated with block BB (that includes barriers and | |
2278 | tablejumps after BB). */ | |
636eb204 | 2279 | rtx_insn * |
96370780 MK |
2280 | get_last_bb_insn (basic_block bb) |
2281 | { | |
8942ee0f | 2282 | rtx_jump_table_data *table; |
636eb204 DM |
2283 | rtx_insn *tmp; |
2284 | rtx_insn *end = BB_END (bb); | |
96370780 MK |
2285 | |
2286 | /* Include any jump table following the basic block. */ | |
8942ee0f DM |
2287 | if (tablejump_p (end, NULL, &table)) |
2288 | end = table; | |
96370780 MK |
2289 | |
2290 | /* Include any barriers that may follow the basic block. */ | |
f40dd646 | 2291 | tmp = next_nonnote_nondebug_insn_bb (end); |
96370780 MK |
2292 | while (tmp && BARRIER_P (tmp)) |
2293 | { | |
2294 | end = tmp; | |
f40dd646 | 2295 | tmp = next_nonnote_nondebug_insn_bb (end); |
96370780 MK |
2296 | } |
2297 | ||
2298 | return end; | |
2299 | } | |
af205f67 | 2300 | |
d9af4fea JH |
2301 | /* Add all BBs reachable from entry via hot paths into the SET. */ |
2302 | ||
2303 | void | |
2304 | find_bbs_reachable_by_hot_paths (hash_set<basic_block> *set) | |
2305 | { | |
2306 | auto_vec<basic_block, 64> worklist; | |
2307 | ||
2308 | set->add (ENTRY_BLOCK_PTR_FOR_FN (cfun)); | |
2309 | worklist.safe_push (ENTRY_BLOCK_PTR_FOR_FN (cfun)); | |
2310 | ||
2311 | while (worklist.length () > 0) | |
2312 | { | |
2313 | basic_block bb = worklist.pop (); | |
2314 | edge_iterator ei; | |
2315 | edge e; | |
2316 | ||
2317 | FOR_EACH_EDGE (e, ei, bb->succs) | |
2318 | if (BB_PARTITION (e->dest) != BB_COLD_PARTITION | |
2319 | && !set->add (e->dest)) | |
2320 | worklist.safe_push (e->dest); | |
2321 | } | |
2322 | } | |
2323 | ||
600b5b1d TJ |
2324 | /* Sanity check partition hotness to ensure that basic blocks in |
2325 | the cold partition don't dominate basic blocks in the hot partition. | |
2326 | If FLAG_ONLY is true, report violations as errors. Otherwise | |
2327 | re-mark the dominated blocks as cold, since this is run after | |
2328 | cfg optimizations that may make hot blocks previously reached | |
2329 | by both hot and cold blocks now only reachable along cold paths. */ | |
2330 | ||
2331 | static vec<basic_block> | |
2332 | find_partition_fixes (bool flag_only) | |
2333 | { | |
2334 | basic_block bb; | |
2335 | vec<basic_block> bbs_in_cold_partition = vNULL; | |
2336 | vec<basic_block> bbs_to_fix = vNULL; | |
d9af4fea | 2337 | hash_set<basic_block> set; |
600b5b1d TJ |
2338 | |
2339 | /* Callers check this. */ | |
2340 | gcc_checking_assert (crtl->has_bb_partition); | |
2341 | ||
d9af4fea | 2342 | find_bbs_reachable_by_hot_paths (&set); |
600b5b1d | 2343 | |
d9af4fea JH |
2344 | FOR_EACH_BB_FN (bb, cfun) |
2345 | if (!set.contains (bb) | |
2346 | && BB_PARTITION (bb) != BB_COLD_PARTITION) | |
2347 | { | |
2348 | if (flag_only) | |
2349 | error ("non-cold basic block %d reachable only " | |
2350 | "by paths crossing the cold partition", bb->index); | |
2351 | else | |
2352 | BB_SET_PARTITION (bb, BB_COLD_PARTITION); | |
2353 | bbs_to_fix.safe_push (bb); | |
2354 | bbs_in_cold_partition.safe_push (bb); | |
2355 | } | |
600b5b1d TJ |
2356 | |
2357 | return bbs_to_fix; | |
2358 | } | |
2359 | ||
2360 | /* Perform cleanup on the hot/cold bb partitioning after optimization | |
2361 | passes that modify the cfg. */ | |
2362 | ||
2363 | void | |
2364 | fixup_partitions (void) | |
2365 | { | |
2366 | basic_block bb; | |
2367 | ||
2368 | if (!crtl->has_bb_partition) | |
2369 | return; | |
2370 | ||
2371 | /* Delete any blocks that became unreachable and weren't | |
2372 | already cleaned up, for example during edge forwarding | |
2373 | and convert_jumps_to_returns. This will expose more | |
2374 | opportunities for fixing the partition boundaries here. | |
2375 | Also, the calculation of the dominance graph during verification | |
2376 | will assert if there are unreachable nodes. */ | |
2377 | delete_unreachable_blocks (); | |
2378 | ||
2379 | /* If there are partitions, do a sanity check on them: A basic block in | |
2380 | a cold partition cannot dominate a basic block in a hot partition. | |
2381 | Fixup any that now violate this requirement, as a result of edge | |
2382 | forwarding and unreachable block deletion. */ | |
2383 | vec<basic_block> bbs_to_fix = find_partition_fixes (false); | |
2384 | ||
2385 | /* Do the partition fixup after all necessary blocks have been converted to | |
2386 | cold, so that we only update the region crossings the minimum number of | |
2387 | places, which can require forcing edges to be non fallthru. */ | |
2388 | while (! bbs_to_fix.is_empty ()) | |
2389 | { | |
2390 | bb = bbs_to_fix.pop (); | |
2391 | fixup_new_cold_bb (bb); | |
2392 | } | |
2393 | } | |
2394 | ||
af205f67 TJ |
2395 | /* Verify, in the basic block chain, that there is at most one switch |
2396 | between hot/cold partitions. This condition will not be true until | |
2397 | after reorder_basic_blocks is called. */ | |
2398 | ||
251a41b9 | 2399 | static int |
af205f67 TJ |
2400 | verify_hot_cold_block_grouping (void) |
2401 | { | |
2402 | basic_block bb; | |
2403 | int err = 0; | |
2404 | bool switched_sections = false; | |
2405 | int current_partition = BB_UNPARTITIONED; | |
2406 | ||
3371a64f TJ |
2407 | /* Even after bb reordering is complete, we go into cfglayout mode |
2408 | again (in compgoto). Ensure we don't call this before going back | |
2409 | into linearized RTL when any layout fixes would have been committed. */ | |
2410 | if (!crtl->bb_reorder_complete | |
c3284718 | 2411 | || current_ir_type () != IR_RTL_CFGRTL) |
251a41b9 | 2412 | return err; |
af205f67 | 2413 | |
11cd3bed | 2414 | FOR_EACH_BB_FN (bb, cfun) |
af205f67 TJ |
2415 | { |
2416 | if (current_partition != BB_UNPARTITIONED | |
2417 | && BB_PARTITION (bb) != current_partition) | |
2418 | { | |
2419 | if (switched_sections) | |
2420 | { | |
2421 | error ("multiple hot/cold transitions found (bb %i)", | |
2422 | bb->index); | |
2423 | err = 1; | |
2424 | } | |
2425 | else | |
2426 | switched_sections = true; | |
2427 | ||
2428 | if (!crtl->has_bb_partition) | |
2429 | error ("partition found but function partition flag not set"); | |
2430 | } | |
2431 | current_partition = BB_PARTITION (bb); | |
2432 | } | |
2433 | ||
251a41b9 | 2434 | return err; |
af205f67 | 2435 | } |
b446e5a2 | 2436 | \f |
ca6c03ca | 2437 | |
251a41b9 TJ |
2438 | /* Perform several checks on the edges out of each block, such as |
2439 | the consistency of the branch probabilities, the correctness | |
2440 | of hot/cold partition crossing edges, and the number of expected | |
600b5b1d TJ |
2441 | successor edges. Also verify that the dominance relationship |
2442 | between hot/cold blocks is sane. */ | |
f470c378 | 2443 | |
10e9fecc | 2444 | static int |
251a41b9 | 2445 | rtl_verify_edges (void) |
ca6c03ca | 2446 | { |
10e9fecc | 2447 | int err = 0; |
94eb5ddb | 2448 | basic_block bb; |
ca6c03ca | 2449 | |
4f42035e | 2450 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
ca6c03ca | 2451 | { |
f99ffaa3 EB |
2452 | int n_fallthru = 0, n_branch = 0, n_abnormal_call = 0, n_sibcall = 0; |
2453 | int n_eh = 0, n_abnormal = 0; | |
3cf54412 | 2454 | edge e, fallthru = NULL; |
628f6a4e | 2455 | edge_iterator ei; |
251a41b9 | 2456 | rtx note; |
3371a64f | 2457 | bool has_crossing_edge = false; |
ca6c03ca | 2458 | |
2085a21f | 2459 | if (JUMP_P (BB_END (bb)) |
a813c111 | 2460 | && (note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX)) |
628f6a4e | 2461 | && EDGE_COUNT (bb->succs) >= 2 |
a813c111 | 2462 | && any_condjump_p (BB_END (bb))) |
5a1a3e5e | 2463 | { |
357067f2 JH |
2464 | if (!BRANCH_EDGE (bb)->probability.initialized_p ()) |
2465 | { | |
a4c57f86 | 2466 | if (profile_status_for_fn (cfun) != PROFILE_ABSENT) |
357067f2 | 2467 | { |
a4c57f86 JH |
2468 | error ("verify_flow_info: " |
2469 | "REG_BR_PROB is set but cfg probability is not"); | |
2470 | err = 1; | |
357067f2 JH |
2471 | } |
2472 | } | |
2473 | else if (XINT (note, 0) | |
5fa396ad | 2474 | != BRANCH_EDGE (bb)->probability.to_reg_br_prob_note () |
357067f2 | 2475 | && profile_status_for_fn (cfun) != PROFILE_ABSENT) |
5a1a3e5e | 2476 | { |
e5af9ddd | 2477 | error ("verify_flow_info: REG_BR_PROB does not match cfg %i %i", |
357067f2 | 2478 | XINT (note, 0), |
5fa396ad | 2479 | BRANCH_EDGE (bb)->probability.to_reg_br_prob_note ()); |
5a1a3e5e JH |
2480 | err = 1; |
2481 | } | |
2482 | } | |
251a41b9 | 2483 | |
628f6a4e | 2484 | FOR_EACH_EDGE (e, ei, bb->succs) |
ca6c03ca | 2485 | { |
0be7e7a6 RH |
2486 | bool is_crossing; |
2487 | ||
ca6c03ca | 2488 | if (e->flags & EDGE_FALLTHRU) |
0be7e7a6 RH |
2489 | n_fallthru++, fallthru = e; |
2490 | ||
2491 | is_crossing = (BB_PARTITION (e->src) != BB_PARTITION (e->dest) | |
fefa31b5 DM |
2492 | && e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
2493 | && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)); | |
3371a64f | 2494 | has_crossing_edge |= is_crossing; |
0be7e7a6 | 2495 | if (e->flags & EDGE_CROSSING) |
750054a2 | 2496 | { |
0be7e7a6 RH |
2497 | if (!is_crossing) |
2498 | { | |
2499 | error ("EDGE_CROSSING incorrectly set across same section"); | |
2500 | err = 1; | |
2501 | } | |
2502 | if (e->flags & EDGE_FALLTHRU) | |
2503 | { | |
f99ffaa3 | 2504 | error ("fallthru edge crosses section boundary in bb %i", |
750054a2 CT |
2505 | e->src->index); |
2506 | err = 1; | |
2507 | } | |
0be7e7a6 RH |
2508 | if (e->flags & EDGE_EH) |
2509 | { | |
f99ffaa3 | 2510 | error ("EH edge crosses section boundary in bb %i", |
0be7e7a6 RH |
2511 | e->src->index); |
2512 | err = 1; | |
2513 | } | |
339ba33b | 2514 | if (JUMP_P (BB_END (bb)) && !CROSSING_JUMP_P (BB_END (bb))) |
3371a64f TJ |
2515 | { |
2516 | error ("No region crossing jump at section boundary in bb %i", | |
2517 | bb->index); | |
2518 | err = 1; | |
2519 | } | |
0be7e7a6 RH |
2520 | } |
2521 | else if (is_crossing) | |
2522 | { | |
2523 | error ("EDGE_CROSSING missing across section boundary"); | |
2524 | err = 1; | |
750054a2 | 2525 | } |
3dec4024 | 2526 | |
65f43cdf ZD |
2527 | if ((e->flags & ~(EDGE_DFS_BACK |
2528 | | EDGE_CAN_FALLTHRU | |
2529 | | EDGE_IRREDUCIBLE_LOOP | |
9beb1c84 | 2530 | | EDGE_LOOP_EXIT |
7e872b90 JJ |
2531 | | EDGE_CROSSING |
2532 | | EDGE_PRESERVE)) == 0) | |
3dec4024 JH |
2533 | n_branch++; |
2534 | ||
2535 | if (e->flags & EDGE_ABNORMAL_CALL) | |
f99ffaa3 EB |
2536 | n_abnormal_call++; |
2537 | ||
2538 | if (e->flags & EDGE_SIBCALL) | |
2539 | n_sibcall++; | |
3dec4024 JH |
2540 | |
2541 | if (e->flags & EDGE_EH) | |
2542 | n_eh++; | |
f99ffaa3 EB |
2543 | |
2544 | if (e->flags & EDGE_ABNORMAL) | |
3dec4024 | 2545 | n_abnormal++; |
ca6c03ca | 2546 | } |
5f0d2358 | 2547 | |
3371a64f | 2548 | if (!has_crossing_edge |
339ba33b RS |
2549 | && JUMP_P (BB_END (bb)) |
2550 | && CROSSING_JUMP_P (BB_END (bb))) | |
3371a64f | 2551 | { |
8264c84d | 2552 | print_rtl_with_bb (stderr, get_insns (), TDF_BLOCKS | TDF_DETAILS); |
3371a64f TJ |
2553 | error ("Region crossing jump across same section in bb %i", |
2554 | bb->index); | |
2555 | err = 1; | |
2556 | } | |
2557 | ||
1d65f45c | 2558 | if (n_eh && !find_reg_note (BB_END (bb), REG_EH_REGION, NULL_RTX)) |
3dec4024 | 2559 | { |
f99ffaa3 | 2560 | error ("missing REG_EH_REGION note at the end of bb %i", bb->index); |
3dec4024 JH |
2561 | err = 1; |
2562 | } | |
1d65f45c RH |
2563 | if (n_eh > 1) |
2564 | { | |
f99ffaa3 | 2565 | error ("too many exception handling edges in bb %i", bb->index); |
1d65f45c RH |
2566 | err = 1; |
2567 | } | |
3dec4024 | 2568 | if (n_branch |
4b4bf941 | 2569 | && (!JUMP_P (BB_END (bb)) |
a813c111 SB |
2570 | || (n_branch > 1 && (any_uncondjump_p (BB_END (bb)) |
2571 | || any_condjump_p (BB_END (bb)))))) | |
3dec4024 | 2572 | { |
ab532386 | 2573 | error ("too many outgoing branch edges from bb %i", bb->index); |
3dec4024 JH |
2574 | err = 1; |
2575 | } | |
a813c111 | 2576 | if (n_fallthru && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 2577 | { |
f99ffaa3 | 2578 | error ("fallthru edge after unconditional jump in bb %i", bb->index); |
3dec4024 JH |
2579 | err = 1; |
2580 | } | |
a813c111 | 2581 | if (n_branch != 1 && any_uncondjump_p (BB_END (bb))) |
3dec4024 | 2582 | { |
f99ffaa3 EB |
2583 | error ("wrong number of branch edges after unconditional jump" |
2584 | " in bb %i", bb->index); | |
3dec4024 JH |
2585 | err = 1; |
2586 | } | |
a813c111 | 2587 | if (n_branch != 1 && any_condjump_p (BB_END (bb)) |
c11fd0b2 | 2588 | && JUMP_LABEL (BB_END (bb)) != BB_HEAD (fallthru->dest)) |
3dec4024 | 2589 | { |
f99ffaa3 EB |
2590 | error ("wrong amount of branch edges after conditional jump" |
2591 | " in bb %i", bb->index); | |
2592 | err = 1; | |
2593 | } | |
2594 | if (n_abnormal_call && !CALL_P (BB_END (bb))) | |
2595 | { | |
2596 | error ("abnormal call edges for non-call insn in bb %i", bb->index); | |
3dec4024 JH |
2597 | err = 1; |
2598 | } | |
f99ffaa3 | 2599 | if (n_sibcall && !CALL_P (BB_END (bb))) |
3dec4024 | 2600 | { |
f99ffaa3 | 2601 | error ("sibcall edges for non-call insn in bb %i", bb->index); |
3dec4024 JH |
2602 | err = 1; |
2603 | } | |
f99ffaa3 EB |
2604 | if (n_abnormal > n_eh |
2605 | && !(CALL_P (BB_END (bb)) | |
2606 | && n_abnormal == n_abnormal_call + n_sibcall) | |
4b4bf941 | 2607 | && (!JUMP_P (BB_END (bb)) |
a813c111 SB |
2608 | || any_condjump_p (BB_END (bb)) |
2609 | || any_uncondjump_p (BB_END (bb)))) | |
3dec4024 | 2610 | { |
ab532386 | 2611 | error ("abnormal edges for no purpose in bb %i", bb->index); |
3dec4024 JH |
2612 | err = 1; |
2613 | } | |
251a41b9 | 2614 | } |
f87c27b4 | 2615 | |
600b5b1d TJ |
2616 | /* If there are partitions, do a sanity check on them: A basic block in |
2617 | a cold partition cannot dominate a basic block in a hot partition. */ | |
2618 | if (crtl->has_bb_partition && !err) | |
2619 | { | |
2620 | vec<basic_block> bbs_to_fix = find_partition_fixes (true); | |
2621 | err = !bbs_to_fix.is_empty (); | |
2622 | } | |
2623 | ||
251a41b9 TJ |
2624 | /* Clean up. */ |
2625 | return err; | |
2626 | } | |
5f0d2358 | 2627 | |
251a41b9 TJ |
2628 | /* Checks on the instructions within blocks. Currently checks that each |
2629 | block starts with a basic block note, and that basic block notes and | |
2630 | control flow jumps are not found in the middle of the block. */ | |
ca6c03ca | 2631 | |
251a41b9 TJ |
2632 | static int |
2633 | rtl_verify_bb_insns (void) | |
2634 | { | |
8879d71c | 2635 | rtx_insn *x; |
251a41b9 TJ |
2636 | int err = 0; |
2637 | basic_block bb; | |
2638 | ||
4f42035e | 2639 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
251a41b9 TJ |
2640 | { |
2641 | /* Now check the header of basic | |
c22cacf3 | 2642 | block. It ought to contain optional CODE_LABEL followed |
ca6c03ca | 2643 | by NOTE_BASIC_BLOCK. */ |
a813c111 | 2644 | x = BB_HEAD (bb); |
4b4bf941 | 2645 | if (LABEL_P (x)) |
ca6c03ca | 2646 | { |
a813c111 | 2647 | if (BB_END (bb) == x) |
ca6c03ca JH |
2648 | { |
2649 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 2650 | bb->index); |
ca6c03ca JH |
2651 | err = 1; |
2652 | } | |
5f0d2358 | 2653 | |
ca6c03ca JH |
2654 | x = NEXT_INSN (x); |
2655 | } | |
5f0d2358 | 2656 | |
ca6c03ca JH |
2657 | if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb) |
2658 | { | |
2659 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
0b17ab2f | 2660 | bb->index); |
ca6c03ca JH |
2661 | err = 1; |
2662 | } | |
2663 | ||
a813c111 | 2664 | if (BB_END (bb) == x) |
49243025 | 2665 | /* Do checks for empty blocks here. */ |
5f0d2358 | 2666 | ; |
ca6c03ca | 2667 | else |
5f0d2358 RK |
2668 | for (x = NEXT_INSN (x); x; x = NEXT_INSN (x)) |
2669 | { | |
2670 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2671 | { | |
2672 | error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d", | |
0b17ab2f | 2673 | INSN_UID (x), bb->index); |
5f0d2358 RK |
2674 | err = 1; |
2675 | } | |
2676 | ||
a813c111 | 2677 | if (x == BB_END (bb)) |
5f0d2358 | 2678 | break; |
ca6c03ca | 2679 | |
83fd323c | 2680 | if (control_flow_insn_p (x)) |
5f0d2358 | 2681 | { |
0b17ab2f | 2682 | error ("in basic block %d:", bb->index); |
5f0d2358 RK |
2683 | fatal_insn ("flow control insn inside a basic block", x); |
2684 | } | |
2685 | } | |
ca6c03ca JH |
2686 | } |
2687 | ||
251a41b9 TJ |
2688 | /* Clean up. */ |
2689 | return err; | |
2690 | } | |
2691 | ||
2692 | /* Verify that block pointers for instructions in basic blocks, headers and | |
2693 | footers are set appropriately. */ | |
2694 | ||
2695 | static int | |
2696 | rtl_verify_bb_pointers (void) | |
2697 | { | |
2698 | int err = 0; | |
2699 | basic_block bb; | |
2700 | ||
2701 | /* Check the general integrity of the basic blocks. */ | |
4f42035e | 2702 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
251a41b9 | 2703 | { |
8879d71c | 2704 | rtx_insn *insn; |
251a41b9 TJ |
2705 | |
2706 | if (!(bb->flags & BB_RTL)) | |
2707 | { | |
2708 | error ("BB_RTL flag not set for block %d", bb->index); | |
2709 | err = 1; | |
2710 | } | |
2711 | ||
2712 | FOR_BB_INSNS (bb, insn) | |
2713 | if (BLOCK_FOR_INSN (insn) != bb) | |
2714 | { | |
2715 | error ("insn %d basic block pointer is %d, should be %d", | |
2716 | INSN_UID (insn), | |
2717 | BLOCK_FOR_INSN (insn) ? BLOCK_FOR_INSN (insn)->index : 0, | |
2718 | bb->index); | |
2719 | err = 1; | |
2720 | } | |
2721 | ||
2722 | for (insn = BB_HEADER (bb); insn; insn = NEXT_INSN (insn)) | |
2723 | if (!BARRIER_P (insn) | |
2724 | && BLOCK_FOR_INSN (insn) != NULL) | |
2725 | { | |
2726 | error ("insn %d in header of bb %d has non-NULL basic block", | |
2727 | INSN_UID (insn), bb->index); | |
2728 | err = 1; | |
2729 | } | |
2730 | for (insn = BB_FOOTER (bb); insn; insn = NEXT_INSN (insn)) | |
2731 | if (!BARRIER_P (insn) | |
2732 | && BLOCK_FOR_INSN (insn) != NULL) | |
2733 | { | |
2734 | error ("insn %d in footer of bb %d has non-NULL basic block", | |
2735 | INSN_UID (insn), bb->index); | |
2736 | err = 1; | |
2737 | } | |
2738 | } | |
af205f67 | 2739 | |
10e9fecc | 2740 | /* Clean up. */ |
10e9fecc JH |
2741 | return err; |
2742 | } | |
5f0d2358 | 2743 | |
10e9fecc JH |
2744 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
2745 | cfglayout RTL. | |
5f0d2358 | 2746 | |
10e9fecc | 2747 | Currently it does following checks: |
251a41b9 TJ |
2748 | |
2749 | - overlapping of basic blocks | |
2750 | - insns with wrong BLOCK_FOR_INSN pointers | |
2751 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) | |
2752 | - tails of basic blocks (ensure that boundary is necessary) | |
2753 | - scans body of the basic block for JUMP_INSN, CODE_LABEL | |
2754 | and NOTE_INSN_BASIC_BLOCK | |
2755 | - verify that no fall_thru edge crosses hot/cold partition boundaries | |
2756 | - verify that there are no pending RTL branch predictions | |
600b5b1d | 2757 | - verify that hot blocks are not dominated by cold blocks |
251a41b9 TJ |
2758 | |
2759 | In future it can be extended check a lot of other stuff as well | |
2760 | (reachability of basic blocks, life information, etc. etc.). */ | |
9eab6785 | 2761 | |
10e9fecc | 2762 | static int |
251a41b9 TJ |
2763 | rtl_verify_flow_info_1 (void) |
2764 | { | |
2765 | int err = 0; | |
2766 | ||
2767 | err |= rtl_verify_bb_pointers (); | |
2768 | ||
2769 | err |= rtl_verify_bb_insns (); | |
2770 | ||
2771 | err |= rtl_verify_edges (); | |
2772 | ||
251a41b9 TJ |
2773 | return err; |
2774 | } | |
2775 | ||
2776 | /* Walk the instruction chain and verify that bb head/end pointers | |
2777 | are correct, and that instructions are in exactly one bb and have | |
2778 | correct block pointers. */ | |
2779 | ||
2780 | static int | |
2781 | rtl_verify_bb_insn_chain (void) | |
10e9fecc JH |
2782 | { |
2783 | basic_block bb; | |
251a41b9 | 2784 | int err = 0; |
8879d71c DM |
2785 | rtx_insn *x; |
2786 | rtx_insn *last_head = get_last_insn (); | |
9eab6785 | 2787 | basic_block *bb_info; |
9eab6785 SB |
2788 | const int max_uid = get_max_uid (); |
2789 | ||
2790 | bb_info = XCNEWVEC (basic_block, max_uid); | |
ca6c03ca | 2791 | |
4f42035e | 2792 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
10e9fecc | 2793 | { |
8879d71c DM |
2794 | rtx_insn *head = BB_HEAD (bb); |
2795 | rtx_insn *end = BB_END (bb); | |
628f6a4e | 2796 | |
9eab6785 | 2797 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) |
a7b87f73 ZD |
2798 | { |
2799 | /* Verify the end of the basic block is in the INSN chain. */ | |
2800 | if (x == end) | |
2801 | break; | |
2802 | ||
251a41b9 TJ |
2803 | /* And that the code outside of basic blocks has NULL bb field. */ |
2804 | if (!BARRIER_P (x) | |
2805 | && BLOCK_FOR_INSN (x) != NULL) | |
2806 | { | |
2807 | error ("insn %d outside of basic blocks has non-NULL bb field", | |
2808 | INSN_UID (x)); | |
2809 | err = 1; | |
2810 | } | |
a7b87f73 | 2811 | } |
9eab6785 SB |
2812 | |
2813 | if (!x) | |
2814 | { | |
2815 | error ("end insn %d for block %d not found in the insn stream", | |
2816 | INSN_UID (end), bb->index); | |
2817 | err = 1; | |
2818 | } | |
2819 | ||
2820 | /* Work backwards from the end to the head of the basic block | |
2821 | to verify the head is in the RTL chain. */ | |
2822 | for (; x != NULL_RTX; x = PREV_INSN (x)) | |
a00d11f0 | 2823 | { |
9eab6785 SB |
2824 | /* While walking over the insn chain, verify insns appear |
2825 | in only one basic block. */ | |
2826 | if (bb_info[INSN_UID (x)] != NULL) | |
2827 | { | |
2828 | error ("insn %d is in multiple basic blocks (%d and %d)", | |
2829 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); | |
2830 | err = 1; | |
2831 | } | |
2832 | ||
2833 | bb_info[INSN_UID (x)] = bb; | |
2834 | ||
2835 | if (x == head) | |
2836 | break; | |
2837 | } | |
2838 | if (!x) | |
2839 | { | |
2840 | error ("head insn %d for block %d not found in the insn stream", | |
2841 | INSN_UID (head), bb->index); | |
a00d11f0 JH |
2842 | err = 1; |
2843 | } | |
2844 | ||
a7b87f73 | 2845 | last_head = PREV_INSN (x); |
251a41b9 TJ |
2846 | } |
2847 | ||
2848 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) | |
2849 | { | |
2850 | /* Check that the code before the first basic block has NULL | |
2851 | bb field. */ | |
2852 | if (!BARRIER_P (x) | |
2853 | && BLOCK_FOR_INSN (x) != NULL) | |
2854 | { | |
2855 | error ("insn %d outside of basic blocks has non-NULL bb field", | |
2856 | INSN_UID (x)); | |
2857 | err = 1; | |
2858 | } | |
2859 | } | |
2860 | free (bb_info); | |
2861 | ||
2862 | return err; | |
2863 | } | |
2864 | ||
2865 | /* Verify that fallthru edges point to adjacent blocks in layout order and | |
2866 | that barriers exist after non-fallthru blocks. */ | |
2867 | ||
2868 | static int | |
2869 | rtl_verify_fallthru (void) | |
2870 | { | |
2871 | basic_block bb; | |
2872 | int err = 0; | |
2873 | ||
4f42035e | 2874 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
251a41b9 TJ |
2875 | { |
2876 | edge e; | |
9eab6785 | 2877 | |
0fd4b31d | 2878 | e = find_fallthru_edge (bb->succs); |
10e9fecc JH |
2879 | if (!e) |
2880 | { | |
8879d71c | 2881 | rtx_insn *insn; |
10e9fecc JH |
2882 | |
2883 | /* Ensure existence of barrier in BB with no fallthru edges. */ | |
468059bc DD |
2884 | for (insn = NEXT_INSN (BB_END (bb)); ; insn = NEXT_INSN (insn)) |
2885 | { | |
2886 | if (!insn || NOTE_INSN_BASIC_BLOCK_P (insn)) | |
10e9fecc JH |
2887 | { |
2888 | error ("missing barrier after block %i", bb->index); | |
2889 | err = 1; | |
2890 | break; | |
2891 | } | |
468059bc DD |
2892 | if (BARRIER_P (insn)) |
2893 | break; | |
2894 | } | |
10e9fecc | 2895 | } |
fefa31b5 DM |
2896 | else if (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
2897 | && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
c22cacf3 | 2898 | { |
8879d71c | 2899 | rtx_insn *insn; |
10e9fecc JH |
2900 | |
2901 | if (e->src->next_bb != e->dest) | |
2902 | { | |
2903 | error | |
2904 | ("verify_flow_info: Incorrect blocks for fallthru %i->%i", | |
2905 | e->src->index, e->dest->index); | |
2906 | err = 1; | |
2907 | } | |
2908 | else | |
a813c111 | 2909 | for (insn = NEXT_INSN (BB_END (e->src)); insn != BB_HEAD (e->dest); |
10e9fecc | 2910 | insn = NEXT_INSN (insn)) |
65f4b875 | 2911 | if (BARRIER_P (insn) || NONDEBUG_INSN_P (insn)) |
10e9fecc JH |
2912 | { |
2913 | error ("verify_flow_info: Incorrect fallthru %i->%i", | |
2914 | e->src->index, e->dest->index); | |
2915 | fatal_insn ("wrong insn in the fallthru edge", insn); | |
2916 | err = 1; | |
2917 | } | |
c22cacf3 | 2918 | } |
10e9fecc | 2919 | } |
ca6c03ca | 2920 | |
251a41b9 TJ |
2921 | return err; |
2922 | } | |
2923 | ||
2924 | /* Verify that blocks are laid out in consecutive order. While walking the | |
2925 | instructions, verify that all expected instructions are inside the basic | |
2926 | blocks, and that all returns are followed by barriers. */ | |
2927 | ||
2928 | static int | |
2929 | rtl_verify_bb_layout (void) | |
2930 | { | |
2931 | basic_block bb; | |
2932 | int err = 0; | |
65f4b875 | 2933 | rtx_insn *x, *y; |
251a41b9 | 2934 | int num_bb_notes; |
8879d71c | 2935 | rtx_insn * const rtx_first = get_insns (); |
fefa31b5 | 2936 | basic_block last_bb_seen = ENTRY_BLOCK_PTR_FOR_FN (cfun), curr_bb = NULL; |
9eab6785 | 2937 | |
ca6c03ca | 2938 | num_bb_notes = 0; |
fefa31b5 | 2939 | last_bb_seen = ENTRY_BLOCK_PTR_FOR_FN (cfun); |
e0082a72 | 2940 | |
5f0d2358 | 2941 | for (x = rtx_first; x; x = NEXT_INSN (x)) |
ca6c03ca JH |
2942 | { |
2943 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2944 | { | |
bf77398c | 2945 | bb = NOTE_BASIC_BLOCK (x); |
5f0d2358 | 2946 | |
ca6c03ca | 2947 | num_bb_notes++; |
e0082a72 | 2948 | if (bb != last_bb_seen->next_bb) |
10e9fecc | 2949 | internal_error ("basic blocks not laid down consecutively"); |
ca6c03ca | 2950 | |
10e9fecc | 2951 | curr_bb = last_bb_seen = bb; |
ca6c03ca JH |
2952 | } |
2953 | ||
10e9fecc | 2954 | if (!curr_bb) |
ca6c03ca JH |
2955 | { |
2956 | switch (GET_CODE (x)) | |
2957 | { | |
2958 | case BARRIER: | |
2959 | case NOTE: | |
2960 | break; | |
2961 | ||
2962 | case CODE_LABEL: | |
39718607 | 2963 | /* An ADDR_VEC is placed outside any basic block. */ |
ca6c03ca | 2964 | if (NEXT_INSN (x) |
481683e1 | 2965 | && JUMP_TABLE_DATA_P (NEXT_INSN (x))) |
5f0d2358 | 2966 | x = NEXT_INSN (x); |
ca6c03ca JH |
2967 | |
2968 | /* But in any case, non-deletable labels can appear anywhere. */ | |
2969 | break; | |
2970 | ||
2971 | default: | |
1f978f5f | 2972 | fatal_insn ("insn outside basic block", x); |
ca6c03ca JH |
2973 | } |
2974 | } | |
2975 | ||
26cae194 | 2976 | if (JUMP_P (x) |
ca6c03ca | 2977 | && returnjump_p (x) && ! condjump_p (x) |
65f4b875 AO |
2978 | && ! ((y = next_nonnote_nondebug_insn (x)) |
2979 | && BARRIER_P (y))) | |
1f978f5f | 2980 | fatal_insn ("return not followed by barrier", x); |
251a41b9 | 2981 | |
a813c111 | 2982 | if (curr_bb && x == BB_END (curr_bb)) |
10e9fecc | 2983 | curr_bb = NULL; |
ca6c03ca JH |
2984 | } |
2985 | ||
0cae8d31 | 2986 | if (num_bb_notes != n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS) |
ca6c03ca | 2987 | internal_error |
0b17ab2f | 2988 | ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)", |
0cae8d31 | 2989 | num_bb_notes, n_basic_blocks_for_fn (cfun)); |
ca6c03ca | 2990 | |
10e9fecc | 2991 | return err; |
ca6c03ca | 2992 | } |
251a41b9 TJ |
2993 | |
2994 | /* Verify the CFG and RTL consistency common for both underlying RTL and | |
2995 | cfglayout RTL, plus consistency checks specific to linearized RTL mode. | |
2996 | ||
2997 | Currently it does following checks: | |
2998 | - all checks of rtl_verify_flow_info_1 | |
2999 | - test head/end pointers | |
3000 | - check that blocks are laid out in consecutive order | |
3001 | - check that all insns are in the basic blocks | |
3002 | (except the switch handling code, barriers and notes) | |
3003 | - check that all returns are followed by barriers | |
600b5b1d TJ |
3004 | - check that all fallthru edge points to the adjacent blocks |
3005 | - verify that there is a single hot/cold partition boundary after bbro */ | |
251a41b9 TJ |
3006 | |
3007 | static int | |
3008 | rtl_verify_flow_info (void) | |
3009 | { | |
3010 | int err = 0; | |
3011 | ||
3012 | err |= rtl_verify_flow_info_1 (); | |
3013 | ||
3014 | err |= rtl_verify_bb_insn_chain (); | |
3015 | ||
3016 | err |= rtl_verify_fallthru (); | |
3017 | ||
3018 | err |= rtl_verify_bb_layout (); | |
3019 | ||
3371a64f TJ |
3020 | err |= verify_hot_cold_block_grouping (); |
3021 | ||
251a41b9 TJ |
3022 | return err; |
3023 | } | |
ca6c03ca | 3024 | \f |
eaec9b3d | 3025 | /* Assume that the preceding pass has possibly eliminated jump instructions |
ca6c03ca JH |
3026 | or converted the unconditional jumps. Eliminate the edges from CFG. |
3027 | Return true if any edges are eliminated. */ | |
3028 | ||
3029 | bool | |
d329e058 | 3030 | purge_dead_edges (basic_block bb) |
ca6c03ca | 3031 | { |
628f6a4e | 3032 | edge e; |
8879d71c DM |
3033 | rtx_insn *insn = BB_END (bb); |
3034 | rtx note; | |
ca6c03ca | 3035 | bool purged = false; |
628f6a4e BE |
3036 | bool found; |
3037 | edge_iterator ei; | |
ca6c03ca | 3038 | |
b5b8b0ac AO |
3039 | if (DEBUG_INSN_P (insn) && insn != BB_HEAD (bb)) |
3040 | do | |
3041 | insn = PREV_INSN (insn); | |
3042 | while ((DEBUG_INSN_P (insn) || NOTE_P (insn)) && insn != BB_HEAD (bb)); | |
3043 | ||
70da1d03 | 3044 | /* If this instruction cannot trap, remove REG_EH_REGION notes. */ |
4b4bf941 | 3045 | if (NONJUMP_INSN_P (insn) |
70da1d03 JH |
3046 | && (note = find_reg_note (insn, REG_EH_REGION, NULL))) |
3047 | { | |
3048 | rtx eqnote; | |
3049 | ||
3050 | if (! may_trap_p (PATTERN (insn)) | |
3051 | || ((eqnote = find_reg_equal_equiv_note (insn)) | |
3052 | && ! may_trap_p (XEXP (eqnote, 0)))) | |
3053 | remove_note (insn, note); | |
3054 | } | |
3055 | ||
546c093e | 3056 | /* Cleanup abnormal edges caused by exceptions or non-local gotos. */ |
628f6a4e | 3057 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
546c093e | 3058 | { |
1d65f45c RH |
3059 | bool remove = false; |
3060 | ||
e5f9a909 JW |
3061 | /* There are three types of edges we need to handle correctly here: EH |
3062 | edges, abnormal call EH edges, and abnormal call non-EH edges. The | |
3063 | latter can appear when nonlocal gotos are used. */ | |
1d65f45c | 3064 | if (e->flags & EDGE_ABNORMAL_CALL) |
546c093e | 3065 | { |
1d65f45c RH |
3066 | if (!CALL_P (insn)) |
3067 | remove = true; | |
3068 | else if (can_nonlocal_goto (insn)) | |
3069 | ; | |
3070 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) | |
3071 | ; | |
0a35513e AH |
3072 | else if (flag_tm && find_reg_note (insn, REG_TM, NULL)) |
3073 | ; | |
1d65f45c RH |
3074 | else |
3075 | remove = true; | |
546c093e | 3076 | } |
1d65f45c RH |
3077 | else if (e->flags & EDGE_EH) |
3078 | remove = !can_throw_internal (insn); | |
3079 | ||
3080 | if (remove) | |
546c093e | 3081 | { |
1d65f45c RH |
3082 | remove_edge (e); |
3083 | df_set_bb_dirty (bb); | |
3084 | purged = true; | |
546c093e RH |
3085 | } |
3086 | else | |
1d65f45c | 3087 | ei_next (&ei); |
546c093e | 3088 | } |
5f0d2358 | 3089 | |
4b4bf941 | 3090 | if (JUMP_P (insn)) |
ca6c03ca JH |
3091 | { |
3092 | rtx note; | |
3093 | edge b,f; | |
628f6a4e | 3094 | edge_iterator ei; |
5f0d2358 | 3095 | |
ca6c03ca JH |
3096 | /* We do care only about conditional jumps and simplejumps. */ |
3097 | if (!any_condjump_p (insn) | |
3098 | && !returnjump_p (insn) | |
3099 | && !simplejump_p (insn)) | |
c51d95ec | 3100 | return purged; |
5f0d2358 | 3101 | |
5a1a3e5e JH |
3102 | /* Branch probability/prediction notes are defined only for |
3103 | condjumps. We've possibly turned condjump into simplejump. */ | |
3104 | if (simplejump_p (insn)) | |
3105 | { | |
3106 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
3107 | if (note) | |
3108 | remove_note (insn, note); | |
3109 | while ((note = find_reg_note (insn, REG_BR_PRED, NULL))) | |
3110 | remove_note (insn, note); | |
3111 | } | |
3112 | ||
628f6a4e | 3113 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
ca6c03ca | 3114 | { |
7fcd7218 JH |
3115 | /* Avoid abnormal flags to leak from computed jumps turned |
3116 | into simplejumps. */ | |
f87c27b4 | 3117 | |
0e1638d4 | 3118 | e->flags &= ~EDGE_ABNORMAL; |
7fcd7218 | 3119 | |
5a566bed MM |
3120 | /* See if this edge is one we should keep. */ |
3121 | if ((e->flags & EDGE_FALLTHRU) && any_condjump_p (insn)) | |
3122 | /* A conditional jump can fall through into the next | |
3123 | block, so we should keep the edge. */ | |
628f6a4e BE |
3124 | { |
3125 | ei_next (&ei); | |
3126 | continue; | |
3127 | } | |
fefa31b5 | 3128 | else if (e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) |
a813c111 | 3129 | && BB_HEAD (e->dest) == JUMP_LABEL (insn)) |
5a566bed MM |
3130 | /* If the destination block is the target of the jump, |
3131 | keep the edge. */ | |
628f6a4e BE |
3132 | { |
3133 | ei_next (&ei); | |
3134 | continue; | |
3135 | } | |
fefa31b5 DM |
3136 | else if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) |
3137 | && returnjump_p (insn)) | |
5a566bed MM |
3138 | /* If the destination block is the exit block, and this |
3139 | instruction is a return, then keep the edge. */ | |
628f6a4e BE |
3140 | { |
3141 | ei_next (&ei); | |
3142 | continue; | |
3143 | } | |
5a566bed MM |
3144 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) |
3145 | /* Keep the edges that correspond to exceptions thrown by | |
0b75beaa EB |
3146 | this instruction and rematerialize the EDGE_ABNORMAL |
3147 | flag we just cleared above. */ | |
3148 | { | |
3149 | e->flags |= EDGE_ABNORMAL; | |
628f6a4e | 3150 | ei_next (&ei); |
0b75beaa EB |
3151 | continue; |
3152 | } | |
5f0d2358 | 3153 | |
5a566bed | 3154 | /* We do not need this edge. */ |
6fb5fa3c | 3155 | df_set_bb_dirty (bb); |
ca6c03ca JH |
3156 | purged = true; |
3157 | remove_edge (e); | |
3158 | } | |
5f0d2358 | 3159 | |
628f6a4e | 3160 | if (EDGE_COUNT (bb->succs) == 0 || !purged) |
c51d95ec | 3161 | return purged; |
5f0d2358 | 3162 | |
c263766c RH |
3163 | if (dump_file) |
3164 | fprintf (dump_file, "Purged edges from bb %i\n", bb->index); | |
5f0d2358 | 3165 | |
ca6c03ca JH |
3166 | if (!optimize) |
3167 | return purged; | |
3168 | ||
3169 | /* Redistribute probabilities. */ | |
c5cbcccf | 3170 | if (single_succ_p (bb)) |
ca6c03ca | 3171 | { |
357067f2 | 3172 | single_succ_edge (bb)->probability = profile_probability::always (); |
f87c27b4 | 3173 | } |
ca6c03ca JH |
3174 | else |
3175 | { | |
3176 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
3177 | if (!note) | |
3178 | return purged; | |
5f0d2358 | 3179 | |
ca6c03ca JH |
3180 | b = BRANCH_EDGE (bb); |
3181 | f = FALLTHRU_EDGE (bb); | |
5fa396ad | 3182 | b->probability = profile_probability::from_reg_br_prob_note |
357067f2 | 3183 | (XINT (note, 0)); |
5fa396ad | 3184 | f->probability = b->probability.invert (); |
ca6c03ca | 3185 | } |
5f0d2358 | 3186 | |
ca6c03ca JH |
3187 | return purged; |
3188 | } | |
4b4bf941 | 3189 | else if (CALL_P (insn) && SIBLING_CALL_P (insn)) |
1722c2c8 RH |
3190 | { |
3191 | /* First, there should not be any EH or ABCALL edges resulting | |
3192 | from non-local gotos and the like. If there were, we shouldn't | |
3193 | have created the sibcall in the first place. Second, there | |
3194 | should of course never have been a fallthru edge. */ | |
c5cbcccf ZD |
3195 | gcc_assert (single_succ_p (bb)); |
3196 | gcc_assert (single_succ_edge (bb)->flags | |
3197 | == (EDGE_SIBCALL | EDGE_ABNORMAL)); | |
1722c2c8 RH |
3198 | |
3199 | return 0; | |
3200 | } | |
ca6c03ca | 3201 | |
ca6c03ca JH |
3202 | /* If we don't see a jump insn, we don't know exactly why the block would |
3203 | have been broken at this point. Look for a simple, non-fallthru edge, | |
3204 | as these are only created by conditional branches. If we find such an | |
3205 | edge we know that there used to be a jump here and can then safely | |
3206 | remove all non-fallthru edges. */ | |
628f6a4e BE |
3207 | found = false; |
3208 | FOR_EACH_EDGE (e, ei, bb->succs) | |
3209 | if (! (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU))) | |
3210 | { | |
3211 | found = true; | |
3212 | break; | |
3213 | } | |
5f0d2358 | 3214 | |
628f6a4e | 3215 | if (!found) |
ca6c03ca | 3216 | return purged; |
5f0d2358 | 3217 | |
2afa8dce DB |
3218 | /* Remove all but the fake and fallthru edges. The fake edge may be |
3219 | the only successor for this block in the case of noreturn | |
3220 | calls. */ | |
628f6a4e | 3221 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
ca6c03ca | 3222 | { |
2afa8dce | 3223 | if (!(e->flags & (EDGE_FALLTHRU | EDGE_FAKE))) |
c51d95ec | 3224 | { |
6fb5fa3c | 3225 | df_set_bb_dirty (bb); |
c51d95ec JH |
3226 | remove_edge (e); |
3227 | purged = true; | |
3228 | } | |
628f6a4e BE |
3229 | else |
3230 | ei_next (&ei); | |
ca6c03ca | 3231 | } |
5f0d2358 | 3232 | |
c5cbcccf | 3233 | gcc_assert (single_succ_p (bb)); |
5f0d2358 | 3234 | |
357067f2 | 3235 | single_succ_edge (bb)->probability = profile_probability::always (); |
ca6c03ca | 3236 | |
c263766c RH |
3237 | if (dump_file) |
3238 | fprintf (dump_file, "Purged non-fallthru edges from bb %i\n", | |
0b17ab2f | 3239 | bb->index); |
ca6c03ca JH |
3240 | return purged; |
3241 | } | |
3242 | ||
5f0d2358 RK |
3243 | /* Search all basic blocks for potentially dead edges and purge them. Return |
3244 | true if some edge has been eliminated. */ | |
ca6c03ca JH |
3245 | |
3246 | bool | |
25cd19de | 3247 | purge_all_dead_edges (void) |
ca6c03ca | 3248 | { |
e0082a72 | 3249 | int purged = false; |
e0082a72 | 3250 | basic_block bb; |
473fb060 | 3251 | |
11cd3bed | 3252 | FOR_EACH_BB_FN (bb, cfun) |
473fb060 | 3253 | { |
e0082a72 | 3254 | bool purged_here = purge_dead_edges (bb); |
5f0d2358 | 3255 | |
473fb060 | 3256 | purged |= purged_here; |
473fb060 | 3257 | } |
5f0d2358 | 3258 | |
ca6c03ca JH |
3259 | return purged; |
3260 | } | |
9ee634e3 | 3261 | |
ba5e9aca EB |
3262 | /* This is used by a few passes that emit some instructions after abnormal |
3263 | calls, moving the basic block's end, while they in fact do want to emit | |
3264 | them on the fallthru edge. Look for abnormal call edges, find backward | |
3265 | the call in the block and insert the instructions on the edge instead. | |
3266 | ||
3267 | Similarly, handle instructions throwing exceptions internally. | |
3268 | ||
3269 | Return true when instructions have been found and inserted on edges. */ | |
3270 | ||
3271 | bool | |
3272 | fixup_abnormal_edges (void) | |
3273 | { | |
3274 | bool inserted = false; | |
3275 | basic_block bb; | |
3276 | ||
11cd3bed | 3277 | FOR_EACH_BB_FN (bb, cfun) |
ba5e9aca EB |
3278 | { |
3279 | edge e; | |
3280 | edge_iterator ei; | |
3281 | ||
3282 | /* Look for cases we are interested in - calls or instructions causing | |
3283 | exceptions. */ | |
3284 | FOR_EACH_EDGE (e, ei, bb->succs) | |
3285 | if ((e->flags & EDGE_ABNORMAL_CALL) | |
3286 | || ((e->flags & (EDGE_ABNORMAL | EDGE_EH)) | |
3287 | == (EDGE_ABNORMAL | EDGE_EH))) | |
3288 | break; | |
3289 | ||
3290 | if (e && !CALL_P (BB_END (bb)) && !can_throw_internal (BB_END (bb))) | |
3291 | { | |
8879d71c | 3292 | rtx_insn *insn; |
ba5e9aca EB |
3293 | |
3294 | /* Get past the new insns generated. Allow notes, as the insns | |
3295 | may be already deleted. */ | |
3296 | insn = BB_END (bb); | |
3297 | while ((NONJUMP_INSN_P (insn) || NOTE_P (insn)) | |
3298 | && !can_throw_internal (insn) | |
3299 | && insn != BB_HEAD (bb)) | |
3300 | insn = PREV_INSN (insn); | |
3301 | ||
3302 | if (CALL_P (insn) || can_throw_internal (insn)) | |
3303 | { | |
8879d71c | 3304 | rtx_insn *stop, *next; |
ba5e9aca EB |
3305 | |
3306 | e = find_fallthru_edge (bb->succs); | |
3307 | ||
3308 | stop = NEXT_INSN (BB_END (bb)); | |
1130d5e3 | 3309 | BB_END (bb) = insn; |
ba5e9aca EB |
3310 | |
3311 | for (insn = NEXT_INSN (insn); insn != stop; insn = next) | |
3312 | { | |
3313 | next = NEXT_INSN (insn); | |
3314 | if (INSN_P (insn)) | |
3315 | { | |
3316 | delete_insn (insn); | |
3317 | ||
3318 | /* Sometimes there's still the return value USE. | |
3319 | If it's placed after a trapping call (i.e. that | |
3320 | call is the last insn anyway), we have no fallthru | |
3321 | edge. Simply delete this use and don't try to insert | |
3322 | on the non-existent edge. */ | |
3323 | if (GET_CODE (PATTERN (insn)) != USE) | |
3324 | { | |
3325 | /* We're not deleting it, we're moving it. */ | |
4654c0cf | 3326 | insn->set_undeleted (); |
0f82e5c9 DM |
3327 | SET_PREV_INSN (insn) = NULL_RTX; |
3328 | SET_NEXT_INSN (insn) = NULL_RTX; | |
ba5e9aca EB |
3329 | |
3330 | insert_insn_on_edge (insn, e); | |
3331 | inserted = true; | |
3332 | } | |
3333 | } | |
3334 | else if (!BARRIER_P (insn)) | |
3335 | set_block_for_insn (insn, NULL); | |
3336 | } | |
3337 | } | |
3338 | ||
3339 | /* It may be that we don't find any trapping insn. In this | |
3340 | case we discovered quite late that the insn that had been | |
3341 | marked as can_throw_internal in fact couldn't trap at all. | |
3342 | So we should in fact delete the EH edges out of the block. */ | |
3343 | else | |
3344 | purge_dead_edges (bb); | |
3345 | } | |
3346 | } | |
3347 | ||
3348 | return inserted; | |
3349 | } | |
78bde837 SB |
3350 | \f |
3351 | /* Cut the insns from FIRST to LAST out of the insns stream. */ | |
3352 | ||
a90c614a | 3353 | rtx_insn * |
9152e0aa | 3354 | unlink_insn_chain (rtx_insn *first, rtx_insn *last) |
78bde837 | 3355 | { |
a90c614a DM |
3356 | rtx_insn *prevfirst = PREV_INSN (first); |
3357 | rtx_insn *nextlast = NEXT_INSN (last); | |
78bde837 | 3358 | |
0f82e5c9 DM |
3359 | SET_PREV_INSN (first) = NULL; |
3360 | SET_NEXT_INSN (last) = NULL; | |
78bde837 | 3361 | if (prevfirst) |
0f82e5c9 | 3362 | SET_NEXT_INSN (prevfirst) = nextlast; |
78bde837 | 3363 | if (nextlast) |
0f82e5c9 | 3364 | SET_PREV_INSN (nextlast) = prevfirst; |
78bde837 SB |
3365 | else |
3366 | set_last_insn (prevfirst); | |
3367 | if (!prevfirst) | |
3368 | set_first_insn (nextlast); | |
9152e0aa | 3369 | return first; |
78bde837 SB |
3370 | } |
3371 | \f | |
3372 | /* Skip over inter-block insns occurring after BB which are typically | |
3373 | associated with BB (e.g., barriers). If there are any such insns, | |
3374 | we return the last one. Otherwise, we return the end of BB. */ | |
3375 | ||
8879d71c | 3376 | static rtx_insn * |
78bde837 SB |
3377 | skip_insns_after_block (basic_block bb) |
3378 | { | |
8879d71c | 3379 | rtx_insn *insn, *last_insn, *next_head, *prev; |
78bde837 | 3380 | |
8879d71c | 3381 | next_head = NULL; |
fefa31b5 | 3382 | if (bb->next_bb != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
78bde837 SB |
3383 | next_head = BB_HEAD (bb->next_bb); |
3384 | ||
3385 | for (last_insn = insn = BB_END (bb); (insn = NEXT_INSN (insn)) != 0; ) | |
3386 | { | |
3387 | if (insn == next_head) | |
3388 | break; | |
3389 | ||
3390 | switch (GET_CODE (insn)) | |
3391 | { | |
3392 | case BARRIER: | |
3393 | last_insn = insn; | |
3394 | continue; | |
3395 | ||
3396 | case NOTE: | |
3397 | switch (NOTE_KIND (insn)) | |
3398 | { | |
3399 | case NOTE_INSN_BLOCK_END: | |
3400 | gcc_unreachable (); | |
3401 | continue; | |
3402 | default: | |
3403 | continue; | |
3404 | break; | |
3405 | } | |
3406 | break; | |
3407 | ||
3408 | case CODE_LABEL: | |
3409 | if (NEXT_INSN (insn) | |
3410 | && JUMP_TABLE_DATA_P (NEXT_INSN (insn))) | |
3411 | { | |
3412 | insn = NEXT_INSN (insn); | |
3413 | last_insn = insn; | |
3414 | continue; | |
3415 | } | |
3416 | break; | |
3417 | ||
3418 | default: | |
3419 | break; | |
3420 | } | |
3421 | ||
3422 | break; | |
3423 | } | |
3424 | ||
3425 | /* It is possible to hit contradictory sequence. For instance: | |
3426 | ||
3427 | jump_insn | |
3428 | NOTE_INSN_BLOCK_BEG | |
3429 | barrier | |
3430 | ||
3431 | Where barrier belongs to jump_insn, but the note does not. This can be | |
3432 | created by removing the basic block originally following | |
3433 | NOTE_INSN_BLOCK_BEG. In such case reorder the notes. */ | |
3434 | ||
3435 | for (insn = last_insn; insn != BB_END (bb); insn = prev) | |
3436 | { | |
3437 | prev = PREV_INSN (insn); | |
3438 | if (NOTE_P (insn)) | |
3439 | switch (NOTE_KIND (insn)) | |
3440 | { | |
3441 | case NOTE_INSN_BLOCK_END: | |
3442 | gcc_unreachable (); | |
3443 | break; | |
3444 | case NOTE_INSN_DELETED: | |
3445 | case NOTE_INSN_DELETED_LABEL: | |
3446 | case NOTE_INSN_DELETED_DEBUG_LABEL: | |
3447 | continue; | |
3448 | default: | |
3449 | reorder_insns (insn, insn, last_insn); | |
3450 | } | |
3451 | } | |
3452 | ||
3453 | return last_insn; | |
3454 | } | |
3455 | ||
3456 | /* Locate or create a label for a given basic block. */ | |
3457 | ||
e67d1102 | 3458 | static rtx_insn * |
78bde837 SB |
3459 | label_for_bb (basic_block bb) |
3460 | { | |
e67d1102 | 3461 | rtx_insn *label = BB_HEAD (bb); |
78bde837 SB |
3462 | |
3463 | if (!LABEL_P (label)) | |
3464 | { | |
3465 | if (dump_file) | |
3466 | fprintf (dump_file, "Emitting label for block %d\n", bb->index); | |
3467 | ||
3468 | label = block_label (bb); | |
3469 | } | |
3470 | ||
3471 | return label; | |
3472 | } | |
3473 | ||
3474 | /* Locate the effective beginning and end of the insn chain for each | |
3475 | block, as defined by skip_insns_after_block above. */ | |
3476 | ||
3477 | static void | |
3478 | record_effective_endpoints (void) | |
3479 | { | |
8879d71c | 3480 | rtx_insn *next_insn; |
78bde837 | 3481 | basic_block bb; |
8879d71c | 3482 | rtx_insn *insn; |
78bde837 SB |
3483 | |
3484 | for (insn = get_insns (); | |
3485 | insn | |
3486 | && NOTE_P (insn) | |
3487 | && NOTE_KIND (insn) != NOTE_INSN_BASIC_BLOCK; | |
3488 | insn = NEXT_INSN (insn)) | |
3489 | continue; | |
3490 | /* No basic blocks at all? */ | |
3491 | gcc_assert (insn); | |
3492 | ||
3493 | if (PREV_INSN (insn)) | |
3494 | cfg_layout_function_header = | |
3495 | unlink_insn_chain (get_insns (), PREV_INSN (insn)); | |
3496 | else | |
9152e0aa | 3497 | cfg_layout_function_header = NULL; |
78bde837 SB |
3498 | |
3499 | next_insn = get_insns (); | |
11cd3bed | 3500 | FOR_EACH_BB_FN (bb, cfun) |
78bde837 | 3501 | { |
8879d71c | 3502 | rtx_insn *end; |
78bde837 SB |
3503 | |
3504 | if (PREV_INSN (BB_HEAD (bb)) && next_insn != BB_HEAD (bb)) | |
1130d5e3 | 3505 | BB_HEADER (bb) = unlink_insn_chain (next_insn, |
190bea87 | 3506 | PREV_INSN (BB_HEAD (bb))); |
78bde837 SB |
3507 | end = skip_insns_after_block (bb); |
3508 | if (NEXT_INSN (BB_END (bb)) && BB_END (bb) != end) | |
d8ce2eae | 3509 | BB_FOOTER (bb) = unlink_insn_chain (NEXT_INSN (BB_END (bb)), end); |
78bde837 SB |
3510 | next_insn = NEXT_INSN (BB_END (bb)); |
3511 | } | |
3512 | ||
3513 | cfg_layout_function_footer = next_insn; | |
3514 | if (cfg_layout_function_footer) | |
3515 | cfg_layout_function_footer = unlink_insn_chain (cfg_layout_function_footer, get_last_insn ()); | |
3516 | } | |
3517 | \f | |
27a4cd48 DM |
3518 | namespace { |
3519 | ||
3520 | const pass_data pass_data_into_cfg_layout_mode = | |
3521 | { | |
3522 | RTL_PASS, /* type */ | |
3523 | "into_cfglayout", /* name */ | |
3524 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
3525 | TV_CFG, /* tv_id */ |
3526 | 0, /* properties_required */ | |
3527 | PROP_cfglayout, /* properties_provided */ | |
3528 | 0, /* properties_destroyed */ | |
3529 | 0, /* todo_flags_start */ | |
3530 | 0, /* todo_flags_finish */ | |
78bde837 SB |
3531 | }; |
3532 | ||
27a4cd48 DM |
3533 | class pass_into_cfg_layout_mode : public rtl_opt_pass |
3534 | { | |
3535 | public: | |
c3284718 RS |
3536 | pass_into_cfg_layout_mode (gcc::context *ctxt) |
3537 | : rtl_opt_pass (pass_data_into_cfg_layout_mode, ctxt) | |
27a4cd48 DM |
3538 | {} |
3539 | ||
3540 | /* opt_pass methods: */ | |
be55bfe6 TS |
3541 | virtual unsigned int execute (function *) |
3542 | { | |
3543 | cfg_layout_initialize (0); | |
3544 | return 0; | |
3545 | } | |
27a4cd48 DM |
3546 | |
3547 | }; // class pass_into_cfg_layout_mode | |
3548 | ||
3549 | } // anon namespace | |
3550 | ||
3551 | rtl_opt_pass * | |
3552 | make_pass_into_cfg_layout_mode (gcc::context *ctxt) | |
3553 | { | |
3554 | return new pass_into_cfg_layout_mode (ctxt); | |
3555 | } | |
3556 | ||
3557 | namespace { | |
3558 | ||
3559 | const pass_data pass_data_outof_cfg_layout_mode = | |
3560 | { | |
3561 | RTL_PASS, /* type */ | |
3562 | "outof_cfglayout", /* name */ | |
3563 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
3564 | TV_CFG, /* tv_id */ |
3565 | 0, /* properties_required */ | |
3566 | 0, /* properties_provided */ | |
3567 | PROP_cfglayout, /* properties_destroyed */ | |
3568 | 0, /* todo_flags_start */ | |
3569 | 0, /* todo_flags_finish */ | |
78bde837 | 3570 | }; |
27a4cd48 DM |
3571 | |
3572 | class pass_outof_cfg_layout_mode : public rtl_opt_pass | |
3573 | { | |
3574 | public: | |
c3284718 RS |
3575 | pass_outof_cfg_layout_mode (gcc::context *ctxt) |
3576 | : rtl_opt_pass (pass_data_outof_cfg_layout_mode, ctxt) | |
27a4cd48 DM |
3577 | {} |
3578 | ||
3579 | /* opt_pass methods: */ | |
be55bfe6 | 3580 | virtual unsigned int execute (function *); |
27a4cd48 DM |
3581 | |
3582 | }; // class pass_outof_cfg_layout_mode | |
3583 | ||
be55bfe6 TS |
3584 | unsigned int |
3585 | pass_outof_cfg_layout_mode::execute (function *fun) | |
3586 | { | |
3587 | basic_block bb; | |
3588 | ||
3589 | FOR_EACH_BB_FN (bb, fun) | |
3590 | if (bb->next_bb != EXIT_BLOCK_PTR_FOR_FN (fun)) | |
3591 | bb->aux = bb->next_bb; | |
3592 | ||
3593 | cfg_layout_finalize (); | |
3594 | ||
3595 | return 0; | |
3596 | } | |
3597 | ||
27a4cd48 DM |
3598 | } // anon namespace |
3599 | ||
3600 | rtl_opt_pass * | |
3601 | make_pass_outof_cfg_layout_mode (gcc::context *ctxt) | |
3602 | { | |
3603 | return new pass_outof_cfg_layout_mode (ctxt); | |
3604 | } | |
78bde837 SB |
3605 | \f |
3606 | ||
3607 | /* Link the basic blocks in the correct order, compacting the basic | |
3608 | block queue while at it. If STAY_IN_CFGLAYOUT_MODE is false, this | |
3609 | function also clears the basic block header and footer fields. | |
3610 | ||
3611 | This function is usually called after a pass (e.g. tracer) finishes | |
3612 | some transformations while in cfglayout mode. The required sequence | |
3613 | of the basic blocks is in a linked list along the bb->aux field. | |
3614 | This functions re-links the basic block prev_bb and next_bb pointers | |
532aafad SB |
3615 | accordingly, and it compacts and renumbers the blocks. |
3616 | ||
3617 | FIXME: This currently works only for RTL, but the only RTL-specific | |
3618 | bits are the STAY_IN_CFGLAYOUT_MODE bits. The tracer pass was moved | |
3619 | to GIMPLE a long time ago, but it doesn't relink the basic block | |
3620 | chain. It could do that (to give better initial RTL) if this function | |
3621 | is made IR-agnostic (and moved to cfganal.c or cfg.c while at it). */ | |
78bde837 SB |
3622 | |
3623 | void | |
3624 | relink_block_chain (bool stay_in_cfglayout_mode) | |
3625 | { | |
3626 | basic_block bb, prev_bb; | |
3627 | int index; | |
3628 | ||
3629 | /* Maybe dump the re-ordered sequence. */ | |
3630 | if (dump_file) | |
3631 | { | |
3632 | fprintf (dump_file, "Reordered sequence:\n"); | |
fefa31b5 DM |
3633 | for (bb = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb, index = |
3634 | NUM_FIXED_BLOCKS; | |
78bde837 SB |
3635 | bb; |
3636 | bb = (basic_block) bb->aux, index++) | |
3637 | { | |
3638 | fprintf (dump_file, " %i ", index); | |
3639 | if (get_bb_original (bb)) | |
3640 | fprintf (dump_file, "duplicate of %i ", | |
3641 | get_bb_original (bb)->index); | |
3642 | else if (forwarder_block_p (bb) | |
3643 | && !LABEL_P (BB_HEAD (bb))) | |
3644 | fprintf (dump_file, "compensation "); | |
3645 | else | |
3646 | fprintf (dump_file, "bb %i ", bb->index); | |
78bde837 SB |
3647 | } |
3648 | } | |
3649 | ||
3650 | /* Now reorder the blocks. */ | |
fefa31b5 DM |
3651 | prev_bb = ENTRY_BLOCK_PTR_FOR_FN (cfun); |
3652 | bb = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb; | |
78bde837 SB |
3653 | for (; bb; prev_bb = bb, bb = (basic_block) bb->aux) |
3654 | { | |
3655 | bb->prev_bb = prev_bb; | |
3656 | prev_bb->next_bb = bb; | |
3657 | } | |
fefa31b5 DM |
3658 | prev_bb->next_bb = EXIT_BLOCK_PTR_FOR_FN (cfun); |
3659 | EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb = prev_bb; | |
78bde837 SB |
3660 | |
3661 | /* Then, clean up the aux fields. */ | |
04a90bec | 3662 | FOR_ALL_BB_FN (bb, cfun) |
78bde837 SB |
3663 | { |
3664 | bb->aux = NULL; | |
3665 | if (!stay_in_cfglayout_mode) | |
1130d5e3 | 3666 | BB_HEADER (bb) = BB_FOOTER (bb) = NULL; |
78bde837 SB |
3667 | } |
3668 | ||
3669 | /* Maybe reset the original copy tables, they are not valid anymore | |
3670 | when we renumber the basic blocks in compact_blocks. If we are | |
3671 | are going out of cfglayout mode, don't re-allocate the tables. */ | |
c2e84327 DM |
3672 | if (original_copy_tables_initialized_p ()) |
3673 | free_original_copy_tables (); | |
78bde837 SB |
3674 | if (stay_in_cfglayout_mode) |
3675 | initialize_original_copy_tables (); | |
3676 | ||
3677 | /* Finally, put basic_block_info in the new order. */ | |
3678 | compact_blocks (); | |
3679 | } | |
3680 | \f | |
3681 | ||
3682 | /* Given a reorder chain, rearrange the code to match. */ | |
3683 | ||
3684 | static void | |
3685 | fixup_reorder_chain (void) | |
3686 | { | |
3687 | basic_block bb; | |
9152e0aa | 3688 | rtx_insn *insn = NULL; |
78bde837 SB |
3689 | |
3690 | if (cfg_layout_function_header) | |
3691 | { | |
3692 | set_first_insn (cfg_layout_function_header); | |
3693 | insn = cfg_layout_function_header; | |
3694 | while (NEXT_INSN (insn)) | |
3695 | insn = NEXT_INSN (insn); | |
3696 | } | |
3697 | ||
3698 | /* First do the bulk reordering -- rechain the blocks without regard to | |
3699 | the needed changes to jumps and labels. */ | |
3700 | ||
fefa31b5 DM |
3701 | for (bb = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb; bb; bb = (basic_block) |
3702 | bb->aux) | |
78bde837 SB |
3703 | { |
3704 | if (BB_HEADER (bb)) | |
3705 | { | |
3706 | if (insn) | |
0f82e5c9 | 3707 | SET_NEXT_INSN (insn) = BB_HEADER (bb); |
78bde837 SB |
3708 | else |
3709 | set_first_insn (BB_HEADER (bb)); | |
0f82e5c9 | 3710 | SET_PREV_INSN (BB_HEADER (bb)) = insn; |
78bde837 SB |
3711 | insn = BB_HEADER (bb); |
3712 | while (NEXT_INSN (insn)) | |
3713 | insn = NEXT_INSN (insn); | |
3714 | } | |
3715 | if (insn) | |
0f82e5c9 | 3716 | SET_NEXT_INSN (insn) = BB_HEAD (bb); |
78bde837 SB |
3717 | else |
3718 | set_first_insn (BB_HEAD (bb)); | |
0f82e5c9 | 3719 | SET_PREV_INSN (BB_HEAD (bb)) = insn; |
78bde837 SB |
3720 | insn = BB_END (bb); |
3721 | if (BB_FOOTER (bb)) | |
3722 | { | |
0f82e5c9 DM |
3723 | SET_NEXT_INSN (insn) = BB_FOOTER (bb); |
3724 | SET_PREV_INSN (BB_FOOTER (bb)) = insn; | |
78bde837 SB |
3725 | while (NEXT_INSN (insn)) |
3726 | insn = NEXT_INSN (insn); | |
3727 | } | |
3728 | } | |
3729 | ||
0f82e5c9 | 3730 | SET_NEXT_INSN (insn) = cfg_layout_function_footer; |
78bde837 | 3731 | if (cfg_layout_function_footer) |
0f82e5c9 | 3732 | SET_PREV_INSN (cfg_layout_function_footer) = insn; |
78bde837 SB |
3733 | |
3734 | while (NEXT_INSN (insn)) | |
3735 | insn = NEXT_INSN (insn); | |
3736 | ||
3737 | set_last_insn (insn); | |
b2b29377 MM |
3738 | if (flag_checking) |
3739 | verify_insn_chain (); | |
78bde837 SB |
3740 | |
3741 | /* Now add jumps and labels as needed to match the blocks new | |
29f3fd5b | 3742 | outgoing edges. */ |
78bde837 | 3743 | |
29f3fd5b SB |
3744 | for (bb = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb; bb ; bb = (basic_block) |
3745 | bb->aux) | |
78bde837 SB |
3746 | { |
3747 | edge e_fall, e_taken, e; | |
8879d71c | 3748 | rtx_insn *bb_end_insn; |
78bde837 | 3749 | rtx ret_label = NULL_RTX; |
3371a64f | 3750 | basic_block nb; |
78bde837 SB |
3751 | edge_iterator ei; |
3752 | ||
3753 | if (EDGE_COUNT (bb->succs) == 0) | |
3754 | continue; | |
3755 | ||
3756 | /* Find the old fallthru edge, and another non-EH edge for | |
3757 | a taken jump. */ | |
3758 | e_taken = e_fall = NULL; | |
3759 | ||
3760 | FOR_EACH_EDGE (e, ei, bb->succs) | |
3761 | if (e->flags & EDGE_FALLTHRU) | |
3762 | e_fall = e; | |
3763 | else if (! (e->flags & EDGE_EH)) | |
3764 | e_taken = e; | |
3765 | ||
3766 | bb_end_insn = BB_END (bb); | |
1476d1bd | 3767 | if (rtx_jump_insn *bb_end_jump = dyn_cast <rtx_jump_insn *> (bb_end_insn)) |
78bde837 | 3768 | { |
1476d1bd MM |
3769 | ret_label = JUMP_LABEL (bb_end_jump); |
3770 | if (any_condjump_p (bb_end_jump)) | |
78bde837 SB |
3771 | { |
3772 | /* This might happen if the conditional jump has side | |
3773 | effects and could therefore not be optimized away. | |
3774 | Make the basic block to end with a barrier in order | |
3775 | to prevent rtl_verify_flow_info from complaining. */ | |
3776 | if (!e_fall) | |
3777 | { | |
1476d1bd MM |
3778 | gcc_assert (!onlyjump_p (bb_end_jump) |
3779 | || returnjump_p (bb_end_jump) | |
91af97c3 | 3780 | || (e_taken->flags & EDGE_CROSSING)); |
1476d1bd | 3781 | emit_barrier_after (bb_end_jump); |
78bde837 SB |
3782 | continue; |
3783 | } | |
3784 | ||
3785 | /* If the old fallthru is still next, nothing to do. */ | |
3786 | if (bb->aux == e_fall->dest | |
fefa31b5 | 3787 | || e_fall->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
78bde837 SB |
3788 | continue; |
3789 | ||
3790 | /* The degenerated case of conditional jump jumping to the next | |
3791 | instruction can happen for jumps with side effects. We need | |
3792 | to construct a forwarder block and this will be done just | |
3793 | fine by force_nonfallthru below. */ | |
3794 | if (!e_taken) | |
3795 | ; | |
3796 | ||
3797 | /* There is another special case: if *neither* block is next, | |
3798 | such as happens at the very end of a function, then we'll | |
3799 | need to add a new unconditional jump. Choose the taken | |
3800 | edge based on known or assumed probability. */ | |
3801 | else if (bb->aux != e_taken->dest) | |
3802 | { | |
1476d1bd | 3803 | rtx note = find_reg_note (bb_end_jump, REG_BR_PROB, 0); |
78bde837 SB |
3804 | |
3805 | if (note | |
5fa396ad JH |
3806 | && profile_probability::from_reg_br_prob_note |
3807 | (XINT (note, 0)) < profile_probability::even () | |
1476d1bd | 3808 | && invert_jump (bb_end_jump, |
fefa31b5 DM |
3809 | (e_fall->dest |
3810 | == EXIT_BLOCK_PTR_FOR_FN (cfun) | |
78bde837 SB |
3811 | ? NULL_RTX |
3812 | : label_for_bb (e_fall->dest)), 0)) | |
3813 | { | |
3814 | e_fall->flags &= ~EDGE_FALLTHRU; | |
3815 | gcc_checking_assert (could_fall_through | |
3816 | (e_taken->src, e_taken->dest)); | |
3817 | e_taken->flags |= EDGE_FALLTHRU; | |
3818 | update_br_prob_note (bb); | |
3819 | e = e_fall, e_fall = e_taken, e_taken = e; | |
3820 | } | |
3821 | } | |
3822 | ||
3823 | /* If the "jumping" edge is a crossing edge, and the fall | |
3824 | through edge is non-crossing, leave things as they are. */ | |
3825 | else if ((e_taken->flags & EDGE_CROSSING) | |
3826 | && !(e_fall->flags & EDGE_CROSSING)) | |
3827 | continue; | |
3828 | ||
3829 | /* Otherwise we can try to invert the jump. This will | |
3830 | basically never fail, however, keep up the pretense. */ | |
1476d1bd | 3831 | else if (invert_jump (bb_end_jump, |
fefa31b5 DM |
3832 | (e_fall->dest |
3833 | == EXIT_BLOCK_PTR_FOR_FN (cfun) | |
78bde837 SB |
3834 | ? NULL_RTX |
3835 | : label_for_bb (e_fall->dest)), 0)) | |
3836 | { | |
3837 | e_fall->flags &= ~EDGE_FALLTHRU; | |
3838 | gcc_checking_assert (could_fall_through | |
3839 | (e_taken->src, e_taken->dest)); | |
3840 | e_taken->flags |= EDGE_FALLTHRU; | |
3841 | update_br_prob_note (bb); | |
3842 | if (LABEL_NUSES (ret_label) == 0 | |
3843 | && single_pred_p (e_taken->dest)) | |
a29f6a2b | 3844 | delete_insn (as_a<rtx_insn *> (ret_label)); |
78bde837 SB |
3845 | continue; |
3846 | } | |
3847 | } | |
3848 | else if (extract_asm_operands (PATTERN (bb_end_insn)) != NULL) | |
3849 | { | |
3850 | /* If the old fallthru is still next or if | |
3851 | asm goto doesn't have a fallthru (e.g. when followed by | |
3852 | __builtin_unreachable ()), nothing to do. */ | |
3853 | if (! e_fall | |
3854 | || bb->aux == e_fall->dest | |
fefa31b5 | 3855 | || e_fall->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
78bde837 SB |
3856 | continue; |
3857 | ||
3858 | /* Otherwise we'll have to use the fallthru fixup below. */ | |
3859 | } | |
3860 | else | |
3861 | { | |
3862 | /* Otherwise we have some return, switch or computed | |
3863 | jump. In the 99% case, there should not have been a | |
3864 | fallthru edge. */ | |
3865 | gcc_assert (returnjump_p (bb_end_insn) || !e_fall); | |
3866 | continue; | |
3867 | } | |
3868 | } | |
3869 | else | |
3870 | { | |
3871 | /* No fallthru implies a noreturn function with EH edges, or | |
3872 | something similarly bizarre. In any case, we don't need to | |
3873 | do anything. */ | |
3874 | if (! e_fall) | |
3875 | continue; | |
3876 | ||
3877 | /* If the fallthru block is still next, nothing to do. */ | |
3878 | if (bb->aux == e_fall->dest) | |
3879 | continue; | |
3880 | ||
3881 | /* A fallthru to exit block. */ | |
fefa31b5 | 3882 | if (e_fall->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
78bde837 SB |
3883 | continue; |
3884 | } | |
3885 | ||
3886 | /* We got here if we need to add a new jump insn. | |
3887 | Note force_nonfallthru can delete E_FALL and thus we have to | |
3888 | save E_FALL->src prior to the call to force_nonfallthru. */ | |
78bde837 SB |
3889 | nb = force_nonfallthru_and_redirect (e_fall, e_fall->dest, ret_label); |
3890 | if (nb) | |
3891 | { | |
3892 | nb->aux = bb->aux; | |
3893 | bb->aux = nb; | |
3894 | /* Don't process this new block. */ | |
3895 | bb = nb; | |
78bde837 SB |
3896 | } |
3897 | } | |
3898 | ||
3899 | relink_block_chain (/*stay_in_cfglayout_mode=*/false); | |
3900 | ||
29f3fd5b | 3901 | /* Annoying special case - jump around dead jumptables left in the code. */ |
11cd3bed | 3902 | FOR_EACH_BB_FN (bb, cfun) |
78bde837 SB |
3903 | { |
3904 | edge e = find_fallthru_edge (bb->succs); | |
3905 | ||
29f3fd5b SB |
3906 | if (e && !can_fallthru (e->src, e->dest)) |
3907 | force_nonfallthru (e); | |
78bde837 SB |
3908 | } |
3909 | ||
3910 | /* Ensure goto_locus from edges has some instructions with that locus | |
3911 | in RTL. */ | |
3912 | if (!optimize) | |
11cd3bed | 3913 | FOR_EACH_BB_FN (bb, cfun) |
78bde837 SB |
3914 | { |
3915 | edge e; | |
3916 | edge_iterator ei; | |
3917 | ||
3918 | FOR_EACH_EDGE (e, ei, bb->succs) | |
2f13f2de | 3919 | if (LOCATION_LOCUS (e->goto_locus) != UNKNOWN_LOCATION |
5368224f | 3920 | && !(e->flags & EDGE_ABNORMAL)) |
78bde837 SB |
3921 | { |
3922 | edge e2; | |
3923 | edge_iterator ei2; | |
3924 | basic_block dest, nb; | |
8879d71c | 3925 | rtx_insn *end; |
78bde837 SB |
3926 | |
3927 | insn = BB_END (e->src); | |
3928 | end = PREV_INSN (BB_HEAD (e->src)); | |
3929 | while (insn != end | |
5368224f | 3930 | && (!NONDEBUG_INSN_P (insn) || !INSN_HAS_LOCATION (insn))) |
78bde837 SB |
3931 | insn = PREV_INSN (insn); |
3932 | if (insn != end | |
5368224f | 3933 | && INSN_LOCATION (insn) == e->goto_locus) |
78bde837 SB |
3934 | continue; |
3935 | if (simplejump_p (BB_END (e->src)) | |
5368224f | 3936 | && !INSN_HAS_LOCATION (BB_END (e->src))) |
78bde837 | 3937 | { |
5368224f | 3938 | INSN_LOCATION (BB_END (e->src)) = e->goto_locus; |
78bde837 SB |
3939 | continue; |
3940 | } | |
3941 | dest = e->dest; | |
fefa31b5 | 3942 | if (dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
78bde837 SB |
3943 | { |
3944 | /* Non-fallthru edges to the exit block cannot be split. */ | |
3945 | if (!(e->flags & EDGE_FALLTHRU)) | |
3946 | continue; | |
3947 | } | |
3948 | else | |
3949 | { | |
3950 | insn = BB_HEAD (dest); | |
3951 | end = NEXT_INSN (BB_END (dest)); | |
3952 | while (insn != end && !NONDEBUG_INSN_P (insn)) | |
3953 | insn = NEXT_INSN (insn); | |
5368224f DC |
3954 | if (insn != end && INSN_HAS_LOCATION (insn) |
3955 | && INSN_LOCATION (insn) == e->goto_locus) | |
78bde837 SB |
3956 | continue; |
3957 | } | |
3958 | nb = split_edge (e); | |
3959 | if (!INSN_P (BB_END (nb))) | |
1130d5e3 | 3960 | BB_END (nb) = emit_insn_after_noloc (gen_nop (), BB_END (nb), |
190bea87 | 3961 | nb); |
5368224f | 3962 | INSN_LOCATION (BB_END (nb)) = e->goto_locus; |
78bde837 SB |
3963 | |
3964 | /* If there are other incoming edges to the destination block | |
3965 | with the same goto locus, redirect them to the new block as | |
3966 | well, this can prevent other such blocks from being created | |
3967 | in subsequent iterations of the loop. */ | |
3968 | for (ei2 = ei_start (dest->preds); (e2 = ei_safe_edge (ei2)); ) | |
2f13f2de | 3969 | if (LOCATION_LOCUS (e2->goto_locus) != UNKNOWN_LOCATION |
78bde837 | 3970 | && !(e2->flags & (EDGE_ABNORMAL | EDGE_FALLTHRU)) |
5368224f | 3971 | && e->goto_locus == e2->goto_locus) |
78bde837 SB |
3972 | redirect_edge_and_branch (e2, nb); |
3973 | else | |
3974 | ei_next (&ei2); | |
3975 | } | |
3976 | } | |
3977 | } | |
3978 | \f | |
3979 | /* Perform sanity checks on the insn chain. | |
3980 | 1. Check that next/prev pointers are consistent in both the forward and | |
3981 | reverse direction. | |
3982 | 2. Count insns in chain, going both directions, and check if equal. | |
3983 | 3. Check that get_last_insn () returns the actual end of chain. */ | |
3984 | ||
3985 | DEBUG_FUNCTION void | |
3986 | verify_insn_chain (void) | |
3987 | { | |
8879d71c | 3988 | rtx_insn *x, *prevx, *nextx; |
78bde837 SB |
3989 | int insn_cnt1, insn_cnt2; |
3990 | ||
3991 | for (prevx = NULL, insn_cnt1 = 1, x = get_insns (); | |
3992 | x != 0; | |
3993 | prevx = x, insn_cnt1++, x = NEXT_INSN (x)) | |
3994 | gcc_assert (PREV_INSN (x) == prevx); | |
3995 | ||
3996 | gcc_assert (prevx == get_last_insn ()); | |
3997 | ||
3998 | for (nextx = NULL, insn_cnt2 = 1, x = get_last_insn (); | |
3999 | x != 0; | |
4000 | nextx = x, insn_cnt2++, x = PREV_INSN (x)) | |
4001 | gcc_assert (NEXT_INSN (x) == nextx); | |
4002 | ||
4003 | gcc_assert (insn_cnt1 == insn_cnt2); | |
4004 | } | |
4005 | \f | |
4006 | /* If we have assembler epilogues, the block falling through to exit must | |
4007 | be the last one in the reordered chain when we reach final. Ensure | |
4008 | that this condition is met. */ | |
4009 | static void | |
4010 | fixup_fallthru_exit_predecessor (void) | |
4011 | { | |
4012 | edge e; | |
4013 | basic_block bb = NULL; | |
4014 | ||
4015 | /* This transformation is not valid before reload, because we might | |
4016 | separate a call from the instruction that copies the return | |
4017 | value. */ | |
4018 | gcc_assert (reload_completed); | |
4019 | ||
fefa31b5 | 4020 | e = find_fallthru_edge (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds); |
78bde837 SB |
4021 | if (e) |
4022 | bb = e->src; | |
4023 | ||
4024 | if (bb && bb->aux) | |
4025 | { | |
fefa31b5 | 4026 | basic_block c = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb; |
78bde837 SB |
4027 | |
4028 | /* If the very first block is the one with the fall-through exit | |
4029 | edge, we have to split that block. */ | |
4030 | if (c == bb) | |
4031 | { | |
c4d281b2 | 4032 | bb = split_block_after_labels (bb)->dest; |
78bde837 SB |
4033 | bb->aux = c->aux; |
4034 | c->aux = bb; | |
d8ce2eae DM |
4035 | BB_FOOTER (bb) = BB_FOOTER (c); |
4036 | BB_FOOTER (c) = NULL; | |
78bde837 SB |
4037 | } |
4038 | ||
4039 | while (c->aux != bb) | |
4040 | c = (basic_block) c->aux; | |
4041 | ||
4042 | c->aux = bb->aux; | |
4043 | while (c->aux) | |
4044 | c = (basic_block) c->aux; | |
4045 | ||
4046 | c->aux = bb; | |
4047 | bb->aux = NULL; | |
4048 | } | |
4049 | } | |
4050 | ||
4051 | /* In case there are more than one fallthru predecessors of exit, force that | |
4052 | there is only one. */ | |
4053 | ||
4054 | static void | |
4055 | force_one_exit_fallthru (void) | |
4056 | { | |
4057 | edge e, predecessor = NULL; | |
4058 | bool more = false; | |
4059 | edge_iterator ei; | |
4060 | basic_block forwarder, bb; | |
4061 | ||
fefa31b5 | 4062 | FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds) |
78bde837 SB |
4063 | if (e->flags & EDGE_FALLTHRU) |
4064 | { | |
4065 | if (predecessor == NULL) | |
4066 | predecessor = e; | |
4067 | else | |
4068 | { | |
4069 | more = true; | |
4070 | break; | |
4071 | } | |
4072 | } | |
4073 | ||
4074 | if (!more) | |
4075 | return; | |
4076 | ||
4077 | /* Exit has several fallthru predecessors. Create a forwarder block for | |
4078 | them. */ | |
4079 | forwarder = split_edge (predecessor); | |
fefa31b5 DM |
4080 | for (ei = ei_start (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds); |
4081 | (e = ei_safe_edge (ei)); ) | |
78bde837 SB |
4082 | { |
4083 | if (e->src == forwarder | |
4084 | || !(e->flags & EDGE_FALLTHRU)) | |
4085 | ei_next (&ei); | |
4086 | else | |
4087 | redirect_edge_and_branch_force (e, forwarder); | |
4088 | } | |
4089 | ||
4090 | /* Fix up the chain of blocks -- make FORWARDER immediately precede the | |
4091 | exit block. */ | |
11cd3bed | 4092 | FOR_EACH_BB_FN (bb, cfun) |
78bde837 SB |
4093 | { |
4094 | if (bb->aux == NULL && bb != forwarder) | |
4095 | { | |
4096 | bb->aux = forwarder; | |
4097 | break; | |
4098 | } | |
4099 | } | |
4100 | } | |
4101 | \f | |
4102 | /* Return true in case it is possible to duplicate the basic block BB. */ | |
4103 | ||
4104 | static bool | |
4105 | cfg_layout_can_duplicate_bb_p (const_basic_block bb) | |
4106 | { | |
4107 | /* Do not attempt to duplicate tablejumps, as we need to unshare | |
4108 | the dispatch table. This is difficult to do, as the instructions | |
4109 | computing jump destination may be hoisted outside the basic block. */ | |
4110 | if (tablejump_p (BB_END (bb), NULL, NULL)) | |
4111 | return false; | |
4112 | ||
4113 | /* Do not duplicate blocks containing insns that can't be copied. */ | |
4114 | if (targetm.cannot_copy_insn_p) | |
4115 | { | |
8879d71c | 4116 | rtx_insn *insn = BB_HEAD (bb); |
78bde837 SB |
4117 | while (1) |
4118 | { | |
4119 | if (INSN_P (insn) && targetm.cannot_copy_insn_p (insn)) | |
4120 | return false; | |
4121 | if (insn == BB_END (bb)) | |
4122 | break; | |
4123 | insn = NEXT_INSN (insn); | |
4124 | } | |
4125 | } | |
4126 | ||
4127 | return true; | |
4128 | } | |
4129 | ||
a90c614a | 4130 | rtx_insn * |
5d34b050 | 4131 | duplicate_insn_chain (rtx_insn *from, rtx_insn *to) |
78bde837 | 4132 | { |
5d34b050 | 4133 | rtx_insn *insn, *next, *copy; |
66e8df53 | 4134 | rtx_note *last; |
78bde837 SB |
4135 | |
4136 | /* Avoid updating of boundaries of previous basic block. The | |
4137 | note will get removed from insn stream in fixup. */ | |
4138 | last = emit_note (NOTE_INSN_DELETED); | |
4139 | ||
4140 | /* Create copy at the end of INSN chain. The chain will | |
4141 | be reordered later. */ | |
4142 | for (insn = from; insn != NEXT_INSN (to); insn = NEXT_INSN (insn)) | |
4143 | { | |
4144 | switch (GET_CODE (insn)) | |
4145 | { | |
4146 | case DEBUG_INSN: | |
4147 | /* Don't duplicate label debug insns. */ | |
65f4b875 AO |
4148 | if (DEBUG_BIND_INSN_P (insn) |
4149 | && TREE_CODE (INSN_VAR_LOCATION_DECL (insn)) == LABEL_DECL) | |
78bde837 SB |
4150 | break; |
4151 | /* FALLTHRU */ | |
4152 | case INSN: | |
4153 | case CALL_INSN: | |
4154 | case JUMP_INSN: | |
78bde837 SB |
4155 | copy = emit_copy_of_insn_after (insn, get_last_insn ()); |
4156 | if (JUMP_P (insn) && JUMP_LABEL (insn) != NULL_RTX | |
4157 | && ANY_RETURN_P (JUMP_LABEL (insn))) | |
4158 | JUMP_LABEL (copy) = JUMP_LABEL (insn); | |
4159 | maybe_copy_prologue_epilogue_insn (insn, copy); | |
4160 | break; | |
4161 | ||
39718607 SB |
4162 | case JUMP_TABLE_DATA: |
4163 | /* Avoid copying of dispatch tables. We never duplicate | |
4164 | tablejumps, so this can hit only in case the table got | |
4165 | moved far from original jump. | |
4166 | Avoid copying following barrier as well if any | |
4167 | (and debug insns in between). */ | |
4168 | for (next = NEXT_INSN (insn); | |
4169 | next != NEXT_INSN (to); | |
4170 | next = NEXT_INSN (next)) | |
4171 | if (!DEBUG_INSN_P (next)) | |
4172 | break; | |
4173 | if (next != NEXT_INSN (to) && BARRIER_P (next)) | |
4174 | insn = next; | |
4175 | break; | |
4176 | ||
78bde837 SB |
4177 | case CODE_LABEL: |
4178 | break; | |
4179 | ||
4180 | case BARRIER: | |
4181 | emit_barrier (); | |
4182 | break; | |
4183 | ||
4184 | case NOTE: | |
4185 | switch (NOTE_KIND (insn)) | |
4186 | { | |
4187 | /* In case prologue is empty and function contain label | |
4188 | in first BB, we may want to copy the block. */ | |
4189 | case NOTE_INSN_PROLOGUE_END: | |
4190 | ||
4191 | case NOTE_INSN_DELETED: | |
4192 | case NOTE_INSN_DELETED_LABEL: | |
4193 | case NOTE_INSN_DELETED_DEBUG_LABEL: | |
4194 | /* No problem to strip these. */ | |
4195 | case NOTE_INSN_FUNCTION_BEG: | |
4196 | /* There is always just single entry to function. */ | |
4197 | case NOTE_INSN_BASIC_BLOCK: | |
3371a64f TJ |
4198 | /* We should only switch text sections once. */ |
4199 | case NOTE_INSN_SWITCH_TEXT_SECTIONS: | |
78bde837 SB |
4200 | break; |
4201 | ||
4202 | case NOTE_INSN_EPILOGUE_BEG: | |
d33606c3 | 4203 | case NOTE_INSN_UPDATE_SJLJ_CONTEXT: |
66e8df53 | 4204 | emit_note_copy (as_a <rtx_note *> (insn)); |
78bde837 SB |
4205 | break; |
4206 | ||
4207 | default: | |
4208 | /* All other notes should have already been eliminated. */ | |
4209 | gcc_unreachable (); | |
4210 | } | |
4211 | break; | |
4212 | default: | |
4213 | gcc_unreachable (); | |
4214 | } | |
4215 | } | |
4216 | insn = NEXT_INSN (last); | |
4217 | delete_insn (last); | |
5d34b050 | 4218 | return insn; |
78bde837 SB |
4219 | } |
4220 | ||
4221 | /* Create a duplicate of the basic block BB. */ | |
4222 | ||
4223 | static basic_block | |
4224 | cfg_layout_duplicate_bb (basic_block bb) | |
4225 | { | |
8879d71c | 4226 | rtx_insn *insn; |
78bde837 SB |
4227 | basic_block new_bb; |
4228 | ||
4229 | insn = duplicate_insn_chain (BB_HEAD (bb), BB_END (bb)); | |
4230 | new_bb = create_basic_block (insn, | |
4231 | insn ? get_last_insn () : NULL, | |
fefa31b5 | 4232 | EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb); |
78bde837 SB |
4233 | |
4234 | BB_COPY_PARTITION (new_bb, bb); | |
4235 | if (BB_HEADER (bb)) | |
4236 | { | |
4237 | insn = BB_HEADER (bb); | |
4238 | while (NEXT_INSN (insn)) | |
4239 | insn = NEXT_INSN (insn); | |
4240 | insn = duplicate_insn_chain (BB_HEADER (bb), insn); | |
4241 | if (insn) | |
1130d5e3 | 4242 | BB_HEADER (new_bb) = unlink_insn_chain (insn, get_last_insn ()); |
78bde837 SB |
4243 | } |
4244 | ||
4245 | if (BB_FOOTER (bb)) | |
4246 | { | |
4247 | insn = BB_FOOTER (bb); | |
4248 | while (NEXT_INSN (insn)) | |
4249 | insn = NEXT_INSN (insn); | |
4250 | insn = duplicate_insn_chain (BB_FOOTER (bb), insn); | |
4251 | if (insn) | |
d8ce2eae | 4252 | BB_FOOTER (new_bb) = unlink_insn_chain (insn, get_last_insn ()); |
78bde837 SB |
4253 | } |
4254 | ||
4255 | return new_bb; | |
4256 | } | |
4257 | ||
4258 | \f | |
4259 | /* Main entry point to this module - initialize the datastructures for | |
4260 | CFG layout changes. It keeps LOOPS up-to-date if not null. | |
4261 | ||
4262 | FLAGS is a set of additional flags to pass to cleanup_cfg(). */ | |
4263 | ||
4264 | void | |
1a817418 | 4265 | cfg_layout_initialize (int flags) |
78bde837 | 4266 | { |
b5241a5a | 4267 | rtx_insn_list *x; |
78bde837 SB |
4268 | basic_block bb; |
4269 | ||
8a9e6b45 BS |
4270 | /* Once bb partitioning is complete, cfg layout mode should not be |
4271 | re-entered. Entering cfg layout mode may require fixups. As an | |
4272 | example, if edge forwarding performed when optimizing the cfg | |
4273 | layout required moving a block from the hot to the cold | |
4274 | section. This would create an illegal partitioning unless some | |
4275 | manual fixup was performed. */ | |
0b6bc904 | 4276 | gcc_assert (!crtl->bb_reorder_complete || !crtl->has_bb_partition); |
4ca19309 | 4277 | |
78bde837 SB |
4278 | initialize_original_copy_tables (); |
4279 | ||
4280 | cfg_layout_rtl_register_cfg_hooks (); | |
4281 | ||
4282 | record_effective_endpoints (); | |
4283 | ||
4284 | /* Make sure that the targets of non local gotos are marked. */ | |
2382940b | 4285 | for (x = nonlocal_goto_handler_labels; x; x = x->next ()) |
78bde837 | 4286 | { |
b5241a5a | 4287 | bb = BLOCK_FOR_INSN (x->insn ()); |
78bde837 SB |
4288 | bb->flags |= BB_NON_LOCAL_GOTO_TARGET; |
4289 | } | |
4290 | ||
4291 | cleanup_cfg (CLEANUP_CFGLAYOUT | flags); | |
4292 | } | |
4293 | ||
4294 | /* Splits superblocks. */ | |
4295 | void | |
4296 | break_superblocks (void) | |
4297 | { | |
78bde837 SB |
4298 | bool need = false; |
4299 | basic_block bb; | |
4300 | ||
7ba9e72d | 4301 | auto_sbitmap superblocks (last_basic_block_for_fn (cfun)); |
f61e445a | 4302 | bitmap_clear (superblocks); |
78bde837 | 4303 | |
11cd3bed | 4304 | FOR_EACH_BB_FN (bb, cfun) |
78bde837 SB |
4305 | if (bb->flags & BB_SUPERBLOCK) |
4306 | { | |
4307 | bb->flags &= ~BB_SUPERBLOCK; | |
d7c028c0 | 4308 | bitmap_set_bit (superblocks, bb->index); |
78bde837 SB |
4309 | need = true; |
4310 | } | |
4311 | ||
4312 | if (need) | |
4313 | { | |
4314 | rebuild_jump_labels (get_insns ()); | |
4315 | find_many_sub_basic_blocks (superblocks); | |
4316 | } | |
78bde837 SB |
4317 | } |
4318 | ||
4319 | /* Finalize the changes: reorder insn list according to the sequence specified | |
29f3fd5b | 4320 | by aux pointers, enter compensation code, rebuild scope forest. */ |
78bde837 SB |
4321 | |
4322 | void | |
4323 | cfg_layout_finalize (void) | |
4324 | { | |
b2b29377 | 4325 | checking_verify_flow_info (); |
63da5ff6 | 4326 | free_dominance_info (CDI_DOMINATORS); |
78bde837 SB |
4327 | force_one_exit_fallthru (); |
4328 | rtl_register_cfg_hooks (); | |
e86a9946 | 4329 | if (reload_completed && !targetm.have_epilogue ()) |
78bde837 SB |
4330 | fixup_fallthru_exit_predecessor (); |
4331 | fixup_reorder_chain (); | |
4332 | ||
29f3fd5b SB |
4333 | rebuild_jump_labels (get_insns ()); |
4334 | delete_dead_jumptables (); | |
4335 | ||
b2b29377 MM |
4336 | if (flag_checking) |
4337 | verify_insn_chain (); | |
4338 | checking_verify_flow_info (); | |
78bde837 SB |
4339 | } |
4340 | ||
ba5e9aca | 4341 | |
9ee634e3 | 4342 | /* Same as split_block but update cfg_layout structures. */ |
f470c378 ZD |
4343 | |
4344 | static basic_block | |
d329e058 | 4345 | cfg_layout_split_block (basic_block bb, void *insnp) |
9ee634e3 | 4346 | { |
ae50c0cb | 4347 | rtx insn = (rtx) insnp; |
f470c378 | 4348 | basic_block new_bb = rtl_split_block (bb, insn); |
9ee634e3 | 4349 | |
d8ce2eae DM |
4350 | BB_FOOTER (new_bb) = BB_FOOTER (bb); |
4351 | BB_FOOTER (bb) = NULL; | |
9ee634e3 | 4352 | |
f470c378 | 4353 | return new_bb; |
9ee634e3 JH |
4354 | } |
4355 | ||
9ee634e3 | 4356 | /* Redirect Edge to DEST. */ |
6de9cd9a | 4357 | static edge |
d329e058 | 4358 | cfg_layout_redirect_edge_and_branch (edge e, basic_block dest) |
9ee634e3 JH |
4359 | { |
4360 | basic_block src = e->src; | |
6de9cd9a | 4361 | edge ret; |
9ee634e3 | 4362 | |
bc35512f | 4363 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
6de9cd9a | 4364 | return NULL; |
bc35512f | 4365 | |
3348b696 | 4366 | if (e->dest == dest) |
6de9cd9a | 4367 | return e; |
bc35512f | 4368 | |
fefa31b5 | 4369 | if (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
6de9cd9a | 4370 | && (ret = try_redirect_by_replacing_jump (e, dest, true))) |
f345f21a | 4371 | { |
6fb5fa3c | 4372 | df_set_bb_dirty (src); |
6de9cd9a | 4373 | return ret; |
f345f21a | 4374 | } |
bc35512f | 4375 | |
fefa31b5 | 4376 | if (e->src == ENTRY_BLOCK_PTR_FOR_FN (cfun) |
bc35512f JH |
4377 | && (e->flags & EDGE_FALLTHRU) && !(e->flags & EDGE_COMPLEX)) |
4378 | { | |
c263766c RH |
4379 | if (dump_file) |
4380 | fprintf (dump_file, "Redirecting entry edge from bb %i to %i\n", | |
bc35512f JH |
4381 | e->src->index, dest->index); |
4382 | ||
6fb5fa3c | 4383 | df_set_bb_dirty (e->src); |
bc35512f | 4384 | redirect_edge_succ (e, dest); |
6de9cd9a | 4385 | return e; |
bc35512f JH |
4386 | } |
4387 | ||
9ee634e3 JH |
4388 | /* Redirect_edge_and_branch may decide to turn branch into fallthru edge |
4389 | in the case the basic block appears to be in sequence. Avoid this | |
4390 | transformation. */ | |
4391 | ||
9ee634e3 JH |
4392 | if (e->flags & EDGE_FALLTHRU) |
4393 | { | |
4394 | /* Redirect any branch edges unified with the fallthru one. */ | |
4b4bf941 | 4395 | if (JUMP_P (BB_END (src)) |
432f982f JH |
4396 | && label_is_jump_target_p (BB_HEAD (e->dest), |
4397 | BB_END (src))) | |
9ee634e3 | 4398 | { |
341c100f | 4399 | edge redirected; |
c22cacf3 | 4400 | |
c263766c RH |
4401 | if (dump_file) |
4402 | fprintf (dump_file, "Fallthru edge unified with branch " | |
432f982f JH |
4403 | "%i->%i redirected to %i\n", |
4404 | e->src->index, e->dest->index, dest->index); | |
4405 | e->flags &= ~EDGE_FALLTHRU; | |
341c100f NS |
4406 | redirected = redirect_branch_edge (e, dest); |
4407 | gcc_assert (redirected); | |
0c617be4 JL |
4408 | redirected->flags |= EDGE_FALLTHRU; |
4409 | df_set_bb_dirty (redirected->src); | |
4410 | return redirected; | |
9ee634e3 JH |
4411 | } |
4412 | /* In case we are redirecting fallthru edge to the branch edge | |
c22cacf3 | 4413 | of conditional jump, remove it. */ |
628f6a4e | 4414 | if (EDGE_COUNT (src->succs) == 2) |
9ee634e3 | 4415 | { |
03101c6f KH |
4416 | /* Find the edge that is different from E. */ |
4417 | edge s = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e); | |
628f6a4e | 4418 | |
9ee634e3 | 4419 | if (s->dest == dest |
a813c111 SB |
4420 | && any_condjump_p (BB_END (src)) |
4421 | && onlyjump_p (BB_END (src))) | |
4422 | delete_insn (BB_END (src)); | |
9ee634e3 | 4423 | } |
c263766c | 4424 | if (dump_file) |
dc764d10 | 4425 | fprintf (dump_file, "Redirecting fallthru edge %i->%i to %i\n", |
bc35512f | 4426 | e->src->index, e->dest->index, dest->index); |
0c617be4 | 4427 | ret = redirect_edge_succ_nodup (e, dest); |
9ee634e3 JH |
4428 | } |
4429 | else | |
bc35512f | 4430 | ret = redirect_branch_edge (e, dest); |
9ee634e3 JH |
4431 | |
4432 | /* We don't want simplejumps in the insn stream during cfglayout. */ | |
341c100f | 4433 | gcc_assert (!simplejump_p (BB_END (src))); |
9ee634e3 | 4434 | |
6fb5fa3c | 4435 | df_set_bb_dirty (src); |
9ee634e3 JH |
4436 | return ret; |
4437 | } | |
4438 | ||
4439 | /* Simple wrapper as we always can redirect fallthru edges. */ | |
4440 | static basic_block | |
d329e058 | 4441 | cfg_layout_redirect_edge_and_branch_force (edge e, basic_block dest) |
9ee634e3 | 4442 | { |
341c100f NS |
4443 | edge redirected = cfg_layout_redirect_edge_and_branch (e, dest); |
4444 | ||
4445 | gcc_assert (redirected); | |
9ee634e3 JH |
4446 | return NULL; |
4447 | } | |
4448 | ||
f470c378 ZD |
4449 | /* Same as delete_basic_block but update cfg_layout structures. */ |
4450 | ||
9ee634e3 | 4451 | static void |
d329e058 | 4452 | cfg_layout_delete_block (basic_block bb) |
9ee634e3 | 4453 | { |
8879d71c | 4454 | rtx_insn *insn, *next, *prev = PREV_INSN (BB_HEAD (bb)), *remaints; |
1130d5e3 | 4455 | rtx_insn **to; |
9ee634e3 | 4456 | |
bcc708fc | 4457 | if (BB_HEADER (bb)) |
9ee634e3 | 4458 | { |
a813c111 | 4459 | next = BB_HEAD (bb); |
9ee634e3 | 4460 | if (prev) |
0f82e5c9 | 4461 | SET_NEXT_INSN (prev) = BB_HEADER (bb); |
9ee634e3 | 4462 | else |
bcc708fc | 4463 | set_first_insn (BB_HEADER (bb)); |
0f82e5c9 | 4464 | SET_PREV_INSN (BB_HEADER (bb)) = prev; |
bcc708fc | 4465 | insn = BB_HEADER (bb); |
9ee634e3 JH |
4466 | while (NEXT_INSN (insn)) |
4467 | insn = NEXT_INSN (insn); | |
0f82e5c9 DM |
4468 | SET_NEXT_INSN (insn) = next; |
4469 | SET_PREV_INSN (next) = insn; | |
9ee634e3 | 4470 | } |
a813c111 | 4471 | next = NEXT_INSN (BB_END (bb)); |
bcc708fc | 4472 | if (BB_FOOTER (bb)) |
9ee634e3 | 4473 | { |
bcc708fc | 4474 | insn = BB_FOOTER (bb); |
bc35512f JH |
4475 | while (insn) |
4476 | { | |
4b4bf941 | 4477 | if (BARRIER_P (insn)) |
bc35512f JH |
4478 | { |
4479 | if (PREV_INSN (insn)) | |
0f82e5c9 | 4480 | SET_NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); |
bc35512f | 4481 | else |
d8ce2eae | 4482 | BB_FOOTER (bb) = NEXT_INSN (insn); |
bc35512f | 4483 | if (NEXT_INSN (insn)) |
0f82e5c9 | 4484 | SET_PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); |
bc35512f | 4485 | } |
4b4bf941 | 4486 | if (LABEL_P (insn)) |
bc35512f JH |
4487 | break; |
4488 | insn = NEXT_INSN (insn); | |
4489 | } | |
bcc708fc | 4490 | if (BB_FOOTER (bb)) |
bc35512f | 4491 | { |
a813c111 | 4492 | insn = BB_END (bb); |
0f82e5c9 DM |
4493 | SET_NEXT_INSN (insn) = BB_FOOTER (bb); |
4494 | SET_PREV_INSN (BB_FOOTER (bb)) = insn; | |
bc35512f JH |
4495 | while (NEXT_INSN (insn)) |
4496 | insn = NEXT_INSN (insn); | |
0f82e5c9 | 4497 | SET_NEXT_INSN (insn) = next; |
bc35512f | 4498 | if (next) |
0f82e5c9 | 4499 | SET_PREV_INSN (next) = insn; |
bc35512f JH |
4500 | else |
4501 | set_last_insn (insn); | |
4502 | } | |
9ee634e3 | 4503 | } |
fefa31b5 | 4504 | if (bb->next_bb != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
1130d5e3 | 4505 | to = &BB_HEADER (bb->next_bb); |
9ee634e3 JH |
4506 | else |
4507 | to = &cfg_layout_function_footer; | |
997de8ed | 4508 | |
9ee634e3 JH |
4509 | rtl_delete_block (bb); |
4510 | ||
4511 | if (prev) | |
4512 | prev = NEXT_INSN (prev); | |
d329e058 | 4513 | else |
9ee634e3 JH |
4514 | prev = get_insns (); |
4515 | if (next) | |
4516 | next = PREV_INSN (next); | |
d329e058 | 4517 | else |
9ee634e3 JH |
4518 | next = get_last_insn (); |
4519 | ||
4520 | if (next && NEXT_INSN (next) != prev) | |
4521 | { | |
4522 | remaints = unlink_insn_chain (prev, next); | |
4523 | insn = remaints; | |
4524 | while (NEXT_INSN (insn)) | |
4525 | insn = NEXT_INSN (insn); | |
0f82e5c9 | 4526 | SET_NEXT_INSN (insn) = *to; |
9ee634e3 | 4527 | if (*to) |
0f82e5c9 | 4528 | SET_PREV_INSN (*to) = insn; |
9ee634e3 JH |
4529 | *to = remaints; |
4530 | } | |
4531 | } | |
4532 | ||
beb235f8 | 4533 | /* Return true when blocks A and B can be safely merged. */ |
b48d0358 | 4534 | |
bc35512f | 4535 | static bool |
b48d0358 | 4536 | cfg_layout_can_merge_blocks_p (basic_block a, basic_block b) |
bc35512f | 4537 | { |
750054a2 CT |
4538 | /* If we are partitioning hot/cold basic blocks, we don't want to |
4539 | mess up unconditional or indirect jumps that cross between hot | |
076c7ab8 ZW |
4540 | and cold sections. |
4541 | ||
8e8d5162 | 4542 | Basic block partitioning may result in some jumps that appear to |
c22cacf3 MS |
4543 | be optimizable (or blocks that appear to be mergeable), but which really |
4544 | must be left untouched (they are required to make it safely across | |
4545 | partition boundaries). See the comments at the top of | |
8e8d5162 CT |
4546 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
4547 | ||
87c8b4be | 4548 | if (BB_PARTITION (a) != BB_PARTITION (b)) |
076c7ab8 | 4549 | return false; |
750054a2 | 4550 | |
7d776ee2 RG |
4551 | /* Protect the loop latches. */ |
4552 | if (current_loops && b->loop_father->latch == b) | |
4553 | return false; | |
4554 | ||
894a84b5 BS |
4555 | /* If we would end up moving B's instructions, make sure it doesn't fall |
4556 | through into the exit block, since we cannot recover from a fallthrough | |
4557 | edge into the exit block occurring in the middle of a function. */ | |
4558 | if (NEXT_INSN (BB_END (a)) != BB_HEAD (b)) | |
4559 | { | |
4560 | edge e = find_fallthru_edge (b->succs); | |
fefa31b5 | 4561 | if (e && e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
894a84b5 BS |
4562 | return false; |
4563 | } | |
4564 | ||
bc35512f | 4565 | /* There must be exactly one edge in between the blocks. */ |
c5cbcccf ZD |
4566 | return (single_succ_p (a) |
4567 | && single_succ (a) == b | |
4568 | && single_pred_p (b) == 1 | |
628f6a4e | 4569 | && a != b |
bc35512f | 4570 | /* Must be simple edge. */ |
c5cbcccf | 4571 | && !(single_succ_edge (a)->flags & EDGE_COMPLEX) |
fefa31b5 DM |
4572 | && a != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
4573 | && b != EXIT_BLOCK_PTR_FOR_FN (cfun) | |
49ea3702 SB |
4574 | /* If the jump insn has side effects, we can't kill the edge. |
4575 | When not optimizing, try_redirect_by_replacing_jump will | |
4576 | not allow us to redirect an edge by replacing a table jump. */ | |
4b4bf941 | 4577 | && (!JUMP_P (BB_END (a)) |
49ea3702 | 4578 | || ((!optimize || reload_completed) |
a813c111 | 4579 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
bc35512f JH |
4580 | } |
4581 | ||
41806d92 NS |
4582 | /* Merge block A and B. The blocks must be mergeable. */ |
4583 | ||
bc35512f JH |
4584 | static void |
4585 | cfg_layout_merge_blocks (basic_block a, basic_block b) | |
4586 | { | |
50a36e42 | 4587 | bool forwarder_p = (b->flags & BB_FORWARDER_BLOCK) != 0; |
8879d71c | 4588 | rtx_insn *insn; |
50a36e42 | 4589 | |
77a74ed7 | 4590 | gcc_checking_assert (cfg_layout_can_merge_blocks_p (a, b)); |
bc35512f | 4591 | |
6fb5fa3c | 4592 | if (dump_file) |
50a36e42 EB |
4593 | fprintf (dump_file, "Merging block %d into block %d...\n", b->index, |
4594 | a->index); | |
6fb5fa3c | 4595 | |
bc35512f | 4596 | /* If there was a CODE_LABEL beginning B, delete it. */ |
4b4bf941 | 4597 | if (LABEL_P (BB_HEAD (b))) |
2c97f8e4 | 4598 | { |
2c97f8e4 RH |
4599 | delete_insn (BB_HEAD (b)); |
4600 | } | |
bc35512f JH |
4601 | |
4602 | /* We should have fallthru edge in a, or we can do dummy redirection to get | |
4603 | it cleaned up. */ | |
4b4bf941 | 4604 | if (JUMP_P (BB_END (a))) |
628f6a4e | 4605 | try_redirect_by_replacing_jump (EDGE_SUCC (a, 0), b, true); |
341c100f | 4606 | gcc_assert (!JUMP_P (BB_END (a))); |
bc35512f | 4607 | |
8a829274 | 4608 | /* When not optimizing and the edge is the only place in RTL which holds |
7241571e | 4609 | some unique locus, emit a nop with that locus in between. */ |
9be94227 EB |
4610 | if (!optimize) |
4611 | emit_nop_for_unique_locus_between (a, b); | |
7241571e | 4612 | |
4c8af858 SB |
4613 | /* Move things from b->footer after a->footer. */ |
4614 | if (BB_FOOTER (b)) | |
bc35512f | 4615 | { |
4c8af858 | 4616 | if (!BB_FOOTER (a)) |
d8ce2eae | 4617 | BB_FOOTER (a) = BB_FOOTER (b); |
4c8af858 SB |
4618 | else |
4619 | { | |
8879d71c | 4620 | rtx_insn *last = BB_FOOTER (a); |
4c8af858 SB |
4621 | |
4622 | while (NEXT_INSN (last)) | |
4623 | last = NEXT_INSN (last); | |
0f82e5c9 DM |
4624 | SET_NEXT_INSN (last) = BB_FOOTER (b); |
4625 | SET_PREV_INSN (BB_FOOTER (b)) = last; | |
4c8af858 | 4626 | } |
d8ce2eae | 4627 | BB_FOOTER (b) = NULL; |
4c8af858 SB |
4628 | } |
4629 | ||
4630 | /* Move things from b->header before a->footer. | |
4631 | Note that this may include dead tablejump data, but we don't clean | |
4632 | those up until we go out of cfglayout mode. */ | |
4633 | if (BB_HEADER (b)) | |
4634 | { | |
4635 | if (! BB_FOOTER (a)) | |
d8ce2eae | 4636 | BB_FOOTER (a) = BB_HEADER (b); |
4c8af858 SB |
4637 | else |
4638 | { | |
8879d71c | 4639 | rtx_insn *last = BB_HEADER (b); |
4c8af858 SB |
4640 | |
4641 | while (NEXT_INSN (last)) | |
4642 | last = NEXT_INSN (last); | |
0f82e5c9 DM |
4643 | SET_NEXT_INSN (last) = BB_FOOTER (a); |
4644 | SET_PREV_INSN (BB_FOOTER (a)) = last; | |
d8ce2eae | 4645 | BB_FOOTER (a) = BB_HEADER (b); |
4c8af858 | 4646 | } |
1130d5e3 | 4647 | BB_HEADER (b) = NULL; |
bc35512f JH |
4648 | } |
4649 | ||
4650 | /* In the case basic blocks are not adjacent, move them around. */ | |
a813c111 | 4651 | if (NEXT_INSN (BB_END (a)) != BB_HEAD (b)) |
bc35512f | 4652 | { |
f9df6f16 | 4653 | insn = unlink_insn_chain (BB_HEAD (b), BB_END (b)); |
6c3d0e31 | 4654 | |
f9df6f16 | 4655 | emit_insn_after_noloc (insn, BB_END (a), a); |
bc35512f JH |
4656 | } |
4657 | /* Otherwise just re-associate the instructions. */ | |
4658 | else | |
4659 | { | |
a813c111 | 4660 | insn = BB_HEAD (b); |
1130d5e3 | 4661 | BB_END (a) = BB_END (b); |
bc35512f JH |
4662 | } |
4663 | ||
f9df6f16 JJ |
4664 | /* emit_insn_after_noloc doesn't call df_insn_change_bb. |
4665 | We need to explicitly call. */ | |
4666 | update_bb_for_insn_chain (insn, BB_END (b), a); | |
4667 | ||
4668 | /* Skip possible DELETED_LABEL insn. */ | |
4669 | if (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
4670 | insn = NEXT_INSN (insn); | |
4671 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn)); | |
1130d5e3 | 4672 | BB_HEAD (b) = BB_END (b) = NULL; |
f9df6f16 JJ |
4673 | delete_insn (insn); |
4674 | ||
6fb5fa3c DB |
4675 | df_bb_delete (b->index); |
4676 | ||
50a36e42 | 4677 | /* If B was a forwarder block, propagate the locus on the edge. */ |
2f13f2de | 4678 | if (forwarder_p |
fbc68f2a | 4679 | && LOCATION_LOCUS (EDGE_SUCC (b, 0)->goto_locus) == UNKNOWN_LOCATION) |
50a36e42 EB |
4680 | EDGE_SUCC (b, 0)->goto_locus = EDGE_SUCC (a, 0)->goto_locus; |
4681 | ||
c263766c | 4682 | if (dump_file) |
50a36e42 | 4683 | fprintf (dump_file, "Merged blocks %d and %d.\n", a->index, b->index); |
bc35512f JH |
4684 | } |
4685 | ||
4686 | /* Split edge E. */ | |
f470c378 | 4687 | |
bc35512f JH |
4688 | static basic_block |
4689 | cfg_layout_split_edge (edge e) | |
4690 | { | |
bc35512f | 4691 | basic_block new_bb = |
fefa31b5 | 4692 | create_basic_block (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
a813c111 | 4693 | ? NEXT_INSN (BB_END (e->src)) : get_insns (), |
bc35512f JH |
4694 | NULL_RTX, e->src); |
4695 | ||
fefa31b5 | 4696 | if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
3e7eb734 JJ |
4697 | BB_COPY_PARTITION (new_bb, e->src); |
4698 | else | |
4699 | BB_COPY_PARTITION (new_bb, e->dest); | |
a9b2ee88 | 4700 | make_edge (new_bb, e->dest, EDGE_FALLTHRU); |
bc35512f JH |
4701 | redirect_edge_and_branch_force (e, new_bb); |
4702 | ||
4703 | return new_bb; | |
4704 | } | |
4705 | ||
f470c378 ZD |
4706 | /* Do postprocessing after making a forwarder block joined by edge FALLTHRU. */ |
4707 | ||
4708 | static void | |
4709 | rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED) | |
4710 | { | |
4711 | } | |
4712 | ||
df92c640 SB |
4713 | /* Return true if BB contains only labels or non-executable |
4714 | instructions. */ | |
4715 | ||
4716 | static bool | |
4717 | rtl_block_empty_p (basic_block bb) | |
4718 | { | |
8879d71c | 4719 | rtx_insn *insn; |
df92c640 | 4720 | |
fefa31b5 DM |
4721 | if (bb == ENTRY_BLOCK_PTR_FOR_FN (cfun) |
4722 | || bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
df92c640 SB |
4723 | return true; |
4724 | ||
4725 | FOR_BB_INSNS (bb, insn) | |
4726 | if (NONDEBUG_INSN_P (insn) && !any_uncondjump_p (insn)) | |
4727 | return false; | |
4728 | ||
4729 | return true; | |
4730 | } | |
4731 | ||
4732 | /* Split a basic block if it ends with a conditional branch and if | |
4733 | the other part of the block is not empty. */ | |
4734 | ||
4735 | static basic_block | |
4736 | rtl_split_block_before_cond_jump (basic_block bb) | |
4737 | { | |
8879d71c DM |
4738 | rtx_insn *insn; |
4739 | rtx_insn *split_point = NULL; | |
4740 | rtx_insn *last = NULL; | |
df92c640 SB |
4741 | bool found_code = false; |
4742 | ||
4743 | FOR_BB_INSNS (bb, insn) | |
4744 | { | |
4745 | if (any_condjump_p (insn)) | |
4746 | split_point = last; | |
4747 | else if (NONDEBUG_INSN_P (insn)) | |
4748 | found_code = true; | |
4749 | last = insn; | |
4750 | } | |
4751 | ||
4752 | /* Did not find everything. */ | |
4753 | if (found_code && split_point) | |
4754 | return split_block (bb, split_point)->dest; | |
4755 | else | |
4756 | return NULL; | |
4757 | } | |
4758 | ||
6de9cd9a DN |
4759 | /* Return 1 if BB ends with a call, possibly followed by some |
4760 | instructions that must stay with the call, 0 otherwise. */ | |
4761 | ||
4762 | static bool | |
b48d0358 | 4763 | rtl_block_ends_with_call_p (basic_block bb) |
6de9cd9a | 4764 | { |
8879d71c | 4765 | rtx_insn *insn = BB_END (bb); |
6de9cd9a | 4766 | |
4b4bf941 | 4767 | while (!CALL_P (insn) |
6de9cd9a | 4768 | && insn != BB_HEAD (bb) |
92ddef69 | 4769 | && (keep_with_call_p (insn) |
b5b8b0ac AO |
4770 | || NOTE_P (insn) |
4771 | || DEBUG_INSN_P (insn))) | |
6de9cd9a | 4772 | insn = PREV_INSN (insn); |
4b4bf941 | 4773 | return (CALL_P (insn)); |
6de9cd9a DN |
4774 | } |
4775 | ||
4776 | /* Return 1 if BB ends with a conditional branch, 0 otherwise. */ | |
4777 | ||
4778 | static bool | |
9678086d | 4779 | rtl_block_ends_with_condjump_p (const_basic_block bb) |
6de9cd9a DN |
4780 | { |
4781 | return any_condjump_p (BB_END (bb)); | |
4782 | } | |
4783 | ||
4784 | /* Return true if we need to add fake edge to exit. | |
4785 | Helper function for rtl_flow_call_edges_add. */ | |
4786 | ||
4787 | static bool | |
8879d71c | 4788 | need_fake_edge_p (const rtx_insn *insn) |
6de9cd9a DN |
4789 | { |
4790 | if (!INSN_P (insn)) | |
4791 | return false; | |
4792 | ||
4b4bf941 | 4793 | if ((CALL_P (insn) |
6de9cd9a DN |
4794 | && !SIBLING_CALL_P (insn) |
4795 | && !find_reg_note (insn, REG_NORETURN, NULL) | |
becfd6e5 | 4796 | && !(RTL_CONST_OR_PURE_CALL_P (insn)))) |
6de9cd9a DN |
4797 | return true; |
4798 | ||
4799 | return ((GET_CODE (PATTERN (insn)) == ASM_OPERANDS | |
4800 | && MEM_VOLATILE_P (PATTERN (insn))) | |
4801 | || (GET_CODE (PATTERN (insn)) == PARALLEL | |
4802 | && asm_noperands (insn) != -1 | |
4803 | && MEM_VOLATILE_P (XVECEXP (PATTERN (insn), 0, 0))) | |
4804 | || GET_CODE (PATTERN (insn)) == ASM_INPUT); | |
4805 | } | |
4806 | ||
4807 | /* Add fake edges to the function exit for any non constant and non noreturn | |
4808 | calls, volatile inline assembly in the bitmap of blocks specified by | |
4809 | BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks | |
4810 | that were split. | |
4811 | ||
4812 | The goal is to expose cases in which entering a basic block does not imply | |
4813 | that all subsequent instructions must be executed. */ | |
4814 | ||
4815 | static int | |
4816 | rtl_flow_call_edges_add (sbitmap blocks) | |
4817 | { | |
4818 | int i; | |
4819 | int blocks_split = 0; | |
8b1c6fd7 | 4820 | int last_bb = last_basic_block_for_fn (cfun); |
6de9cd9a DN |
4821 | bool check_last_block = false; |
4822 | ||
0cae8d31 | 4823 | if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS) |
6de9cd9a DN |
4824 | return 0; |
4825 | ||
4826 | if (! blocks) | |
4827 | check_last_block = true; | |
4828 | else | |
fefa31b5 DM |
4829 | check_last_block = bitmap_bit_p (blocks, |
4830 | EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb->index); | |
6de9cd9a DN |
4831 | |
4832 | /* In the last basic block, before epilogue generation, there will be | |
4833 | a fallthru edge to EXIT. Special care is required if the last insn | |
4834 | of the last basic block is a call because make_edge folds duplicate | |
4835 | edges, which would result in the fallthru edge also being marked | |
4836 | fake, which would result in the fallthru edge being removed by | |
4837 | remove_fake_edges, which would result in an invalid CFG. | |
4838 | ||
4839 | Moreover, we can't elide the outgoing fake edge, since the block | |
4840 | profiler needs to take this into account in order to solve the minimal | |
4841 | spanning tree in the case that the call doesn't return. | |
4842 | ||
4843 | Handle this by adding a dummy instruction in a new last basic block. */ | |
4844 | if (check_last_block) | |
4845 | { | |
fefa31b5 | 4846 | basic_block bb = EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb; |
8879d71c | 4847 | rtx_insn *insn = BB_END (bb); |
6de9cd9a DN |
4848 | |
4849 | /* Back up past insns that must be kept in the same block as a call. */ | |
4850 | while (insn != BB_HEAD (bb) | |
4851 | && keep_with_call_p (insn)) | |
4852 | insn = PREV_INSN (insn); | |
4853 | ||
4854 | if (need_fake_edge_p (insn)) | |
4855 | { | |
4856 | edge e; | |
4857 | ||
fefa31b5 | 4858 | e = find_edge (bb, EXIT_BLOCK_PTR_FOR_FN (cfun)); |
9ff3d2de JL |
4859 | if (e) |
4860 | { | |
c41c1387 | 4861 | insert_insn_on_edge (gen_use (const0_rtx), e); |
9ff3d2de JL |
4862 | commit_edge_insertions (); |
4863 | } | |
6de9cd9a DN |
4864 | } |
4865 | } | |
4866 | ||
4867 | /* Now add fake edges to the function exit for any non constant | |
4868 | calls since there is no way that we can determine if they will | |
4869 | return or not... */ | |
4870 | ||
24bd1a0b | 4871 | for (i = NUM_FIXED_BLOCKS; i < last_bb; i++) |
6de9cd9a | 4872 | { |
06e28de2 | 4873 | basic_block bb = BASIC_BLOCK_FOR_FN (cfun, i); |
8879d71c DM |
4874 | rtx_insn *insn; |
4875 | rtx_insn *prev_insn; | |
6de9cd9a DN |
4876 | |
4877 | if (!bb) | |
4878 | continue; | |
4879 | ||
d7c028c0 | 4880 | if (blocks && !bitmap_bit_p (blocks, i)) |
6de9cd9a DN |
4881 | continue; |
4882 | ||
4883 | for (insn = BB_END (bb); ; insn = prev_insn) | |
4884 | { | |
4885 | prev_insn = PREV_INSN (insn); | |
4886 | if (need_fake_edge_p (insn)) | |
4887 | { | |
4888 | edge e; | |
8879d71c | 4889 | rtx_insn *split_at_insn = insn; |
6de9cd9a DN |
4890 | |
4891 | /* Don't split the block between a call and an insn that should | |
c22cacf3 | 4892 | remain in the same block as the call. */ |
4b4bf941 | 4893 | if (CALL_P (insn)) |
6de9cd9a DN |
4894 | while (split_at_insn != BB_END (bb) |
4895 | && keep_with_call_p (NEXT_INSN (split_at_insn))) | |
4896 | split_at_insn = NEXT_INSN (split_at_insn); | |
4897 | ||
4898 | /* The handling above of the final block before the epilogue | |
c22cacf3 | 4899 | should be enough to verify that there is no edge to the exit |
6de9cd9a DN |
4900 | block in CFG already. Calling make_edge in such case would |
4901 | cause us to mark that edge as fake and remove it later. */ | |
4902 | ||
b2b29377 | 4903 | if (flag_checking && split_at_insn == BB_END (bb)) |
628f6a4e | 4904 | { |
fefa31b5 | 4905 | e = find_edge (bb, EXIT_BLOCK_PTR_FOR_FN (cfun)); |
9ff3d2de | 4906 | gcc_assert (e == NULL); |
628f6a4e | 4907 | } |
6de9cd9a DN |
4908 | |
4909 | /* Note that the following may create a new basic block | |
4910 | and renumber the existing basic blocks. */ | |
4911 | if (split_at_insn != BB_END (bb)) | |
4912 | { | |
4913 | e = split_block (bb, split_at_insn); | |
4914 | if (e) | |
4915 | blocks_split++; | |
4916 | } | |
4917 | ||
36d95aa8 JH |
4918 | edge ne = make_edge (bb, EXIT_BLOCK_PTR_FOR_FN (cfun), EDGE_FAKE); |
4919 | ne->probability = profile_probability::guessed_never (); | |
6de9cd9a DN |
4920 | } |
4921 | ||
4922 | if (insn == BB_HEAD (bb)) | |
4923 | break; | |
4924 | } | |
4925 | } | |
4926 | ||
4927 | if (blocks_split) | |
4928 | verify_flow_info (); | |
4929 | ||
4930 | return blocks_split; | |
4931 | } | |
4932 | ||
1cb7dfc3 | 4933 | /* Add COMP_RTX as a condition at end of COND_BB. FIRST_HEAD is |
315682fb | 4934 | the conditional branch target, SECOND_HEAD should be the fall-thru |
1cb7dfc3 MH |
4935 | there is no need to handle this here the loop versioning code handles |
4936 | this. the reason for SECON_HEAD is that it is needed for condition | |
4937 | in trees, and this should be of the same type since it is a hook. */ | |
4938 | static void | |
4939 | rtl_lv_add_condition_to_bb (basic_block first_head , | |
c22cacf3 MS |
4940 | basic_block second_head ATTRIBUTE_UNUSED, |
4941 | basic_block cond_bb, void *comp_rtx) | |
1cb7dfc3 | 4942 | { |
1476d1bd | 4943 | rtx_code_label *label; |
8879d71c | 4944 | rtx_insn *seq, *jump; |
1cb7dfc3 MH |
4945 | rtx op0 = XEXP ((rtx)comp_rtx, 0); |
4946 | rtx op1 = XEXP ((rtx)comp_rtx, 1); | |
4947 | enum rtx_code comp = GET_CODE ((rtx)comp_rtx); | |
ef4bddc2 | 4948 | machine_mode mode; |
1cb7dfc3 MH |
4949 | |
4950 | ||
4951 | label = block_label (first_head); | |
4952 | mode = GET_MODE (op0); | |
4953 | if (mode == VOIDmode) | |
4954 | mode = GET_MODE (op1); | |
4955 | ||
4956 | start_sequence (); | |
4957 | op0 = force_operand (op0, NULL_RTX); | |
4958 | op1 = force_operand (op1, NULL_RTX); | |
357067f2 JH |
4959 | do_compare_rtx_and_jump (op0, op1, comp, 0, mode, NULL_RTX, NULL, label, |
4960 | profile_probability::uninitialized ()); | |
1cb7dfc3 MH |
4961 | jump = get_last_insn (); |
4962 | JUMP_LABEL (jump) = label; | |
4963 | LABEL_NUSES (label)++; | |
4964 | seq = get_insns (); | |
4965 | end_sequence (); | |
4966 | ||
2b9c63a2 | 4967 | /* Add the new cond, in the new head. */ |
c3284718 | 4968 | emit_insn_after (seq, BB_END (cond_bb)); |
1cb7dfc3 MH |
4969 | } |
4970 | ||
4971 | ||
4972 | /* Given a block B with unconditional branch at its end, get the | |
4973 | store the return the branch edge and the fall-thru edge in | |
4974 | BRANCH_EDGE and FALLTHRU_EDGE respectively. */ | |
4975 | static void | |
4976 | rtl_extract_cond_bb_edges (basic_block b, edge *branch_edge, | |
4977 | edge *fallthru_edge) | |
4978 | { | |
4979 | edge e = EDGE_SUCC (b, 0); | |
4980 | ||
4981 | if (e->flags & EDGE_FALLTHRU) | |
4982 | { | |
4983 | *fallthru_edge = e; | |
4984 | *branch_edge = EDGE_SUCC (b, 1); | |
4985 | } | |
4986 | else | |
4987 | { | |
4988 | *branch_edge = e; | |
4989 | *fallthru_edge = EDGE_SUCC (b, 1); | |
4990 | } | |
4991 | } | |
4992 | ||
5e2d947c JH |
4993 | void |
4994 | init_rtl_bb_info (basic_block bb) | |
4995 | { | |
bcc708fc MM |
4996 | gcc_assert (!bb->il.x.rtl); |
4997 | bb->il.x.head_ = NULL; | |
766090c2 | 4998 | bb->il.x.rtl = ggc_cleared_alloc<rtl_bb_info> (); |
5e2d947c JH |
4999 | } |
5000 | ||
14fa2cc0 ZD |
5001 | /* Returns true if it is possible to remove edge E by redirecting |
5002 | it to the destination of the other edge from E->src. */ | |
5003 | ||
5004 | static bool | |
9678086d | 5005 | rtl_can_remove_branch_p (const_edge e) |
14fa2cc0 | 5006 | { |
9678086d KG |
5007 | const_basic_block src = e->src; |
5008 | const_basic_block target = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest; | |
8879d71c DM |
5009 | const rtx_insn *insn = BB_END (src); |
5010 | rtx set; | |
14fa2cc0 ZD |
5011 | |
5012 | /* The conditions are taken from try_redirect_by_replacing_jump. */ | |
fefa31b5 | 5013 | if (target == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
14fa2cc0 ZD |
5014 | return false; |
5015 | ||
5016 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) | |
5017 | return false; | |
5018 | ||
3371a64f | 5019 | if (BB_PARTITION (src) != BB_PARTITION (target)) |
14fa2cc0 ZD |
5020 | return false; |
5021 | ||
5022 | if (!onlyjump_p (insn) | |
5023 | || tablejump_p (insn, NULL, NULL)) | |
5024 | return false; | |
5025 | ||
5026 | set = single_set (insn); | |
5027 | if (!set || side_effects_p (set)) | |
5028 | return false; | |
5029 | ||
5030 | return true; | |
5031 | } | |
5032 | ||
ffe14686 AM |
5033 | static basic_block |
5034 | rtl_duplicate_bb (basic_block bb) | |
5035 | { | |
5036 | bb = cfg_layout_duplicate_bb (bb); | |
5037 | bb->aux = NULL; | |
5038 | return bb; | |
5039 | } | |
5040 | ||
aa4723d7 SB |
5041 | /* Do book-keeping of basic block BB for the profile consistency checker. |
5042 | If AFTER_PASS is 0, do pre-pass accounting, or if AFTER_PASS is 1 | |
5043 | then do post-pass accounting. Store the counting in RECORD. */ | |
5044 | static void | |
5045 | rtl_account_profile_record (basic_block bb, int after_pass, | |
5046 | struct profile_record *record) | |
5047 | { | |
8879d71c | 5048 | rtx_insn *insn; |
aa4723d7 SB |
5049 | FOR_BB_INSNS (bb, insn) |
5050 | if (INSN_P (insn)) | |
5051 | { | |
d09e78e8 | 5052 | record->size[after_pass] += insn_cost (insn, false); |
3995f3a2 | 5053 | if (bb->count.initialized_p ()) |
aa4723d7 | 5054 | record->time[after_pass] |
d09e78e8 | 5055 | += insn_cost (insn, true) * bb->count.to_gcov_type (); |
0a6a6ac9 | 5056 | else if (profile_status_for_fn (cfun) == PROFILE_GUESSED) |
aa4723d7 | 5057 | record->time[after_pass] |
e7a74006 | 5058 | += insn_cost (insn, true) * bb->count.to_frequency (cfun); |
aa4723d7 SB |
5059 | } |
5060 | } | |
5061 | ||
9ee634e3 JH |
5062 | /* Implementation of CFG manipulation for linearized RTL. */ |
5063 | struct cfg_hooks rtl_cfg_hooks = { | |
f470c378 | 5064 | "rtl", |
9ee634e3 | 5065 | rtl_verify_flow_info, |
10e9fecc | 5066 | rtl_dump_bb, |
2c895bd1 | 5067 | rtl_dump_bb_for_graph, |
bc35512f | 5068 | rtl_create_basic_block, |
9ee634e3 JH |
5069 | rtl_redirect_edge_and_branch, |
5070 | rtl_redirect_edge_and_branch_force, | |
14fa2cc0 | 5071 | rtl_can_remove_branch_p, |
9ee634e3 JH |
5072 | rtl_delete_block, |
5073 | rtl_split_block, | |
f470c378 | 5074 | rtl_move_block_after, |
bc35512f JH |
5075 | rtl_can_merge_blocks, /* can_merge_blocks_p */ |
5076 | rtl_merge_blocks, | |
6de9cd9a DN |
5077 | rtl_predict_edge, |
5078 | rtl_predicted_by_p, | |
ffe14686 AM |
5079 | cfg_layout_can_duplicate_bb_p, |
5080 | rtl_duplicate_bb, | |
f470c378 ZD |
5081 | rtl_split_edge, |
5082 | rtl_make_forwarder_block, | |
6de9cd9a | 5083 | rtl_tidy_fallthru_edge, |
cf103ca4 | 5084 | rtl_force_nonfallthru, |
6de9cd9a DN |
5085 | rtl_block_ends_with_call_p, |
5086 | rtl_block_ends_with_condjump_p, | |
d9d4706f KH |
5087 | rtl_flow_call_edges_add, |
5088 | NULL, /* execute_on_growing_pred */ | |
1cb7dfc3 MH |
5089 | NULL, /* execute_on_shrinking_pred */ |
5090 | NULL, /* duplicate loop for trees */ | |
5091 | NULL, /* lv_add_condition_to_bb */ | |
5092 | NULL, /* lv_adjust_loop_header_phi*/ | |
5093 | NULL, /* extract_cond_bb_edges */ | |
df92c640 SB |
5094 | NULL, /* flush_pending_stmts */ |
5095 | rtl_block_empty_p, /* block_empty_p */ | |
5096 | rtl_split_block_before_cond_jump, /* split_block_before_cond_jump */ | |
aa4723d7 | 5097 | rtl_account_profile_record, |
9ee634e3 JH |
5098 | }; |
5099 | ||
5100 | /* Implementation of CFG manipulation for cfg layout RTL, where | |
5101 | basic block connected via fallthru edges does not have to be adjacent. | |
5102 | This representation will hopefully become the default one in future | |
5103 | version of the compiler. */ | |
6de9cd9a | 5104 | |
9ee634e3 | 5105 | struct cfg_hooks cfg_layout_rtl_cfg_hooks = { |
f470c378 | 5106 | "cfglayout mode", |
bc35512f | 5107 | rtl_verify_flow_info_1, |
10e9fecc | 5108 | rtl_dump_bb, |
2c895bd1 | 5109 | rtl_dump_bb_for_graph, |
bc35512f | 5110 | cfg_layout_create_basic_block, |
9ee634e3 JH |
5111 | cfg_layout_redirect_edge_and_branch, |
5112 | cfg_layout_redirect_edge_and_branch_force, | |
14fa2cc0 | 5113 | rtl_can_remove_branch_p, |
9ee634e3 JH |
5114 | cfg_layout_delete_block, |
5115 | cfg_layout_split_block, | |
f470c378 | 5116 | rtl_move_block_after, |
bc35512f JH |
5117 | cfg_layout_can_merge_blocks_p, |
5118 | cfg_layout_merge_blocks, | |
6de9cd9a DN |
5119 | rtl_predict_edge, |
5120 | rtl_predicted_by_p, | |
5121 | cfg_layout_can_duplicate_bb_p, | |
5122 | cfg_layout_duplicate_bb, | |
f470c378 ZD |
5123 | cfg_layout_split_edge, |
5124 | rtl_make_forwarder_block, | |
cf103ca4 EB |
5125 | NULL, /* tidy_fallthru_edge */ |
5126 | rtl_force_nonfallthru, | |
6de9cd9a DN |
5127 | rtl_block_ends_with_call_p, |
5128 | rtl_block_ends_with_condjump_p, | |
d9d4706f KH |
5129 | rtl_flow_call_edges_add, |
5130 | NULL, /* execute_on_growing_pred */ | |
1cb7dfc3 MH |
5131 | NULL, /* execute_on_shrinking_pred */ |
5132 | duplicate_loop_to_header_edge, /* duplicate loop for trees */ | |
5133 | rtl_lv_add_condition_to_bb, /* lv_add_condition_to_bb */ | |
5134 | NULL, /* lv_adjust_loop_header_phi*/ | |
5135 | rtl_extract_cond_bb_edges, /* extract_cond_bb_edges */ | |
df92c640 SB |
5136 | NULL, /* flush_pending_stmts */ |
5137 | rtl_block_empty_p, /* block_empty_p */ | |
5138 | rtl_split_block_before_cond_jump, /* split_block_before_cond_jump */ | |
aa4723d7 | 5139 | rtl_account_profile_record, |
9ee634e3 | 5140 | }; |
78bde837 SB |
5141 | |
5142 | #include "gt-cfgrtl.h" |