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b36d64df | 1 | /* Control flow graph manipulation code for GNU compiler. |
fbd26352 | 2 | Copyright (C) 1987-2019 Free Software Foundation, Inc. |
b36d64df | 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 | |
8c4c00c1 | 8 | Software Foundation; either version 3, or (at your option) any later |
b36d64df | 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 | |
8c4c00c1 | 17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ | |
b36d64df | 19 | |
5cc577b6 | 20 | /* This file contains low level functions to manipulate the CFG and analyze it |
21 | that are aware of the RTL intermediate language. | |
b36d64df | 22 | |
23 | Available functionality: | |
c60fa3a7 | 24 | - Basic CFG/RTL manipulation API documented in cfghooks.h |
5cc577b6 | 25 | - CFG-aware instruction chain manipulation |
b36d64df | 26 | delete_insn, delete_insn_chain |
c60fa3a7 | 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 | |
54f21e20 | 31 | - CFG fixing after coarse manipulation |
32 | fixup_abnormal_edges | |
c60fa3a7 | 33 | |
34 | Functions not supposed for generic use: | |
5cc577b6 | 35 | - Infrastructure to determine quickly basic block for insn |
b36d64df | 36 | compute_bb_for_insn, update_bb_for_insn, set_block_for_insn, |
5cc577b6 | 37 | - Edge redirection with updating and optimizing of insn chain |
c60fa3a7 | 38 | block_label, tidy_fallthru_edge, force_nonfallthru */ |
b36d64df | 39 | \f |
40 | #include "config.h" | |
41 | #include "system.h" | |
805e22b2 | 42 | #include "coretypes.h" |
9ef16211 | 43 | #include "backend.h" |
7c29e30e | 44 | #include "target.h" |
9ef16211 | 45 | #include "rtl.h" |
7c29e30e | 46 | #include "tree.h" |
47 | #include "cfghooks.h" | |
9ef16211 | 48 | #include "df.h" |
7c29e30e | 49 | #include "insn-config.h" |
ad7b10a2 | 50 | #include "memmodel.h" |
7c29e30e | 51 | #include "emit-rtl.h" |
94ea8568 | 52 | #include "cfgrtl.h" |
53 | #include "cfganal.h" | |
54 | #include "cfgbuild.h" | |
55 | #include "cfgcleanup.h" | |
94ea8568 | 56 | #include "bb-reorder.h" |
d7091a76 | 57 | #include "rtl-error.h" |
225e5f6f | 58 | #include "insn-attr.h" |
d53441c8 | 59 | #include "dojump.h" |
804e497b | 60 | #include "expr.h" |
c50ae675 | 61 | #include "cfgloop.h" |
77fce4cd | 62 | #include "tree-pass.h" |
397881d3 | 63 | #include "print-rtl.h" |
b36d64df | 64 | |
62c34df8 | 65 | /* Disable warnings about missing quoting in GCC diagnostics. */ |
66 | #if __GNUC__ >= 10 | |
67 | # pragma GCC diagnostic push | |
68 | # pragma GCC diagnostic ignored "-Wformat-diag" | |
69 | #endif | |
70 | ||
23a070f3 | 71 | /* Holds the interesting leading and trailing notes for the function. |
72 | Only applicable if the CFG is in cfglayout mode. */ | |
26bb3cb2 | 73 | static GTY(()) rtx_insn *cfg_layout_function_footer; |
3e75e92b | 74 | static GTY(()) rtx_insn *cfg_layout_function_header; |
23a070f3 | 75 | |
3d90435a | 76 | static rtx_insn *skip_insns_after_block (basic_block); |
23a070f3 | 77 | static void record_effective_endpoints (void); |
23a070f3 | 78 | static void fixup_reorder_chain (void); |
79 | ||
80 | void verify_insn_chain (void); | |
81 | static void fixup_fallthru_exit_predecessor (void); | |
3d90435a | 82 | static int can_delete_note_p (const rtx_note *); |
83 | static int can_delete_label_p (const rtx_code_label *); | |
4c9e08a4 | 84 | static basic_block rtl_split_edge (edge); |
5f5d4cd1 | 85 | static bool rtl_move_block_after (basic_block, basic_block); |
4c9e08a4 | 86 | static int rtl_verify_flow_info (void); |
5f5d4cd1 | 87 | static basic_block cfg_layout_split_block (basic_block, void *); |
4ee9c684 | 88 | static edge cfg_layout_redirect_edge_and_branch (edge, basic_block); |
4c9e08a4 | 89 | static basic_block cfg_layout_redirect_edge_and_branch_force (edge, basic_block); |
90 | static void cfg_layout_delete_block (basic_block); | |
91 | static void rtl_delete_block (basic_block); | |
92 | static basic_block rtl_redirect_edge_and_branch_force (edge, basic_block); | |
4ee9c684 | 93 | static edge rtl_redirect_edge_and_branch (edge, basic_block); |
5f5d4cd1 | 94 | static basic_block rtl_split_block (basic_block, void *); |
3f6e5ced | 95 | static void rtl_dump_bb (FILE *, basic_block, int, dump_flags_t); |
4c9e08a4 | 96 | static int rtl_verify_flow_info_1 (void); |
5f5d4cd1 | 97 | static void rtl_make_forwarder_block (edge); |
b36d64df | 98 | \f |
99 | /* Return true if NOTE is not one of the ones that must be kept paired, | |
5cc577b6 | 100 | so that we may simply delete it. */ |
b36d64df | 101 | |
102 | static int | |
3d90435a | 103 | can_delete_note_p (const rtx_note *note) |
b36d64df | 104 | { |
25e880b1 | 105 | switch (NOTE_KIND (note)) |
106 | { | |
107 | case NOTE_INSN_DELETED: | |
108 | case NOTE_INSN_BASIC_BLOCK: | |
109 | case NOTE_INSN_EPILOGUE_BEG: | |
110 | return true; | |
111 | ||
112 | default: | |
113 | return false; | |
114 | } | |
b36d64df | 115 | } |
116 | ||
117 | /* True if a given label can be deleted. */ | |
118 | ||
119 | static int | |
3d90435a | 120 | can_delete_label_p (const rtx_code_label *label) |
b36d64df | 121 | { |
5cc577b6 | 122 | return (!LABEL_PRESERVE_P (label) |
123 | /* User declared labels must be preserved. */ | |
124 | && LABEL_NAME (label) == 0 | |
de039705 | 125 | && !vec_safe_contains<rtx_insn *> (forced_labels, |
126 | const_cast<rtx_code_label *> (label))); | |
b36d64df | 127 | } |
128 | ||
a2b85e40 | 129 | /* Delete INSN by patching it out. */ |
b36d64df | 130 | |
a2b85e40 | 131 | void |
283e5dd9 | 132 | delete_insn (rtx_insn *insn) |
b36d64df | 133 | { |
b36d64df | 134 | rtx note; |
135 | bool really_delete = true; | |
136 | ||
6d7dc5b9 | 137 | if (LABEL_P (insn)) |
b36d64df | 138 | { |
139 | /* Some labels can't be directly removed from the INSN chain, as they | |
a0c938f0 | 140 | might be references via variables, constant pool etc. |
141 | Convert them to the special NOTE_INSN_DELETED_LABEL note. */ | |
3d90435a | 142 | if (! can_delete_label_p (as_a <rtx_code_label *> (insn))) |
b36d64df | 143 | { |
144 | const char *name = LABEL_NAME (insn); | |
6de7acd5 | 145 | basic_block bb = BLOCK_FOR_INSN (insn); |
3d90435a | 146 | rtx_insn *bb_note = NEXT_INSN (insn); |
b36d64df | 147 | |
148 | really_delete = false; | |
149 | PUT_CODE (insn, NOTE); | |
ad4583d9 | 150 | NOTE_KIND (insn) = NOTE_INSN_DELETED_LABEL; |
7bd3dcc4 | 151 | NOTE_DELETED_LABEL_NAME (insn) = name; |
a2b85e40 | 152 | |
fb848efb | 153 | /* If the note following the label starts a basic block, and the |
6de7acd5 | 154 | label is a member of the same basic block, interchange the two. */ |
fb848efb | 155 | if (bb_note != NULL_RTX |
156 | && NOTE_INSN_BASIC_BLOCK_P (bb_note) | |
6de7acd5 | 157 | && bb != NULL |
158 | && bb == BLOCK_FOR_INSN (bb_note)) | |
a2b85e40 | 159 | { |
160 | reorder_insns_nobb (insn, insn, bb_note); | |
26bb3cb2 | 161 | BB_HEAD (bb) = bb_note; |
a2b85e40 | 162 | if (BB_END (bb) == bb_note) |
26bb3cb2 | 163 | BB_END (bb) = insn; |
a2b85e40 | 164 | } |
b36d64df | 165 | } |
5cc577b6 | 166 | |
a4de1c23 | 167 | remove_node_from_insn_list (insn, &nonlocal_goto_handler_labels); |
b36d64df | 168 | } |
169 | ||
170 | if (really_delete) | |
171 | { | |
e172357f | 172 | /* If this insn has already been deleted, something is very wrong. */ |
dd1286fb | 173 | gcc_assert (!insn->deleted ()); |
93ff53d3 | 174 | if (INSN_P (insn)) |
175 | df_insn_delete (insn); | |
b36d64df | 176 | remove_insn (insn); |
dd1286fb | 177 | insn->set_deleted (); |
b36d64df | 178 | } |
179 | ||
180 | /* If deleting a jump, decrement the use count of the label. Deleting | |
181 | the label itself should happen in the normal course of block merging. */ | |
19d2fe05 | 182 | if (JUMP_P (insn)) |
242dafee | 183 | { |
19d2fe05 | 184 | if (JUMP_LABEL (insn) |
185 | && LABEL_P (JUMP_LABEL (insn))) | |
186 | LABEL_NUSES (JUMP_LABEL (insn))--; | |
187 | ||
188 | /* If there are more targets, remove them too. */ | |
189 | while ((note | |
190 | = find_reg_note (insn, REG_LABEL_TARGET, NULL_RTX)) != NULL_RTX | |
6d7dc5b9 | 191 | && LABEL_P (XEXP (note, 0))) |
242dafee | 192 | { |
193 | LABEL_NUSES (XEXP (note, 0))--; | |
194 | remove_note (insn, note); | |
195 | } | |
196 | } | |
b36d64df | 197 | |
19d2fe05 | 198 | /* Also if deleting any insn that references a label as an operand. */ |
199 | while ((note = find_reg_note (insn, REG_LABEL_OPERAND, NULL_RTX)) != NULL_RTX | |
200 | && LABEL_P (XEXP (note, 0))) | |
201 | { | |
202 | LABEL_NUSES (XEXP (note, 0))--; | |
203 | remove_note (insn, note); | |
204 | } | |
205 | ||
b77639be | 206 | if (rtx_jump_table_data *table = dyn_cast <rtx_jump_table_data *> (insn)) |
b36d64df | 207 | { |
b77639be | 208 | rtvec vec = table->get_labels (); |
209 | int len = GET_NUM_ELEM (vec); | |
b36d64df | 210 | int i; |
211 | ||
212 | for (i = 0; i < len; i++) | |
fd0d7f8c | 213 | { |
b77639be | 214 | rtx label = XEXP (RTVEC_ELT (vec, i), 0); |
fd0d7f8c | 215 | |
216 | /* When deleting code in bulk (e.g. removing many unreachable | |
217 | blocks) we can delete a label that's a target of the vector | |
218 | before deleting the vector itself. */ | |
6d7dc5b9 | 219 | if (!NOTE_P (label)) |
fd0d7f8c | 220 | LABEL_NUSES (label)--; |
221 | } | |
b36d64df | 222 | } |
b36d64df | 223 | } |
224 | ||
bfa8ea12 | 225 | /* Like delete_insn but also purge dead edges from BB. |
226 | Return true if any edges are eliminated. */ | |
ebc94641 | 227 | |
bfa8ea12 | 228 | bool |
0c4d52cf | 229 | delete_insn_and_edges (rtx_insn *insn) |
fb20d6fa | 230 | { |
fb20d6fa | 231 | bool purge = false; |
232 | ||
ab87d1bc | 233 | if (INSN_P (insn) |
fb20d6fa | 234 | && BLOCK_FOR_INSN (insn) |
5496dbfc | 235 | && BB_END (BLOCK_FOR_INSN (insn)) == insn) |
fb20d6fa | 236 | purge = true; |
a2b85e40 | 237 | delete_insn (insn); |
fb20d6fa | 238 | if (purge) |
bfa8ea12 | 239 | return purge_dead_edges (BLOCK_FOR_INSN (insn)); |
240 | return false; | |
fb20d6fa | 241 | } |
242 | ||
b36d64df | 243 | /* Unlink a chain of insns between START and FINISH, leaving notes |
39257eb5 | 244 | that must be paired. If CLEAR_BB is true, we set bb field for |
245 | insns that cannot be removed to NULL. */ | |
b36d64df | 246 | |
247 | void | |
bb9538d6 | 248 | delete_insn_chain (rtx start, rtx_insn *finish, bool clear_bb) |
b36d64df | 249 | { |
5cc577b6 | 250 | /* Unchain the insns one by one. It would be quicker to delete all of these |
251 | with a single unchaining, rather than one at a time, but we need to keep | |
252 | the NOTE's. */ | |
bb9538d6 | 253 | rtx_insn *current = finish; |
b36d64df | 254 | while (1) |
255 | { | |
bb9538d6 | 256 | rtx_insn *prev = PREV_INSN (current); |
3d90435a | 257 | if (NOTE_P (current) && !can_delete_note_p (as_a <rtx_note *> (current))) |
b36d64df | 258 | ; |
259 | else | |
a2b85e40 | 260 | delete_insn (current); |
b36d64df | 261 | |
dd1286fb | 262 | if (clear_bb && !current->deleted ()) |
a2b85e40 | 263 | set_block_for_insn (current, NULL); |
39257eb5 | 264 | |
a2b85e40 | 265 | if (current == start) |
b36d64df | 266 | break; |
a2b85e40 | 267 | current = prev; |
b36d64df | 268 | } |
269 | } | |
270 | \f | |
5cc577b6 | 271 | /* Create a new basic block consisting of the instructions between HEAD and END |
272 | inclusive. This function is designed to allow fast BB construction - reuses | |
273 | the note and basic block struct in BB_NOTE, if any and do not grow | |
274 | BASIC_BLOCK chain and should be used directly only by CFG construction code. | |
275 | END can be NULL in to create new empty basic block before HEAD. Both END | |
7fa55aef | 276 | and HEAD can be NULL to create basic block at the end of INSN chain. |
277 | AFTER is the basic block we should be put after. */ | |
b36d64df | 278 | |
279 | basic_block | |
3c3f97b4 | 280 | create_basic_block_structure (rtx_insn *head, rtx_insn *end, rtx_note *bb_note, |
cef3d8ad | 281 | basic_block after) |
b36d64df | 282 | { |
283 | basic_block bb; | |
284 | ||
285 | if (bb_note | |
b36d64df | 286 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL |
287 | && bb->aux == NULL) | |
288 | { | |
289 | /* If we found an existing note, thread it back onto the chain. */ | |
290 | ||
57c26b3a | 291 | rtx_insn *after; |
b36d64df | 292 | |
6d7dc5b9 | 293 | if (LABEL_P (head)) |
b36d64df | 294 | after = head; |
295 | else | |
296 | { | |
297 | after = PREV_INSN (head); | |
298 | head = bb_note; | |
299 | } | |
300 | ||
301 | if (after != bb_note && NEXT_INSN (after) != bb_note) | |
ab87d1bc | 302 | reorder_insns_nobb (bb_note, bb_note, after); |
b36d64df | 303 | } |
304 | else | |
305 | { | |
306 | /* Otherwise we must create a note and a basic block structure. */ | |
307 | ||
308 | bb = alloc_block (); | |
309 | ||
e0dde8f8 | 310 | init_rtl_bb_info (bb); |
b36d64df | 311 | if (!head && !end) |
5cc577b6 | 312 | head = end = bb_note |
313 | = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); | |
6d7dc5b9 | 314 | else if (LABEL_P (head) && end) |
b36d64df | 315 | { |
316 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); | |
317 | if (head == end) | |
318 | end = bb_note; | |
319 | } | |
320 | else | |
321 | { | |
322 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); | |
323 | head = bb_note; | |
324 | if (!end) | |
325 | end = head; | |
326 | } | |
5cc577b6 | 327 | |
b36d64df | 328 | NOTE_BASIC_BLOCK (bb_note) = bb; |
329 | } | |
330 | ||
331 | /* Always include the bb note in the block. */ | |
332 | if (NEXT_INSN (end) == bb_note) | |
333 | end = bb_note; | |
334 | ||
26bb3cb2 | 335 | BB_HEAD (bb) = head; |
336 | BB_END (bb) = end; | |
fe672ac0 | 337 | bb->index = last_basic_block_for_fn (cfun)++; |
e0dde8f8 | 338 | bb->flags = BB_NEW | BB_RTL; |
7fa55aef | 339 | link_block (bb, after); |
f64d2ca4 | 340 | SET_BASIC_BLOCK_FOR_FN (cfun, bb->index, bb); |
3072d30e | 341 | df_bb_refs_record (bb->index, false); |
ab87d1bc | 342 | update_bb_for_insn (bb); |
7562ed74 | 343 | BB_SET_PARTITION (bb, BB_UNPARTITIONED); |
b36d64df | 344 | |
345 | /* Tag the block so that we know it has been used when considering | |
346 | other basic block notes. */ | |
347 | bb->aux = bb; | |
348 | ||
349 | return bb; | |
350 | } | |
351 | ||
5cc577b6 | 352 | /* Create new basic block consisting of instructions in between HEAD and END |
0a55d497 | 353 | and place it to the BB chain after block AFTER. END can be NULL to |
354 | create a new empty basic block before HEAD. Both END and HEAD can be | |
355 | NULL to create basic block at the end of INSN chain. */ | |
b36d64df | 356 | |
c60fa3a7 | 357 | static basic_block |
358 | rtl_create_basic_block (void *headp, void *endp, basic_block after) | |
b36d64df | 359 | { |
3c3f97b4 | 360 | rtx_insn *head = (rtx_insn *) headp; |
361 | rtx_insn *end = (rtx_insn *) endp; | |
b36d64df | 362 | basic_block bb; |
b3d6de89 | 363 | |
743ff5bb | 364 | /* Grow the basic block array if needed. */ |
fe672ac0 | 365 | if ((size_t) last_basic_block_for_fn (cfun) |
366 | >= basic_block_info_for_fn (cfun)->length ()) | |
743ff5bb | 367 | { |
fe672ac0 | 368 | size_t new_size = |
369 | (last_basic_block_for_fn (cfun) | |
370 | + (last_basic_block_for_fn (cfun) + 3) / 4); | |
9ca41bd1 | 371 | vec_safe_grow_cleared (basic_block_info_for_fn (cfun), new_size); |
743ff5bb | 372 | } |
b3d6de89 | 373 | |
a28770e1 | 374 | n_basic_blocks_for_fn (cfun)++; |
b36d64df | 375 | |
f23d9a22 | 376 | bb = create_basic_block_structure (head, end, NULL, after); |
b36d64df | 377 | bb->aux = NULL; |
378 | return bb; | |
379 | } | |
c60fa3a7 | 380 | |
381 | static basic_block | |
382 | cfg_layout_create_basic_block (void *head, void *end, basic_block after) | |
383 | { | |
384 | basic_block newbb = rtl_create_basic_block (head, end, after); | |
385 | ||
c60fa3a7 | 386 | return newbb; |
387 | } | |
b36d64df | 388 | \f |
389 | /* Delete the insns in a (non-live) block. We physically delete every | |
390 | non-deleted-note insn, and update the flow graph appropriately. | |
391 | ||
392 | Return nonzero if we deleted an exception handler. */ | |
393 | ||
394 | /* ??? Preserving all such notes strikes me as wrong. It would be nice | |
395 | to post-process the stream to remove empty blocks, loops, ranges, etc. */ | |
396 | ||
5f704f9f | 397 | static void |
4c9e08a4 | 398 | rtl_delete_block (basic_block b) |
b36d64df | 399 | { |
3d90435a | 400 | rtx_insn *insn, *end; |
b36d64df | 401 | |
402 | /* If the head of this block is a CODE_LABEL, then it might be the | |
57548910 | 403 | label for an exception handler which can't be reached. We need |
404 | to remove the label from the exception_handler_label list. */ | |
5496dbfc | 405 | insn = BB_HEAD (b); |
b36d64df | 406 | |
5d65a39c | 407 | end = get_last_bb_insn (b); |
b36d64df | 408 | |
409 | /* Selectively delete the entire chain. */ | |
26bb3cb2 | 410 | BB_HEAD (b) = NULL; |
39257eb5 | 411 | delete_insn_chain (insn, end, true); |
412 | ||
3072d30e | 413 | |
414 | if (dump_file) | |
415 | fprintf (dump_file, "deleting block %d\n", b->index); | |
416 | df_bb_delete (b->index); | |
b36d64df | 417 | } |
418 | \f | |
f23d9a22 | 419 | /* Records the basic block struct in BLOCK_FOR_INSN for every insn. */ |
b36d64df | 420 | |
421 | void | |
4c9e08a4 | 422 | compute_bb_for_insn (void) |
b36d64df | 423 | { |
4c26117a | 424 | basic_block bb; |
b36d64df | 425 | |
fc00614f | 426 | FOR_EACH_BB_FN (bb, cfun) |
b36d64df | 427 | { |
3d90435a | 428 | rtx_insn *end = BB_END (bb); |
429 | rtx_insn *insn; | |
b36d64df | 430 | |
5496dbfc | 431 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
b36d64df | 432 | { |
ab87d1bc | 433 | BLOCK_FOR_INSN (insn) = bb; |
b36d64df | 434 | if (insn == end) |
435 | break; | |
b36d64df | 436 | } |
437 | } | |
438 | } | |
439 | ||
440 | /* Release the basic_block_for_insn array. */ | |
441 | ||
2a1990e9 | 442 | unsigned int |
4c9e08a4 | 443 | free_bb_for_insn (void) |
b36d64df | 444 | { |
3d90435a | 445 | rtx_insn *insn; |
ab87d1bc | 446 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) |
6d7dc5b9 | 447 | if (!BARRIER_P (insn)) |
ab87d1bc | 448 | BLOCK_FOR_INSN (insn) = NULL; |
2a1990e9 | 449 | return 0; |
b36d64df | 450 | } |
451 | ||
cbe8bda8 | 452 | namespace { |
453 | ||
454 | const pass_data pass_data_free_cfg = | |
455 | { | |
456 | RTL_PASS, /* type */ | |
457 | "*free_cfg", /* name */ | |
458 | OPTGROUP_NONE, /* optinfo_flags */ | |
cbe8bda8 | 459 | TV_NONE, /* tv_id */ |
460 | 0, /* properties_required */ | |
461 | 0, /* properties_provided */ | |
462 | PROP_cfg, /* properties_destroyed */ | |
463 | 0, /* todo_flags_start */ | |
464 | 0, /* todo_flags_finish */ | |
77fce4cd | 465 | }; |
466 | ||
cbe8bda8 | 467 | class pass_free_cfg : public rtl_opt_pass |
468 | { | |
469 | public: | |
9af5ce0c | 470 | pass_free_cfg (gcc::context *ctxt) |
471 | : rtl_opt_pass (pass_data_free_cfg, ctxt) | |
cbe8bda8 | 472 | {} |
473 | ||
474 | /* opt_pass methods: */ | |
65b0537f | 475 | virtual unsigned int execute (function *); |
cbe8bda8 | 476 | |
477 | }; // class pass_free_cfg | |
478 | ||
65b0537f | 479 | unsigned int |
480 | pass_free_cfg::execute (function *) | |
481 | { | |
65b0537f | 482 | /* The resource.c machinery uses DF but the CFG isn't guaranteed to be |
483 | valid at that point so it would be too late to call df_analyze. */ | |
9d463a01 | 484 | if (DELAY_SLOTS && optimize > 0 && flag_delayed_branch) |
65b0537f | 485 | { |
486 | df_note_add_problem (); | |
487 | df_analyze (); | |
488 | } | |
65b0537f | 489 | |
490 | if (crtl->has_bb_partition) | |
491 | insert_section_boundary_note (); | |
492 | ||
493 | free_bb_for_insn (); | |
494 | return 0; | |
495 | } | |
496 | ||
cbe8bda8 | 497 | } // anon namespace |
498 | ||
499 | rtl_opt_pass * | |
500 | make_pass_free_cfg (gcc::context *ctxt) | |
501 | { | |
502 | return new pass_free_cfg (ctxt); | |
503 | } | |
504 | ||
a0fee14a | 505 | /* Return RTX to emit after when we want to emit code on the entry of function. */ |
dec0d4e1 | 506 | rtx_insn * |
a0fee14a | 507 | entry_of_function (void) |
508 | { | |
a28770e1 | 509 | return (n_basic_blocks_for_fn (cfun) > NUM_FIXED_BLOCKS ? |
34154e27 | 510 | BB_HEAD (ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb) : get_insns ()); |
a0fee14a | 511 | } |
512 | ||
aa02fa19 | 513 | /* Emit INSN at the entry point of the function, ensuring that it is only |
514 | executed once per function. */ | |
515 | void | |
516 | emit_insn_at_entry (rtx insn) | |
517 | { | |
34154e27 | 518 | edge_iterator ei = ei_start (ENTRY_BLOCK_PTR_FOR_FN (cfun)->succs); |
aa02fa19 | 519 | edge e = ei_safe_edge (ei); |
1db61145 | 520 | gcc_assert (e->flags & EDGE_FALLTHRU); |
aa02fa19 | 521 | |
522 | insert_insn_on_edge (insn, e); | |
523 | commit_edge_insertions (); | |
524 | } | |
525 | ||
f41d4683 | 526 | /* Update BLOCK_FOR_INSN of insns between BEGIN and END |
48e1416a | 527 | (or BARRIER if found) and notify df of the bb change. |
f41d4683 | 528 | The insn chain range is inclusive |
529 | (i.e. both BEGIN and END will be updated. */ | |
b36d64df | 530 | |
f41d4683 | 531 | static void |
3d90435a | 532 | update_bb_for_insn_chain (rtx_insn *begin, rtx_insn *end, basic_block bb) |
b36d64df | 533 | { |
3d90435a | 534 | rtx_insn *insn; |
b36d64df | 535 | |
f41d4683 | 536 | end = NEXT_INSN (end); |
537 | for (insn = begin; insn != end; insn = NEXT_INSN (insn)) | |
a2bdd643 | 538 | if (!BARRIER_P (insn)) |
539 | df_insn_change_bb (insn, bb); | |
b36d64df | 540 | } |
f41d4683 | 541 | |
542 | /* Update BLOCK_FOR_INSN of insns in BB to BB, | |
543 | and notify df of the change. */ | |
544 | ||
545 | void | |
546 | update_bb_for_insn (basic_block bb) | |
547 | { | |
548 | update_bb_for_insn_chain (BB_HEAD (bb), BB_END (bb), bb); | |
549 | } | |
550 | ||
4a020a8c | 551 | \f |
3114c9f4 | 552 | /* Like active_insn_p, except keep the return value use or clobber around |
4a020a8c | 553 | even after reload. */ |
554 | ||
555 | static bool | |
3d90435a | 556 | flow_active_insn_p (const rtx_insn *insn) |
4a020a8c | 557 | { |
558 | if (active_insn_p (insn)) | |
559 | return true; | |
560 | ||
561 | /* A clobber of the function return value exists for buggy | |
562 | programs that fail to return a value. Its effect is to | |
563 | keep the return value from being live across the entire | |
564 | function. If we allow it to be skipped, we introduce the | |
3114c9f4 | 565 | possibility for register lifetime confusion. |
566 | Similarly, keep a USE of the function return value, otherwise | |
567 | the USE is dropped and we could fail to thread jump if USE | |
568 | appears on some paths and not on others, see PR90257. */ | |
569 | if ((GET_CODE (PATTERN (insn)) == CLOBBER | |
570 | || GET_CODE (PATTERN (insn)) == USE) | |
4a020a8c | 571 | && REG_P (XEXP (PATTERN (insn), 0)) |
572 | && REG_FUNCTION_VALUE_P (XEXP (PATTERN (insn), 0))) | |
573 | return true; | |
574 | ||
575 | return false; | |
576 | } | |
577 | ||
578 | /* Return true if the block has no effect and only forwards control flow to | |
579 | its single destination. */ | |
4a020a8c | 580 | |
581 | bool | |
bbdfcf34 | 582 | contains_no_active_insn_p (const_basic_block bb) |
4a020a8c | 583 | { |
3d90435a | 584 | rtx_insn *insn; |
4a020a8c | 585 | |
94d511af | 586 | if (bb == EXIT_BLOCK_PTR_FOR_FN (cfun) |
587 | || bb == ENTRY_BLOCK_PTR_FOR_FN (cfun) | |
588 | || !single_succ_p (bb) | |
589 | || (single_succ_edge (bb)->flags & EDGE_FAKE) != 0) | |
4a020a8c | 590 | return false; |
591 | ||
bbdfcf34 | 592 | for (insn = BB_HEAD (bb); insn != BB_END (bb); insn = NEXT_INSN (insn)) |
593 | if (INSN_P (insn) && flow_active_insn_p (insn)) | |
594 | return false; | |
595 | ||
596 | return (!INSN_P (insn) | |
597 | || (JUMP_P (insn) && simplejump_p (insn)) | |
598 | || !flow_active_insn_p (insn)); | |
599 | } | |
600 | ||
601 | /* Likewise, but protect loop latches, headers and preheaders. */ | |
602 | /* FIXME: Make this a cfg hook. */ | |
603 | ||
604 | bool | |
605 | forwarder_block_p (const_basic_block bb) | |
606 | { | |
607 | if (!contains_no_active_insn_p (bb)) | |
608 | return false; | |
609 | ||
4a020a8c | 610 | /* Protect loop latches, headers and preheaders. */ |
611 | if (current_loops) | |
612 | { | |
613 | basic_block dest; | |
614 | if (bb->loop_father->header == bb) | |
615 | return false; | |
616 | dest = EDGE_SUCC (bb, 0)->dest; | |
617 | if (dest->loop_father->header == dest) | |
618 | return false; | |
619 | } | |
620 | ||
bbdfcf34 | 621 | return true; |
4a020a8c | 622 | } |
623 | ||
624 | /* Return nonzero if we can reach target from src by falling through. */ | |
cd316116 | 625 | /* FIXME: Make this a cfg hook, the result is only valid in cfgrtl mode. */ |
4a020a8c | 626 | |
627 | bool | |
628 | can_fallthru (basic_block src, basic_block target) | |
629 | { | |
3d90435a | 630 | rtx_insn *insn = BB_END (src); |
631 | rtx_insn *insn2; | |
4a020a8c | 632 | edge e; |
633 | edge_iterator ei; | |
634 | ||
34154e27 | 635 | if (target == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
4a020a8c | 636 | return true; |
637 | if (src->next_bb != target) | |
cd316116 | 638 | return false; |
639 | ||
640 | /* ??? Later we may add code to move jump tables offline. */ | |
641 | if (tablejump_p (insn, NULL, NULL)) | |
642 | return false; | |
643 | ||
4a020a8c | 644 | FOR_EACH_EDGE (e, ei, src->succs) |
34154e27 | 645 | if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) |
4a020a8c | 646 | && e->flags & EDGE_FALLTHRU) |
cd316116 | 647 | return false; |
4a020a8c | 648 | |
649 | insn2 = BB_HEAD (target); | |
cd316116 | 650 | if (!active_insn_p (insn2)) |
4a020a8c | 651 | insn2 = next_active_insn (insn2); |
652 | ||
4a020a8c | 653 | return next_active_insn (insn) == insn2; |
654 | } | |
655 | ||
656 | /* Return nonzero if we could reach target from src by falling through, | |
657 | if the target was made adjacent. If we already have a fall-through | |
658 | edge to the exit block, we can't do that. */ | |
659 | static bool | |
660 | could_fall_through (basic_block src, basic_block target) | |
661 | { | |
662 | edge e; | |
663 | edge_iterator ei; | |
664 | ||
34154e27 | 665 | if (target == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
4a020a8c | 666 | return true; |
667 | FOR_EACH_EDGE (e, ei, src->succs) | |
34154e27 | 668 | if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) |
4a020a8c | 669 | && e->flags & EDGE_FALLTHRU) |
670 | return 0; | |
671 | return true; | |
672 | } | |
b36d64df | 673 | \f |
018f0595 | 674 | /* Return the NOTE_INSN_BASIC_BLOCK of BB. */ |
61f9f451 | 675 | rtx_note * |
018f0595 | 676 | bb_note (basic_block bb) |
677 | { | |
3d90435a | 678 | rtx_insn *note; |
018f0595 | 679 | |
680 | note = BB_HEAD (bb); | |
681 | if (LABEL_P (note)) | |
682 | note = NEXT_INSN (note); | |
683 | ||
684 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (note)); | |
61f9f451 | 685 | return as_a <rtx_note *> (note); |
018f0595 | 686 | } |
687 | ||
3072d30e | 688 | /* Return the INSN immediately following the NOTE_INSN_BASIC_BLOCK |
689 | note associated with the BLOCK. */ | |
690 | ||
3d90435a | 691 | static rtx_insn * |
3072d30e | 692 | first_insn_after_basic_block_note (basic_block block) |
693 | { | |
3d90435a | 694 | rtx_insn *insn; |
3072d30e | 695 | |
696 | /* Get the first instruction in the block. */ | |
697 | insn = BB_HEAD (block); | |
698 | ||
699 | if (insn == NULL_RTX) | |
3d90435a | 700 | return NULL; |
3072d30e | 701 | if (LABEL_P (insn)) |
702 | insn = NEXT_INSN (insn); | |
703 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn)); | |
704 | ||
705 | return NEXT_INSN (insn); | |
706 | } | |
707 | ||
3ad55f68 | 708 | /* Creates a new basic block just after basic block BB by splitting |
709 | everything after specified instruction INSNP. */ | |
b36d64df | 710 | |
5f5d4cd1 | 711 | static basic_block |
4c9e08a4 | 712 | rtl_split_block (basic_block bb, void *insnp) |
b36d64df | 713 | { |
714 | basic_block new_bb; | |
3d90435a | 715 | rtx_insn *insn = (rtx_insn *) insnp; |
5f5d4cd1 | 716 | edge e; |
cd665a06 | 717 | edge_iterator ei; |
b36d64df | 718 | |
5f5d4cd1 | 719 | if (!insn) |
720 | { | |
721 | insn = first_insn_after_basic_block_note (bb); | |
722 | ||
723 | if (insn) | |
9845d120 | 724 | { |
3d90435a | 725 | rtx_insn *next = insn; |
9845d120 | 726 | |
727 | insn = PREV_INSN (insn); | |
728 | ||
729 | /* If the block contains only debug insns, insn would have | |
730 | been NULL in a non-debug compilation, and then we'd end | |
731 | up emitting a DELETED note. For -fcompare-debug | |
732 | stability, emit the note too. */ | |
733 | if (insn != BB_END (bb) | |
734 | && DEBUG_INSN_P (next) | |
735 | && DEBUG_INSN_P (BB_END (bb))) | |
736 | { | |
737 | while (next != BB_END (bb) && DEBUG_INSN_P (next)) | |
738 | next = NEXT_INSN (next); | |
739 | ||
740 | if (next == BB_END (bb)) | |
741 | emit_note_after (NOTE_INSN_DELETED, next); | |
742 | } | |
743 | } | |
5f5d4cd1 | 744 | else |
745 | insn = get_last_insn (); | |
746 | } | |
747 | ||
748 | /* We probably should check type of the insn so that we do not create | |
749 | inconsistent cfg. It is checked in verify_flow_info anyway, so do not | |
750 | bother. */ | |
751 | if (insn == BB_END (bb)) | |
752 | emit_note_after (NOTE_INSN_DELETED, insn); | |
b36d64df | 753 | |
754 | /* Create the new basic block. */ | |
5496dbfc | 755 | new_bb = create_basic_block (NEXT_INSN (insn), BB_END (bb), bb); |
7562ed74 | 756 | BB_COPY_PARTITION (new_bb, bb); |
26bb3cb2 | 757 | BB_END (bb) = insn; |
b36d64df | 758 | |
759 | /* Redirect the outgoing edges. */ | |
cd665a06 | 760 | new_bb->succs = bb->succs; |
761 | bb->succs = NULL; | |
762 | FOR_EACH_EDGE (e, ei, new_bb->succs) | |
b36d64df | 763 | e->src = new_bb; |
764 | ||
3072d30e | 765 | /* The new block starts off being dirty. */ |
766 | df_set_bb_dirty (bb); | |
5f5d4cd1 | 767 | return new_bb; |
c60fa3a7 | 768 | } |
769 | ||
8ddad41d | 770 | /* Return true if the single edge between blocks A and B is the only place |
771 | in RTL which holds some unique locus. */ | |
772 | ||
773 | static bool | |
774 | unique_locus_on_edge_between_p (basic_block a, basic_block b) | |
775 | { | |
5169661d | 776 | const location_t goto_locus = EDGE_SUCC (a, 0)->goto_locus; |
3d90435a | 777 | rtx_insn *insn, *end; |
8ddad41d | 778 | |
8e7408e3 | 779 | if (LOCATION_LOCUS (goto_locus) == UNKNOWN_LOCATION) |
8ddad41d | 780 | return false; |
781 | ||
782 | /* First scan block A backward. */ | |
783 | insn = BB_END (a); | |
784 | end = PREV_INSN (BB_HEAD (a)); | |
5169661d | 785 | while (insn != end && (!NONDEBUG_INSN_P (insn) || !INSN_HAS_LOCATION (insn))) |
8ddad41d | 786 | insn = PREV_INSN (insn); |
787 | ||
5169661d | 788 | if (insn != end && INSN_LOCATION (insn) == goto_locus) |
8ddad41d | 789 | return false; |
790 | ||
791 | /* Then scan block B forward. */ | |
792 | insn = BB_HEAD (b); | |
793 | if (insn) | |
794 | { | |
795 | end = NEXT_INSN (BB_END (b)); | |
796 | while (insn != end && !NONDEBUG_INSN_P (insn)) | |
797 | insn = NEXT_INSN (insn); | |
798 | ||
5169661d | 799 | if (insn != end && INSN_HAS_LOCATION (insn) |
800 | && INSN_LOCATION (insn) == goto_locus) | |
8ddad41d | 801 | return false; |
802 | } | |
803 | ||
804 | return true; | |
805 | } | |
806 | ||
807 | /* If the single edge between blocks A and B is the only place in RTL which | |
808 | holds some unique locus, emit a nop with that locus between the blocks. */ | |
809 | ||
810 | static void | |
811 | emit_nop_for_unique_locus_between (basic_block a, basic_block b) | |
812 | { | |
813 | if (!unique_locus_on_edge_between_p (a, b)) | |
814 | return; | |
815 | ||
26bb3cb2 | 816 | BB_END (a) = emit_insn_after_noloc (gen_nop (), BB_END (a), a); |
5169661d | 817 | INSN_LOCATION (BB_END (a)) = EDGE_SUCC (a, 0)->goto_locus; |
8ddad41d | 818 | } |
819 | ||
b36d64df | 820 | /* Blocks A and B are to be merged into a single block A. The insns |
c60fa3a7 | 821 | are already contiguous. */ |
b36d64df | 822 | |
c60fa3a7 | 823 | static void |
824 | rtl_merge_blocks (basic_block a, basic_block b) | |
b36d64df | 825 | { |
d0ae7eeb | 826 | /* If B is a forwarder block whose outgoing edge has no location, we'll |
827 | propagate the locus of the edge between A and B onto it. */ | |
828 | const bool forward_edge_locus | |
829 | = (b->flags & BB_FORWARDER_BLOCK) != 0 | |
830 | && LOCATION_LOCUS (EDGE_SUCC (b, 0)->goto_locus) == UNKNOWN_LOCATION; | |
3d90435a | 831 | rtx_insn *b_head = BB_HEAD (b), *b_end = BB_END (b), *a_end = BB_END (a); |
832 | rtx_insn *del_first = NULL, *del_last = NULL; | |
833 | rtx_insn *b_debug_start = b_end, *b_debug_end = b_end; | |
b36d64df | 834 | int b_empty = 0; |
835 | ||
3072d30e | 836 | if (dump_file) |
18b762f0 | 837 | fprintf (dump_file, "Merging block %d into block %d...\n", b->index, |
838 | a->index); | |
3072d30e | 839 | |
9845d120 | 840 | while (DEBUG_INSN_P (b_end)) |
841 | b_end = PREV_INSN (b_debug_start = b_end); | |
842 | ||
b36d64df | 843 | /* If there was a CODE_LABEL beginning B, delete it. */ |
6d7dc5b9 | 844 | if (LABEL_P (b_head)) |
b36d64df | 845 | { |
846 | /* Detect basic blocks with nothing but a label. This can happen | |
847 | in particular at the end of a function. */ | |
848 | if (b_head == b_end) | |
849 | b_empty = 1; | |
5cc577b6 | 850 | |
b36d64df | 851 | del_first = del_last = b_head; |
852 | b_head = NEXT_INSN (b_head); | |
853 | } | |
854 | ||
5cc577b6 | 855 | /* Delete the basic block note and handle blocks containing just that |
856 | note. */ | |
b36d64df | 857 | if (NOTE_INSN_BASIC_BLOCK_P (b_head)) |
858 | { | |
859 | if (b_head == b_end) | |
860 | b_empty = 1; | |
861 | if (! del_last) | |
862 | del_first = b_head; | |
5cc577b6 | 863 | |
b36d64df | 864 | del_last = b_head; |
865 | b_head = NEXT_INSN (b_head); | |
866 | } | |
867 | ||
868 | /* If there was a jump out of A, delete it. */ | |
6d7dc5b9 | 869 | if (JUMP_P (a_end)) |
b36d64df | 870 | { |
3d90435a | 871 | rtx_insn *prev; |
b36d64df | 872 | |
873 | for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev)) | |
6d7dc5b9 | 874 | if (!NOTE_P (prev) |
ad4583d9 | 875 | || NOTE_INSN_BASIC_BLOCK_P (prev) |
5496dbfc | 876 | || prev == BB_HEAD (a)) |
b36d64df | 877 | break; |
878 | ||
879 | del_first = a_end; | |
880 | ||
b36d64df | 881 | /* If this was a conditional jump, we need to also delete |
882 | the insn that set cc0. */ | |
ff900b8e | 883 | if (HAVE_cc0 && only_sets_cc0_p (prev)) |
b36d64df | 884 | { |
3d90435a | 885 | rtx_insn *tmp = prev; |
5cc577b6 | 886 | |
b36d64df | 887 | prev = prev_nonnote_insn (prev); |
888 | if (!prev) | |
5496dbfc | 889 | prev = BB_HEAD (a); |
b36d64df | 890 | del_first = tmp; |
891 | } | |
b36d64df | 892 | |
893 | a_end = PREV_INSN (del_first); | |
894 | } | |
6d7dc5b9 | 895 | else if (BARRIER_P (NEXT_INSN (a_end))) |
b36d64df | 896 | del_first = NEXT_INSN (a_end); |
897 | ||
b36d64df | 898 | /* Delete everything marked above as well as crap that might be |
899 | hanging out between the two blocks. */ | |
26bb3cb2 | 900 | BB_END (a) = a_end; |
901 | BB_HEAD (b) = b_empty ? NULL : b_head; | |
39257eb5 | 902 | delete_insn_chain (del_first, del_last, true); |
b36d64df | 903 | |
d0ae7eeb | 904 | /* If not optimizing, preserve the locus of the single edge between |
905 | blocks A and B if necessary by emitting a nop. */ | |
906 | if (!optimize | |
907 | && !forward_edge_locus | |
908 | && !DECL_IGNORED_P (current_function_decl)) | |
8ddad41d | 909 | { |
910 | emit_nop_for_unique_locus_between (a, b); | |
911 | a_end = BB_END (a); | |
912 | } | |
913 | ||
b36d64df | 914 | /* Reassociate the insns of B with A. */ |
915 | if (!b_empty) | |
916 | { | |
9845d120 | 917 | update_bb_for_insn_chain (a_end, b_debug_end, a); |
5cc577b6 | 918 | |
26bb3cb2 | 919 | BB_END (a) = b_debug_end; |
920 | BB_HEAD (b) = NULL; | |
9845d120 | 921 | } |
922 | else if (b_end != b_debug_end) | |
923 | { | |
924 | /* Move any deleted labels and other notes between the end of A | |
925 | and the debug insns that make up B after the debug insns, | |
926 | bringing the debug insns into A while keeping the notes after | |
927 | the end of A. */ | |
928 | if (NEXT_INSN (a_end) != b_debug_start) | |
929 | reorder_insns_nobb (NEXT_INSN (a_end), PREV_INSN (b_debug_start), | |
930 | b_debug_end); | |
931 | update_bb_for_insn_chain (b_debug_start, b_debug_end, a); | |
26bb3cb2 | 932 | BB_END (a) = b_debug_end; |
b36d64df | 933 | } |
5cc577b6 | 934 | |
3072d30e | 935 | df_bb_delete (b->index); |
18b762f0 | 936 | |
d0ae7eeb | 937 | if (forward_edge_locus) |
18b762f0 | 938 | EDGE_SUCC (b, 0)->goto_locus = EDGE_SUCC (a, 0)->goto_locus; |
939 | ||
940 | if (dump_file) | |
941 | fprintf (dump_file, "Merged blocks %d and %d.\n", a->index, b->index); | |
b36d64df | 942 | } |
c60fa3a7 | 943 | |
3072d30e | 944 | |
c60fa3a7 | 945 | /* Return true when block A and B can be merged. */ |
5493cb9a | 946 | |
47aaf6e6 | 947 | static bool |
948 | rtl_can_merge_blocks (basic_block a, basic_block b) | |
c60fa3a7 | 949 | { |
4f18499c | 950 | /* If we are partitioning hot/cold basic blocks, we don't want to |
951 | mess up unconditional or indirect jumps that cross between hot | |
7562ed74 | 952 | and cold sections. |
953 | ||
1118aef7 | 954 | Basic block partitioning may result in some jumps that appear to |
a0c938f0 | 955 | be optimizable (or blocks that appear to be mergeable), but which really |
956 | must be left untouched (they are required to make it safely across | |
957 | partition boundaries). See the comments at the top of | |
1118aef7 | 958 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
7562ed74 | 959 | |
1897b881 | 960 | if (BB_PARTITION (a) != BB_PARTITION (b)) |
7562ed74 | 961 | return false; |
4f18499c | 962 | |
79f958cb | 963 | /* Protect the loop latches. */ |
964 | if (current_loops && b->loop_father->latch == b) | |
965 | return false; | |
966 | ||
c60fa3a7 | 967 | /* There must be exactly one edge in between the blocks. */ |
ea091dfd | 968 | return (single_succ_p (a) |
969 | && single_succ (a) == b | |
970 | && single_pred_p (b) | |
cd665a06 | 971 | && a != b |
c60fa3a7 | 972 | /* Must be simple edge. */ |
ea091dfd | 973 | && !(single_succ_edge (a)->flags & EDGE_COMPLEX) |
c60fa3a7 | 974 | && a->next_bb == b |
34154e27 | 975 | && a != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
976 | && b != EXIT_BLOCK_PTR_FOR_FN (cfun) | |
c60fa3a7 | 977 | /* If the jump insn has side effects, |
978 | we can't kill the edge. */ | |
6d7dc5b9 | 979 | && (!JUMP_P (BB_END (a)) |
18f811c9 | 980 | || (reload_completed |
5496dbfc | 981 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
c60fa3a7 | 982 | } |
b36d64df | 983 | \f |
5cc577b6 | 984 | /* Return the label in the head of basic block BLOCK. Create one if it doesn't |
985 | exist. */ | |
b36d64df | 986 | |
f9a00e9e | 987 | rtx_code_label * |
4c9e08a4 | 988 | block_label (basic_block block) |
b36d64df | 989 | { |
34154e27 | 990 | if (block == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
f9a00e9e | 991 | return NULL; |
5cc577b6 | 992 | |
6d7dc5b9 | 993 | if (!LABEL_P (BB_HEAD (block))) |
b36d64df | 994 | { |
26bb3cb2 | 995 | BB_HEAD (block) = emit_label_before (gen_label_rtx (), BB_HEAD (block)); |
b36d64df | 996 | } |
5cc577b6 | 997 | |
f9a00e9e | 998 | return as_a <rtx_code_label *> (BB_HEAD (block)); |
b36d64df | 999 | } |
1000 | ||
eb258b7d | 1001 | /* Remove all barriers from BB_FOOTER of a BB. */ |
1002 | ||
1003 | static void | |
1004 | remove_barriers_from_footer (basic_block bb) | |
1005 | { | |
1006 | rtx_insn *insn = BB_FOOTER (bb); | |
1007 | ||
1008 | /* Remove barriers but keep jumptables. */ | |
1009 | while (insn) | |
1010 | { | |
1011 | if (BARRIER_P (insn)) | |
1012 | { | |
1013 | if (PREV_INSN (insn)) | |
1014 | SET_NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
1015 | else | |
1016 | BB_FOOTER (bb) = NEXT_INSN (insn); | |
1017 | if (NEXT_INSN (insn)) | |
1018 | SET_PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
1019 | } | |
1020 | if (LABEL_P (insn)) | |
1021 | return; | |
1022 | insn = NEXT_INSN (insn); | |
1023 | } | |
1024 | } | |
1025 | ||
b36d64df | 1026 | /* Attempt to perform edge redirection by replacing possibly complex jump |
5cc577b6 | 1027 | instruction by unconditional jump or removing jump completely. This can |
1028 | apply only if all edges now point to the same block. The parameters and | |
1029 | return values are equivalent to redirect_edge_and_branch. */ | |
b36d64df | 1030 | |
4ee9c684 | 1031 | edge |
c60fa3a7 | 1032 | try_redirect_by_replacing_jump (edge e, basic_block target, bool in_cfglayout) |
b36d64df | 1033 | { |
1034 | basic_block src = e->src; | |
3d90435a | 1035 | rtx_insn *insn = BB_END (src), *kill_from; |
b19beda9 | 1036 | rtx set; |
b36d64df | 1037 | int fallthru = 0; |
4f18499c | 1038 | |
1039 | /* If we are partitioning hot/cold basic blocks, we don't want to | |
1040 | mess up unconditional or indirect jumps that cross between hot | |
1118aef7 | 1041 | and cold sections. |
1042 | ||
1043 | Basic block partitioning may result in some jumps that appear to | |
a0c938f0 | 1044 | be optimizable (or blocks that appear to be mergeable), but which really |
1045 | must be left untouched (they are required to make it safely across | |
1046 | partition boundaries). See the comments at the top of | |
1118aef7 | 1047 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
a0c938f0 | 1048 | |
aa78dca5 | 1049 | if (BB_PARTITION (src) != BB_PARTITION (target)) |
53f8294f | 1050 | return NULL; |
4f18499c | 1051 | |
34f05bfa | 1052 | /* We can replace or remove a complex jump only when we have exactly |
1053 | two edges. Also, if we have exactly one outgoing edge, we can | |
1054 | redirect that. */ | |
1055 | if (EDGE_COUNT (src->succs) >= 3 | |
1056 | /* Verify that all targets will be TARGET. Specifically, the | |
1057 | edge that is not E must also go to TARGET. */ | |
1058 | || (EDGE_COUNT (src->succs) == 2 | |
1059 | && EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)) | |
1060 | return NULL; | |
5cc577b6 | 1061 | |
34f05bfa | 1062 | if (!onlyjump_p (insn)) |
4ee9c684 | 1063 | return NULL; |
e5562ab8 | 1064 | if ((!optimize || reload_completed) && tablejump_p (insn, NULL, NULL)) |
4ee9c684 | 1065 | return NULL; |
b36d64df | 1066 | |
1067 | /* Avoid removing branch with side effects. */ | |
1068 | set = single_set (insn); | |
1069 | if (!set || side_effects_p (set)) | |
4ee9c684 | 1070 | return NULL; |
b36d64df | 1071 | |
1072 | /* In case we zap a conditional jump, we'll need to kill | |
1073 | the cc0 setter too. */ | |
1074 | kill_from = insn; | |
ff900b8e | 1075 | if (HAVE_cc0 && reg_mentioned_p (cc0_rtx, PATTERN (insn)) |
3d5a3e76 | 1076 | && only_sets_cc0_p (PREV_INSN (insn))) |
b36d64df | 1077 | kill_from = PREV_INSN (insn); |
b36d64df | 1078 | |
1079 | /* See if we can create the fallthru edge. */ | |
c60fa3a7 | 1080 | if (in_cfglayout || can_fallthru (src, target)) |
b36d64df | 1081 | { |
450d042a | 1082 | if (dump_file) |
1083 | fprintf (dump_file, "Removing jump %i.\n", INSN_UID (insn)); | |
b36d64df | 1084 | fallthru = 1; |
1085 | ||
4a82352a | 1086 | /* Selectively unlink whole insn chain. */ |
c60fa3a7 | 1087 | if (in_cfglayout) |
1088 | { | |
39257eb5 | 1089 | delete_insn_chain (kill_from, BB_END (src), false); |
eb258b7d | 1090 | remove_barriers_from_footer (src); |
c60fa3a7 | 1091 | } |
1092 | else | |
39257eb5 | 1093 | delete_insn_chain (kill_from, PREV_INSN (BB_HEAD (target)), |
1094 | false); | |
b36d64df | 1095 | } |
5cc577b6 | 1096 | |
b36d64df | 1097 | /* If this already is simplejump, redirect it. */ |
1098 | else if (simplejump_p (insn)) | |
1099 | { | |
1100 | if (e->dest == target) | |
4ee9c684 | 1101 | return NULL; |
450d042a | 1102 | if (dump_file) |
1103 | fprintf (dump_file, "Redirecting jump %i from %i to %i.\n", | |
b3d6de89 | 1104 | INSN_UID (insn), e->dest->index, target->index); |
f9a00e9e | 1105 | if (!redirect_jump (as_a <rtx_jump_insn *> (insn), |
1106 | block_label (target), 0)) | |
8963581a | 1107 | { |
34154e27 | 1108 | gcc_assert (target == EXIT_BLOCK_PTR_FOR_FN (cfun)); |
cc636d56 | 1109 | return NULL; |
8963581a | 1110 | } |
b36d64df | 1111 | } |
5cc577b6 | 1112 | |
8963581a | 1113 | /* Cannot do anything for target exit block. */ |
34154e27 | 1114 | else if (target == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
4ee9c684 | 1115 | return NULL; |
8963581a | 1116 | |
b36d64df | 1117 | /* Or replace possibly complicated jump insn by simple jump insn. */ |
1118 | else | |
1119 | { | |
9ed997be | 1120 | rtx_code_label *target_label = block_label (target); |
3d90435a | 1121 | rtx_insn *barrier; |
bc5cd04e | 1122 | rtx_insn *label; |
c86d86ff | 1123 | rtx_jump_table_data *table; |
b36d64df | 1124 | |
1d5ad681 | 1125 | emit_jump_insn_after_noloc (targetm.gen_jump (target_label), insn); |
5496dbfc | 1126 | JUMP_LABEL (BB_END (src)) = target_label; |
b36d64df | 1127 | LABEL_NUSES (target_label)++; |
450d042a | 1128 | if (dump_file) |
1129 | fprintf (dump_file, "Replacing insn %i by jump %i\n", | |
5496dbfc | 1130 | INSN_UID (insn), INSN_UID (BB_END (src))); |
b36d64df | 1131 | |
1ed8ccdb | 1132 | |
201f6961 | 1133 | delete_insn_chain (kill_from, insn, false); |
1134 | ||
1ed8ccdb | 1135 | /* Recognize a tablejump that we are converting to a |
1136 | simple jump and remove its associated CODE_LABEL | |
1137 | and ADDR_VEC or ADDR_DIFF_VEC. */ | |
201f6961 | 1138 | if (tablejump_p (insn, &label, &table)) |
1139 | delete_insn_chain (label, table, false); | |
669f9131 | 1140 | |
bce107d7 | 1141 | barrier = next_nonnote_nondebug_insn (BB_END (src)); |
6d7dc5b9 | 1142 | if (!barrier || !BARRIER_P (barrier)) |
5496dbfc | 1143 | emit_barrier_after (BB_END (src)); |
1824678b | 1144 | else |
1145 | { | |
5496dbfc | 1146 | if (barrier != NEXT_INSN (BB_END (src))) |
1824678b | 1147 | { |
1148 | /* Move the jump before barrier so that the notes | |
1149 | which originally were or were created before jump table are | |
1150 | inside the basic block. */ | |
3d90435a | 1151 | rtx_insn *new_insn = BB_END (src); |
1824678b | 1152 | |
f41d4683 | 1153 | update_bb_for_insn_chain (NEXT_INSN (BB_END (src)), |
1154 | PREV_INSN (barrier), src); | |
1824678b | 1155 | |
4a57a2e8 | 1156 | SET_NEXT_INSN (PREV_INSN (new_insn)) = NEXT_INSN (new_insn); |
1157 | SET_PREV_INSN (NEXT_INSN (new_insn)) = PREV_INSN (new_insn); | |
1824678b | 1158 | |
4a57a2e8 | 1159 | SET_NEXT_INSN (new_insn) = barrier; |
1160 | SET_NEXT_INSN (PREV_INSN (barrier)) = new_insn; | |
1824678b | 1161 | |
4a57a2e8 | 1162 | SET_PREV_INSN (new_insn) = PREV_INSN (barrier); |
1163 | SET_PREV_INSN (barrier) = new_insn; | |
1824678b | 1164 | } |
1165 | } | |
b36d64df | 1166 | } |
1167 | ||
1168 | /* Keep only one edge out and set proper flags. */ | |
ea091dfd | 1169 | if (!single_succ_p (src)) |
cd665a06 | 1170 | remove_edge (e); |
ea091dfd | 1171 | gcc_assert (single_succ_p (src)); |
cd665a06 | 1172 | |
ea091dfd | 1173 | e = single_succ_edge (src); |
b36d64df | 1174 | if (fallthru) |
1175 | e->flags = EDGE_FALLTHRU; | |
1176 | else | |
1177 | e->flags = 0; | |
5cc577b6 | 1178 | |
720cfc43 | 1179 | e->probability = profile_probability::always (); |
b36d64df | 1180 | |
b36d64df | 1181 | if (e->dest != target) |
1182 | redirect_edge_succ (e, target); | |
4ee9c684 | 1183 | return e; |
b36d64df | 1184 | } |
1185 | ||
a8dd994c | 1186 | /* Subroutine of redirect_branch_edge that tries to patch the jump |
1187 | instruction INSN so that it reaches block NEW. Do this | |
1188 | only when it originally reached block OLD. Return true if this | |
1189 | worked or the original target wasn't OLD, return false if redirection | |
1190 | doesn't work. */ | |
1191 | ||
1192 | static bool | |
3d90435a | 1193 | patch_jump_insn (rtx_insn *insn, rtx_insn *old_label, basic_block new_bb) |
b36d64df | 1194 | { |
c86d86ff | 1195 | rtx_jump_table_data *table; |
b36d64df | 1196 | rtx tmp; |
b36d64df | 1197 | /* Recognize a tablejump and adjust all matching cases. */ |
c86d86ff | 1198 | if (tablejump_p (insn, NULL, &table)) |
b36d64df | 1199 | { |
1200 | rtvec vec; | |
1201 | int j; | |
9ed997be | 1202 | rtx_code_label *new_label = block_label (new_bb); |
b36d64df | 1203 | |
34154e27 | 1204 | if (new_bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
a8dd994c | 1205 | return false; |
b77639be | 1206 | vec = table->get_labels (); |
b36d64df | 1207 | |
1208 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
1209 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
1210 | { | |
1211 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (Pmode, new_label); | |
1212 | --LABEL_NUSES (old_label); | |
1213 | ++LABEL_NUSES (new_label); | |
1214 | } | |
1215 | ||
2358393e | 1216 | /* Handle casesi dispatch insns. */ |
7848fa7d | 1217 | if ((tmp = tablejump_casesi_pattern (insn)) != NULL_RTX |
c7799456 | 1218 | && label_ref_label (XEXP (SET_SRC (tmp), 2)) == old_label) |
b36d64df | 1219 | { |
514b43f8 | 1220 | XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (Pmode, |
b36d64df | 1221 | new_label); |
1222 | --LABEL_NUSES (old_label); | |
1223 | ++LABEL_NUSES (new_label); | |
1224 | } | |
1225 | } | |
78f55ca8 | 1226 | else if ((tmp = extract_asm_operands (PATTERN (insn))) != NULL) |
1227 | { | |
1228 | int i, n = ASM_OPERANDS_LABEL_LENGTH (tmp); | |
9ed997be | 1229 | rtx note; |
78f55ca8 | 1230 | |
34154e27 | 1231 | if (new_bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
78f55ca8 | 1232 | return false; |
9ed997be | 1233 | rtx_code_label *new_label = block_label (new_bb); |
78f55ca8 | 1234 | |
1235 | for (i = 0; i < n; ++i) | |
1236 | { | |
1237 | rtx old_ref = ASM_OPERANDS_LABEL (tmp, i); | |
1238 | gcc_assert (GET_CODE (old_ref) == LABEL_REF); | |
1239 | if (XEXP (old_ref, 0) == old_label) | |
1240 | { | |
1241 | ASM_OPERANDS_LABEL (tmp, i) | |
1242 | = gen_rtx_LABEL_REF (Pmode, new_label); | |
1243 | --LABEL_NUSES (old_label); | |
1244 | ++LABEL_NUSES (new_label); | |
1245 | } | |
1246 | } | |
1247 | ||
1248 | if (JUMP_LABEL (insn) == old_label) | |
1249 | { | |
1250 | JUMP_LABEL (insn) = new_label; | |
1251 | note = find_reg_note (insn, REG_LABEL_TARGET, new_label); | |
1252 | if (note) | |
1253 | remove_note (insn, note); | |
1254 | } | |
1255 | else | |
1256 | { | |
1257 | note = find_reg_note (insn, REG_LABEL_TARGET, old_label); | |
1258 | if (note) | |
1259 | remove_note (insn, note); | |
1260 | if (JUMP_LABEL (insn) != new_label | |
1261 | && !find_reg_note (insn, REG_LABEL_TARGET, new_label)) | |
1262 | add_reg_note (insn, REG_LABEL_TARGET, new_label); | |
1263 | } | |
dcb172b4 | 1264 | while ((note = find_reg_note (insn, REG_LABEL_OPERAND, old_label)) |
1265 | != NULL_RTX) | |
1266 | XEXP (note, 0) = new_label; | |
78f55ca8 | 1267 | } |
b36d64df | 1268 | else |
1269 | { | |
1270 | /* ?? We may play the games with moving the named labels from | |
1271 | one basic block to the other in case only one computed_jump is | |
1272 | available. */ | |
5cc577b6 | 1273 | if (computed_jump_p (insn) |
1274 | /* A return instruction can't be redirected. */ | |
1275 | || returnjump_p (insn)) | |
a8dd994c | 1276 | return false; |
8963581a | 1277 | |
a8dd994c | 1278 | if (!currently_expanding_to_rtl || JUMP_LABEL (insn) == old_label) |
8963581a | 1279 | { |
a8dd994c | 1280 | /* If the insn doesn't go where we think, we're confused. */ |
1281 | gcc_assert (JUMP_LABEL (insn) == old_label); | |
1282 | ||
1283 | /* If the substitution doesn't succeed, die. This can happen | |
1284 | if the back end emitted unrecognizable instructions or if | |
6b8784b2 | 1285 | target is exit block on some arches. Or for crossing |
1286 | jumps. */ | |
f9a00e9e | 1287 | if (!redirect_jump (as_a <rtx_jump_insn *> (insn), |
1288 | block_label (new_bb), 0)) | |
a8dd994c | 1289 | { |
6b8784b2 | 1290 | gcc_assert (new_bb == EXIT_BLOCK_PTR_FOR_FN (cfun) |
1291 | || CROSSING_JUMP_P (insn)); | |
a8dd994c | 1292 | return false; |
1293 | } | |
8963581a | 1294 | } |
b36d64df | 1295 | } |
a8dd994c | 1296 | return true; |
1297 | } | |
1298 | ||
1299 | ||
1300 | /* Redirect edge representing branch of (un)conditional jump or tablejump, | |
1301 | NULL on failure */ | |
1302 | static edge | |
1303 | redirect_branch_edge (edge e, basic_block target) | |
1304 | { | |
3d90435a | 1305 | rtx_insn *old_label = BB_HEAD (e->dest); |
a8dd994c | 1306 | basic_block src = e->src; |
3d90435a | 1307 | rtx_insn *insn = BB_END (src); |
a8dd994c | 1308 | |
1309 | /* We can only redirect non-fallthru edges of jump insn. */ | |
1310 | if (e->flags & EDGE_FALLTHRU) | |
1311 | return NULL; | |
1312 | else if (!JUMP_P (insn) && !currently_expanding_to_rtl) | |
1313 | return NULL; | |
1314 | ||
1315 | if (!currently_expanding_to_rtl) | |
1316 | { | |
f9a00e9e | 1317 | if (!patch_jump_insn (as_a <rtx_jump_insn *> (insn), old_label, target)) |
a8dd994c | 1318 | return NULL; |
1319 | } | |
1320 | else | |
1321 | /* When expanding this BB might actually contain multiple | |
1322 | jumps (i.e. not yet split by find_many_sub_basic_blocks). | |
1323 | Redirect all of those that match our label. */ | |
50b15e04 | 1324 | FOR_BB_INSNS (src, insn) |
f9a00e9e | 1325 | if (JUMP_P (insn) && !patch_jump_insn (as_a <rtx_jump_insn *> (insn), |
1326 | old_label, target)) | |
a8dd994c | 1327 | return NULL; |
b36d64df | 1328 | |
450d042a | 1329 | if (dump_file) |
1330 | fprintf (dump_file, "Edge %i->%i redirected to %i\n", | |
b3d6de89 | 1331 | e->src->index, e->dest->index, target->index); |
5cc577b6 | 1332 | |
b36d64df | 1333 | if (e->dest != target) |
4ee9c684 | 1334 | e = redirect_edge_succ_nodup (e, target); |
3072d30e | 1335 | |
4ee9c684 | 1336 | return e; |
c60fa3a7 | 1337 | } |
1338 | ||
aa78dca5 | 1339 | /* Called when edge E has been redirected to a new destination, |
1340 | in order to update the region crossing flag on the edge and | |
1341 | jump. */ | |
1342 | ||
1343 | static void | |
1344 | fixup_partition_crossing (edge e) | |
1345 | { | |
34154e27 | 1346 | if (e->src == ENTRY_BLOCK_PTR_FOR_FN (cfun) || e->dest |
1347 | == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
aa78dca5 | 1348 | return; |
1349 | /* If we redirected an existing edge, it may already be marked | |
1350 | crossing, even though the new src is missing a reg crossing note. | |
1351 | But make sure reg crossing note doesn't already exist before | |
1352 | inserting. */ | |
1353 | if (BB_PARTITION (e->src) != BB_PARTITION (e->dest)) | |
1354 | { | |
1355 | e->flags |= EDGE_CROSSING; | |
f5c4a944 | 1356 | if (JUMP_P (BB_END (e->src))) |
8f869004 | 1357 | CROSSING_JUMP_P (BB_END (e->src)) = 1; |
aa78dca5 | 1358 | } |
1359 | else if (BB_PARTITION (e->src) == BB_PARTITION (e->dest)) | |
1360 | { | |
1361 | e->flags &= ~EDGE_CROSSING; | |
1362 | /* Remove the section crossing note from jump at end of | |
1363 | src if it exists, and if no other successors are | |
1364 | still crossing. */ | |
8f869004 | 1365 | if (JUMP_P (BB_END (e->src)) && CROSSING_JUMP_P (BB_END (e->src))) |
aa78dca5 | 1366 | { |
1367 | bool has_crossing_succ = false; | |
1368 | edge e2; | |
1369 | edge_iterator ei; | |
1370 | FOR_EACH_EDGE (e2, ei, e->src->succs) | |
1371 | { | |
1372 | has_crossing_succ |= (e2->flags & EDGE_CROSSING); | |
1373 | if (has_crossing_succ) | |
1374 | break; | |
1375 | } | |
1376 | if (!has_crossing_succ) | |
8f869004 | 1377 | CROSSING_JUMP_P (BB_END (e->src)) = 0; |
aa78dca5 | 1378 | } |
1379 | } | |
1380 | } | |
1381 | ||
80adc5a6 | 1382 | /* Called when block BB has been reassigned to the cold partition, |
1383 | because it is now dominated by another cold block, | |
1384 | to ensure that the region crossing attributes are updated. */ | |
1385 | ||
1386 | static void | |
1387 | fixup_new_cold_bb (basic_block bb) | |
1388 | { | |
1389 | edge e; | |
1390 | edge_iterator ei; | |
1391 | ||
1392 | /* This is called when a hot bb is found to now be dominated | |
1393 | by a cold bb and therefore needs to become cold. Therefore, | |
1394 | its preds will no longer be region crossing. Any non-dominating | |
1395 | preds that were previously hot would also have become cold | |
1396 | in the caller for the same region. Any preds that were previously | |
1397 | region-crossing will be adjusted in fixup_partition_crossing. */ | |
1398 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1399 | { | |
1400 | fixup_partition_crossing (e); | |
1401 | } | |
1402 | ||
1403 | /* Possibly need to make bb's successor edges region crossing, | |
1404 | or remove stale region crossing. */ | |
1405 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1406 | { | |
1407 | /* We can't have fall-through edges across partition boundaries. | |
1408 | Note that force_nonfallthru will do any necessary partition | |
1409 | boundary fixup by calling fixup_partition_crossing itself. */ | |
1410 | if ((e->flags & EDGE_FALLTHRU) | |
1411 | && BB_PARTITION (bb) != BB_PARTITION (e->dest) | |
34154e27 | 1412 | && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
80adc5a6 | 1413 | force_nonfallthru (e); |
1414 | else | |
1415 | fixup_partition_crossing (e); | |
1416 | } | |
1417 | } | |
1418 | ||
c60fa3a7 | 1419 | /* Attempt to change code to redirect edge E to TARGET. Don't do that on |
1420 | expense of adding new instructions or reordering basic blocks. | |
1421 | ||
1422 | Function can be also called with edge destination equivalent to the TARGET. | |
1423 | Then it should try the simplifications and do nothing if none is possible. | |
1424 | ||
4ee9c684 | 1425 | Return edge representing the branch if transformation succeeded. Return NULL |
1426 | on failure. | |
1427 | We still return NULL in case E already destinated TARGET and we didn't | |
1428 | managed to simplify instruction stream. */ | |
c60fa3a7 | 1429 | |
4ee9c684 | 1430 | static edge |
f82b06e0 | 1431 | rtl_redirect_edge_and_branch (edge e, basic_block target) |
c60fa3a7 | 1432 | { |
4ee9c684 | 1433 | edge ret; |
adee86a0 | 1434 | basic_block src = e->src; |
aa78dca5 | 1435 | basic_block dest = e->dest; |
adee86a0 | 1436 | |
c60fa3a7 | 1437 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
4ee9c684 | 1438 | return NULL; |
c60fa3a7 | 1439 | |
aa78dca5 | 1440 | if (dest == target) |
4ee9c684 | 1441 | return e; |
e5562ab8 | 1442 | |
4ee9c684 | 1443 | if ((ret = try_redirect_by_replacing_jump (e, target, false)) != NULL) |
adee86a0 | 1444 | { |
3072d30e | 1445 | df_set_bb_dirty (src); |
aa78dca5 | 1446 | fixup_partition_crossing (ret); |
4ee9c684 | 1447 | return ret; |
adee86a0 | 1448 | } |
c60fa3a7 | 1449 | |
4ee9c684 | 1450 | ret = redirect_branch_edge (e, target); |
1451 | if (!ret) | |
1452 | return NULL; | |
5cc577b6 | 1453 | |
3072d30e | 1454 | df_set_bb_dirty (src); |
aa78dca5 | 1455 | fixup_partition_crossing (ret); |
4ee9c684 | 1456 | return ret; |
b36d64df | 1457 | } |
1458 | ||
aa78dca5 | 1459 | /* Emit a barrier after BB, into the footer if we are in CFGLAYOUT mode. */ |
1460 | ||
1461 | void | |
1462 | emit_barrier_after_bb (basic_block bb) | |
1463 | { | |
722334ea | 1464 | rtx_barrier *barrier = emit_barrier_after (BB_END (bb)); |
9af5ce0c | 1465 | gcc_assert (current_ir_type () == IR_RTL_CFGRTL |
aa78dca5 | 1466 | || current_ir_type () == IR_RTL_CFGLAYOUT); |
1467 | if (current_ir_type () == IR_RTL_CFGLAYOUT) | |
fb773ec9 | 1468 | { |
1469 | rtx_insn *insn = unlink_insn_chain (barrier, barrier); | |
1470 | ||
1471 | if (BB_FOOTER (bb)) | |
1472 | { | |
1473 | rtx_insn *footer_tail = BB_FOOTER (bb); | |
1474 | ||
1475 | while (NEXT_INSN (footer_tail)) | |
1476 | footer_tail = NEXT_INSN (footer_tail); | |
1477 | if (!BARRIER_P (footer_tail)) | |
1478 | { | |
1479 | SET_NEXT_INSN (footer_tail) = insn; | |
1480 | SET_PREV_INSN (insn) = footer_tail; | |
1481 | } | |
1482 | } | |
1483 | else | |
1484 | BB_FOOTER (bb) = insn; | |
1485 | } | |
aa78dca5 | 1486 | } |
1487 | ||
20dd417a | 1488 | /* Like force_nonfallthru below, but additionally performs redirection |
9cb2517e | 1489 | Used by redirect_edge_and_branch_force. JUMP_LABEL is used only |
1490 | when redirecting to the EXIT_BLOCK, it is either ret_rtx or | |
1491 | simple_return_rtx, indicating which kind of returnjump to create. | |
1492 | It should be NULL otherwise. */ | |
b36d64df | 1493 | |
4115ac36 | 1494 | basic_block |
9cb2517e | 1495 | force_nonfallthru_and_redirect (edge e, basic_block target, rtx jump_label) |
b36d64df | 1496 | { |
498d173d | 1497 | basic_block jump_block, new_bb = NULL, src = e->src; |
b36d64df | 1498 | rtx note; |
1499 | edge new_edge; | |
498d173d | 1500 | int abnormal_edge_flags = 0; |
d7ff3ab6 | 1501 | bool asm_goto_edge = false; |
9c388755 | 1502 | int loc; |
b36d64df | 1503 | |
accd6c44 | 1504 | /* In the case the last instruction is conditional jump to the next |
1505 | instruction, first redirect the jump itself and then continue | |
df07c3ae | 1506 | by creating a basic block afterwards to redirect fallthru edge. */ |
34154e27 | 1507 | if (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
1508 | && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) | |
5496dbfc | 1509 | && any_condjump_p (BB_END (e->src)) |
5496dbfc | 1510 | && JUMP_LABEL (BB_END (e->src)) == BB_HEAD (e->dest)) |
accd6c44 | 1511 | { |
1512 | rtx note; | |
d9aa52be | 1513 | edge b = unchecked_make_edge (e->src, target, 0); |
cc636d56 | 1514 | bool redirected; |
accd6c44 | 1515 | |
f9a00e9e | 1516 | redirected = redirect_jump (as_a <rtx_jump_insn *> (BB_END (e->src)), |
1517 | block_label (target), 0); | |
cc636d56 | 1518 | gcc_assert (redirected); |
a0c938f0 | 1519 | |
5496dbfc | 1520 | note = find_reg_note (BB_END (e->src), REG_BR_PROB, NULL_RTX); |
accd6c44 | 1521 | if (note) |
1522 | { | |
9eb946de | 1523 | int prob = XINT (note, 0); |
accd6c44 | 1524 | |
61cb1816 | 1525 | b->probability = profile_probability::from_reg_br_prob_note (prob); |
accd6c44 | 1526 | e->probability -= e->probability; |
accd6c44 | 1527 | } |
1528 | } | |
1529 | ||
b36d64df | 1530 | if (e->flags & EDGE_ABNORMAL) |
498d173d | 1531 | { |
1532 | /* Irritating special case - fallthru edge to the same block as abnormal | |
1533 | edge. | |
1534 | We can't redirect abnormal edge, but we still can split the fallthru | |
4c9e08a4 | 1535 | one and create separate abnormal edge to original destination. |
498d173d | 1536 | This allows bb-reorder to make such edge non-fallthru. */ |
cc636d56 | 1537 | gcc_assert (e->dest == target); |
4ecbba1a | 1538 | abnormal_edge_flags = e->flags & ~EDGE_FALLTHRU; |
1539 | e->flags &= EDGE_FALLTHRU; | |
498d173d | 1540 | } |
cc636d56 | 1541 | else |
76cc9616 | 1542 | { |
cc636d56 | 1543 | gcc_assert (e->flags & EDGE_FALLTHRU); |
34154e27 | 1544 | if (e->src == ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
cc636d56 | 1545 | { |
1546 | /* We can't redirect the entry block. Create an empty block | |
cd665a06 | 1547 | at the start of the function which we use to add the new |
1548 | jump. */ | |
1549 | edge tmp; | |
1550 | edge_iterator ei; | |
1551 | bool found = false; | |
a0c938f0 | 1552 | |
34154e27 | 1553 | basic_block bb = create_basic_block (BB_HEAD (e->dest), NULL, |
1554 | ENTRY_BLOCK_PTR_FOR_FN (cfun)); | |
205ce1aa | 1555 | bb->count = ENTRY_BLOCK_PTR_FOR_FN (cfun)->count; |
a0c938f0 | 1556 | |
9e9fa2b6 | 1557 | /* Make sure new block ends up in correct hot/cold section. */ |
1558 | BB_COPY_PARTITION (bb, e->dest); | |
1559 | ||
cc636d56 | 1560 | /* Change the existing edge's source to be the new block, and add |
1561 | a new edge from the entry block to the new block. */ | |
1562 | e->src = bb; | |
34154e27 | 1563 | for (ei = ei_start (ENTRY_BLOCK_PTR_FOR_FN (cfun)->succs); |
1564 | (tmp = ei_safe_edge (ei)); ) | |
cd665a06 | 1565 | { |
1566 | if (tmp == e) | |
1567 | { | |
34154e27 | 1568 | ENTRY_BLOCK_PTR_FOR_FN (cfun)->succs->unordered_remove (ei.index); |
cd665a06 | 1569 | found = true; |
1570 | break; | |
1571 | } | |
1572 | else | |
1573 | ei_next (&ei); | |
1574 | } | |
a0c938f0 | 1575 | |
cd665a06 | 1576 | gcc_assert (found); |
a0c938f0 | 1577 | |
f1f41a6c | 1578 | vec_safe_push (bb->succs, e); |
34154e27 | 1579 | make_single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun), bb, |
1580 | EDGE_FALLTHRU); | |
cc636d56 | 1581 | } |
76cc9616 | 1582 | } |
1583 | ||
d7ff3ab6 | 1584 | /* If e->src ends with asm goto, see if any of the ASM_OPERANDS_LABELs |
92f67f6e | 1585 | don't point to the target or fallthru label. */ |
d7ff3ab6 | 1586 | if (JUMP_P (BB_END (e->src)) |
34154e27 | 1587 | && target != EXIT_BLOCK_PTR_FOR_FN (cfun) |
d7ff3ab6 | 1588 | && (e->flags & EDGE_FALLTHRU) |
1589 | && (note = extract_asm_operands (PATTERN (BB_END (e->src))))) | |
b36d64df | 1590 | { |
d7ff3ab6 | 1591 | int i, n = ASM_OPERANDS_LABEL_LENGTH (note); |
ca632883 | 1592 | bool adjust_jump_target = false; |
d7ff3ab6 | 1593 | |
1594 | for (i = 0; i < n; ++i) | |
92f67f6e | 1595 | { |
1596 | if (XEXP (ASM_OPERANDS_LABEL (note, i), 0) == BB_HEAD (e->dest)) | |
ca632883 | 1597 | { |
1598 | LABEL_NUSES (XEXP (ASM_OPERANDS_LABEL (note, i), 0))--; | |
1599 | XEXP (ASM_OPERANDS_LABEL (note, i), 0) = block_label (target); | |
1600 | LABEL_NUSES (XEXP (ASM_OPERANDS_LABEL (note, i), 0))++; | |
1601 | adjust_jump_target = true; | |
1602 | } | |
92f67f6e | 1603 | if (XEXP (ASM_OPERANDS_LABEL (note, i), 0) == BB_HEAD (target)) |
d7ff3ab6 | 1604 | asm_goto_edge = true; |
92f67f6e | 1605 | } |
ca632883 | 1606 | if (adjust_jump_target) |
1607 | { | |
3d90435a | 1608 | rtx_insn *insn = BB_END (e->src); |
1609 | rtx note; | |
1610 | rtx_insn *old_label = BB_HEAD (e->dest); | |
1611 | rtx_insn *new_label = BB_HEAD (target); | |
ca632883 | 1612 | |
1613 | if (JUMP_LABEL (insn) == old_label) | |
1614 | { | |
1615 | JUMP_LABEL (insn) = new_label; | |
1616 | note = find_reg_note (insn, REG_LABEL_TARGET, new_label); | |
1617 | if (note) | |
1618 | remove_note (insn, note); | |
1619 | } | |
1620 | else | |
1621 | { | |
1622 | note = find_reg_note (insn, REG_LABEL_TARGET, old_label); | |
1623 | if (note) | |
1624 | remove_note (insn, note); | |
1625 | if (JUMP_LABEL (insn) != new_label | |
1626 | && !find_reg_note (insn, REG_LABEL_TARGET, new_label)) | |
1627 | add_reg_note (insn, REG_LABEL_TARGET, new_label); | |
1628 | } | |
1629 | while ((note = find_reg_note (insn, REG_LABEL_OPERAND, old_label)) | |
1630 | != NULL_RTX) | |
1631 | XEXP (note, 0) = new_label; | |
1632 | } | |
d7ff3ab6 | 1633 | } |
1634 | ||
1635 | if (EDGE_COUNT (e->src->succs) >= 2 || abnormal_edge_flags || asm_goto_edge) | |
1636 | { | |
4cd001d5 | 1637 | rtx_insn *new_head; |
ea5d3981 | 1638 | profile_count count = e->count (); |
720cfc43 | 1639 | profile_probability probability = e->probability; |
b36d64df | 1640 | /* Create the new structures. */ |
3160014e | 1641 | |
7a1fee99 | 1642 | /* If the old block ended with a tablejump, skip its table |
1643 | by searching forward from there. Otherwise start searching | |
1644 | forward from the last instruction of the old block. */ | |
c86d86ff | 1645 | rtx_jump_table_data *table; |
1646 | if (tablejump_p (BB_END (e->src), NULL, &table)) | |
4cd001d5 | 1647 | new_head = table; |
c86d86ff | 1648 | else |
4cd001d5 | 1649 | new_head = BB_END (e->src); |
1650 | new_head = NEXT_INSN (new_head); | |
3160014e | 1651 | |
4cd001d5 | 1652 | jump_block = create_basic_block (new_head, NULL, e->src); |
d7ff3ab6 | 1653 | jump_block->count = count; |
b36d64df | 1654 | |
4f18499c | 1655 | /* Make sure new block ends up in correct hot/cold section. */ |
1656 | ||
7562ed74 | 1657 | BB_COPY_PARTITION (jump_block, e->src); |
a0c938f0 | 1658 | |
b36d64df | 1659 | /* Wire edge in. */ |
1660 | new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU); | |
d7ff3ab6 | 1661 | new_edge->probability = probability; |
b36d64df | 1662 | |
1663 | /* Redirect old edge. */ | |
1664 | redirect_edge_pred (e, jump_block); | |
720cfc43 | 1665 | e->probability = profile_probability::always (); |
b36d64df | 1666 | |
aa78dca5 | 1667 | /* If e->src was previously region crossing, it no longer is |
1668 | and the reg crossing note should be removed. */ | |
1669 | fixup_partition_crossing (new_edge); | |
1670 | ||
d7ff3ab6 | 1671 | /* If asm goto has any label refs to target's label, |
1672 | add also edge from asm goto bb to target. */ | |
1673 | if (asm_goto_edge) | |
1674 | { | |
720cfc43 | 1675 | new_edge->probability = new_edge->probability.apply_scale (1, 2); |
db9cef39 | 1676 | jump_block->count = jump_block->count.apply_scale (1, 2); |
db9cef39 | 1677 | edge new_edge2 = make_edge (new_edge->src, target, |
1678 | e->flags & ~EDGE_FALLTHRU); | |
1679 | new_edge2->probability = probability - new_edge->probability; | |
d7ff3ab6 | 1680 | } |
1681 | ||
b36d64df | 1682 | new_bb = jump_block; |
1683 | } | |
1684 | else | |
1685 | jump_block = e->src; | |
5cc577b6 | 1686 | |
8e7408e3 | 1687 | loc = e->goto_locus; |
b36d64df | 1688 | e->flags &= ~EDGE_FALLTHRU; |
34154e27 | 1689 | if (target == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
b36d64df | 1690 | { |
9cb2517e | 1691 | if (jump_label == ret_rtx) |
5da5e283 | 1692 | emit_jump_insn_after_setloc (targetm.gen_return (), |
1693 | BB_END (jump_block), loc); | |
9cb2517e | 1694 | else |
1695 | { | |
1696 | gcc_assert (jump_label == simple_return_rtx); | |
5da5e283 | 1697 | emit_jump_insn_after_setloc (targetm.gen_simple_return (), |
9cb2517e | 1698 | BB_END (jump_block), loc); |
9cb2517e | 1699 | } |
31a53363 | 1700 | set_return_jump_label (BB_END (jump_block)); |
b36d64df | 1701 | } |
1702 | else | |
1703 | { | |
9ed997be | 1704 | rtx_code_label *label = block_label (target); |
1d5ad681 | 1705 | emit_jump_insn_after_setloc (targetm.gen_jump (label), |
1706 | BB_END (jump_block), loc); | |
5496dbfc | 1707 | JUMP_LABEL (BB_END (jump_block)) = label; |
b36d64df | 1708 | LABEL_NUSES (label)++; |
1709 | } | |
5cc577b6 | 1710 | |
aa78dca5 | 1711 | /* We might be in cfg layout mode, and if so, the following routine will |
1712 | insert the barrier correctly. */ | |
1713 | emit_barrier_after_bb (jump_block); | |
b36d64df | 1714 | redirect_edge_succ_nodup (e, target); |
1715 | ||
498d173d | 1716 | if (abnormal_edge_flags) |
1717 | make_edge (src, target, abnormal_edge_flags); | |
1718 | ||
48e1416a | 1719 | df_mark_solutions_dirty (); |
aa78dca5 | 1720 | fixup_partition_crossing (e); |
b36d64df | 1721 | return new_bb; |
1722 | } | |
1723 | ||
1724 | /* Edge E is assumed to be fallthru edge. Emit needed jump instruction | |
1725 | (and possibly create new basic block) to make edge non-fallthru. | |
1726 | Return newly created BB or NULL if none. */ | |
5cc577b6 | 1727 | |
202bbc06 | 1728 | static basic_block |
1729 | rtl_force_nonfallthru (edge e) | |
b36d64df | 1730 | { |
9cb2517e | 1731 | return force_nonfallthru_and_redirect (e, e->dest, NULL_RTX); |
b36d64df | 1732 | } |
1733 | ||
1734 | /* Redirect edge even at the expense of creating new jump insn or | |
1735 | basic block. Return new basic block if created, NULL otherwise. | |
a53ff4c1 | 1736 | Conversion must be possible. */ |
b36d64df | 1737 | |
1026363d | 1738 | static basic_block |
4c9e08a4 | 1739 | rtl_redirect_edge_and_branch_force (edge e, basic_block target) |
b36d64df | 1740 | { |
5cc577b6 | 1741 | if (redirect_edge_and_branch (e, target) |
1742 | || e->dest == target) | |
b36d64df | 1743 | return NULL; |
1744 | ||
1745 | /* In case the edge redirection failed, try to force it to be non-fallthru | |
1746 | and redirect newly created simplejump. */ | |
3072d30e | 1747 | df_set_bb_dirty (e->src); |
9cb2517e | 1748 | return force_nonfallthru_and_redirect (e, target, NULL_RTX); |
b36d64df | 1749 | } |
1750 | ||
1751 | /* The given edge should potentially be a fallthru edge. If that is in | |
1752 | fact true, delete the jump and barriers that are in the way. */ | |
1753 | ||
5f5d4cd1 | 1754 | static void |
1755 | rtl_tidy_fallthru_edge (edge e) | |
b36d64df | 1756 | { |
3d90435a | 1757 | rtx_insn *q; |
5f5d4cd1 | 1758 | basic_block b = e->src, c = b->next_bb; |
1759 | ||
b36d64df | 1760 | /* ??? In a late-running flow pass, other folks may have deleted basic |
1761 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
442e3cb9 | 1762 | and the target label. They ought to be chastised and fixed. |
b36d64df | 1763 | |
1764 | We can also wind up with a sequence of undeletable labels between | |
1765 | one block and the next. | |
1766 | ||
1767 | So search through a sequence of barriers, labels, and notes for | |
1768 | the head of block C and assert that we really do fall through. */ | |
1769 | ||
5496dbfc | 1770 | for (q = NEXT_INSN (BB_END (b)); q != BB_HEAD (c); q = NEXT_INSN (q)) |
bce107d7 | 1771 | if (NONDEBUG_INSN_P (q)) |
ac25a327 | 1772 | return; |
b36d64df | 1773 | |
1774 | /* Remove what will soon cease being the jump insn from the source block. | |
1775 | If block B consisted only of this single jump, turn it into a deleted | |
1776 | note. */ | |
5496dbfc | 1777 | q = BB_END (b); |
6d7dc5b9 | 1778 | if (JUMP_P (q) |
b36d64df | 1779 | && onlyjump_p (q) |
1780 | && (any_uncondjump_p (q) | |
ea091dfd | 1781 | || single_succ_p (b))) |
b36d64df | 1782 | { |
bc5cd04e | 1783 | rtx_insn *label; |
1f78217c | 1784 | rtx_jump_table_data *table; |
1785 | ||
1786 | if (tablejump_p (q, &label, &table)) | |
1787 | { | |
1788 | /* The label is likely mentioned in some instruction before | |
1789 | the tablejump and might not be DCEd, so turn it into | |
1790 | a note instead and move before the tablejump that is going to | |
1791 | be deleted. */ | |
1792 | const char *name = LABEL_NAME (label); | |
1793 | PUT_CODE (label, NOTE); | |
1794 | NOTE_KIND (label) = NOTE_INSN_DELETED_LABEL; | |
1795 | NOTE_DELETED_LABEL_NAME (label) = name; | |
bc5cd04e | 1796 | reorder_insns (label, label, PREV_INSN (q)); |
1f78217c | 1797 | delete_insn (table); |
1798 | } | |
1799 | ||
b36d64df | 1800 | /* If this was a conditional jump, we need to also delete |
1801 | the insn that set cc0. */ | |
ff900b8e | 1802 | if (HAVE_cc0 && any_condjump_p (q) && only_sets_cc0_p (PREV_INSN (q))) |
b36d64df | 1803 | q = PREV_INSN (q); |
b36d64df | 1804 | |
1805 | q = PREV_INSN (q); | |
b36d64df | 1806 | } |
e55e93ca | 1807 | /* Unconditional jumps with side-effects (i.e. which we can't just delete |
1808 | together with the barrier) should never have a fallthru edge. */ | |
1809 | else if (JUMP_P (q) && any_uncondjump_p (q)) | |
1810 | return; | |
b36d64df | 1811 | |
1812 | /* Selectively unlink the sequence. */ | |
5496dbfc | 1813 | if (q != PREV_INSN (BB_HEAD (c))) |
39257eb5 | 1814 | delete_insn_chain (NEXT_INSN (q), PREV_INSN (BB_HEAD (c)), false); |
b36d64df | 1815 | |
1816 | e->flags |= EDGE_FALLTHRU; | |
1817 | } | |
b36d64df | 1818 | \f |
5f5d4cd1 | 1819 | /* Should move basic block BB after basic block AFTER. NIY. */ |
1820 | ||
1821 | static bool | |
1822 | rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED, | |
1823 | basic_block after ATTRIBUTE_UNUSED) | |
1824 | { | |
1825 | return false; | |
1826 | } | |
1827 | ||
aa78dca5 | 1828 | /* Locate the last bb in the same partition as START_BB. */ |
1829 | ||
1830 | static basic_block | |
1831 | last_bb_in_partition (basic_block start_bb) | |
1832 | { | |
1833 | basic_block bb; | |
34154e27 | 1834 | FOR_BB_BETWEEN (bb, start_bb, EXIT_BLOCK_PTR_FOR_FN (cfun), next_bb) |
aa78dca5 | 1835 | { |
1836 | if (BB_PARTITION (start_bb) != BB_PARTITION (bb->next_bb)) | |
1837 | return bb; | |
1838 | } | |
efee62d1 | 1839 | /* Return bb before the exit block. */ |
aa78dca5 | 1840 | return bb->prev_bb; |
1841 | } | |
1842 | ||
b36d64df | 1843 | /* Split a (typically critical) edge. Return the new block. |
a53ff4c1 | 1844 | The edge must not be abnormal. |
b36d64df | 1845 | |
1846 | ??? The code generally expects to be called on critical edges. | |
1847 | The case of a block ending in an unconditional jump to a | |
1848 | block with multiple predecessors is not handled optimally. */ | |
1849 | ||
9140e457 | 1850 | static basic_block |
4c9e08a4 | 1851 | rtl_split_edge (edge edge_in) |
b36d64df | 1852 | { |
aa78dca5 | 1853 | basic_block bb, new_bb; |
3d90435a | 1854 | rtx_insn *before; |
b36d64df | 1855 | |
1856 | /* Abnormal edges cannot be split. */ | |
cc636d56 | 1857 | gcc_assert (!(edge_in->flags & EDGE_ABNORMAL)); |
b36d64df | 1858 | |
1859 | /* We are going to place the new block in front of edge destination. | |
4a82352a | 1860 | Avoid existence of fallthru predecessors. */ |
b36d64df | 1861 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) |
1862 | { | |
7f58c05e | 1863 | edge e = find_fallthru_edge (edge_in->dest->preds); |
b36d64df | 1864 | |
1865 | if (e) | |
1866 | force_nonfallthru (e); | |
1867 | } | |
1868 | ||
588aadb7 | 1869 | /* Create the basic block note. */ |
34154e27 | 1870 | if (edge_in->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
5496dbfc | 1871 | before = BB_HEAD (edge_in->dest); |
b36d64df | 1872 | else |
3d90435a | 1873 | before = NULL; |
b36d64df | 1874 | |
9bb8a4af | 1875 | /* If this is a fall through edge to the exit block, the blocks might be |
0a55d497 | 1876 | not adjacent, and the right place is after the source. */ |
34154e27 | 1877 | if ((edge_in->flags & EDGE_FALLTHRU) |
1878 | && edge_in->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
9bb8a4af | 1879 | { |
1880 | before = NEXT_INSN (BB_END (edge_in->src)); | |
9bb8a4af | 1881 | bb = create_basic_block (before, NULL, edge_in->src); |
7562ed74 | 1882 | BB_COPY_PARTITION (bb, edge_in->src); |
9bb8a4af | 1883 | } |
1884 | else | |
065efcb1 | 1885 | { |
34154e27 | 1886 | if (edge_in->src == ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
aa78dca5 | 1887 | { |
1888 | bb = create_basic_block (before, NULL, edge_in->dest->prev_bb); | |
1889 | BB_COPY_PARTITION (bb, edge_in->dest); | |
1890 | } | |
1891 | else | |
1892 | { | |
1893 | basic_block after = edge_in->dest->prev_bb; | |
1894 | /* If this is post-bb reordering, and the edge crosses a partition | |
1895 | boundary, the new block needs to be inserted in the bb chain | |
1896 | at the end of the src partition (since we put the new bb into | |
1897 | that partition, see below). Otherwise we may end up creating | |
1898 | an extra partition crossing in the chain, which is illegal. | |
1899 | It can't go after the src, because src may have a fall-through | |
1900 | to a different block. */ | |
1901 | if (crtl->bb_reorder_complete | |
1902 | && (edge_in->flags & EDGE_CROSSING)) | |
1903 | { | |
1904 | after = last_bb_in_partition (edge_in->src); | |
33a2aaa4 | 1905 | before = get_last_bb_insn (after); |
aa78dca5 | 1906 | /* The instruction following the last bb in partition should |
1907 | be a barrier, since it cannot end in a fall-through. */ | |
1908 | gcc_checking_assert (BARRIER_P (before)); | |
1909 | before = NEXT_INSN (before); | |
1910 | } | |
1911 | bb = create_basic_block (before, NULL, after); | |
1912 | /* Put the split bb into the src partition, to avoid creating | |
1913 | a situation where a cold bb dominates a hot bb, in the case | |
1914 | where src is cold and dest is hot. The src will dominate | |
1915 | the new bb (whereas it might not have dominated dest). */ | |
1916 | BB_COPY_PARTITION (bb, edge_in->src); | |
1917 | } | |
065efcb1 | 1918 | } |
b36d64df | 1919 | |
805e22b2 | 1920 | make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU); |
b36d64df | 1921 | |
aa78dca5 | 1922 | /* Can't allow a region crossing edge to be fallthrough. */ |
1923 | if (BB_PARTITION (bb) != BB_PARTITION (edge_in->dest) | |
34154e27 | 1924 | && edge_in->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
aa78dca5 | 1925 | { |
1926 | new_bb = force_nonfallthru (single_succ_edge (bb)); | |
1927 | gcc_assert (!new_bb); | |
1928 | } | |
1929 | ||
917bbcab | 1930 | /* For non-fallthru edges, we must adjust the predecessor's |
b36d64df | 1931 | jump instruction to target our new block. */ |
1932 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1933 | { | |
cc636d56 | 1934 | edge redirected = redirect_edge_and_branch (edge_in, bb); |
1935 | gcc_assert (redirected); | |
b36d64df | 1936 | } |
1937 | else | |
dcb172b4 | 1938 | { |
34154e27 | 1939 | if (edge_in->src != ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
dcb172b4 | 1940 | { |
1941 | /* For asm goto even splitting of fallthru edge might | |
1942 | need insn patching, as other labels might point to the | |
1943 | old label. */ | |
3d90435a | 1944 | rtx_insn *last = BB_END (edge_in->src); |
dcb172b4 | 1945 | if (last |
1946 | && JUMP_P (last) | |
34154e27 | 1947 | && edge_in->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) |
d9017e57 | 1948 | && (extract_asm_operands (PATTERN (last)) |
1949 | || JUMP_LABEL (last) == before) | |
dcb172b4 | 1950 | && patch_jump_insn (last, before, bb)) |
1951 | df_set_bb_dirty (edge_in->src); | |
1952 | } | |
1953 | redirect_edge_succ (edge_in, bb); | |
1954 | } | |
b36d64df | 1955 | |
1956 | return bb; | |
1957 | } | |
1958 | ||
1959 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1960 | The new instructions and basic blocks (if any) will not appear in the | |
1961 | CFG until commit_edge_insertions is called. */ | |
1962 | ||
1963 | void | |
4c9e08a4 | 1964 | insert_insn_on_edge (rtx pattern, edge e) |
b36d64df | 1965 | { |
1966 | /* We cannot insert instructions on an abnormal critical edge. | |
1967 | It will be easier to find the culprit if we die now. */ | |
cc636d56 | 1968 | gcc_assert (!((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e))); |
b36d64df | 1969 | |
4ee9c684 | 1970 | if (e->insns.r == NULL_RTX) |
b36d64df | 1971 | start_sequence (); |
1972 | else | |
4ee9c684 | 1973 | push_to_sequence (e->insns.r); |
b36d64df | 1974 | |
1975 | emit_insn (pattern); | |
1976 | ||
4ee9c684 | 1977 | e->insns.r = get_insns (); |
b36d64df | 1978 | end_sequence (); |
1979 | } | |
1980 | ||
1981 | /* Update the CFG for the instructions queued on edge E. */ | |
1982 | ||
a8dd994c | 1983 | void |
ca462ec0 | 1984 | commit_one_edge_insertion (edge e) |
b36d64df | 1985 | { |
3d90435a | 1986 | rtx_insn *before = NULL, *after = NULL, *insns, *tmp, *last; |
53105d88 | 1987 | basic_block bb; |
b36d64df | 1988 | |
1989 | /* Pull the insns off the edge now since the edge might go away. */ | |
ae5e6486 | 1990 | insns = e->insns.r; |
1991 | e->insns.r = NULL; | |
b36d64df | 1992 | |
53105d88 | 1993 | /* Figure out where to put these insns. If the destination has |
1994 | one predecessor, insert there. Except for the exit block. */ | |
34154e27 | 1995 | if (single_pred_p (e->dest) && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
b36d64df | 1996 | { |
53105d88 | 1997 | bb = e->dest; |
1998 | ||
1999 | /* Get the location correct wrt a code label, and "nice" wrt | |
2000 | a basic block note, and before everything else. */ | |
2001 | tmp = BB_HEAD (bb); | |
2002 | if (LABEL_P (tmp)) | |
2003 | tmp = NEXT_INSN (tmp); | |
2004 | if (NOTE_INSN_BASIC_BLOCK_P (tmp)) | |
2005 | tmp = NEXT_INSN (tmp); | |
2006 | if (tmp == BB_HEAD (bb)) | |
2007 | before = tmp; | |
2008 | else if (tmp) | |
2009 | after = PREV_INSN (tmp); | |
2010 | else | |
2011 | after = get_last_insn (); | |
2012 | } | |
fb20d6fa | 2013 | |
53105d88 | 2014 | /* If the source has one successor and the edge is not abnormal, |
8315fc61 | 2015 | insert there. Except for the entry block. |
2016 | Don't do this if the predecessor ends in a jump other than | |
2017 | unconditional simple jump. E.g. for asm goto that points all | |
2018 | its labels at the fallthru basic block, we can't insert instructions | |
2019 | before the asm goto, as the asm goto can have various of side effects, | |
2020 | and can't emit instructions after the asm goto, as it must end | |
2021 | the basic block. */ | |
53105d88 | 2022 | else if ((e->flags & EDGE_ABNORMAL) == 0 |
2023 | && single_succ_p (e->src) | |
34154e27 | 2024 | && e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
8315fc61 | 2025 | && (!JUMP_P (BB_END (e->src)) |
2026 | || simplejump_p (BB_END (e->src)))) | |
53105d88 | 2027 | { |
2028 | bb = e->src; | |
fb20d6fa | 2029 | |
53105d88 | 2030 | /* It is possible to have a non-simple jump here. Consider a target |
2031 | where some forms of unconditional jumps clobber a register. This | |
2032 | happens on the fr30 for example. | |
b36d64df | 2033 | |
53105d88 | 2034 | We know this block has a single successor, so we can just emit |
2035 | the queued insns before the jump. */ | |
2036 | if (JUMP_P (BB_END (bb))) | |
2037 | before = BB_END (bb); | |
fb20d6fa | 2038 | else |
2039 | { | |
53105d88 | 2040 | /* We'd better be fallthru, or we've lost track of what's what. */ |
2041 | gcc_assert (e->flags & EDGE_FALLTHRU); | |
4f18499c | 2042 | |
53105d88 | 2043 | after = BB_END (bb); |
b36d64df | 2044 | } |
2045 | } | |
2046 | ||
53105d88 | 2047 | /* Otherwise we must split the edge. */ |
2048 | else | |
2049 | { | |
2050 | bb = split_edge (e); | |
aa78dca5 | 2051 | |
2052 | /* If E crossed a partition boundary, we needed to make bb end in | |
2053 | a region-crossing jump, even though it was originally fallthru. */ | |
2054 | if (JUMP_P (BB_END (bb))) | |
2055 | before = BB_END (bb); | |
2056 | else | |
2057 | after = BB_END (bb); | |
53105d88 | 2058 | } |
2059 | ||
2060 | /* Now that we've found the spot, do the insertion. */ | |
b36d64df | 2061 | if (before) |
2062 | { | |
3072d30e | 2063 | emit_insn_before_noloc (insns, before, bb); |
b36d64df | 2064 | last = prev_nonnote_insn (before); |
2065 | } | |
2066 | else | |
3072d30e | 2067 | last = emit_insn_after_noloc (insns, after, bb); |
b36d64df | 2068 | |
2069 | if (returnjump_p (last)) | |
2070 | { | |
2071 | /* ??? Remove all outgoing edges from BB and add one for EXIT. | |
a0c938f0 | 2072 | This is not currently a problem because this only happens |
2073 | for the (single) epilogue, which already has a fallthru edge | |
2074 | to EXIT. */ | |
b36d64df | 2075 | |
ea091dfd | 2076 | e = single_succ_edge (bb); |
34154e27 | 2077 | gcc_assert (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) |
ea091dfd | 2078 | && single_succ_p (bb) && (e->flags & EDGE_FALLTHRU)); |
b36d64df | 2079 | |
5cc577b6 | 2080 | e->flags &= ~EDGE_FALLTHRU; |
b36d64df | 2081 | emit_barrier_after (last); |
b3d6de89 | 2082 | |
b36d64df | 2083 | if (before) |
2084 | delete_insn (before); | |
2085 | } | |
cc636d56 | 2086 | else |
2087 | gcc_assert (!JUMP_P (last)); | |
b36d64df | 2088 | } |
2089 | ||
2090 | /* Update the CFG for all queued instructions. */ | |
2091 | ||
2092 | void | |
4c9e08a4 | 2093 | commit_edge_insertions (void) |
b36d64df | 2094 | { |
b36d64df | 2095 | basic_block bb; |
2096 | ||
80adc5a6 | 2097 | /* Optimization passes that invoke this routine can cause hot blocks |
2098 | previously reached by both hot and cold blocks to become dominated only | |
2099 | by cold blocks. This will cause the verification below to fail, | |
2100 | and lead to now cold code in the hot section. In some cases this | |
2101 | may only be visible after newly unreachable blocks are deleted, | |
2102 | which will be done by fixup_partitions. */ | |
2103 | fixup_partitions (); | |
2104 | ||
28cf2b46 | 2105 | if (!currently_expanding_to_rtl) |
2106 | checking_verify_flow_info (); | |
b36d64df | 2107 | |
34154e27 | 2108 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (cfun), |
2109 | EXIT_BLOCK_PTR_FOR_FN (cfun), next_bb) | |
b36d64df | 2110 | { |
cd665a06 | 2111 | edge e; |
2112 | edge_iterator ei; | |
b36d64df | 2113 | |
cd665a06 | 2114 | FOR_EACH_EDGE (e, ei, bb->succs) |
2115 | if (e->insns.r) | |
357d109c | 2116 | { |
2117 | if (currently_expanding_to_rtl) | |
2118 | rebuild_jump_labels_chain (e->insns.r); | |
2119 | commit_one_edge_insertion (e); | |
2120 | } | |
fb20d6fa | 2121 | } |
b36d64df | 2122 | } |
2123 | \f | |
3072d30e | 2124 | |
5f5d4cd1 | 2125 | /* Print out RTL-specific basic block information (live information |
5147ec07 | 2126 | at start and end with TDF_DETAILS). FLAGS are the TDF_* masks |
2127 | documented in dumpfile.h. */ | |
b36d64df | 2128 | |
028f8cc7 | 2129 | static void |
3f6e5ced | 2130 | rtl_dump_bb (FILE *outf, basic_block bb, int indent, dump_flags_t flags) |
b36d64df | 2131 | { |
5f5d4cd1 | 2132 | char *s_indent; |
b36d64df | 2133 | |
f780cc25 | 2134 | s_indent = (char *) alloca ((size_t) indent + 1); |
4acc30e5 | 2135 | memset (s_indent, ' ', (size_t) indent); |
5f5d4cd1 | 2136 | s_indent[indent] = '\0'; |
48e1416a | 2137 | |
5147ec07 | 2138 | if (df && (flags & TDF_DETAILS)) |
3072d30e | 2139 | { |
2140 | df_dump_top (bb, outf); | |
2141 | putc ('\n', outf); | |
2142 | } | |
b36d64df | 2143 | |
4c2112a3 | 2144 | if (bb->index != ENTRY_BLOCK && bb->index != EXIT_BLOCK) |
f5d62967 | 2145 | { |
2146 | rtx_insn *last = BB_END (bb); | |
2147 | if (last) | |
2148 | last = NEXT_INSN (last); | |
2149 | for (rtx_insn *insn = BB_HEAD (bb); insn != last; insn = NEXT_INSN (insn)) | |
2150 | { | |
2151 | if (flags & TDF_DETAILS) | |
2152 | df_dump_insn_top (insn, outf); | |
2153 | if (! (flags & TDF_SLIM)) | |
2154 | print_rtl_single (outf, insn); | |
2155 | else | |
2156 | dump_insn_slim (outf, insn); | |
2157 | if (flags & TDF_DETAILS) | |
2158 | df_dump_insn_bottom (insn, outf); | |
2159 | } | |
2160 | } | |
5147ec07 | 2161 | |
2162 | if (df && (flags & TDF_DETAILS)) | |
3072d30e | 2163 | { |
2164 | df_dump_bottom (bb, outf); | |
2165 | putc ('\n', outf); | |
2166 | } | |
2167 | ||
b36d64df | 2168 | } |
2169 | \f | |
bec2cf98 | 2170 | /* Like dump_function_to_file, but for RTL. Print out dataflow information |
2171 | for the start of each basic block. FLAGS are the TDF_* masks documented | |
2172 | in dumpfile.h. */ | |
b36d64df | 2173 | |
2174 | void | |
3f6e5ced | 2175 | print_rtl_with_bb (FILE *outf, const rtx_insn *rtx_first, dump_flags_t flags) |
b36d64df | 2176 | { |
e149ca56 | 2177 | const rtx_insn *tmp_rtx; |
b36d64df | 2178 | if (rtx_first == 0) |
2179 | fprintf (outf, "(nil)\n"); | |
2180 | else | |
2181 | { | |
b36d64df | 2182 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
2183 | int max_uid = get_max_uid (); | |
4c36ffe6 | 2184 | basic_block *start = XCNEWVEC (basic_block, max_uid); |
2185 | basic_block *end = XCNEWVEC (basic_block, max_uid); | |
2186 | enum bb_state *in_bb_p = XCNEWVEC (enum bb_state, max_uid); | |
4c26117a | 2187 | basic_block bb; |
2188 | ||
bec2cf98 | 2189 | /* After freeing the CFG, we still have BLOCK_FOR_INSN set on most |
2190 | insns, but the CFG is not maintained so the basic block info | |
2191 | is not reliable. Therefore it's omitted from the dumps. */ | |
2192 | if (! (cfun->curr_properties & PROP_cfg)) | |
2193 | flags &= ~TDF_BLOCKS; | |
2194 | ||
3072d30e | 2195 | if (df) |
2196 | df_dump_start (outf); | |
2197 | ||
49e05c32 | 2198 | if (cfun->curr_properties & PROP_cfg) |
b36d64df | 2199 | { |
7a46197b | 2200 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
b36d64df | 2201 | { |
3d90435a | 2202 | rtx_insn *x; |
bec2cf98 | 2203 | |
2204 | start[INSN_UID (BB_HEAD (bb))] = bb; | |
2205 | end[INSN_UID (BB_END (bb))] = bb; | |
49e05c32 | 2206 | if (flags & TDF_BLOCKS) |
bec2cf98 | 2207 | { |
49e05c32 | 2208 | for (x = BB_HEAD (bb); x != NULL_RTX; x = NEXT_INSN (x)) |
2209 | { | |
2210 | enum bb_state state = IN_MULTIPLE_BB; | |
5cc577b6 | 2211 | |
49e05c32 | 2212 | if (in_bb_p[INSN_UID (x)] == NOT_IN_BB) |
2213 | state = IN_ONE_BB; | |
2214 | in_bb_p[INSN_UID (x)] = state; | |
b36d64df | 2215 | |
49e05c32 | 2216 | if (x == BB_END (bb)) |
2217 | break; | |
2218 | } | |
bec2cf98 | 2219 | } |
b36d64df | 2220 | } |
2221 | } | |
2222 | ||
c9281ef8 | 2223 | for (tmp_rtx = rtx_first; tmp_rtx != NULL; tmp_rtx = NEXT_INSN (tmp_rtx)) |
b36d64df | 2224 | { |
bec2cf98 | 2225 | if (flags & TDF_BLOCKS) |
2226 | { | |
2227 | bb = start[INSN_UID (tmp_rtx)]; | |
2228 | if (bb != NULL) | |
2229 | { | |
7f337d45 | 2230 | dump_bb_info (outf, bb, 0, dump_flags, true, false); |
bec2cf98 | 2231 | if (df && (flags & TDF_DETAILS)) |
2232 | df_dump_top (bb, outf); | |
2233 | } | |
b36d64df | 2234 | |
bec2cf98 | 2235 | if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB |
2236 | && !NOTE_P (tmp_rtx) | |
2237 | && !BARRIER_P (tmp_rtx)) | |
2238 | fprintf (outf, ";; Insn is not within a basic block\n"); | |
2239 | else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB) | |
2240 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); | |
2241 | } | |
b36d64df | 2242 | |
ea9538fb | 2243 | if (flags & TDF_DETAILS) |
2244 | df_dump_insn_top (tmp_rtx, outf); | |
5147ec07 | 2245 | if (! (flags & TDF_SLIM)) |
2246 | print_rtl_single (outf, tmp_rtx); | |
2247 | else | |
2248 | dump_insn_slim (outf, tmp_rtx); | |
ea9538fb | 2249 | if (flags & TDF_DETAILS) |
2250 | df_dump_insn_bottom (tmp_rtx, outf); | |
b36d64df | 2251 | |
49e05c32 | 2252 | bb = end[INSN_UID (tmp_rtx)]; |
2253 | if (bb != NULL) | |
bec2cf98 | 2254 | { |
49e05c32 | 2255 | if (flags & TDF_BLOCKS) |
bec2cf98 | 2256 | { |
7f337d45 | 2257 | dump_bb_info (outf, bb, 0, dump_flags, false, true); |
bec2cf98 | 2258 | if (df && (flags & TDF_DETAILS)) |
2259 | df_dump_bottom (bb, outf); | |
a30975d4 | 2260 | putc ('\n', outf); |
bec2cf98 | 2261 | } |
49e05c32 | 2262 | /* Emit a hint if the fallthrough target of current basic block |
2263 | isn't the one placed right next. */ | |
2264 | else if (EDGE_COUNT (bb->succs) > 0) | |
2265 | { | |
2266 | gcc_assert (BB_END (bb) == tmp_rtx); | |
2267 | const rtx_insn *ninsn = NEXT_INSN (tmp_rtx); | |
2268 | /* Bypass intervening deleted-insn notes and debug insns. */ | |
2269 | while (ninsn | |
2270 | && !NONDEBUG_INSN_P (ninsn) | |
2271 | && !start[INSN_UID (ninsn)]) | |
2272 | ninsn = NEXT_INSN (ninsn); | |
2273 | edge e = find_fallthru_edge (bb->succs); | |
2274 | if (e && ninsn) | |
2275 | { | |
2276 | basic_block dest = e->dest; | |
2277 | if (start[INSN_UID (ninsn)] != dest) | |
2278 | fprintf (outf, "%s ; pc falls through to BB %d\n", | |
2279 | print_rtx_head, dest->index); | |
2280 | } | |
2281 | } | |
bec2cf98 | 2282 | } |
b36d64df | 2283 | } |
2284 | ||
2285 | free (start); | |
2286 | free (end); | |
2287 | free (in_bb_p); | |
2288 | } | |
b36d64df | 2289 | } |
2290 | \f | |
4a020a8c | 2291 | /* Update the branch probability of BB if a REG_BR_PROB is present. */ |
2292 | ||
f884e43f | 2293 | void |
4c9e08a4 | 2294 | update_br_prob_note (basic_block bb) |
f884e43f | 2295 | { |
2296 | rtx note; | |
5496dbfc | 2297 | note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX); |
205ce1aa | 2298 | if (!JUMP_P (BB_END (bb)) || !BRANCH_EDGE (bb)->probability.initialized_p ()) |
2299 | { | |
2300 | if (note) | |
2301 | { | |
2302 | rtx *note_link, this_rtx; | |
2303 | ||
2304 | note_link = ®_NOTES (BB_END (bb)); | |
2305 | for (this_rtx = *note_link; this_rtx; this_rtx = XEXP (this_rtx, 1)) | |
2306 | if (this_rtx == note) | |
2307 | { | |
2308 | *note_link = XEXP (this_rtx, 1); | |
2309 | break; | |
2310 | } | |
2311 | } | |
2312 | return; | |
2313 | } | |
720cfc43 | 2314 | if (!note |
61cb1816 | 2315 | || XINT (note, 0) == BRANCH_EDGE (bb)->probability.to_reg_br_prob_note ()) |
f884e43f | 2316 | return; |
61cb1816 | 2317 | XINT (note, 0) = BRANCH_EDGE (bb)->probability.to_reg_br_prob_note (); |
f884e43f | 2318 | } |
5d65a39c | 2319 | |
2320 | /* Get the last insn associated with block BB (that includes barriers and | |
2321 | tablejumps after BB). */ | |
2d63955f | 2322 | rtx_insn * |
5d65a39c | 2323 | get_last_bb_insn (basic_block bb) |
2324 | { | |
c86d86ff | 2325 | rtx_jump_table_data *table; |
2d63955f | 2326 | rtx_insn *tmp; |
2327 | rtx_insn *end = BB_END (bb); | |
5d65a39c | 2328 | |
2329 | /* Include any jump table following the basic block. */ | |
c86d86ff | 2330 | if (tablejump_p (end, NULL, &table)) |
2331 | end = table; | |
5d65a39c | 2332 | |
2333 | /* Include any barriers that may follow the basic block. */ | |
18fc6357 | 2334 | tmp = next_nonnote_nondebug_insn_bb (end); |
5d65a39c | 2335 | while (tmp && BARRIER_P (tmp)) |
2336 | { | |
2337 | end = tmp; | |
18fc6357 | 2338 | tmp = next_nonnote_nondebug_insn_bb (end); |
5d65a39c | 2339 | } |
2340 | ||
2341 | return end; | |
2342 | } | |
812ca88e | 2343 | |
bfe34407 | 2344 | /* Add all BBs reachable from entry via hot paths into the SET. */ |
2345 | ||
2346 | void | |
2347 | find_bbs_reachable_by_hot_paths (hash_set<basic_block> *set) | |
2348 | { | |
2349 | auto_vec<basic_block, 64> worklist; | |
2350 | ||
2351 | set->add (ENTRY_BLOCK_PTR_FOR_FN (cfun)); | |
2352 | worklist.safe_push (ENTRY_BLOCK_PTR_FOR_FN (cfun)); | |
2353 | ||
2354 | while (worklist.length () > 0) | |
2355 | { | |
2356 | basic_block bb = worklist.pop (); | |
2357 | edge_iterator ei; | |
2358 | edge e; | |
2359 | ||
2360 | FOR_EACH_EDGE (e, ei, bb->succs) | |
2361 | if (BB_PARTITION (e->dest) != BB_COLD_PARTITION | |
2362 | && !set->add (e->dest)) | |
2363 | worklist.safe_push (e->dest); | |
2364 | } | |
2365 | } | |
2366 | ||
80adc5a6 | 2367 | /* Sanity check partition hotness to ensure that basic blocks in |
2368 | Â the cold partition don't dominate basic blocks in the hot partition. | |
2369 | If FLAG_ONLY is true, report violations as errors. Otherwise | |
2370 | re-mark the dominated blocks as cold, since this is run after | |
2371 | cfg optimizations that may make hot blocks previously reached | |
2372 | by both hot and cold blocks now only reachable along cold paths. */ | |
2373 | ||
2374 | static vec<basic_block> | |
2375 | find_partition_fixes (bool flag_only) | |
2376 | { | |
2377 | basic_block bb; | |
80adc5a6 | 2378 | vec<basic_block> bbs_to_fix = vNULL; |
bfe34407 | 2379 | hash_set<basic_block> set; |
80adc5a6 | 2380 | |
2381 | /* Callers check this. */ | |
2382 | gcc_checking_assert (crtl->has_bb_partition); | |
2383 | ||
bfe34407 | 2384 | find_bbs_reachable_by_hot_paths (&set); |
80adc5a6 | 2385 | |
bfe34407 | 2386 | FOR_EACH_BB_FN (bb, cfun) |
2387 | if (!set.contains (bb) | |
2388 | && BB_PARTITION (bb) != BB_COLD_PARTITION) | |
2389 | { | |
2390 | if (flag_only) | |
2391 | error ("non-cold basic block %d reachable only " | |
2392 | "by paths crossing the cold partition", bb->index); | |
2393 | else | |
2394 | BB_SET_PARTITION (bb, BB_COLD_PARTITION); | |
2395 | bbs_to_fix.safe_push (bb); | |
bfe34407 | 2396 | } |
80adc5a6 | 2397 | |
2398 | return bbs_to_fix; | |
2399 | } | |
2400 | ||
2401 | /* Perform cleanup on the hot/cold bb partitioning after optimization | |
2402 | passes that modify the cfg. */ | |
2403 | ||
2404 | void | |
2405 | fixup_partitions (void) | |
2406 | { | |
2407 | basic_block bb; | |
2408 | ||
2409 | if (!crtl->has_bb_partition) | |
2410 | return; | |
2411 | ||
2412 | /* Delete any blocks that became unreachable and weren't | |
2413 | already cleaned up, for example during edge forwarding | |
2414 | and convert_jumps_to_returns. This will expose more | |
2415 | opportunities for fixing the partition boundaries here. | |
2416 | Also, the calculation of the dominance graph during verification | |
2417 | will assert if there are unreachable nodes. */ | |
2418 | delete_unreachable_blocks (); | |
2419 | ||
2420 | /* If there are partitions, do a sanity check on them: A basic block in | |
2421 | Â a cold partition cannot dominate a basic block in a hot partition. | |
2422 | Fixup any that now violate this requirement, as a result of edge | |
2423 | forwarding and unreachable block deletion. Â */ | |
2424 | vec<basic_block> bbs_to_fix = find_partition_fixes (false); | |
2425 | ||
2426 | /* Do the partition fixup after all necessary blocks have been converted to | |
2427 | cold, so that we only update the region crossings the minimum number of | |
2428 | places, which can require forcing edges to be non fallthru. */ | |
2429 | while (! bbs_to_fix.is_empty ()) | |
2430 | { | |
2431 | bb = bbs_to_fix.pop (); | |
2432 | fixup_new_cold_bb (bb); | |
2433 | } | |
2434 | } | |
2435 | ||
812ca88e | 2436 | /* Verify, in the basic block chain, that there is at most one switch |
2437 | between hot/cold partitions. This condition will not be true until | |
2438 | after reorder_basic_blocks is called. */ | |
2439 | ||
4bf32a77 | 2440 | static int |
812ca88e | 2441 | verify_hot_cold_block_grouping (void) |
2442 | { | |
2443 | basic_block bb; | |
2444 | int err = 0; | |
2445 | bool switched_sections = false; | |
2446 | int current_partition = BB_UNPARTITIONED; | |
2447 | ||
aa78dca5 | 2448 | /* Even after bb reordering is complete, we go into cfglayout mode |
2449 | again (in compgoto). Ensure we don't call this before going back | |
2450 | into linearized RTL when any layout fixes would have been committed. */ | |
2451 | if (!crtl->bb_reorder_complete | |
9af5ce0c | 2452 | || current_ir_type () != IR_RTL_CFGRTL) |
4bf32a77 | 2453 | return err; |
812ca88e | 2454 | |
fc00614f | 2455 | FOR_EACH_BB_FN (bb, cfun) |
812ca88e | 2456 | { |
2457 | if (current_partition != BB_UNPARTITIONED | |
2458 | && BB_PARTITION (bb) != current_partition) | |
2459 | { | |
2460 | if (switched_sections) | |
2461 | { | |
2462 | error ("multiple hot/cold transitions found (bb %i)", | |
2463 | bb->index); | |
2464 | err = 1; | |
2465 | } | |
2466 | else | |
2467 | switched_sections = true; | |
2468 | ||
2469 | if (!crtl->has_bb_partition) | |
2470 | error ("partition found but function partition flag not set"); | |
2471 | } | |
2472 | current_partition = BB_PARTITION (bb); | |
2473 | } | |
2474 | ||
4bf32a77 | 2475 | return err; |
812ca88e | 2476 | } |
f884e43f | 2477 | \f |
b36d64df | 2478 | |
4bf32a77 | 2479 | /* Perform several checks on the edges out of each block, such as |
2480 | the consistency of the branch probabilities, the correctness | |
2481 | of hot/cold partition crossing edges, and the number of expected | |
80adc5a6 | 2482 | successor edges. Also verify that the dominance relationship |
2483 | between hot/cold blocks is sane. */ | |
5f5d4cd1 | 2484 | |
028f8cc7 | 2485 | static int |
4bf32a77 | 2486 | rtl_verify_edges (void) |
b36d64df | 2487 | { |
028f8cc7 | 2488 | int err = 0; |
d207f783 | 2489 | basic_block bb; |
b36d64df | 2490 | |
7a46197b | 2491 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
b36d64df | 2492 | { |
103dfb10 | 2493 | int n_fallthru = 0, n_branch = 0, n_abnormal_call = 0, n_sibcall = 0; |
2494 | int n_eh = 0, n_abnormal = 0; | |
e6261ab0 | 2495 | edge e, fallthru = NULL; |
cd665a06 | 2496 | edge_iterator ei; |
4bf32a77 | 2497 | rtx note; |
aa78dca5 | 2498 | bool has_crossing_edge = false; |
b36d64df | 2499 | |
e6d1500f | 2500 | if (JUMP_P (BB_END (bb)) |
5496dbfc | 2501 | && (note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX)) |
cd665a06 | 2502 | && EDGE_COUNT (bb->succs) >= 2 |
5496dbfc | 2503 | && any_condjump_p (BB_END (bb))) |
a2e42321 | 2504 | { |
720cfc43 | 2505 | if (!BRANCH_EDGE (bb)->probability.initialized_p ()) |
2506 | { | |
76b29368 | 2507 | if (profile_status_for_fn (cfun) != PROFILE_ABSENT) |
720cfc43 | 2508 | { |
76b29368 | 2509 | error ("verify_flow_info: " |
2510 | "REG_BR_PROB is set but cfg probability is not"); | |
2511 | err = 1; | |
720cfc43 | 2512 | } |
2513 | } | |
2514 | else if (XINT (note, 0) | |
61cb1816 | 2515 | != BRANCH_EDGE (bb)->probability.to_reg_br_prob_note () |
720cfc43 | 2516 | && profile_status_for_fn (cfun) != PROFILE_ABSENT) |
a2e42321 | 2517 | { |
9eb946de | 2518 | error ("verify_flow_info: REG_BR_PROB does not match cfg %i %i", |
720cfc43 | 2519 | XINT (note, 0), |
61cb1816 | 2520 | BRANCH_EDGE (bb)->probability.to_reg_br_prob_note ()); |
a2e42321 | 2521 | err = 1; |
2522 | } | |
2523 | } | |
4bf32a77 | 2524 | |
cd665a06 | 2525 | FOR_EACH_EDGE (e, ei, bb->succs) |
b36d64df | 2526 | { |
f59cbcbf | 2527 | bool is_crossing; |
2528 | ||
b36d64df | 2529 | if (e->flags & EDGE_FALLTHRU) |
f59cbcbf | 2530 | n_fallthru++, fallthru = e; |
2531 | ||
2532 | is_crossing = (BB_PARTITION (e->src) != BB_PARTITION (e->dest) | |
34154e27 | 2533 | && e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
2534 | && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)); | |
aa78dca5 | 2535 | has_crossing_edge |= is_crossing; |
f59cbcbf | 2536 | if (e->flags & EDGE_CROSSING) |
4f18499c | 2537 | { |
f59cbcbf | 2538 | if (!is_crossing) |
2539 | { | |
2540 | error ("EDGE_CROSSING incorrectly set across same section"); | |
2541 | err = 1; | |
2542 | } | |
2543 | if (e->flags & EDGE_FALLTHRU) | |
2544 | { | |
103dfb10 | 2545 | error ("fallthru edge crosses section boundary in bb %i", |
4f18499c | 2546 | e->src->index); |
2547 | err = 1; | |
2548 | } | |
f59cbcbf | 2549 | if (e->flags & EDGE_EH) |
2550 | { | |
103dfb10 | 2551 | error ("EH edge crosses section boundary in bb %i", |
f59cbcbf | 2552 | e->src->index); |
2553 | err = 1; | |
2554 | } | |
8f869004 | 2555 | if (JUMP_P (BB_END (bb)) && !CROSSING_JUMP_P (BB_END (bb))) |
aa78dca5 | 2556 | { |
2557 | error ("No region crossing jump at section boundary in bb %i", | |
2558 | bb->index); | |
2559 | err = 1; | |
2560 | } | |
f59cbcbf | 2561 | } |
2562 | else if (is_crossing) | |
2563 | { | |
2564 | error ("EDGE_CROSSING missing across section boundary"); | |
2565 | err = 1; | |
4f18499c | 2566 | } |
fb20d6fa | 2567 | |
7f42fe24 | 2568 | if ((e->flags & ~(EDGE_DFS_BACK |
2569 | | EDGE_CAN_FALLTHRU | |
2570 | | EDGE_IRREDUCIBLE_LOOP | |
f50b5bd0 | 2571 | | EDGE_LOOP_EXIT |
acc48fa6 | 2572 | | EDGE_CROSSING |
2573 | | EDGE_PRESERVE)) == 0) | |
fb20d6fa | 2574 | n_branch++; |
2575 | ||
2576 | if (e->flags & EDGE_ABNORMAL_CALL) | |
103dfb10 | 2577 | n_abnormal_call++; |
2578 | ||
2579 | if (e->flags & EDGE_SIBCALL) | |
2580 | n_sibcall++; | |
fb20d6fa | 2581 | |
2582 | if (e->flags & EDGE_EH) | |
2583 | n_eh++; | |
103dfb10 | 2584 | |
2585 | if (e->flags & EDGE_ABNORMAL) | |
fb20d6fa | 2586 | n_abnormal++; |
b36d64df | 2587 | } |
5cc577b6 | 2588 | |
fc032acd | 2589 | if (!has_crossing_edge |
2590 | && JUMP_P (BB_END (bb)) | |
2591 | && CROSSING_JUMP_P (BB_END (bb))) | |
2592 | { | |
2593 | print_rtl_with_bb (stderr, get_insns (), TDF_BLOCKS | TDF_DETAILS); | |
2594 | error ("Region crossing jump across same section in bb %i", | |
2595 | bb->index); | |
2596 | err = 1; | |
2597 | } | |
aa78dca5 | 2598 | |
e38def9c | 2599 | if (n_eh && !find_reg_note (BB_END (bb), REG_EH_REGION, NULL_RTX)) |
fb20d6fa | 2600 | { |
103dfb10 | 2601 | error ("missing REG_EH_REGION note at the end of bb %i", bb->index); |
fb20d6fa | 2602 | err = 1; |
2603 | } | |
e38def9c | 2604 | if (n_eh > 1) |
2605 | { | |
103dfb10 | 2606 | error ("too many exception handling edges in bb %i", bb->index); |
e38def9c | 2607 | err = 1; |
2608 | } | |
fb20d6fa | 2609 | if (n_branch |
6d7dc5b9 | 2610 | && (!JUMP_P (BB_END (bb)) |
5496dbfc | 2611 | || (n_branch > 1 && (any_uncondjump_p (BB_END (bb)) |
2612 | || any_condjump_p (BB_END (bb)))))) | |
fb20d6fa | 2613 | { |
0a81f5a0 | 2614 | error ("too many outgoing branch edges from bb %i", bb->index); |
fb20d6fa | 2615 | err = 1; |
2616 | } | |
5496dbfc | 2617 | if (n_fallthru && any_uncondjump_p (BB_END (bb))) |
fb20d6fa | 2618 | { |
103dfb10 | 2619 | error ("fallthru edge after unconditional jump in bb %i", bb->index); |
fb20d6fa | 2620 | err = 1; |
2621 | } | |
5496dbfc | 2622 | if (n_branch != 1 && any_uncondjump_p (BB_END (bb))) |
fb20d6fa | 2623 | { |
103dfb10 | 2624 | error ("wrong number of branch edges after unconditional jump" |
2625 | " in bb %i", bb->index); | |
fb20d6fa | 2626 | err = 1; |
2627 | } | |
5496dbfc | 2628 | if (n_branch != 1 && any_condjump_p (BB_END (bb)) |
8345ac1a | 2629 | && JUMP_LABEL (BB_END (bb)) != BB_HEAD (fallthru->dest)) |
fb20d6fa | 2630 | { |
103dfb10 | 2631 | error ("wrong amount of branch edges after conditional jump" |
2632 | " in bb %i", bb->index); | |
2633 | err = 1; | |
2634 | } | |
2635 | if (n_abnormal_call && !CALL_P (BB_END (bb))) | |
2636 | { | |
2637 | error ("abnormal call edges for non-call insn in bb %i", bb->index); | |
fb20d6fa | 2638 | err = 1; |
2639 | } | |
103dfb10 | 2640 | if (n_sibcall && !CALL_P (BB_END (bb))) |
fb20d6fa | 2641 | { |
103dfb10 | 2642 | error ("sibcall edges for non-call insn in bb %i", bb->index); |
fb20d6fa | 2643 | err = 1; |
2644 | } | |
103dfb10 | 2645 | if (n_abnormal > n_eh |
2646 | && !(CALL_P (BB_END (bb)) | |
2647 | && n_abnormal == n_abnormal_call + n_sibcall) | |
6d7dc5b9 | 2648 | && (!JUMP_P (BB_END (bb)) |
5496dbfc | 2649 | || any_condjump_p (BB_END (bb)) |
2650 | || any_uncondjump_p (BB_END (bb)))) | |
fb20d6fa | 2651 | { |
0a81f5a0 | 2652 | error ("abnormal edges for no purpose in bb %i", bb->index); |
fb20d6fa | 2653 | err = 1; |
2654 | } | |
fc032acd | 2655 | |
2656 | int has_eh = -1; | |
2657 | FOR_EACH_EDGE (e, ei, bb->preds) | |
2658 | { | |
2659 | if (has_eh == -1) | |
2660 | has_eh = (e->flags & EDGE_EH); | |
2661 | if ((e->flags & EDGE_EH) == has_eh) | |
2662 | continue; | |
2663 | error ("EH incoming edge mixed with non-EH incoming edges " | |
2664 | "in bb %i", bb->index); | |
2665 | err = 1; | |
2666 | break; | |
2667 | } | |
4bf32a77 | 2668 | } |
db34a109 | 2669 | |
80adc5a6 | 2670 | /* If there are partitions, do a sanity check on them: A basic block in |
2671 | Â a cold partition cannot dominate a basic block in a hot partition. Â */ | |
4b8e8fea | 2672 | if (crtl->has_bb_partition && !err |
2673 | && current_ir_type () == IR_RTL_CFGLAYOUT) | |
80adc5a6 | 2674 | { |
2675 | vec<basic_block> bbs_to_fix = find_partition_fixes (true); | |
2676 | err = !bbs_to_fix.is_empty (); | |
2677 | } | |
2678 | ||
4bf32a77 | 2679 | /* Clean up. */ |
2680 | return err; | |
2681 | } | |
5cc577b6 | 2682 | |
4bf32a77 | 2683 | /* Checks on the instructions within blocks. Currently checks that each |
2684 | block starts with a basic block note, and that basic block notes and | |
2685 | control flow jumps are not found in the middle of the block. */ | |
b36d64df | 2686 | |
4bf32a77 | 2687 | static int |
2688 | rtl_verify_bb_insns (void) | |
2689 | { | |
3d90435a | 2690 | rtx_insn *x; |
4bf32a77 | 2691 | int err = 0; |
2692 | basic_block bb; | |
2693 | ||
7a46197b | 2694 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
4bf32a77 | 2695 | { |
2696 | /* Now check the header of basic | |
a0c938f0 | 2697 | block. It ought to contain optional CODE_LABEL followed |
b36d64df | 2698 | by NOTE_BASIC_BLOCK. */ |
5496dbfc | 2699 | x = BB_HEAD (bb); |
6d7dc5b9 | 2700 | if (LABEL_P (x)) |
b36d64df | 2701 | { |
5496dbfc | 2702 | if (BB_END (bb) == x) |
b36d64df | 2703 | { |
2704 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
b3d6de89 | 2705 | bb->index); |
b36d64df | 2706 | err = 1; |
2707 | } | |
5cc577b6 | 2708 | |
b36d64df | 2709 | x = NEXT_INSN (x); |
2710 | } | |
5cc577b6 | 2711 | |
b36d64df | 2712 | if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb) |
2713 | { | |
2714 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
b3d6de89 | 2715 | bb->index); |
b36d64df | 2716 | err = 1; |
2717 | } | |
2718 | ||
5496dbfc | 2719 | if (BB_END (bb) == x) |
f3e2a363 | 2720 | /* Do checks for empty blocks here. */ |
5cc577b6 | 2721 | ; |
b36d64df | 2722 | else |
5cc577b6 | 2723 | for (x = NEXT_INSN (x); x; x = NEXT_INSN (x)) |
2724 | { | |
2725 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2726 | { | |
2727 | error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d", | |
b3d6de89 | 2728 | INSN_UID (x), bb->index); |
5cc577b6 | 2729 | err = 1; |
2730 | } | |
2731 | ||
5496dbfc | 2732 | if (x == BB_END (bb)) |
5cc577b6 | 2733 | break; |
b36d64df | 2734 | |
aaf52ffb | 2735 | if (control_flow_insn_p (x)) |
5cc577b6 | 2736 | { |
b3d6de89 | 2737 | error ("in basic block %d:", bb->index); |
5cc577b6 | 2738 | fatal_insn ("flow control insn inside a basic block", x); |
2739 | } | |
2740 | } | |
b36d64df | 2741 | } |
2742 | ||
4bf32a77 | 2743 | /* Clean up. */ |
2744 | return err; | |
2745 | } | |
2746 | ||
2747 | /* Verify that block pointers for instructions in basic blocks, headers and | |
2748 | footers are set appropriately. */ | |
2749 | ||
2750 | static int | |
2751 | rtl_verify_bb_pointers (void) | |
2752 | { | |
2753 | int err = 0; | |
2754 | basic_block bb; | |
2755 | ||
2756 | /* Check the general integrity of the basic blocks. */ | |
7a46197b | 2757 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
4bf32a77 | 2758 | { |
3d90435a | 2759 | rtx_insn *insn; |
4bf32a77 | 2760 | |
2761 | if (!(bb->flags & BB_RTL)) | |
2762 | { | |
2763 | error ("BB_RTL flag not set for block %d", bb->index); | |
2764 | err = 1; | |
2765 | } | |
2766 | ||
2767 | FOR_BB_INSNS (bb, insn) | |
2768 | if (BLOCK_FOR_INSN (insn) != bb) | |
2769 | { | |
2770 | error ("insn %d basic block pointer is %d, should be %d", | |
2771 | INSN_UID (insn), | |
2772 | BLOCK_FOR_INSN (insn) ? BLOCK_FOR_INSN (insn)->index : 0, | |
2773 | bb->index); | |
2774 | err = 1; | |
2775 | } | |
2776 | ||
2777 | for (insn = BB_HEADER (bb); insn; insn = NEXT_INSN (insn)) | |
2778 | if (!BARRIER_P (insn) | |
2779 | && BLOCK_FOR_INSN (insn) != NULL) | |
2780 | { | |
2781 | error ("insn %d in header of bb %d has non-NULL basic block", | |
2782 | INSN_UID (insn), bb->index); | |
2783 | err = 1; | |
2784 | } | |
2785 | for (insn = BB_FOOTER (bb); insn; insn = NEXT_INSN (insn)) | |
2786 | if (!BARRIER_P (insn) | |
2787 | && BLOCK_FOR_INSN (insn) != NULL) | |
2788 | { | |
2789 | error ("insn %d in footer of bb %d has non-NULL basic block", | |
2790 | INSN_UID (insn), bb->index); | |
2791 | err = 1; | |
2792 | } | |
2793 | } | |
812ca88e | 2794 | |
028f8cc7 | 2795 | /* Clean up. */ |
028f8cc7 | 2796 | return err; |
2797 | } | |
5cc577b6 | 2798 | |
028f8cc7 | 2799 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
2800 | cfglayout RTL. | |
5cc577b6 | 2801 | |
028f8cc7 | 2802 | Currently it does following checks: |
4bf32a77 | 2803 | |
2804 | - overlapping of basic blocks | |
2805 | - insns with wrong BLOCK_FOR_INSN pointers | |
2806 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) | |
2807 | - tails of basic blocks (ensure that boundary is necessary) | |
2808 | - scans body of the basic block for JUMP_INSN, CODE_LABEL | |
2809 | and NOTE_INSN_BASIC_BLOCK | |
2810 | - verify that no fall_thru edge crosses hot/cold partition boundaries | |
2811 | - verify that there are no pending RTL branch predictions | |
80adc5a6 | 2812 | - verify that hot blocks are not dominated by cold blocks |
4bf32a77 | 2813 | |
2814 | In future it can be extended check a lot of other stuff as well | |
2815 | (reachability of basic blocks, life information, etc. etc.). */ | |
fcde5c9e | 2816 | |
028f8cc7 | 2817 | static int |
4bf32a77 | 2818 | rtl_verify_flow_info_1 (void) |
2819 | { | |
2820 | int err = 0; | |
2821 | ||
2822 | err |= rtl_verify_bb_pointers (); | |
2823 | ||
2824 | err |= rtl_verify_bb_insns (); | |
2825 | ||
2826 | err |= rtl_verify_edges (); | |
2827 | ||
4bf32a77 | 2828 | return err; |
2829 | } | |
2830 | ||
2831 | /* Walk the instruction chain and verify that bb head/end pointers | |
2832 | are correct, and that instructions are in exactly one bb and have | |
2833 | correct block pointers. */ | |
2834 | ||
2835 | static int | |
2836 | rtl_verify_bb_insn_chain (void) | |
028f8cc7 | 2837 | { |
2838 | basic_block bb; | |
4bf32a77 | 2839 | int err = 0; |
3d90435a | 2840 | rtx_insn *x; |
2841 | rtx_insn *last_head = get_last_insn (); | |
fcde5c9e | 2842 | basic_block *bb_info; |
fcde5c9e | 2843 | const int max_uid = get_max_uid (); |
2844 | ||
2845 | bb_info = XCNEWVEC (basic_block, max_uid); | |
b36d64df | 2846 | |
7a46197b | 2847 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
028f8cc7 | 2848 | { |
3d90435a | 2849 | rtx_insn *head = BB_HEAD (bb); |
2850 | rtx_insn *end = BB_END (bb); | |
cd665a06 | 2851 | |
fcde5c9e | 2852 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) |
39257eb5 | 2853 | { |
2854 | /* Verify the end of the basic block is in the INSN chain. */ | |
2855 | if (x == end) | |
2856 | break; | |
2857 | ||
4bf32a77 | 2858 | /* And that the code outside of basic blocks has NULL bb field. */ |
2859 | if (!BARRIER_P (x) | |
2860 | && BLOCK_FOR_INSN (x) != NULL) | |
2861 | { | |
2862 | error ("insn %d outside of basic blocks has non-NULL bb field", | |
2863 | INSN_UID (x)); | |
2864 | err = 1; | |
2865 | } | |
39257eb5 | 2866 | } |
fcde5c9e | 2867 | |
2868 | if (!x) | |
2869 | { | |
2870 | error ("end insn %d for block %d not found in the insn stream", | |
2871 | INSN_UID (end), bb->index); | |
2872 | err = 1; | |
2873 | } | |
2874 | ||
2875 | /* Work backwards from the end to the head of the basic block | |
2876 | to verify the head is in the RTL chain. */ | |
2877 | for (; x != NULL_RTX; x = PREV_INSN (x)) | |
d5043f32 | 2878 | { |
fcde5c9e | 2879 | /* While walking over the insn chain, verify insns appear |
2880 | in only one basic block. */ | |
2881 | if (bb_info[INSN_UID (x)] != NULL) | |
2882 | { | |
2883 | error ("insn %d is in multiple basic blocks (%d and %d)", | |
2884 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); | |
2885 | err = 1; | |
2886 | } | |
2887 | ||
2888 | bb_info[INSN_UID (x)] = bb; | |
2889 | ||
2890 | if (x == head) | |
2891 | break; | |
2892 | } | |
2893 | if (!x) | |
2894 | { | |
2895 | error ("head insn %d for block %d not found in the insn stream", | |
2896 | INSN_UID (head), bb->index); | |
d5043f32 | 2897 | err = 1; |
2898 | } | |
2899 | ||
39257eb5 | 2900 | last_head = PREV_INSN (x); |
4bf32a77 | 2901 | } |
2902 | ||
2903 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) | |
2904 | { | |
2905 | /* Check that the code before the first basic block has NULL | |
2906 | bb field. */ | |
2907 | if (!BARRIER_P (x) | |
2908 | && BLOCK_FOR_INSN (x) != NULL) | |
2909 | { | |
2910 | error ("insn %d outside of basic blocks has non-NULL bb field", | |
2911 | INSN_UID (x)); | |
2912 | err = 1; | |
2913 | } | |
2914 | } | |
2915 | free (bb_info); | |
2916 | ||
2917 | return err; | |
2918 | } | |
2919 | ||
2920 | /* Verify that fallthru edges point to adjacent blocks in layout order and | |
2921 | that barriers exist after non-fallthru blocks. */ | |
2922 | ||
2923 | static int | |
2924 | rtl_verify_fallthru (void) | |
2925 | { | |
2926 | basic_block bb; | |
2927 | int err = 0; | |
2928 | ||
7a46197b | 2929 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
4bf32a77 | 2930 | { |
2931 | edge e; | |
fcde5c9e | 2932 | |
7f58c05e | 2933 | e = find_fallthru_edge (bb->succs); |
028f8cc7 | 2934 | if (!e) |
2935 | { | |
3d90435a | 2936 | rtx_insn *insn; |
028f8cc7 | 2937 | |
2938 | /* Ensure existence of barrier in BB with no fallthru edges. */ | |
d2b48f0c | 2939 | for (insn = NEXT_INSN (BB_END (bb)); ; insn = NEXT_INSN (insn)) |
2940 | { | |
2941 | if (!insn || NOTE_INSN_BASIC_BLOCK_P (insn)) | |
028f8cc7 | 2942 | { |
2943 | error ("missing barrier after block %i", bb->index); | |
2944 | err = 1; | |
2945 | break; | |
2946 | } | |
d2b48f0c | 2947 | if (BARRIER_P (insn)) |
2948 | break; | |
2949 | } | |
028f8cc7 | 2950 | } |
34154e27 | 2951 | else if (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
2952 | && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
a0c938f0 | 2953 | { |
3d90435a | 2954 | rtx_insn *insn; |
028f8cc7 | 2955 | |
2956 | if (e->src->next_bb != e->dest) | |
2957 | { | |
2958 | error | |
2959 | ("verify_flow_info: Incorrect blocks for fallthru %i->%i", | |
2960 | e->src->index, e->dest->index); | |
2961 | err = 1; | |
2962 | } | |
2963 | else | |
5496dbfc | 2964 | for (insn = NEXT_INSN (BB_END (e->src)); insn != BB_HEAD (e->dest); |
028f8cc7 | 2965 | insn = NEXT_INSN (insn)) |
bce107d7 | 2966 | if (BARRIER_P (insn) || NONDEBUG_INSN_P (insn)) |
028f8cc7 | 2967 | { |
2968 | error ("verify_flow_info: Incorrect fallthru %i->%i", | |
2969 | e->src->index, e->dest->index); | |
2970 | fatal_insn ("wrong insn in the fallthru edge", insn); | |
2971 | err = 1; | |
2972 | } | |
a0c938f0 | 2973 | } |
028f8cc7 | 2974 | } |
b36d64df | 2975 | |
4bf32a77 | 2976 | return err; |
2977 | } | |
2978 | ||
2979 | /* Verify that blocks are laid out in consecutive order. While walking the | |
2980 | instructions, verify that all expected instructions are inside the basic | |
2981 | blocks, and that all returns are followed by barriers. */ | |
2982 | ||
2983 | static int | |
2984 | rtl_verify_bb_layout (void) | |
2985 | { | |
2986 | basic_block bb; | |
2987 | int err = 0; | |
bce107d7 | 2988 | rtx_insn *x, *y; |
4bf32a77 | 2989 | int num_bb_notes; |
3d90435a | 2990 | rtx_insn * const rtx_first = get_insns (); |
34154e27 | 2991 | basic_block last_bb_seen = ENTRY_BLOCK_PTR_FOR_FN (cfun), curr_bb = NULL; |
fcde5c9e | 2992 | |
b36d64df | 2993 | num_bb_notes = 0; |
4c26117a | 2994 | |
5cc577b6 | 2995 | for (x = rtx_first; x; x = NEXT_INSN (x)) |
b36d64df | 2996 | { |
2997 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2998 | { | |
3c0a32c9 | 2999 | bb = NOTE_BASIC_BLOCK (x); |
5cc577b6 | 3000 | |
b36d64df | 3001 | num_bb_notes++; |
4c26117a | 3002 | if (bb != last_bb_seen->next_bb) |
028f8cc7 | 3003 | internal_error ("basic blocks not laid down consecutively"); |
b36d64df | 3004 | |
028f8cc7 | 3005 | curr_bb = last_bb_seen = bb; |
b36d64df | 3006 | } |
3007 | ||
028f8cc7 | 3008 | if (!curr_bb) |
b36d64df | 3009 | { |
3010 | switch (GET_CODE (x)) | |
3011 | { | |
3012 | case BARRIER: | |
3013 | case NOTE: | |
3014 | break; | |
3015 | ||
3016 | case CODE_LABEL: | |
91f71fa3 | 3017 | /* An ADDR_VEC is placed outside any basic block. */ |
b36d64df | 3018 | if (NEXT_INSN (x) |
971ba038 | 3019 | && JUMP_TABLE_DATA_P (NEXT_INSN (x))) |
5cc577b6 | 3020 | x = NEXT_INSN (x); |
b36d64df | 3021 | |
3022 | /* But in any case, non-deletable labels can appear anywhere. */ | |
3023 | break; | |
3024 | ||
3025 | default: | |
cb8bacb6 | 3026 | fatal_insn ("insn outside basic block", x); |
b36d64df | 3027 | } |
3028 | } | |
3029 | ||
345f9e8c | 3030 | if (JUMP_P (x) |
b36d64df | 3031 | && returnjump_p (x) && ! condjump_p (x) |
bce107d7 | 3032 | && ! ((y = next_nonnote_nondebug_insn (x)) |
3033 | && BARRIER_P (y))) | |
cb8bacb6 | 3034 | fatal_insn ("return not followed by barrier", x); |
4bf32a77 | 3035 | |
5496dbfc | 3036 | if (curr_bb && x == BB_END (curr_bb)) |
028f8cc7 | 3037 | curr_bb = NULL; |
b36d64df | 3038 | } |
3039 | ||
a28770e1 | 3040 | if (num_bb_notes != n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS) |
b36d64df | 3041 | internal_error |
b3d6de89 | 3042 | ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)", |
a28770e1 | 3043 | num_bb_notes, n_basic_blocks_for_fn (cfun)); |
b36d64df | 3044 | |
028f8cc7 | 3045 | return err; |
b36d64df | 3046 | } |
4bf32a77 | 3047 | |
3048 | /* Verify the CFG and RTL consistency common for both underlying RTL and | |
3049 | cfglayout RTL, plus consistency checks specific to linearized RTL mode. | |
3050 | ||
3051 | Currently it does following checks: | |
3052 | - all checks of rtl_verify_flow_info_1 | |
3053 | - test head/end pointers | |
3054 | - check that blocks are laid out in consecutive order | |
3055 | - check that all insns are in the basic blocks | |
3056 | (except the switch handling code, barriers and notes) | |
3057 | - check that all returns are followed by barriers | |
80adc5a6 | 3058 | - check that all fallthru edge points to the adjacent blocks |
3059 | - verify that there is a single hot/cold partition boundary after bbro */ | |
4bf32a77 | 3060 | |
3061 | static int | |
3062 | rtl_verify_flow_info (void) | |
3063 | { | |
3064 | int err = 0; | |
3065 | ||
3066 | err |= rtl_verify_flow_info_1 (); | |
3067 | ||
3068 | err |= rtl_verify_bb_insn_chain (); | |
3069 | ||
3070 | err |= rtl_verify_fallthru (); | |
3071 | ||
3072 | err |= rtl_verify_bb_layout (); | |
3073 | ||
aa78dca5 | 3074 | err |= verify_hot_cold_block_grouping (); |
3075 | ||
4bf32a77 | 3076 | return err; |
3077 | } | |
b36d64df | 3078 | \f |
4a82352a | 3079 | /* Assume that the preceding pass has possibly eliminated jump instructions |
b36d64df | 3080 | or converted the unconditional jumps. Eliminate the edges from CFG. |
3081 | Return true if any edges are eliminated. */ | |
3082 | ||
3083 | bool | |
4c9e08a4 | 3084 | purge_dead_edges (basic_block bb) |
b36d64df | 3085 | { |
cd665a06 | 3086 | edge e; |
3d90435a | 3087 | rtx_insn *insn = BB_END (bb); |
3088 | rtx note; | |
b36d64df | 3089 | bool purged = false; |
cd665a06 | 3090 | bool found; |
3091 | edge_iterator ei; | |
b36d64df | 3092 | |
9845d120 | 3093 | if (DEBUG_INSN_P (insn) && insn != BB_HEAD (bb)) |
3094 | do | |
3095 | insn = PREV_INSN (insn); | |
3096 | while ((DEBUG_INSN_P (insn) || NOTE_P (insn)) && insn != BB_HEAD (bb)); | |
3097 | ||
11808932 | 3098 | /* If this instruction cannot trap, remove REG_EH_REGION notes. */ |
6d7dc5b9 | 3099 | if (NONJUMP_INSN_P (insn) |
11808932 | 3100 | && (note = find_reg_note (insn, REG_EH_REGION, NULL))) |
3101 | { | |
3102 | rtx eqnote; | |
3103 | ||
3104 | if (! may_trap_p (PATTERN (insn)) | |
3105 | || ((eqnote = find_reg_equal_equiv_note (insn)) | |
3106 | && ! may_trap_p (XEXP (eqnote, 0)))) | |
3107 | remove_note (insn, note); | |
3108 | } | |
3109 | ||
f178f44b | 3110 | /* Cleanup abnormal edges caused by exceptions or non-local gotos. */ |
cd665a06 | 3111 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
f178f44b | 3112 | { |
e38def9c | 3113 | bool remove = false; |
3114 | ||
04166d08 | 3115 | /* There are three types of edges we need to handle correctly here: EH |
3116 | edges, abnormal call EH edges, and abnormal call non-EH edges. The | |
3117 | latter can appear when nonlocal gotos are used. */ | |
e38def9c | 3118 | if (e->flags & EDGE_ABNORMAL_CALL) |
f178f44b | 3119 | { |
e38def9c | 3120 | if (!CALL_P (insn)) |
3121 | remove = true; | |
3122 | else if (can_nonlocal_goto (insn)) | |
3123 | ; | |
3124 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) | |
3125 | ; | |
4c0315d0 | 3126 | else if (flag_tm && find_reg_note (insn, REG_TM, NULL)) |
3127 | ; | |
e38def9c | 3128 | else |
3129 | remove = true; | |
f178f44b | 3130 | } |
e38def9c | 3131 | else if (e->flags & EDGE_EH) |
3132 | remove = !can_throw_internal (insn); | |
3133 | ||
3134 | if (remove) | |
f178f44b | 3135 | { |
e38def9c | 3136 | remove_edge (e); |
3137 | df_set_bb_dirty (bb); | |
3138 | purged = true; | |
f178f44b | 3139 | } |
3140 | else | |
e38def9c | 3141 | ei_next (&ei); |
f178f44b | 3142 | } |
5cc577b6 | 3143 | |
6d7dc5b9 | 3144 | if (JUMP_P (insn)) |
b36d64df | 3145 | { |
3146 | rtx note; | |
3147 | edge b,f; | |
cd665a06 | 3148 | edge_iterator ei; |
5cc577b6 | 3149 | |
b36d64df | 3150 | /* We do care only about conditional jumps and simplejumps. */ |
3151 | if (!any_condjump_p (insn) | |
3152 | && !returnjump_p (insn) | |
3153 | && !simplejump_p (insn)) | |
461eeb14 | 3154 | return purged; |
5cc577b6 | 3155 | |
a2e42321 | 3156 | /* Branch probability/prediction notes are defined only for |
3157 | condjumps. We've possibly turned condjump into simplejump. */ | |
3158 | if (simplejump_p (insn)) | |
3159 | { | |
3160 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
3161 | if (note) | |
3162 | remove_note (insn, note); | |
3163 | while ((note = find_reg_note (insn, REG_BR_PRED, NULL))) | |
3164 | remove_note (insn, note); | |
3165 | } | |
3166 | ||
cd665a06 | 3167 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
b36d64df | 3168 | { |
4270b4b9 | 3169 | /* Avoid abnormal flags to leak from computed jumps turned |
3170 | into simplejumps. */ | |
db34a109 | 3171 | |
a0fb7382 | 3172 | e->flags &= ~EDGE_ABNORMAL; |
4270b4b9 | 3173 | |
14abf923 | 3174 | /* See if this edge is one we should keep. */ |
3175 | if ((e->flags & EDGE_FALLTHRU) && any_condjump_p (insn)) | |
3176 | /* A conditional jump can fall through into the next | |
3177 | block, so we should keep the edge. */ | |
cd665a06 | 3178 | { |
3179 | ei_next (&ei); | |
3180 | continue; | |
3181 | } | |
34154e27 | 3182 | else if (e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) |
5496dbfc | 3183 | && BB_HEAD (e->dest) == JUMP_LABEL (insn)) |
14abf923 | 3184 | /* If the destination block is the target of the jump, |
3185 | keep the edge. */ | |
cd665a06 | 3186 | { |
3187 | ei_next (&ei); | |
3188 | continue; | |
3189 | } | |
34154e27 | 3190 | else if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) |
3191 | && returnjump_p (insn)) | |
14abf923 | 3192 | /* If the destination block is the exit block, and this |
3193 | instruction is a return, then keep the edge. */ | |
cd665a06 | 3194 | { |
3195 | ei_next (&ei); | |
3196 | continue; | |
3197 | } | |
14abf923 | 3198 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) |
3199 | /* Keep the edges that correspond to exceptions thrown by | |
1b64239d | 3200 | this instruction and rematerialize the EDGE_ABNORMAL |
3201 | flag we just cleared above. */ | |
3202 | { | |
3203 | e->flags |= EDGE_ABNORMAL; | |
cd665a06 | 3204 | ei_next (&ei); |
1b64239d | 3205 | continue; |
3206 | } | |
5cc577b6 | 3207 | |
14abf923 | 3208 | /* We do not need this edge. */ |
3072d30e | 3209 | df_set_bb_dirty (bb); |
b36d64df | 3210 | purged = true; |
3211 | remove_edge (e); | |
3212 | } | |
5cc577b6 | 3213 | |
cd665a06 | 3214 | if (EDGE_COUNT (bb->succs) == 0 || !purged) |
461eeb14 | 3215 | return purged; |
5cc577b6 | 3216 | |
450d042a | 3217 | if (dump_file) |
3218 | fprintf (dump_file, "Purged edges from bb %i\n", bb->index); | |
5cc577b6 | 3219 | |
b36d64df | 3220 | if (!optimize) |
3221 | return purged; | |
3222 | ||
3223 | /* Redistribute probabilities. */ | |
ea091dfd | 3224 | if (single_succ_p (bb)) |
b36d64df | 3225 | { |
720cfc43 | 3226 | single_succ_edge (bb)->probability = profile_probability::always (); |
db34a109 | 3227 | } |
b36d64df | 3228 | else |
3229 | { | |
3230 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
3231 | if (!note) | |
3232 | return purged; | |
5cc577b6 | 3233 | |
b36d64df | 3234 | b = BRANCH_EDGE (bb); |
3235 | f = FALLTHRU_EDGE (bb); | |
61cb1816 | 3236 | b->probability = profile_probability::from_reg_br_prob_note |
720cfc43 | 3237 | (XINT (note, 0)); |
61cb1816 | 3238 | f->probability = b->probability.invert (); |
b36d64df | 3239 | } |
5cc577b6 | 3240 | |
b36d64df | 3241 | return purged; |
3242 | } | |
6d7dc5b9 | 3243 | else if (CALL_P (insn) && SIBLING_CALL_P (insn)) |
bf4311e9 | 3244 | { |
3245 | /* First, there should not be any EH or ABCALL edges resulting | |
3246 | from non-local gotos and the like. If there were, we shouldn't | |
3247 | have created the sibcall in the first place. Second, there | |
3248 | should of course never have been a fallthru edge. */ | |
ea091dfd | 3249 | gcc_assert (single_succ_p (bb)); |
3250 | gcc_assert (single_succ_edge (bb)->flags | |
3251 | == (EDGE_SIBCALL | EDGE_ABNORMAL)); | |
bf4311e9 | 3252 | |
3253 | return 0; | |
3254 | } | |
b36d64df | 3255 | |
b36d64df | 3256 | /* If we don't see a jump insn, we don't know exactly why the block would |
3257 | have been broken at this point. Look for a simple, non-fallthru edge, | |
3258 | as these are only created by conditional branches. If we find such an | |
3259 | edge we know that there used to be a jump here and can then safely | |
3260 | remove all non-fallthru edges. */ | |
cd665a06 | 3261 | found = false; |
3262 | FOR_EACH_EDGE (e, ei, bb->succs) | |
3263 | if (! (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU))) | |
3264 | { | |
3265 | found = true; | |
3266 | break; | |
3267 | } | |
5cc577b6 | 3268 | |
cd665a06 | 3269 | if (!found) |
b36d64df | 3270 | return purged; |
5cc577b6 | 3271 | |
6e81a369 | 3272 | /* Remove all but the fake and fallthru edges. The fake edge may be |
3273 | the only successor for this block in the case of noreturn | |
3274 | calls. */ | |
cd665a06 | 3275 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
b36d64df | 3276 | { |
6e81a369 | 3277 | if (!(e->flags & (EDGE_FALLTHRU | EDGE_FAKE))) |
461eeb14 | 3278 | { |
3072d30e | 3279 | df_set_bb_dirty (bb); |
461eeb14 | 3280 | remove_edge (e); |
3281 | purged = true; | |
3282 | } | |
cd665a06 | 3283 | else |
3284 | ei_next (&ei); | |
b36d64df | 3285 | } |
5cc577b6 | 3286 | |
ea091dfd | 3287 | gcc_assert (single_succ_p (bb)); |
5cc577b6 | 3288 | |
720cfc43 | 3289 | single_succ_edge (bb)->probability = profile_probability::always (); |
b36d64df | 3290 | |
450d042a | 3291 | if (dump_file) |
3292 | fprintf (dump_file, "Purged non-fallthru edges from bb %i\n", | |
b3d6de89 | 3293 | bb->index); |
b36d64df | 3294 | return purged; |
3295 | } | |
3296 | ||
5cc577b6 | 3297 | /* Search all basic blocks for potentially dead edges and purge them. Return |
3298 | true if some edge has been eliminated. */ | |
b36d64df | 3299 | |
3300 | bool | |
94ee50e8 | 3301 | purge_all_dead_edges (void) |
b36d64df | 3302 | { |
4c26117a | 3303 | int purged = false; |
4c26117a | 3304 | basic_block bb; |
0922c912 | 3305 | |
fc00614f | 3306 | FOR_EACH_BB_FN (bb, cfun) |
0922c912 | 3307 | { |
4c26117a | 3308 | bool purged_here = purge_dead_edges (bb); |
5cc577b6 | 3309 | |
0922c912 | 3310 | purged |= purged_here; |
0922c912 | 3311 | } |
5cc577b6 | 3312 | |
b36d64df | 3313 | return purged; |
3314 | } | |
1026363d | 3315 | |
54f21e20 | 3316 | /* This is used by a few passes that emit some instructions after abnormal |
3317 | calls, moving the basic block's end, while they in fact do want to emit | |
3318 | them on the fallthru edge. Look for abnormal call edges, find backward | |
3319 | the call in the block and insert the instructions on the edge instead. | |
3320 | ||
3321 | Similarly, handle instructions throwing exceptions internally. | |
3322 | ||
3323 | Return true when instructions have been found and inserted on edges. */ | |
3324 | ||
3325 | bool | |
3326 | fixup_abnormal_edges (void) | |
3327 | { | |
3328 | bool inserted = false; | |
3329 | basic_block bb; | |
3330 | ||
fc00614f | 3331 | FOR_EACH_BB_FN (bb, cfun) |
54f21e20 | 3332 | { |
3333 | edge e; | |
3334 | edge_iterator ei; | |
3335 | ||
3336 | /* Look for cases we are interested in - calls or instructions causing | |
3337 | exceptions. */ | |
3338 | FOR_EACH_EDGE (e, ei, bb->succs) | |
3339 | if ((e->flags & EDGE_ABNORMAL_CALL) | |
3340 | || ((e->flags & (EDGE_ABNORMAL | EDGE_EH)) | |
3341 | == (EDGE_ABNORMAL | EDGE_EH))) | |
3342 | break; | |
3343 | ||
3344 | if (e && !CALL_P (BB_END (bb)) && !can_throw_internal (BB_END (bb))) | |
3345 | { | |
3d90435a | 3346 | rtx_insn *insn; |
54f21e20 | 3347 | |
3348 | /* Get past the new insns generated. Allow notes, as the insns | |
3349 | may be already deleted. */ | |
3350 | insn = BB_END (bb); | |
3351 | while ((NONJUMP_INSN_P (insn) || NOTE_P (insn)) | |
3352 | && !can_throw_internal (insn) | |
3353 | && insn != BB_HEAD (bb)) | |
3354 | insn = PREV_INSN (insn); | |
3355 | ||
3356 | if (CALL_P (insn) || can_throw_internal (insn)) | |
3357 | { | |
3d90435a | 3358 | rtx_insn *stop, *next; |
54f21e20 | 3359 | |
3360 | e = find_fallthru_edge (bb->succs); | |
3361 | ||
3362 | stop = NEXT_INSN (BB_END (bb)); | |
26bb3cb2 | 3363 | BB_END (bb) = insn; |
54f21e20 | 3364 | |
3365 | for (insn = NEXT_INSN (insn); insn != stop; insn = next) | |
3366 | { | |
3367 | next = NEXT_INSN (insn); | |
3368 | if (INSN_P (insn)) | |
3369 | { | |
3370 | delete_insn (insn); | |
3371 | ||
3372 | /* Sometimes there's still the return value USE. | |
3373 | If it's placed after a trapping call (i.e. that | |
3374 | call is the last insn anyway), we have no fallthru | |
3375 | edge. Simply delete this use and don't try to insert | |
a3f619a1 | 3376 | on the non-existent edge. |
3377 | Similarly, sometimes a call that can throw is | |
3378 | followed in the source with __builtin_unreachable (), | |
3379 | meaning that there is UB if the call returns rather | |
3380 | than throws. If there weren't any instructions | |
3381 | following such calls before, supposedly even the ones | |
3382 | we've deleted aren't significant and can be | |
3383 | removed. */ | |
3384 | if (e) | |
54f21e20 | 3385 | { |
3386 | /* We're not deleting it, we're moving it. */ | |
dd1286fb | 3387 | insn->set_undeleted (); |
4a57a2e8 | 3388 | SET_PREV_INSN (insn) = NULL_RTX; |
3389 | SET_NEXT_INSN (insn) = NULL_RTX; | |
54f21e20 | 3390 | |
3391 | insert_insn_on_edge (insn, e); | |
3392 | inserted = true; | |
3393 | } | |
3394 | } | |
3395 | else if (!BARRIER_P (insn)) | |
3396 | set_block_for_insn (insn, NULL); | |
3397 | } | |
3398 | } | |
3399 | ||
3400 | /* It may be that we don't find any trapping insn. In this | |
3401 | case we discovered quite late that the insn that had been | |
3402 | marked as can_throw_internal in fact couldn't trap at all. | |
3403 | So we should in fact delete the EH edges out of the block. */ | |
3404 | else | |
3405 | purge_dead_edges (bb); | |
3406 | } | |
3407 | } | |
3408 | ||
3409 | return inserted; | |
3410 | } | |
23a070f3 | 3411 | \f |
3412 | /* Cut the insns from FIRST to LAST out of the insns stream. */ | |
3413 | ||
aa935352 | 3414 | rtx_insn * |
3e75e92b | 3415 | unlink_insn_chain (rtx_insn *first, rtx_insn *last) |
23a070f3 | 3416 | { |
aa935352 | 3417 | rtx_insn *prevfirst = PREV_INSN (first); |
3418 | rtx_insn *nextlast = NEXT_INSN (last); | |
23a070f3 | 3419 | |
4a57a2e8 | 3420 | SET_PREV_INSN (first) = NULL; |
3421 | SET_NEXT_INSN (last) = NULL; | |
23a070f3 | 3422 | if (prevfirst) |
4a57a2e8 | 3423 | SET_NEXT_INSN (prevfirst) = nextlast; |
23a070f3 | 3424 | if (nextlast) |
4a57a2e8 | 3425 | SET_PREV_INSN (nextlast) = prevfirst; |
23a070f3 | 3426 | else |
3427 | set_last_insn (prevfirst); | |
3428 | if (!prevfirst) | |
3429 | set_first_insn (nextlast); | |
3e75e92b | 3430 | return first; |
23a070f3 | 3431 | } |
3432 | \f | |
3433 | /* Skip over inter-block insns occurring after BB which are typically | |
3434 | associated with BB (e.g., barriers). If there are any such insns, | |
3435 | we return the last one. Otherwise, we return the end of BB. */ | |
3436 | ||
3d90435a | 3437 | static rtx_insn * |
23a070f3 | 3438 | skip_insns_after_block (basic_block bb) |
3439 | { | |
3d90435a | 3440 | rtx_insn *insn, *last_insn, *next_head, *prev; |
23a070f3 | 3441 | |
3d90435a | 3442 | next_head = NULL; |
34154e27 | 3443 | if (bb->next_bb != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
23a070f3 | 3444 | next_head = BB_HEAD (bb->next_bb); |
3445 | ||
3446 | for (last_insn = insn = BB_END (bb); (insn = NEXT_INSN (insn)) != 0; ) | |
3447 | { | |
3448 | if (insn == next_head) | |
3449 | break; | |
3450 | ||
3451 | switch (GET_CODE (insn)) | |
3452 | { | |
3453 | case BARRIER: | |
3454 | last_insn = insn; | |
3455 | continue; | |
3456 | ||
3457 | case NOTE: | |
3458 | switch (NOTE_KIND (insn)) | |
3459 | { | |
3460 | case NOTE_INSN_BLOCK_END: | |
3461 | gcc_unreachable (); | |
3462 | continue; | |
3463 | default: | |
3464 | continue; | |
3465 | break; | |
3466 | } | |
3467 | break; | |
3468 | ||
3469 | case CODE_LABEL: | |
3470 | if (NEXT_INSN (insn) | |
3471 | && JUMP_TABLE_DATA_P (NEXT_INSN (insn))) | |
3472 | { | |
3473 | insn = NEXT_INSN (insn); | |
3474 | last_insn = insn; | |
3475 | continue; | |
3476 | } | |
3477 | break; | |
3478 | ||
3479 | default: | |
3480 | break; | |
3481 | } | |
3482 | ||
3483 | break; | |
3484 | } | |
3485 | ||
3486 | /* It is possible to hit contradictory sequence. For instance: | |
3487 | ||
3488 | jump_insn | |
3489 | NOTE_INSN_BLOCK_BEG | |
3490 | barrier | |
3491 | ||
3492 | Where barrier belongs to jump_insn, but the note does not. This can be | |
3493 | created by removing the basic block originally following | |
3494 | NOTE_INSN_BLOCK_BEG. In such case reorder the notes. */ | |
3495 | ||
3496 | for (insn = last_insn; insn != BB_END (bb); insn = prev) | |
3497 | { | |
3498 | prev = PREV_INSN (insn); | |
3499 | if (NOTE_P (insn)) | |
3500 | switch (NOTE_KIND (insn)) | |
3501 | { | |
3502 | case NOTE_INSN_BLOCK_END: | |
3503 | gcc_unreachable (); | |
3504 | break; | |
3505 | case NOTE_INSN_DELETED: | |
3506 | case NOTE_INSN_DELETED_LABEL: | |
3507 | case NOTE_INSN_DELETED_DEBUG_LABEL: | |
3508 | continue; | |
3509 | default: | |
3510 | reorder_insns (insn, insn, last_insn); | |
3511 | } | |
3512 | } | |
3513 | ||
3514 | return last_insn; | |
3515 | } | |
3516 | ||
3517 | /* Locate or create a label for a given basic block. */ | |
3518 | ||
9ed997be | 3519 | static rtx_insn * |
23a070f3 | 3520 | label_for_bb (basic_block bb) |
3521 | { | |
9ed997be | 3522 | rtx_insn *label = BB_HEAD (bb); |
23a070f3 | 3523 | |
3524 | if (!LABEL_P (label)) | |
3525 | { | |
3526 | if (dump_file) | |
3527 | fprintf (dump_file, "Emitting label for block %d\n", bb->index); | |
3528 | ||
3529 | label = block_label (bb); | |
3530 | } | |
3531 | ||
3532 | return label; | |
3533 | } | |
3534 | ||
3535 | /* Locate the effective beginning and end of the insn chain for each | |
3536 | block, as defined by skip_insns_after_block above. */ | |
3537 | ||
3538 | static void | |
3539 | record_effective_endpoints (void) | |
3540 | { | |
3d90435a | 3541 | rtx_insn *next_insn; |
23a070f3 | 3542 | basic_block bb; |
3d90435a | 3543 | rtx_insn *insn; |
23a070f3 | 3544 | |
3545 | for (insn = get_insns (); | |
3546 | insn | |
3547 | && NOTE_P (insn) | |
3548 | && NOTE_KIND (insn) != NOTE_INSN_BASIC_BLOCK; | |
3549 | insn = NEXT_INSN (insn)) | |
3550 | continue; | |
3551 | /* No basic blocks at all? */ | |
3552 | gcc_assert (insn); | |
3553 | ||
3554 | if (PREV_INSN (insn)) | |
3555 | cfg_layout_function_header = | |
3556 | unlink_insn_chain (get_insns (), PREV_INSN (insn)); | |
3557 | else | |
3e75e92b | 3558 | cfg_layout_function_header = NULL; |
23a070f3 | 3559 | |
3560 | next_insn = get_insns (); | |
fc00614f | 3561 | FOR_EACH_BB_FN (bb, cfun) |
23a070f3 | 3562 | { |
3d90435a | 3563 | rtx_insn *end; |
23a070f3 | 3564 | |
3565 | if (PREV_INSN (BB_HEAD (bb)) && next_insn != BB_HEAD (bb)) | |
26bb3cb2 | 3566 | BB_HEADER (bb) = unlink_insn_chain (next_insn, |
a684cb04 | 3567 | PREV_INSN (BB_HEAD (bb))); |
23a070f3 | 3568 | end = skip_insns_after_block (bb); |
3569 | if (NEXT_INSN (BB_END (bb)) && BB_END (bb) != end) | |
943ea6fa | 3570 | BB_FOOTER (bb) = unlink_insn_chain (NEXT_INSN (BB_END (bb)), end); |
23a070f3 | 3571 | next_insn = NEXT_INSN (BB_END (bb)); |
3572 | } | |
3573 | ||
3574 | cfg_layout_function_footer = next_insn; | |
3575 | if (cfg_layout_function_footer) | |
3576 | cfg_layout_function_footer = unlink_insn_chain (cfg_layout_function_footer, get_last_insn ()); | |
3577 | } | |
3578 | \f | |
cbe8bda8 | 3579 | namespace { |
3580 | ||
3581 | const pass_data pass_data_into_cfg_layout_mode = | |
3582 | { | |
3583 | RTL_PASS, /* type */ | |
3584 | "into_cfglayout", /* name */ | |
3585 | OPTGROUP_NONE, /* optinfo_flags */ | |
cbe8bda8 | 3586 | TV_CFG, /* tv_id */ |
3587 | 0, /* properties_required */ | |
3588 | PROP_cfglayout, /* properties_provided */ | |
3589 | 0, /* properties_destroyed */ | |
3590 | 0, /* todo_flags_start */ | |
3591 | 0, /* todo_flags_finish */ | |
23a070f3 | 3592 | }; |
3593 | ||
cbe8bda8 | 3594 | class pass_into_cfg_layout_mode : public rtl_opt_pass |
3595 | { | |
3596 | public: | |
9af5ce0c | 3597 | pass_into_cfg_layout_mode (gcc::context *ctxt) |
3598 | : rtl_opt_pass (pass_data_into_cfg_layout_mode, ctxt) | |
cbe8bda8 | 3599 | {} |
3600 | ||
3601 | /* opt_pass methods: */ | |
65b0537f | 3602 | virtual unsigned int execute (function *) |
3603 | { | |
3604 | cfg_layout_initialize (0); | |
3605 | return 0; | |
3606 | } | |
cbe8bda8 | 3607 | |
3608 | }; // class pass_into_cfg_layout_mode | |
3609 | ||
3610 | } // anon namespace | |
3611 | ||
3612 | rtl_opt_pass * | |
3613 | make_pass_into_cfg_layout_mode (gcc::context *ctxt) | |
3614 | { | |
3615 | return new pass_into_cfg_layout_mode (ctxt); | |
3616 | } | |
3617 | ||
3618 | namespace { | |
3619 | ||
3620 | const pass_data pass_data_outof_cfg_layout_mode = | |
3621 | { | |
3622 | RTL_PASS, /* type */ | |
3623 | "outof_cfglayout", /* name */ | |
3624 | OPTGROUP_NONE, /* optinfo_flags */ | |
cbe8bda8 | 3625 | TV_CFG, /* tv_id */ |
3626 | 0, /* properties_required */ | |
3627 | 0, /* properties_provided */ | |
3628 | PROP_cfglayout, /* properties_destroyed */ | |
3629 | 0, /* todo_flags_start */ | |
3630 | 0, /* todo_flags_finish */ | |
23a070f3 | 3631 | }; |
cbe8bda8 | 3632 | |
3633 | class pass_outof_cfg_layout_mode : public rtl_opt_pass | |
3634 | { | |
3635 | public: | |
9af5ce0c | 3636 | pass_outof_cfg_layout_mode (gcc::context *ctxt) |
3637 | : rtl_opt_pass (pass_data_outof_cfg_layout_mode, ctxt) | |
cbe8bda8 | 3638 | {} |
3639 | ||
3640 | /* opt_pass methods: */ | |
65b0537f | 3641 | virtual unsigned int execute (function *); |
cbe8bda8 | 3642 | |
3643 | }; // class pass_outof_cfg_layout_mode | |
3644 | ||
65b0537f | 3645 | unsigned int |
3646 | pass_outof_cfg_layout_mode::execute (function *fun) | |
3647 | { | |
3648 | basic_block bb; | |
3649 | ||
3650 | FOR_EACH_BB_FN (bb, fun) | |
3651 | if (bb->next_bb != EXIT_BLOCK_PTR_FOR_FN (fun)) | |
3652 | bb->aux = bb->next_bb; | |
3653 | ||
3654 | cfg_layout_finalize (); | |
3655 | ||
3656 | return 0; | |
3657 | } | |
3658 | ||
cbe8bda8 | 3659 | } // anon namespace |
3660 | ||
3661 | rtl_opt_pass * | |
3662 | make_pass_outof_cfg_layout_mode (gcc::context *ctxt) | |
3663 | { | |
3664 | return new pass_outof_cfg_layout_mode (ctxt); | |
3665 | } | |
23a070f3 | 3666 | \f |
3667 | ||
3668 | /* Link the basic blocks in the correct order, compacting the basic | |
3669 | block queue while at it. If STAY_IN_CFGLAYOUT_MODE is false, this | |
3670 | function also clears the basic block header and footer fields. | |
3671 | ||
3672 | This function is usually called after a pass (e.g. tracer) finishes | |
3673 | some transformations while in cfglayout mode. The required sequence | |
3674 | of the basic blocks is in a linked list along the bb->aux field. | |
3675 | This functions re-links the basic block prev_bb and next_bb pointers | |
4a020a8c | 3676 | accordingly, and it compacts and renumbers the blocks. |
3677 | ||
3678 | FIXME: This currently works only for RTL, but the only RTL-specific | |
3679 | bits are the STAY_IN_CFGLAYOUT_MODE bits. The tracer pass was moved | |
3680 | to GIMPLE a long time ago, but it doesn't relink the basic block | |
3681 | chain. It could do that (to give better initial RTL) if this function | |
3682 | is made IR-agnostic (and moved to cfganal.c or cfg.c while at it). */ | |
23a070f3 | 3683 | |
3684 | void | |
3685 | relink_block_chain (bool stay_in_cfglayout_mode) | |
3686 | { | |
3687 | basic_block bb, prev_bb; | |
3688 | int index; | |
3689 | ||
3690 | /* Maybe dump the re-ordered sequence. */ | |
3691 | if (dump_file) | |
3692 | { | |
3693 | fprintf (dump_file, "Reordered sequence:\n"); | |
34154e27 | 3694 | for (bb = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb, index = |
3695 | NUM_FIXED_BLOCKS; | |
23a070f3 | 3696 | bb; |
3697 | bb = (basic_block) bb->aux, index++) | |
3698 | { | |
3699 | fprintf (dump_file, " %i ", index); | |
3700 | if (get_bb_original (bb)) | |
a8c2576b | 3701 | fprintf (dump_file, "duplicate of %i\n", |
23a070f3 | 3702 | get_bb_original (bb)->index); |
3703 | else if (forwarder_block_p (bb) | |
3704 | && !LABEL_P (BB_HEAD (bb))) | |
a8c2576b | 3705 | fprintf (dump_file, "compensation\n"); |
23a070f3 | 3706 | else |
a8c2576b | 3707 | fprintf (dump_file, "bb %i\n", bb->index); |
23a070f3 | 3708 | } |
3709 | } | |
3710 | ||
3711 | /* Now reorder the blocks. */ | |
34154e27 | 3712 | prev_bb = ENTRY_BLOCK_PTR_FOR_FN (cfun); |
3713 | bb = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb; | |
23a070f3 | 3714 | for (; bb; prev_bb = bb, bb = (basic_block) bb->aux) |
3715 | { | |
3716 | bb->prev_bb = prev_bb; | |
3717 | prev_bb->next_bb = bb; | |
3718 | } | |
34154e27 | 3719 | prev_bb->next_bb = EXIT_BLOCK_PTR_FOR_FN (cfun); |
3720 | EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb = prev_bb; | |
23a070f3 | 3721 | |
3722 | /* Then, clean up the aux fields. */ | |
ed7d889a | 3723 | FOR_ALL_BB_FN (bb, cfun) |
23a070f3 | 3724 | { |
3725 | bb->aux = NULL; | |
3726 | if (!stay_in_cfglayout_mode) | |
26bb3cb2 | 3727 | BB_HEADER (bb) = BB_FOOTER (bb) = NULL; |
23a070f3 | 3728 | } |
3729 | ||
3730 | /* Maybe reset the original copy tables, they are not valid anymore | |
3731 | when we renumber the basic blocks in compact_blocks. If we are | |
3732 | are going out of cfglayout mode, don't re-allocate the tables. */ | |
175e0d6b | 3733 | if (original_copy_tables_initialized_p ()) |
3734 | free_original_copy_tables (); | |
23a070f3 | 3735 | if (stay_in_cfglayout_mode) |
3736 | initialize_original_copy_tables (); | |
3737 | ||
3738 | /* Finally, put basic_block_info in the new order. */ | |
3739 | compact_blocks (); | |
3740 | } | |
3741 | \f | |
3742 | ||
3743 | /* Given a reorder chain, rearrange the code to match. */ | |
3744 | ||
3745 | static void | |
3746 | fixup_reorder_chain (void) | |
3747 | { | |
3748 | basic_block bb; | |
3e75e92b | 3749 | rtx_insn *insn = NULL; |
23a070f3 | 3750 | |
3751 | if (cfg_layout_function_header) | |
3752 | { | |
3753 | set_first_insn (cfg_layout_function_header); | |
3754 | insn = cfg_layout_function_header; | |
3755 | while (NEXT_INSN (insn)) | |
3756 | insn = NEXT_INSN (insn); | |
3757 | } | |
3758 | ||
3759 | /* First do the bulk reordering -- rechain the blocks without regard to | |
3760 | the needed changes to jumps and labels. */ | |
3761 | ||
34154e27 | 3762 | for (bb = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb; bb; bb = (basic_block) |
3763 | bb->aux) | |
23a070f3 | 3764 | { |
3765 | if (BB_HEADER (bb)) | |
3766 | { | |
3767 | if (insn) | |
4a57a2e8 | 3768 | SET_NEXT_INSN (insn) = BB_HEADER (bb); |
23a070f3 | 3769 | else |
3770 | set_first_insn (BB_HEADER (bb)); | |
4a57a2e8 | 3771 | SET_PREV_INSN (BB_HEADER (bb)) = insn; |
23a070f3 | 3772 | insn = BB_HEADER (bb); |
3773 | while (NEXT_INSN (insn)) | |
3774 | insn = NEXT_INSN (insn); | |
3775 | } | |
3776 | if (insn) | |
4a57a2e8 | 3777 | SET_NEXT_INSN (insn) = BB_HEAD (bb); |
23a070f3 | 3778 | else |
3779 | set_first_insn (BB_HEAD (bb)); | |
4a57a2e8 | 3780 | SET_PREV_INSN (BB_HEAD (bb)) = insn; |
23a070f3 | 3781 | insn = BB_END (bb); |
3782 | if (BB_FOOTER (bb)) | |
3783 | { | |
4a57a2e8 | 3784 | SET_NEXT_INSN (insn) = BB_FOOTER (bb); |
3785 | SET_PREV_INSN (BB_FOOTER (bb)) = insn; | |
23a070f3 | 3786 | while (NEXT_INSN (insn)) |
3787 | insn = NEXT_INSN (insn); | |
3788 | } | |
3789 | } | |
3790 | ||
4a57a2e8 | 3791 | SET_NEXT_INSN (insn) = cfg_layout_function_footer; |
23a070f3 | 3792 | if (cfg_layout_function_footer) |
4a57a2e8 | 3793 | SET_PREV_INSN (cfg_layout_function_footer) = insn; |
23a070f3 | 3794 | |
3795 | while (NEXT_INSN (insn)) | |
3796 | insn = NEXT_INSN (insn); | |
3797 | ||
3798 | set_last_insn (insn); | |
382ecba7 | 3799 | if (flag_checking) |
3800 | verify_insn_chain (); | |
23a070f3 | 3801 | |
3802 | /* Now add jumps and labels as needed to match the blocks new | |
c38b28e7 | 3803 | outgoing edges. */ |
23a070f3 | 3804 | |
c38b28e7 | 3805 | for (bb = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb; bb ; bb = (basic_block) |
3806 | bb->aux) | |
23a070f3 | 3807 | { |
3808 | edge e_fall, e_taken, e; | |
3d90435a | 3809 | rtx_insn *bb_end_insn; |
23a070f3 | 3810 | rtx ret_label = NULL_RTX; |
aa78dca5 | 3811 | basic_block nb; |
23a070f3 | 3812 | edge_iterator ei; |
3813 | ||
3814 | if (EDGE_COUNT (bb->succs) == 0) | |
3815 | continue; | |
3816 | ||
3817 | /* Find the old fallthru edge, and another non-EH edge for | |
3818 | a taken jump. */ | |
3819 | e_taken = e_fall = NULL; | |
3820 | ||
3821 | FOR_EACH_EDGE (e, ei, bb->succs) | |
3822 | if (e->flags & EDGE_FALLTHRU) | |
3823 | e_fall = e; | |
3824 | else if (! (e->flags & EDGE_EH)) | |
3825 | e_taken = e; | |
3826 | ||
3827 | bb_end_insn = BB_END (bb); | |
f9a00e9e | 3828 | if (rtx_jump_insn *bb_end_jump = dyn_cast <rtx_jump_insn *> (bb_end_insn)) |
23a070f3 | 3829 | { |
f9a00e9e | 3830 | ret_label = JUMP_LABEL (bb_end_jump); |
3831 | if (any_condjump_p (bb_end_jump)) | |
23a070f3 | 3832 | { |
3833 | /* This might happen if the conditional jump has side | |
3834 | effects and could therefore not be optimized away. | |
3835 | Make the basic block to end with a barrier in order | |
3836 | to prevent rtl_verify_flow_info from complaining. */ | |
3837 | if (!e_fall) | |
3838 | { | |
f9a00e9e | 3839 | gcc_assert (!onlyjump_p (bb_end_jump) |
3840 | || returnjump_p (bb_end_jump) | |
3b649e5d | 3841 | || (e_taken->flags & EDGE_CROSSING)); |
f9a00e9e | 3842 | emit_barrier_after (bb_end_jump); |
23a070f3 | 3843 | continue; |
3844 | } | |
3845 | ||
3846 | /* If the old fallthru is still next, nothing to do. */ | |
3847 | if (bb->aux == e_fall->dest | |
34154e27 | 3848 | || e_fall->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
23a070f3 | 3849 | continue; |
3850 | ||
3851 | /* The degenerated case of conditional jump jumping to the next | |
3852 | instruction can happen for jumps with side effects. We need | |
3853 | to construct a forwarder block and this will be done just | |
3854 | fine by force_nonfallthru below. */ | |
3855 | if (!e_taken) | |
3856 | ; | |
3857 | ||
3858 | /* There is another special case: if *neither* block is next, | |
3859 | such as happens at the very end of a function, then we'll | |
3860 | need to add a new unconditional jump. Choose the taken | |
3861 | edge based on known or assumed probability. */ | |
3862 | else if (bb->aux != e_taken->dest) | |
3863 | { | |
f9a00e9e | 3864 | rtx note = find_reg_note (bb_end_jump, REG_BR_PROB, 0); |
23a070f3 | 3865 | |
3866 | if (note | |
61cb1816 | 3867 | && profile_probability::from_reg_br_prob_note |
3868 | (XINT (note, 0)) < profile_probability::even () | |
f9a00e9e | 3869 | && invert_jump (bb_end_jump, |
34154e27 | 3870 | (e_fall->dest |
3871 | == EXIT_BLOCK_PTR_FOR_FN (cfun) | |
23a070f3 | 3872 | ? NULL_RTX |
3873 | : label_for_bb (e_fall->dest)), 0)) | |
3874 | { | |
3875 | e_fall->flags &= ~EDGE_FALLTHRU; | |
3876 | gcc_checking_assert (could_fall_through | |
3877 | (e_taken->src, e_taken->dest)); | |
3878 | e_taken->flags |= EDGE_FALLTHRU; | |
3879 | update_br_prob_note (bb); | |
3880 | e = e_fall, e_fall = e_taken, e_taken = e; | |
3881 | } | |
3882 | } | |
3883 | ||
3884 | /* If the "jumping" edge is a crossing edge, and the fall | |
3885 | through edge is non-crossing, leave things as they are. */ | |
3886 | else if ((e_taken->flags & EDGE_CROSSING) | |
3887 | && !(e_fall->flags & EDGE_CROSSING)) | |
3888 | continue; | |
3889 | ||
3890 | /* Otherwise we can try to invert the jump. This will | |
3891 | basically never fail, however, keep up the pretense. */ | |
f9a00e9e | 3892 | else if (invert_jump (bb_end_jump, |
34154e27 | 3893 | (e_fall->dest |
3894 | == EXIT_BLOCK_PTR_FOR_FN (cfun) | |
23a070f3 | 3895 | ? NULL_RTX |
3896 | : label_for_bb (e_fall->dest)), 0)) | |
3897 | { | |
3898 | e_fall->flags &= ~EDGE_FALLTHRU; | |
3899 | gcc_checking_assert (could_fall_through | |
3900 | (e_taken->src, e_taken->dest)); | |
3901 | e_taken->flags |= EDGE_FALLTHRU; | |
3902 | update_br_prob_note (bb); | |
3903 | if (LABEL_NUSES (ret_label) == 0 | |
3904 | && single_pred_p (e_taken->dest)) | |
283e5dd9 | 3905 | delete_insn (as_a<rtx_insn *> (ret_label)); |
23a070f3 | 3906 | continue; |
3907 | } | |
3908 | } | |
3909 | else if (extract_asm_operands (PATTERN (bb_end_insn)) != NULL) | |
3910 | { | |
3911 | /* If the old fallthru is still next or if | |
3912 | asm goto doesn't have a fallthru (e.g. when followed by | |
3913 | __builtin_unreachable ()), nothing to do. */ | |
3914 | if (! e_fall | |
3915 | || bb->aux == e_fall->dest | |
34154e27 | 3916 | || e_fall->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
23a070f3 | 3917 | continue; |
3918 | ||
3919 | /* Otherwise we'll have to use the fallthru fixup below. */ | |
3920 | } | |
3921 | else | |
3922 | { | |
3923 | /* Otherwise we have some return, switch or computed | |
3924 | jump. In the 99% case, there should not have been a | |
3925 | fallthru edge. */ | |
3926 | gcc_assert (returnjump_p (bb_end_insn) || !e_fall); | |
3927 | continue; | |
3928 | } | |
3929 | } | |
3930 | else | |
3931 | { | |
3932 | /* No fallthru implies a noreturn function with EH edges, or | |
3933 | something similarly bizarre. In any case, we don't need to | |
3934 | do anything. */ | |
3935 | if (! e_fall) | |
3936 | continue; | |
3937 | ||
3938 | /* If the fallthru block is still next, nothing to do. */ | |
3939 | if (bb->aux == e_fall->dest) | |
3940 | continue; | |
3941 | ||
3942 | /* A fallthru to exit block. */ | |
34154e27 | 3943 | if (e_fall->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
23a070f3 | 3944 | continue; |
3945 | } | |
3946 | ||
3947 | /* We got here if we need to add a new jump insn. | |
3948 | Note force_nonfallthru can delete E_FALL and thus we have to | |
3949 | save E_FALL->src prior to the call to force_nonfallthru. */ | |
23a070f3 | 3950 | nb = force_nonfallthru_and_redirect (e_fall, e_fall->dest, ret_label); |
3951 | if (nb) | |
3952 | { | |
3953 | nb->aux = bb->aux; | |
3954 | bb->aux = nb; | |
3955 | /* Don't process this new block. */ | |
3956 | bb = nb; | |
23a070f3 | 3957 | } |
3958 | } | |
3959 | ||
3960 | relink_block_chain (/*stay_in_cfglayout_mode=*/false); | |
3961 | ||
c38b28e7 | 3962 | /* Annoying special case - jump around dead jumptables left in the code. */ |
fc00614f | 3963 | FOR_EACH_BB_FN (bb, cfun) |
23a070f3 | 3964 | { |
3965 | edge e = find_fallthru_edge (bb->succs); | |
3966 | ||
c38b28e7 | 3967 | if (e && !can_fallthru (e->src, e->dest)) |
3968 | force_nonfallthru (e); | |
23a070f3 | 3969 | } |
3970 | ||
d0ae7eeb | 3971 | /* Ensure goto_locus from edges has some instructions with that locus in RTL |
3972 | when not optimizing. */ | |
3973 | if (!optimize && !DECL_IGNORED_P (current_function_decl)) | |
fc00614f | 3974 | FOR_EACH_BB_FN (bb, cfun) |
23a070f3 | 3975 | { |
3976 | edge e; | |
3977 | edge_iterator ei; | |
3978 | ||
3979 | FOR_EACH_EDGE (e, ei, bb->succs) | |
8e7408e3 | 3980 | if (LOCATION_LOCUS (e->goto_locus) != UNKNOWN_LOCATION |
5169661d | 3981 | && !(e->flags & EDGE_ABNORMAL)) |
23a070f3 | 3982 | { |
3983 | edge e2; | |
3984 | edge_iterator ei2; | |
3985 | basic_block dest, nb; | |
3d90435a | 3986 | rtx_insn *end; |
23a070f3 | 3987 | |
3988 | insn = BB_END (e->src); | |
3989 | end = PREV_INSN (BB_HEAD (e->src)); | |
3990 | while (insn != end | |
5169661d | 3991 | && (!NONDEBUG_INSN_P (insn) || !INSN_HAS_LOCATION (insn))) |
23a070f3 | 3992 | insn = PREV_INSN (insn); |
3993 | if (insn != end | |
5169661d | 3994 | && INSN_LOCATION (insn) == e->goto_locus) |
23a070f3 | 3995 | continue; |
3996 | if (simplejump_p (BB_END (e->src)) | |
5169661d | 3997 | && !INSN_HAS_LOCATION (BB_END (e->src))) |
23a070f3 | 3998 | { |
5169661d | 3999 | INSN_LOCATION (BB_END (e->src)) = e->goto_locus; |
23a070f3 | 4000 | continue; |
4001 | } | |
4002 | dest = e->dest; | |
34154e27 | 4003 | if (dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
23a070f3 | 4004 | { |
4005 | /* Non-fallthru edges to the exit block cannot be split. */ | |
4006 | if (!(e->flags & EDGE_FALLTHRU)) | |
4007 | continue; | |
4008 | } | |
4009 | else | |
4010 | { | |
4011 | insn = BB_HEAD (dest); | |
4012 | end = NEXT_INSN (BB_END (dest)); | |
4013 | while (insn != end && !NONDEBUG_INSN_P (insn)) | |
4014 | insn = NEXT_INSN (insn); | |
5169661d | 4015 | if (insn != end && INSN_HAS_LOCATION (insn) |
4016 | && INSN_LOCATION (insn) == e->goto_locus) | |
23a070f3 | 4017 | continue; |
4018 | } | |
4019 | nb = split_edge (e); | |
4020 | if (!INSN_P (BB_END (nb))) | |
26bb3cb2 | 4021 | BB_END (nb) = emit_insn_after_noloc (gen_nop (), BB_END (nb), |
a684cb04 | 4022 | nb); |
5169661d | 4023 | INSN_LOCATION (BB_END (nb)) = e->goto_locus; |
23a070f3 | 4024 | |
4025 | /* If there are other incoming edges to the destination block | |
4026 | with the same goto locus, redirect them to the new block as | |
4027 | well, this can prevent other such blocks from being created | |
4028 | in subsequent iterations of the loop. */ | |
4029 | for (ei2 = ei_start (dest->preds); (e2 = ei_safe_edge (ei2)); ) | |
8e7408e3 | 4030 | if (LOCATION_LOCUS (e2->goto_locus) != UNKNOWN_LOCATION |
23a070f3 | 4031 | && !(e2->flags & (EDGE_ABNORMAL | EDGE_FALLTHRU)) |
5169661d | 4032 | && e->goto_locus == e2->goto_locus) |
23a070f3 | 4033 | redirect_edge_and_branch (e2, nb); |
4034 | else | |
4035 | ei_next (&ei2); | |
4036 | } | |
4037 | } | |
4038 | } | |
4039 | \f | |
4040 | /* Perform sanity checks on the insn chain. | |
4041 | 1. Check that next/prev pointers are consistent in both the forward and | |
4042 | reverse direction. | |
4043 | 2. Count insns in chain, going both directions, and check if equal. | |
4044 | 3. Check that get_last_insn () returns the actual end of chain. */ | |
4045 | ||
4046 | DEBUG_FUNCTION void | |
4047 | verify_insn_chain (void) | |
4048 | { | |
3d90435a | 4049 | rtx_insn *x, *prevx, *nextx; |
23a070f3 | 4050 | int insn_cnt1, insn_cnt2; |
4051 | ||
4052 | for (prevx = NULL, insn_cnt1 = 1, x = get_insns (); | |
4053 | x != 0; | |
4054 | prevx = x, insn_cnt1++, x = NEXT_INSN (x)) | |
4055 | gcc_assert (PREV_INSN (x) == prevx); | |
4056 | ||
4057 | gcc_assert (prevx == get_last_insn ()); | |
4058 | ||
4059 | for (nextx = NULL, insn_cnt2 = 1, x = get_last_insn (); | |
4060 | x != 0; | |
4061 | nextx = x, insn_cnt2++, x = PREV_INSN (x)) | |
4062 | gcc_assert (NEXT_INSN (x) == nextx); | |
4063 | ||
4064 | gcc_assert (insn_cnt1 == insn_cnt2); | |
4065 | } | |
4066 | \f | |
4067 | /* If we have assembler epilogues, the block falling through to exit must | |
4068 | be the last one in the reordered chain when we reach final. Ensure | |
4069 | that this condition is met. */ | |
4070 | static void | |
4071 | fixup_fallthru_exit_predecessor (void) | |
4072 | { | |
4073 | edge e; | |
4074 | basic_block bb = NULL; | |
4075 | ||
4076 | /* This transformation is not valid before reload, because we might | |
4077 | separate a call from the instruction that copies the return | |
4078 | value. */ | |
4079 | gcc_assert (reload_completed); | |
4080 | ||
34154e27 | 4081 | e = find_fallthru_edge (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds); |
23a070f3 | 4082 | if (e) |
4083 | bb = e->src; | |
4084 | ||
4085 | if (bb && bb->aux) | |
4086 | { | |
34154e27 | 4087 | basic_block c = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb; |
23a070f3 | 4088 | |
4089 | /* If the very first block is the one with the fall-through exit | |
4090 | edge, we have to split that block. */ | |
4091 | if (c == bb) | |
4092 | { | |
4302d619 | 4093 | bb = split_block_after_labels (bb)->dest; |
23a070f3 | 4094 | bb->aux = c->aux; |
4095 | c->aux = bb; | |
943ea6fa | 4096 | BB_FOOTER (bb) = BB_FOOTER (c); |
4097 | BB_FOOTER (c) = NULL; | |
23a070f3 | 4098 | } |
4099 | ||
4100 | while (c->aux != bb) | |
4101 | c = (basic_block) c->aux; | |
4102 | ||
4103 | c->aux = bb->aux; | |
4104 | while (c->aux) | |
4105 | c = (basic_block) c->aux; | |
4106 | ||
4107 | c->aux = bb; | |
4108 | bb->aux = NULL; | |
4109 | } | |
4110 | } | |
4111 | ||
4112 | /* In case there are more than one fallthru predecessors of exit, force that | |
4113 | there is only one. */ | |
4114 | ||
4115 | static void | |
4116 | force_one_exit_fallthru (void) | |
4117 | { | |
4118 | edge e, predecessor = NULL; | |
4119 | bool more = false; | |
4120 | edge_iterator ei; | |
4121 | basic_block forwarder, bb; | |
4122 | ||
34154e27 | 4123 | FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds) |
23a070f3 | 4124 | if (e->flags & EDGE_FALLTHRU) |
4125 | { | |
4126 | if (predecessor == NULL) | |
4127 | predecessor = e; | |
4128 | else | |
4129 | { | |
4130 | more = true; | |
4131 | break; | |
4132 | } | |
4133 | } | |
4134 | ||
4135 | if (!more) | |
4136 | return; | |
4137 | ||
4138 | /* Exit has several fallthru predecessors. Create a forwarder block for | |
4139 | them. */ | |
4140 | forwarder = split_edge (predecessor); | |
34154e27 | 4141 | for (ei = ei_start (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds); |
4142 | (e = ei_safe_edge (ei)); ) | |
23a070f3 | 4143 | { |
4144 | if (e->src == forwarder | |
4145 | || !(e->flags & EDGE_FALLTHRU)) | |
4146 | ei_next (&ei); | |
4147 | else | |
4148 | redirect_edge_and_branch_force (e, forwarder); | |
4149 | } | |
4150 | ||
4151 | /* Fix up the chain of blocks -- make FORWARDER immediately precede the | |
4152 | exit block. */ | |
fc00614f | 4153 | FOR_EACH_BB_FN (bb, cfun) |
23a070f3 | 4154 | { |
4155 | if (bb->aux == NULL && bb != forwarder) | |
4156 | { | |
4157 | bb->aux = forwarder; | |
4158 | break; | |
4159 | } | |
4160 | } | |
4161 | } | |
4162 | \f | |
4163 | /* Return true in case it is possible to duplicate the basic block BB. */ | |
4164 | ||
4165 | static bool | |
4166 | cfg_layout_can_duplicate_bb_p (const_basic_block bb) | |
4167 | { | |
4168 | /* Do not attempt to duplicate tablejumps, as we need to unshare | |
4169 | the dispatch table. This is difficult to do, as the instructions | |
4170 | computing jump destination may be hoisted outside the basic block. */ | |
4171 | if (tablejump_p (BB_END (bb), NULL, NULL)) | |
4172 | return false; | |
4173 | ||
4174 | /* Do not duplicate blocks containing insns that can't be copied. */ | |
4175 | if (targetm.cannot_copy_insn_p) | |
4176 | { | |
3d90435a | 4177 | rtx_insn *insn = BB_HEAD (bb); |
23a070f3 | 4178 | while (1) |
4179 | { | |
4180 | if (INSN_P (insn) && targetm.cannot_copy_insn_p (insn)) | |
4181 | return false; | |
4182 | if (insn == BB_END (bb)) | |
4183 | break; | |
4184 | insn = NEXT_INSN (insn); | |
4185 | } | |
4186 | } | |
4187 | ||
4188 | return true; | |
4189 | } | |
4190 | ||
aa935352 | 4191 | rtx_insn * |
baa294b4 | 4192 | duplicate_insn_chain (rtx_insn *from, rtx_insn *to) |
23a070f3 | 4193 | { |
baa294b4 | 4194 | rtx_insn *insn, *next, *copy; |
cef3d8ad | 4195 | rtx_note *last; |
23a070f3 | 4196 | |
4197 | /* Avoid updating of boundaries of previous basic block. The | |
4198 | note will get removed from insn stream in fixup. */ | |
4199 | last = emit_note (NOTE_INSN_DELETED); | |
4200 | ||
4201 | /* Create copy at the end of INSN chain. The chain will | |
4202 | be reordered later. */ | |
4203 | for (insn = from; insn != NEXT_INSN (to); insn = NEXT_INSN (insn)) | |
4204 | { | |
4205 | switch (GET_CODE (insn)) | |
4206 | { | |
4207 | case DEBUG_INSN: | |
4208 | /* Don't duplicate label debug insns. */ | |
bce107d7 | 4209 | if (DEBUG_BIND_INSN_P (insn) |
4210 | && TREE_CODE (INSN_VAR_LOCATION_DECL (insn)) == LABEL_DECL) | |
23a070f3 | 4211 | break; |
4212 | /* FALLTHRU */ | |
4213 | case INSN: | |
4214 | case CALL_INSN: | |
4215 | case JUMP_INSN: | |
23a070f3 | 4216 | copy = emit_copy_of_insn_after (insn, get_last_insn ()); |
4217 | if (JUMP_P (insn) && JUMP_LABEL (insn) != NULL_RTX | |
4218 | && ANY_RETURN_P (JUMP_LABEL (insn))) | |
4219 | JUMP_LABEL (copy) = JUMP_LABEL (insn); | |
4220 | maybe_copy_prologue_epilogue_insn (insn, copy); | |
4221 | break; | |
4222 | ||
91f71fa3 | 4223 | case JUMP_TABLE_DATA: |
4224 | /* Avoid copying of dispatch tables. We never duplicate | |
4225 | tablejumps, so this can hit only in case the table got | |
4226 | moved far from original jump. | |
4227 | Avoid copying following barrier as well if any | |
4228 | (and debug insns in between). */ | |
4229 | for (next = NEXT_INSN (insn); | |
4230 | next != NEXT_INSN (to); | |
4231 | next = NEXT_INSN (next)) | |
4232 | if (!DEBUG_INSN_P (next)) | |
4233 | break; | |
4234 | if (next != NEXT_INSN (to) && BARRIER_P (next)) | |
4235 | insn = next; | |
4236 | break; | |
4237 | ||
23a070f3 | 4238 | case CODE_LABEL: |
4239 | break; | |
4240 | ||
4241 | case BARRIER: | |
4242 | emit_barrier (); | |
4243 | break; | |
4244 | ||
4245 | case NOTE: | |
4246 | switch (NOTE_KIND (insn)) | |
4247 | { | |
4248 | /* In case prologue is empty and function contain label | |
4249 | in first BB, we may want to copy the block. */ | |
4250 | case NOTE_INSN_PROLOGUE_END: | |
4251 | ||
4252 | case NOTE_INSN_DELETED: | |
4253 | case NOTE_INSN_DELETED_LABEL: | |
4254 | case NOTE_INSN_DELETED_DEBUG_LABEL: | |
4255 | /* No problem to strip these. */ | |
4256 | case NOTE_INSN_FUNCTION_BEG: | |
4257 | /* There is always just single entry to function. */ | |
4258 | case NOTE_INSN_BASIC_BLOCK: | |
aa78dca5 | 4259 | /* We should only switch text sections once. */ |
4260 | case NOTE_INSN_SWITCH_TEXT_SECTIONS: | |
23a070f3 | 4261 | break; |
4262 | ||
4263 | case NOTE_INSN_EPILOGUE_BEG: | |
97354ae4 | 4264 | case NOTE_INSN_UPDATE_SJLJ_CONTEXT: |
cef3d8ad | 4265 | emit_note_copy (as_a <rtx_note *> (insn)); |
23a070f3 | 4266 | break; |
4267 | ||
4268 | default: | |
4269 | /* All other notes should have already been eliminated. */ | |
4270 | gcc_unreachable (); | |
4271 | } | |
4272 | break; | |
4273 | default: | |
4274 | gcc_unreachable (); | |
4275 | } | |
4276 | } | |
4277 | insn = NEXT_INSN (last); | |
4278 | delete_insn (last); | |
baa294b4 | 4279 | return insn; |
23a070f3 | 4280 | } |
4281 | ||
4282 | /* Create a duplicate of the basic block BB. */ | |
4283 | ||
4284 | static basic_block | |
3350055c | 4285 | cfg_layout_duplicate_bb (basic_block bb, copy_bb_data *) |
23a070f3 | 4286 | { |
3d90435a | 4287 | rtx_insn *insn; |
23a070f3 | 4288 | basic_block new_bb; |
4289 | ||
4290 | insn = duplicate_insn_chain (BB_HEAD (bb), BB_END (bb)); | |
4291 | new_bb = create_basic_block (insn, | |
4292 | insn ? get_last_insn () : NULL, | |
34154e27 | 4293 | EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb); |
23a070f3 | 4294 | |
4295 | BB_COPY_PARTITION (new_bb, bb); | |
4296 | if (BB_HEADER (bb)) | |
4297 | { | |
4298 | insn = BB_HEADER (bb); | |
4299 | while (NEXT_INSN (insn)) | |
4300 | insn = NEXT_INSN (insn); | |
4301 | insn = duplicate_insn_chain (BB_HEADER (bb), insn); | |
4302 | if (insn) | |
26bb3cb2 | 4303 | BB_HEADER (new_bb) = unlink_insn_chain (insn, get_last_insn ()); |
23a070f3 | 4304 | } |
4305 | ||
4306 | if (BB_FOOTER (bb)) | |
4307 | { | |
4308 | insn = BB_FOOTER (bb); | |
4309 | while (NEXT_INSN (insn)) | |
4310 | insn = NEXT_INSN (insn); | |
4311 | insn = duplicate_insn_chain (BB_FOOTER (bb), insn); | |
4312 | if (insn) | |
943ea6fa | 4313 | BB_FOOTER (new_bb) = unlink_insn_chain (insn, get_last_insn ()); |
23a070f3 | 4314 | } |
4315 | ||
4316 | return new_bb; | |
4317 | } | |
4318 | ||
4319 | \f | |
4320 | /* Main entry point to this module - initialize the datastructures for | |
4321 | CFG layout changes. It keeps LOOPS up-to-date if not null. | |
4322 | ||
4323 | FLAGS is a set of additional flags to pass to cleanup_cfg(). */ | |
4324 | ||
4325 | void | |
3f6e5ced | 4326 | cfg_layout_initialize (int flags) |
23a070f3 | 4327 | { |
a4de1c23 | 4328 | rtx_insn_list *x; |
23a070f3 | 4329 | basic_block bb; |
4330 | ||
e22c35e9 | 4331 | /* Once bb partitioning is complete, cfg layout mode should not be |
4332 | re-entered. Entering cfg layout mode may require fixups. As an | |
4333 | example, if edge forwarding performed when optimizing the cfg | |
4334 | layout required moving a block from the hot to the cold | |
4335 | section. This would create an illegal partitioning unless some | |
4336 | manual fixup was performed. */ | |
bb5a804f | 4337 | gcc_assert (!crtl->bb_reorder_complete || !crtl->has_bb_partition); |
e31c70b9 | 4338 | |
23a070f3 | 4339 | initialize_original_copy_tables (); |
4340 | ||
4341 | cfg_layout_rtl_register_cfg_hooks (); | |
4342 | ||
4343 | record_effective_endpoints (); | |
4344 | ||
4345 | /* Make sure that the targets of non local gotos are marked. */ | |
6e16e157 | 4346 | for (x = nonlocal_goto_handler_labels; x; x = x->next ()) |
23a070f3 | 4347 | { |
a4de1c23 | 4348 | bb = BLOCK_FOR_INSN (x->insn ()); |
23a070f3 | 4349 | bb->flags |= BB_NON_LOCAL_GOTO_TARGET; |
4350 | } | |
4351 | ||
4352 | cleanup_cfg (CLEANUP_CFGLAYOUT | flags); | |
4353 | } | |
4354 | ||
4355 | /* Splits superblocks. */ | |
4356 | void | |
4357 | break_superblocks (void) | |
4358 | { | |
23a070f3 | 4359 | bool need = false; |
4360 | basic_block bb; | |
4361 | ||
3c6549f8 | 4362 | auto_sbitmap superblocks (last_basic_block_for_fn (cfun)); |
53c5d9d4 | 4363 | bitmap_clear (superblocks); |
23a070f3 | 4364 | |
fc00614f | 4365 | FOR_EACH_BB_FN (bb, cfun) |
23a070f3 | 4366 | if (bb->flags & BB_SUPERBLOCK) |
4367 | { | |
4368 | bb->flags &= ~BB_SUPERBLOCK; | |
08b7917c | 4369 | bitmap_set_bit (superblocks, bb->index); |
23a070f3 | 4370 | need = true; |
4371 | } | |
4372 | ||
4373 | if (need) | |
4374 | { | |
4375 | rebuild_jump_labels (get_insns ()); | |
4376 | find_many_sub_basic_blocks (superblocks); | |
4377 | } | |
23a070f3 | 4378 | } |
4379 | ||
4380 | /* Finalize the changes: reorder insn list according to the sequence specified | |
c38b28e7 | 4381 | by aux pointers, enter compensation code, rebuild scope forest. */ |
23a070f3 | 4382 | |
4383 | void | |
4384 | cfg_layout_finalize (void) | |
4385 | { | |
f3c921eb | 4386 | free_dominance_info (CDI_DOMINATORS); |
23a070f3 | 4387 | force_one_exit_fallthru (); |
4388 | rtl_register_cfg_hooks (); | |
cf3a33c8 | 4389 | if (reload_completed && !targetm.have_epilogue ()) |
23a070f3 | 4390 | fixup_fallthru_exit_predecessor (); |
4391 | fixup_reorder_chain (); | |
4392 | ||
c38b28e7 | 4393 | rebuild_jump_labels (get_insns ()); |
4394 | delete_dead_jumptables (); | |
4395 | ||
382ecba7 | 4396 | if (flag_checking) |
4397 | verify_insn_chain (); | |
4398 | checking_verify_flow_info (); | |
23a070f3 | 4399 | } |
4400 | ||
54f21e20 | 4401 | |
1026363d | 4402 | /* Same as split_block but update cfg_layout structures. */ |
5f5d4cd1 | 4403 | |
4404 | static basic_block | |
4c9e08a4 | 4405 | cfg_layout_split_block (basic_block bb, void *insnp) |
1026363d | 4406 | { |
f780cc25 | 4407 | rtx insn = (rtx) insnp; |
5f5d4cd1 | 4408 | basic_block new_bb = rtl_split_block (bb, insn); |
1026363d | 4409 | |
943ea6fa | 4410 | BB_FOOTER (new_bb) = BB_FOOTER (bb); |
4411 | BB_FOOTER (bb) = NULL; | |
1026363d | 4412 | |
5f5d4cd1 | 4413 | return new_bb; |
1026363d | 4414 | } |
4415 | ||
1026363d | 4416 | /* Redirect Edge to DEST. */ |
4ee9c684 | 4417 | static edge |
4c9e08a4 | 4418 | cfg_layout_redirect_edge_and_branch (edge e, basic_block dest) |
1026363d | 4419 | { |
4420 | basic_block src = e->src; | |
4ee9c684 | 4421 | edge ret; |
1026363d | 4422 | |
c60fa3a7 | 4423 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
4ee9c684 | 4424 | return NULL; |
c60fa3a7 | 4425 | |
e5562ab8 | 4426 | if (e->dest == dest) |
4ee9c684 | 4427 | return e; |
c60fa3a7 | 4428 | |
ec796344 | 4429 | if (e->flags & EDGE_CROSSING |
4430 | && BB_PARTITION (e->src) == BB_PARTITION (dest) | |
4431 | && simplejump_p (BB_END (src))) | |
4432 | { | |
4433 | if (dump_file) | |
4434 | fprintf (dump_file, | |
4435 | "Removing crossing jump while redirecting edge form %i to %i\n", | |
4436 | e->src->index, dest->index); | |
4437 | delete_insn (BB_END (src)); | |
eb258b7d | 4438 | remove_barriers_from_footer (src); |
ec796344 | 4439 | e->flags |= EDGE_FALLTHRU; |
4440 | } | |
4441 | ||
34154e27 | 4442 | if (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
4ee9c684 | 4443 | && (ret = try_redirect_by_replacing_jump (e, dest, true))) |
adee86a0 | 4444 | { |
3072d30e | 4445 | df_set_bb_dirty (src); |
4ee9c684 | 4446 | return ret; |
adee86a0 | 4447 | } |
c60fa3a7 | 4448 | |
34154e27 | 4449 | if (e->src == ENTRY_BLOCK_PTR_FOR_FN (cfun) |
c60fa3a7 | 4450 | && (e->flags & EDGE_FALLTHRU) && !(e->flags & EDGE_COMPLEX)) |
4451 | { | |
450d042a | 4452 | if (dump_file) |
4453 | fprintf (dump_file, "Redirecting entry edge from bb %i to %i\n", | |
c60fa3a7 | 4454 | e->src->index, dest->index); |
4455 | ||
3072d30e | 4456 | df_set_bb_dirty (e->src); |
c60fa3a7 | 4457 | redirect_edge_succ (e, dest); |
4ee9c684 | 4458 | return e; |
c60fa3a7 | 4459 | } |
4460 | ||
1026363d | 4461 | /* Redirect_edge_and_branch may decide to turn branch into fallthru edge |
4462 | in the case the basic block appears to be in sequence. Avoid this | |
4463 | transformation. */ | |
4464 | ||
1026363d | 4465 | if (e->flags & EDGE_FALLTHRU) |
4466 | { | |
4467 | /* Redirect any branch edges unified with the fallthru one. */ | |
6d7dc5b9 | 4468 | if (JUMP_P (BB_END (src)) |
b9de5542 | 4469 | && label_is_jump_target_p (BB_HEAD (e->dest), |
4470 | BB_END (src))) | |
1026363d | 4471 | { |
cc636d56 | 4472 | edge redirected; |
a0c938f0 | 4473 | |
450d042a | 4474 | if (dump_file) |
4475 | fprintf (dump_file, "Fallthru edge unified with branch " | |
b9de5542 | 4476 | "%i->%i redirected to %i\n", |
4477 | e->src->index, e->dest->index, dest->index); | |
4478 | e->flags &= ~EDGE_FALLTHRU; | |
cc636d56 | 4479 | redirected = redirect_branch_edge (e, dest); |
4480 | gcc_assert (redirected); | |
d5321455 | 4481 | redirected->flags |= EDGE_FALLTHRU; |
4482 | df_set_bb_dirty (redirected->src); | |
4483 | return redirected; | |
1026363d | 4484 | } |
4485 | /* In case we are redirecting fallthru edge to the branch edge | |
a0c938f0 | 4486 | of conditional jump, remove it. */ |
cd665a06 | 4487 | if (EDGE_COUNT (src->succs) == 2) |
1026363d | 4488 | { |
9ea57afb | 4489 | /* Find the edge that is different from E. */ |
4490 | edge s = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e); | |
cd665a06 | 4491 | |
1026363d | 4492 | if (s->dest == dest |
5496dbfc | 4493 | && any_condjump_p (BB_END (src)) |
4494 | && onlyjump_p (BB_END (src))) | |
4495 | delete_insn (BB_END (src)); | |
1026363d | 4496 | } |
450d042a | 4497 | if (dump_file) |
6d31b223 | 4498 | fprintf (dump_file, "Redirecting fallthru edge %i->%i to %i\n", |
c60fa3a7 | 4499 | e->src->index, e->dest->index, dest->index); |
d5321455 | 4500 | ret = redirect_edge_succ_nodup (e, dest); |
1026363d | 4501 | } |
4502 | else | |
c60fa3a7 | 4503 | ret = redirect_branch_edge (e, dest); |
1026363d | 4504 | |
6b8784b2 | 4505 | if (!ret) |
4506 | return NULL; | |
4507 | ||
ec796344 | 4508 | fixup_partition_crossing (ret); |
1026363d | 4509 | /* We don't want simplejumps in the insn stream during cfglayout. */ |
ec796344 | 4510 | gcc_assert (!simplejump_p (BB_END (src)) || CROSSING_JUMP_P (BB_END (src))); |
1026363d | 4511 | |
3072d30e | 4512 | df_set_bb_dirty (src); |
1026363d | 4513 | return ret; |
4514 | } | |
4515 | ||
4516 | /* Simple wrapper as we always can redirect fallthru edges. */ | |
4517 | static basic_block | |
4c9e08a4 | 4518 | cfg_layout_redirect_edge_and_branch_force (edge e, basic_block dest) |
1026363d | 4519 | { |
cc636d56 | 4520 | edge redirected = cfg_layout_redirect_edge_and_branch (e, dest); |
4521 | ||
4522 | gcc_assert (redirected); | |
1026363d | 4523 | return NULL; |
4524 | } | |
4525 | ||
5f5d4cd1 | 4526 | /* Same as delete_basic_block but update cfg_layout structures. */ |
4527 | ||
1026363d | 4528 | static void |
4c9e08a4 | 4529 | cfg_layout_delete_block (basic_block bb) |
1026363d | 4530 | { |
3d90435a | 4531 | rtx_insn *insn, *next, *prev = PREV_INSN (BB_HEAD (bb)), *remaints; |
26bb3cb2 | 4532 | rtx_insn **to; |
1026363d | 4533 | |
43e94e51 | 4534 | if (BB_HEADER (bb)) |
1026363d | 4535 | { |
5496dbfc | 4536 | next = BB_HEAD (bb); |
1026363d | 4537 | if (prev) |
4a57a2e8 | 4538 | SET_NEXT_INSN (prev) = BB_HEADER (bb); |
1026363d | 4539 | else |
43e94e51 | 4540 | set_first_insn (BB_HEADER (bb)); |
4a57a2e8 | 4541 | SET_PREV_INSN (BB_HEADER (bb)) = prev; |
43e94e51 | 4542 | insn = BB_HEADER (bb); |
1026363d | 4543 | while (NEXT_INSN (insn)) |
4544 | insn = NEXT_INSN (insn); | |
4a57a2e8 | 4545 | SET_NEXT_INSN (insn) = next; |
4546 | SET_PREV_INSN (next) = insn; | |
1026363d | 4547 | } |
5496dbfc | 4548 | next = NEXT_INSN (BB_END (bb)); |
43e94e51 | 4549 | if (BB_FOOTER (bb)) |
1026363d | 4550 | { |
43e94e51 | 4551 | insn = BB_FOOTER (bb); |
c60fa3a7 | 4552 | while (insn) |
4553 | { | |
6d7dc5b9 | 4554 | if (BARRIER_P (insn)) |
c60fa3a7 | 4555 | { |
4556 | if (PREV_INSN (insn)) | |
4a57a2e8 | 4557 | SET_NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); |
c60fa3a7 | 4558 | else |
943ea6fa | 4559 | BB_FOOTER (bb) = NEXT_INSN (insn); |
c60fa3a7 | 4560 | if (NEXT_INSN (insn)) |
4a57a2e8 | 4561 | SET_PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); |
c60fa3a7 | 4562 | } |
6d7dc5b9 | 4563 | if (LABEL_P (insn)) |
c60fa3a7 | 4564 | break; |
4565 | insn = NEXT_INSN (insn); | |
4566 | } | |
43e94e51 | 4567 | if (BB_FOOTER (bb)) |
c60fa3a7 | 4568 | { |
5496dbfc | 4569 | insn = BB_END (bb); |
4a57a2e8 | 4570 | SET_NEXT_INSN (insn) = BB_FOOTER (bb); |
4571 | SET_PREV_INSN (BB_FOOTER (bb)) = insn; | |
c60fa3a7 | 4572 | while (NEXT_INSN (insn)) |
4573 | insn = NEXT_INSN (insn); | |
4a57a2e8 | 4574 | SET_NEXT_INSN (insn) = next; |
c60fa3a7 | 4575 | if (next) |
4a57a2e8 | 4576 | SET_PREV_INSN (next) = insn; |
c60fa3a7 | 4577 | else |
4578 | set_last_insn (insn); | |
4579 | } | |
1026363d | 4580 | } |
34154e27 | 4581 | if (bb->next_bb != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
26bb3cb2 | 4582 | to = &BB_HEADER (bb->next_bb); |
1026363d | 4583 | else |
4584 | to = &cfg_layout_function_footer; | |
7a22afab | 4585 | |
1026363d | 4586 | rtl_delete_block (bb); |
4587 | ||
4588 | if (prev) | |
4589 | prev = NEXT_INSN (prev); | |
4c9e08a4 | 4590 | else |
1026363d | 4591 | prev = get_insns (); |
4592 | if (next) | |
4593 | next = PREV_INSN (next); | |
4c9e08a4 | 4594 | else |
1026363d | 4595 | next = get_last_insn (); |
4596 | ||
4597 | if (next && NEXT_INSN (next) != prev) | |
4598 | { | |
4599 | remaints = unlink_insn_chain (prev, next); | |
4600 | insn = remaints; | |
4601 | while (NEXT_INSN (insn)) | |
4602 | insn = NEXT_INSN (insn); | |
4a57a2e8 | 4603 | SET_NEXT_INSN (insn) = *to; |
1026363d | 4604 | if (*to) |
4a57a2e8 | 4605 | SET_PREV_INSN (*to) = insn; |
1026363d | 4606 | *to = remaints; |
4607 | } | |
4608 | } | |
4609 | ||
139c3f48 | 4610 | /* Return true when blocks A and B can be safely merged. */ |
47aaf6e6 | 4611 | |
c60fa3a7 | 4612 | static bool |
47aaf6e6 | 4613 | cfg_layout_can_merge_blocks_p (basic_block a, basic_block b) |
c60fa3a7 | 4614 | { |
4f18499c | 4615 | /* If we are partitioning hot/cold basic blocks, we don't want to |
4616 | mess up unconditional or indirect jumps that cross between hot | |
7562ed74 | 4617 | and cold sections. |
4618 | ||
1118aef7 | 4619 | Basic block partitioning may result in some jumps that appear to |
a0c938f0 | 4620 | be optimizable (or blocks that appear to be mergeable), but which really |
4621 | must be left untouched (they are required to make it safely across | |
4622 | partition boundaries). See the comments at the top of | |
1118aef7 | 4623 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
4624 | ||
1897b881 | 4625 | if (BB_PARTITION (a) != BB_PARTITION (b)) |
7562ed74 | 4626 | return false; |
4f18499c | 4627 | |
79f958cb | 4628 | /* Protect the loop latches. */ |
4629 | if (current_loops && b->loop_father->latch == b) | |
4630 | return false; | |
4631 | ||
d945554e | 4632 | /* If we would end up moving B's instructions, make sure it doesn't fall |
4633 | through into the exit block, since we cannot recover from a fallthrough | |
4634 | edge into the exit block occurring in the middle of a function. */ | |
4635 | if (NEXT_INSN (BB_END (a)) != BB_HEAD (b)) | |
4636 | { | |
4637 | edge e = find_fallthru_edge (b->succs); | |
34154e27 | 4638 | if (e && e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
d945554e | 4639 | return false; |
4640 | } | |
4641 | ||
c60fa3a7 | 4642 | /* There must be exactly one edge in between the blocks. */ |
ea091dfd | 4643 | return (single_succ_p (a) |
4644 | && single_succ (a) == b | |
4645 | && single_pred_p (b) == 1 | |
cd665a06 | 4646 | && a != b |
c60fa3a7 | 4647 | /* Must be simple edge. */ |
ea091dfd | 4648 | && !(single_succ_edge (a)->flags & EDGE_COMPLEX) |
34154e27 | 4649 | && a != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
4650 | && b != EXIT_BLOCK_PTR_FOR_FN (cfun) | |
4aaec180 | 4651 | /* If the jump insn has side effects, we can't kill the edge. |
4652 | When not optimizing, try_redirect_by_replacing_jump will | |
4653 | not allow us to redirect an edge by replacing a table jump. */ | |
6d7dc5b9 | 4654 | && (!JUMP_P (BB_END (a)) |
4aaec180 | 4655 | || ((!optimize || reload_completed) |
5496dbfc | 4656 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
c60fa3a7 | 4657 | } |
4658 | ||
a53ff4c1 | 4659 | /* Merge block A and B. The blocks must be mergeable. */ |
4660 | ||
c60fa3a7 | 4661 | static void |
4662 | cfg_layout_merge_blocks (basic_block a, basic_block b) | |
4663 | { | |
d0ae7eeb | 4664 | /* If B is a forwarder block whose outgoing edge has no location, we'll |
4665 | propagate the locus of the edge between A and B onto it. */ | |
4666 | const bool forward_edge_locus | |
4667 | = (b->flags & BB_FORWARDER_BLOCK) != 0 | |
4668 | && LOCATION_LOCUS (EDGE_SUCC (b, 0)->goto_locus) == UNKNOWN_LOCATION; | |
3d90435a | 4669 | rtx_insn *insn; |
18b762f0 | 4670 | |
1b4345f7 | 4671 | gcc_checking_assert (cfg_layout_can_merge_blocks_p (a, b)); |
c60fa3a7 | 4672 | |
3072d30e | 4673 | if (dump_file) |
18b762f0 | 4674 | fprintf (dump_file, "Merging block %d into block %d...\n", b->index, |
4675 | a->index); | |
3072d30e | 4676 | |
c60fa3a7 | 4677 | /* If there was a CODE_LABEL beginning B, delete it. */ |
6d7dc5b9 | 4678 | if (LABEL_P (BB_HEAD (b))) |
7b07eae7 | 4679 | { |
7b07eae7 | 4680 | delete_insn (BB_HEAD (b)); |
4681 | } | |
c60fa3a7 | 4682 | |
4683 | /* We should have fallthru edge in a, or we can do dummy redirection to get | |
4684 | it cleaned up. */ | |
6d7dc5b9 | 4685 | if (JUMP_P (BB_END (a))) |
cd665a06 | 4686 | try_redirect_by_replacing_jump (EDGE_SUCC (a, 0), b, true); |
cc636d56 | 4687 | gcc_assert (!JUMP_P (BB_END (a))); |
c60fa3a7 | 4688 | |
d0ae7eeb | 4689 | /* If not optimizing, preserve the locus of the single edge between |
4690 | blocks A and B if necessary by emitting a nop. */ | |
4691 | if (!optimize | |
4692 | && !forward_edge_locus | |
4693 | && !DECL_IGNORED_P (current_function_decl)) | |
8ddad41d | 4694 | emit_nop_for_unique_locus_between (a, b); |
9c388755 | 4695 | |
eda57d74 | 4696 | /* Move things from b->footer after a->footer. */ |
4697 | if (BB_FOOTER (b)) | |
c60fa3a7 | 4698 | { |
eda57d74 | 4699 | if (!BB_FOOTER (a)) |
943ea6fa | 4700 | BB_FOOTER (a) = BB_FOOTER (b); |
eda57d74 | 4701 | else |
4702 | { | |
3d90435a | 4703 | rtx_insn *last = BB_FOOTER (a); |
eda57d74 | 4704 | |
4705 | while (NEXT_INSN (last)) | |
4706 | last = NEXT_INSN (last); | |
4a57a2e8 | 4707 | SET_NEXT_INSN (last) = BB_FOOTER (b); |
4708 | SET_PREV_INSN (BB_FOOTER (b)) = last; | |
eda57d74 | 4709 | } |
943ea6fa | 4710 | BB_FOOTER (b) = NULL; |
eda57d74 | 4711 | } |
4712 | ||
4713 | /* Move things from b->header before a->footer. | |
4714 | Note that this may include dead tablejump data, but we don't clean | |
4715 | those up until we go out of cfglayout mode. */ | |
4716 | if (BB_HEADER (b)) | |
4717 | { | |
4718 | if (! BB_FOOTER (a)) | |
943ea6fa | 4719 | BB_FOOTER (a) = BB_HEADER (b); |
eda57d74 | 4720 | else |
4721 | { | |
3d90435a | 4722 | rtx_insn *last = BB_HEADER (b); |
eda57d74 | 4723 | |
4724 | while (NEXT_INSN (last)) | |
4725 | last = NEXT_INSN (last); | |
4a57a2e8 | 4726 | SET_NEXT_INSN (last) = BB_FOOTER (a); |
4727 | SET_PREV_INSN (BB_FOOTER (a)) = last; | |
943ea6fa | 4728 | BB_FOOTER (a) = BB_HEADER (b); |
eda57d74 | 4729 | } |
26bb3cb2 | 4730 | BB_HEADER (b) = NULL; |
c60fa3a7 | 4731 | } |
4732 | ||
4733 | /* In the case basic blocks are not adjacent, move them around. */ | |
5496dbfc | 4734 | if (NEXT_INSN (BB_END (a)) != BB_HEAD (b)) |
c60fa3a7 | 4735 | { |
d4afc00c | 4736 | insn = unlink_insn_chain (BB_HEAD (b), BB_END (b)); |
f41d4683 | 4737 | |
d4afc00c | 4738 | emit_insn_after_noloc (insn, BB_END (a), a); |
c60fa3a7 | 4739 | } |
4740 | /* Otherwise just re-associate the instructions. */ | |
4741 | else | |
4742 | { | |
5496dbfc | 4743 | insn = BB_HEAD (b); |
26bb3cb2 | 4744 | BB_END (a) = BB_END (b); |
c60fa3a7 | 4745 | } |
4746 | ||
d4afc00c | 4747 | /* emit_insn_after_noloc doesn't call df_insn_change_bb. |
4748 | We need to explicitly call. */ | |
4749 | update_bb_for_insn_chain (insn, BB_END (b), a); | |
4750 | ||
4751 | /* Skip possible DELETED_LABEL insn. */ | |
4752 | if (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
4753 | insn = NEXT_INSN (insn); | |
4754 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn)); | |
26bb3cb2 | 4755 | BB_HEAD (b) = BB_END (b) = NULL; |
d4afc00c | 4756 | delete_insn (insn); |
4757 | ||
3072d30e | 4758 | df_bb_delete (b->index); |
4759 | ||
d0ae7eeb | 4760 | if (forward_edge_locus) |
18b762f0 | 4761 | EDGE_SUCC (b, 0)->goto_locus = EDGE_SUCC (a, 0)->goto_locus; |
4762 | ||
450d042a | 4763 | if (dump_file) |
18b762f0 | 4764 | fprintf (dump_file, "Merged blocks %d and %d.\n", a->index, b->index); |
c60fa3a7 | 4765 | } |
4766 | ||
4767 | /* Split edge E. */ | |
5f5d4cd1 | 4768 | |
c60fa3a7 | 4769 | static basic_block |
4770 | cfg_layout_split_edge (edge e) | |
4771 | { | |
c60fa3a7 | 4772 | basic_block new_bb = |
34154e27 | 4773 | create_basic_block (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
5496dbfc | 4774 | ? NEXT_INSN (BB_END (e->src)) : get_insns (), |
c60fa3a7 | 4775 | NULL_RTX, e->src); |
4776 | ||
34154e27 | 4777 | if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
e1b2b77c | 4778 | BB_COPY_PARTITION (new_bb, e->src); |
4779 | else | |
4780 | BB_COPY_PARTITION (new_bb, e->dest); | |
3bdc4312 | 4781 | make_edge (new_bb, e->dest, EDGE_FALLTHRU); |
c60fa3a7 | 4782 | redirect_edge_and_branch_force (e, new_bb); |
4783 | ||
4784 | return new_bb; | |
4785 | } | |
4786 | ||
5f5d4cd1 | 4787 | /* Do postprocessing after making a forwarder block joined by edge FALLTHRU. */ |
4788 | ||
4789 | static void | |
4790 | rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED) | |
4791 | { | |
4792 | } | |
4793 | ||
9631926a | 4794 | /* Return true if BB contains only labels or non-executable |
4795 | instructions. */ | |
4796 | ||
4797 | static bool | |
4798 | rtl_block_empty_p (basic_block bb) | |
4799 | { | |
3d90435a | 4800 | rtx_insn *insn; |
9631926a | 4801 | |
34154e27 | 4802 | if (bb == ENTRY_BLOCK_PTR_FOR_FN (cfun) |
4803 | || bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
9631926a | 4804 | return true; |
4805 | ||
4806 | FOR_BB_INSNS (bb, insn) | |
4807 | if (NONDEBUG_INSN_P (insn) && !any_uncondjump_p (insn)) | |
4808 | return false; | |
4809 | ||
4810 | return true; | |
4811 | } | |
4812 | ||
4813 | /* Split a basic block if it ends with a conditional branch and if | |
4814 | the other part of the block is not empty. */ | |
4815 | ||
4816 | static basic_block | |
4817 | rtl_split_block_before_cond_jump (basic_block bb) | |
4818 | { | |
3d90435a | 4819 | rtx_insn *insn; |
4820 | rtx_insn *split_point = NULL; | |
4821 | rtx_insn *last = NULL; | |
9631926a | 4822 | bool found_code = false; |
4823 | ||
4824 | FOR_BB_INSNS (bb, insn) | |
4825 | { | |
4826 | if (any_condjump_p (insn)) | |
4827 | split_point = last; | |
4828 | else if (NONDEBUG_INSN_P (insn)) | |
4829 | found_code = true; | |
4830 | last = insn; | |
4831 | } | |
4832 | ||
4833 | /* Did not find everything. */ | |
4834 | if (found_code && split_point) | |
4835 | return split_block (bb, split_point)->dest; | |
4836 | else | |
4837 | return NULL; | |
4838 | } | |
4839 | ||
4ee9c684 | 4840 | /* Return 1 if BB ends with a call, possibly followed by some |
4841 | instructions that must stay with the call, 0 otherwise. */ | |
4842 | ||
4843 | static bool | |
47aaf6e6 | 4844 | rtl_block_ends_with_call_p (basic_block bb) |
4ee9c684 | 4845 | { |
3d90435a | 4846 | rtx_insn *insn = BB_END (bb); |
4ee9c684 | 4847 | |
6d7dc5b9 | 4848 | while (!CALL_P (insn) |
4ee9c684 | 4849 | && insn != BB_HEAD (bb) |
f69dfa18 | 4850 | && (keep_with_call_p (insn) |
9845d120 | 4851 | || NOTE_P (insn) |
4852 | || DEBUG_INSN_P (insn))) | |
4ee9c684 | 4853 | insn = PREV_INSN (insn); |
6d7dc5b9 | 4854 | return (CALL_P (insn)); |
4ee9c684 | 4855 | } |
4856 | ||
4857 | /* Return 1 if BB ends with a conditional branch, 0 otherwise. */ | |
4858 | ||
4859 | static bool | |
5493cb9a | 4860 | rtl_block_ends_with_condjump_p (const_basic_block bb) |
4ee9c684 | 4861 | { |
4862 | return any_condjump_p (BB_END (bb)); | |
4863 | } | |
4864 | ||
4865 | /* Return true if we need to add fake edge to exit. | |
4866 | Helper function for rtl_flow_call_edges_add. */ | |
4867 | ||
4868 | static bool | |
3d90435a | 4869 | need_fake_edge_p (const rtx_insn *insn) |
4ee9c684 | 4870 | { |
4871 | if (!INSN_P (insn)) | |
4872 | return false; | |
4873 | ||
6d7dc5b9 | 4874 | if ((CALL_P (insn) |
4ee9c684 | 4875 | && !SIBLING_CALL_P (insn) |
4876 | && !find_reg_note (insn, REG_NORETURN, NULL) | |
9c2a0c05 | 4877 | && !(RTL_CONST_OR_PURE_CALL_P (insn)))) |
4ee9c684 | 4878 | return true; |
4879 | ||
4880 | return ((GET_CODE (PATTERN (insn)) == ASM_OPERANDS | |
4881 | && MEM_VOLATILE_P (PATTERN (insn))) | |
4882 | || (GET_CODE (PATTERN (insn)) == PARALLEL | |
4883 | && asm_noperands (insn) != -1 | |
4884 | && MEM_VOLATILE_P (XVECEXP (PATTERN (insn), 0, 0))) | |
4885 | || GET_CODE (PATTERN (insn)) == ASM_INPUT); | |
4886 | } | |
4887 | ||
4888 | /* Add fake edges to the function exit for any non constant and non noreturn | |
4889 | calls, volatile inline assembly in the bitmap of blocks specified by | |
4890 | BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks | |
4891 | that were split. | |
4892 | ||
4893 | The goal is to expose cases in which entering a basic block does not imply | |
4894 | that all subsequent instructions must be executed. */ | |
4895 | ||
4896 | static int | |
4897 | rtl_flow_call_edges_add (sbitmap blocks) | |
4898 | { | |
4899 | int i; | |
4900 | int blocks_split = 0; | |
fe672ac0 | 4901 | int last_bb = last_basic_block_for_fn (cfun); |
4ee9c684 | 4902 | bool check_last_block = false; |
4903 | ||
a28770e1 | 4904 | if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS) |
4ee9c684 | 4905 | return 0; |
4906 | ||
4907 | if (! blocks) | |
4908 | check_last_block = true; | |
4909 | else | |
34154e27 | 4910 | check_last_block = bitmap_bit_p (blocks, |
4911 | EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb->index); | |
4ee9c684 | 4912 | |
4913 | /* In the last basic block, before epilogue generation, there will be | |
4914 | a fallthru edge to EXIT. Special care is required if the last insn | |
4915 | of the last basic block is a call because make_edge folds duplicate | |
4916 | edges, which would result in the fallthru edge also being marked | |
4917 | fake, which would result in the fallthru edge being removed by | |
4918 | remove_fake_edges, which would result in an invalid CFG. | |
4919 | ||
4920 | Moreover, we can't elide the outgoing fake edge, since the block | |
4921 | profiler needs to take this into account in order to solve the minimal | |
4922 | spanning tree in the case that the call doesn't return. | |
4923 | ||
4924 | Handle this by adding a dummy instruction in a new last basic block. */ | |
4925 | if (check_last_block) | |
4926 | { | |
34154e27 | 4927 | basic_block bb = EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb; |
3d90435a | 4928 | rtx_insn *insn = BB_END (bb); |
4ee9c684 | 4929 | |
4930 | /* Back up past insns that must be kept in the same block as a call. */ | |
4931 | while (insn != BB_HEAD (bb) | |
4932 | && keep_with_call_p (insn)) | |
4933 | insn = PREV_INSN (insn); | |
4934 | ||
4935 | if (need_fake_edge_p (insn)) | |
4936 | { | |
4937 | edge e; | |
4938 | ||
34154e27 | 4939 | e = find_edge (bb, EXIT_BLOCK_PTR_FOR_FN (cfun)); |
c6356c17 | 4940 | if (e) |
4941 | { | |
18b42941 | 4942 | insert_insn_on_edge (gen_use (const0_rtx), e); |
c6356c17 | 4943 | commit_edge_insertions (); |
4944 | } | |
4ee9c684 | 4945 | } |
4946 | } | |
4947 | ||
4948 | /* Now add fake edges to the function exit for any non constant | |
4949 | calls since there is no way that we can determine if they will | |
4950 | return or not... */ | |
4951 | ||
4d2e5d52 | 4952 | for (i = NUM_FIXED_BLOCKS; i < last_bb; i++) |
4ee9c684 | 4953 | { |
f5a6b05f | 4954 | basic_block bb = BASIC_BLOCK_FOR_FN (cfun, i); |
3d90435a | 4955 | rtx_insn *insn; |
4956 | rtx_insn *prev_insn; | |
4ee9c684 | 4957 | |
4958 | if (!bb) | |
4959 | continue; | |
4960 | ||
08b7917c | 4961 | if (blocks && !bitmap_bit_p (blocks, i)) |
4ee9c684 | 4962 | continue; |
4963 | ||
4964 | for (insn = BB_END (bb); ; insn = prev_insn) | |
4965 | { | |
4966 | prev_insn = PREV_INSN (insn); | |
4967 | if (need_fake_edge_p (insn)) | |
4968 | { | |
4969 | edge e; | |
3d90435a | 4970 | rtx_insn *split_at_insn = insn; |
4ee9c684 | 4971 | |
4972 | /* Don't split the block between a call and an insn that should | |
a0c938f0 | 4973 | remain in the same block as the call. */ |
6d7dc5b9 | 4974 | if (CALL_P (insn)) |
4ee9c684 | 4975 | while (split_at_insn != BB_END (bb) |
4976 | && keep_with_call_p (NEXT_INSN (split_at_insn))) | |
4977 | split_at_insn = NEXT_INSN (split_at_insn); | |
4978 | ||
4979 | /* The handling above of the final block before the epilogue | |
a0c938f0 | 4980 | should be enough to verify that there is no edge to the exit |
4ee9c684 | 4981 | block in CFG already. Calling make_edge in such case would |
4982 | cause us to mark that edge as fake and remove it later. */ | |
4983 | ||
382ecba7 | 4984 | if (flag_checking && split_at_insn == BB_END (bb)) |
cd665a06 | 4985 | { |
34154e27 | 4986 | e = find_edge (bb, EXIT_BLOCK_PTR_FOR_FN (cfun)); |
c6356c17 | 4987 | gcc_assert (e == NULL); |
cd665a06 | 4988 | } |
4ee9c684 | 4989 | |
4990 | /* Note that the following may create a new basic block | |
4991 | and renumber the existing basic blocks. */ | |
4992 | if (split_at_insn != BB_END (bb)) | |
4993 | { | |
4994 | e = split_block (bb, split_at_insn); | |
4995 | if (e) | |
4996 | blocks_split++; | |
4997 | } | |
4998 | ||
7880fcaf | 4999 | edge ne = make_edge (bb, EXIT_BLOCK_PTR_FOR_FN (cfun), EDGE_FAKE); |
5000 | ne->probability = profile_probability::guessed_never (); | |
4ee9c684 | 5001 | } |
5002 | ||
5003 | if (insn == BB_HEAD (bb)) | |
5004 | break; | |
5005 | } | |
5006 | } | |
5007 | ||
5008 | if (blocks_split) | |
5009 | verify_flow_info (); | |
5010 | ||
5011 | return blocks_split; | |
5012 | } | |
5013 | ||
c50ae675 | 5014 | /* Add COMP_RTX as a condition at end of COND_BB. FIRST_HEAD is |
d90dbd3e | 5015 | the conditional branch target, SECOND_HEAD should be the fall-thru |
c50ae675 | 5016 | there is no need to handle this here the loop versioning code handles |
5017 | this. the reason for SECON_HEAD is that it is needed for condition | |
5018 | in trees, and this should be of the same type since it is a hook. */ | |
5019 | static void | |
5020 | rtl_lv_add_condition_to_bb (basic_block first_head , | |
a0c938f0 | 5021 | basic_block second_head ATTRIBUTE_UNUSED, |
5022 | basic_block cond_bb, void *comp_rtx) | |
c50ae675 | 5023 | { |
f9a00e9e | 5024 | rtx_code_label *label; |
3d90435a | 5025 | rtx_insn *seq, *jump; |
c50ae675 | 5026 | rtx op0 = XEXP ((rtx)comp_rtx, 0); |
5027 | rtx op1 = XEXP ((rtx)comp_rtx, 1); | |
5028 | enum rtx_code comp = GET_CODE ((rtx)comp_rtx); | |
3754d046 | 5029 | machine_mode mode; |
c50ae675 | 5030 | |
5031 | ||
5032 | label = block_label (first_head); | |
5033 | mode = GET_MODE (op0); | |
5034 | if (mode == VOIDmode) | |
5035 | mode = GET_MODE (op1); | |
5036 | ||
5037 | start_sequence (); | |
5038 | op0 = force_operand (op0, NULL_RTX); | |
5039 | op1 = force_operand (op1, NULL_RTX); | |
720cfc43 | 5040 | do_compare_rtx_and_jump (op0, op1, comp, 0, mode, NULL_RTX, NULL, label, |
5041 | profile_probability::uninitialized ()); | |
c50ae675 | 5042 | jump = get_last_insn (); |
5043 | JUMP_LABEL (jump) = label; | |
5044 | LABEL_NUSES (label)++; | |
5045 | seq = get_insns (); | |
5046 | end_sequence (); | |
5047 | ||
3ad55f68 | 5048 | /* Add the new cond, in the new head. */ |
9af5ce0c | 5049 | emit_insn_after (seq, BB_END (cond_bb)); |
c50ae675 | 5050 | } |
5051 | ||
5052 | ||
5053 | /* Given a block B with unconditional branch at its end, get the | |
5054 | store the return the branch edge and the fall-thru edge in | |
5055 | BRANCH_EDGE and FALLTHRU_EDGE respectively. */ | |
5056 | static void | |
5057 | rtl_extract_cond_bb_edges (basic_block b, edge *branch_edge, | |
5058 | edge *fallthru_edge) | |
5059 | { | |
5060 | edge e = EDGE_SUCC (b, 0); | |
5061 | ||
5062 | if (e->flags & EDGE_FALLTHRU) | |
5063 | { | |
5064 | *fallthru_edge = e; | |
5065 | *branch_edge = EDGE_SUCC (b, 1); | |
5066 | } | |
5067 | else | |
5068 | { | |
5069 | *branch_edge = e; | |
5070 | *fallthru_edge = EDGE_SUCC (b, 1); | |
5071 | } | |
5072 | } | |
5073 | ||
e0dde8f8 | 5074 | void |
5075 | init_rtl_bb_info (basic_block bb) | |
5076 | { | |
43e94e51 | 5077 | gcc_assert (!bb->il.x.rtl); |
5078 | bb->il.x.head_ = NULL; | |
25a27413 | 5079 | bb->il.x.rtl = ggc_cleared_alloc<rtl_bb_info> (); |
e0dde8f8 | 5080 | } |
5081 | ||
611d2ac1 | 5082 | /* Returns true if it is possible to remove edge E by redirecting |
5083 | it to the destination of the other edge from E->src. */ | |
5084 | ||
5085 | static bool | |
5493cb9a | 5086 | rtl_can_remove_branch_p (const_edge e) |
611d2ac1 | 5087 | { |
5493cb9a | 5088 | const_basic_block src = e->src; |
5089 | const_basic_block target = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest; | |
3d90435a | 5090 | const rtx_insn *insn = BB_END (src); |
5091 | rtx set; | |
611d2ac1 | 5092 | |
5093 | /* The conditions are taken from try_redirect_by_replacing_jump. */ | |
34154e27 | 5094 | if (target == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
611d2ac1 | 5095 | return false; |
5096 | ||
5097 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) | |
5098 | return false; | |
5099 | ||
aa78dca5 | 5100 | if (BB_PARTITION (src) != BB_PARTITION (target)) |
611d2ac1 | 5101 | return false; |
5102 | ||
5103 | if (!onlyjump_p (insn) | |
5104 | || tablejump_p (insn, NULL, NULL)) | |
5105 | return false; | |
5106 | ||
5107 | set = single_set (insn); | |
5108 | if (!set || side_effects_p (set)) | |
5109 | return false; | |
5110 | ||
5111 | return true; | |
5112 | } | |
5113 | ||
0a55d497 | 5114 | static basic_block |
3350055c | 5115 | rtl_duplicate_bb (basic_block bb, copy_bb_data *id) |
0a55d497 | 5116 | { |
3350055c | 5117 | bb = cfg_layout_duplicate_bb (bb, id); |
0a55d497 | 5118 | bb->aux = NULL; |
5119 | return bb; | |
5120 | } | |
5121 | ||
98193482 | 5122 | /* Do book-keeping of basic block BB for the profile consistency checker. |
ae1e77fa | 5123 | Store the counting in RECORD. */ |
98193482 | 5124 | static void |
ae1e77fa | 5125 | rtl_account_profile_record (basic_block bb, struct profile_record *record) |
98193482 | 5126 | { |
3d90435a | 5127 | rtx_insn *insn; |
98193482 | 5128 | FOR_BB_INSNS (bb, insn) |
5129 | if (INSN_P (insn)) | |
5130 | { | |
ae1e77fa | 5131 | record->size += insn_cost (insn, false); |
db9cef39 | 5132 | if (bb->count.initialized_p ()) |
ae1e77fa | 5133 | record->time |
3bdb5a4d | 5134 | += insn_cost (insn, true) * bb->count.to_gcov_type (); |
f26d8580 | 5135 | else if (profile_status_for_fn (cfun) == PROFILE_GUESSED) |
ae1e77fa | 5136 | record->time |
205ce1aa | 5137 | += insn_cost (insn, true) * bb->count.to_frequency (cfun); |
98193482 | 5138 | } |
5139 | } | |
5140 | ||
1026363d | 5141 | /* Implementation of CFG manipulation for linearized RTL. */ |
5142 | struct cfg_hooks rtl_cfg_hooks = { | |
5f5d4cd1 | 5143 | "rtl", |
1026363d | 5144 | rtl_verify_flow_info, |
028f8cc7 | 5145 | rtl_dump_bb, |
e079344a | 5146 | rtl_dump_bb_for_graph, |
c60fa3a7 | 5147 | rtl_create_basic_block, |
1026363d | 5148 | rtl_redirect_edge_and_branch, |
5149 | rtl_redirect_edge_and_branch_force, | |
611d2ac1 | 5150 | rtl_can_remove_branch_p, |
1026363d | 5151 | rtl_delete_block, |
5152 | rtl_split_block, | |
5f5d4cd1 | 5153 | rtl_move_block_after, |
c60fa3a7 | 5154 | rtl_can_merge_blocks, /* can_merge_blocks_p */ |
5155 | rtl_merge_blocks, | |
4ee9c684 | 5156 | rtl_predict_edge, |
5157 | rtl_predicted_by_p, | |
0a55d497 | 5158 | cfg_layout_can_duplicate_bb_p, |
5159 | rtl_duplicate_bb, | |
5f5d4cd1 | 5160 | rtl_split_edge, |
5161 | rtl_make_forwarder_block, | |
4ee9c684 | 5162 | rtl_tidy_fallthru_edge, |
202bbc06 | 5163 | rtl_force_nonfallthru, |
4ee9c684 | 5164 | rtl_block_ends_with_call_p, |
5165 | rtl_block_ends_with_condjump_p, | |
26b12c91 | 5166 | rtl_flow_call_edges_add, |
5167 | NULL, /* execute_on_growing_pred */ | |
c50ae675 | 5168 | NULL, /* execute_on_shrinking_pred */ |
5169 | NULL, /* duplicate loop for trees */ | |
5170 | NULL, /* lv_add_condition_to_bb */ | |
5171 | NULL, /* lv_adjust_loop_header_phi*/ | |
5172 | NULL, /* extract_cond_bb_edges */ | |
9631926a | 5173 | NULL, /* flush_pending_stmts */ |
5174 | rtl_block_empty_p, /* block_empty_p */ | |
5175 | rtl_split_block_before_cond_jump, /* split_block_before_cond_jump */ | |
98193482 | 5176 | rtl_account_profile_record, |
1026363d | 5177 | }; |
5178 | ||
5179 | /* Implementation of CFG manipulation for cfg layout RTL, where | |
5180 | basic block connected via fallthru edges does not have to be adjacent. | |
5181 | This representation will hopefully become the default one in future | |
5182 | version of the compiler. */ | |
4ee9c684 | 5183 | |
1026363d | 5184 | struct cfg_hooks cfg_layout_rtl_cfg_hooks = { |
5f5d4cd1 | 5185 | "cfglayout mode", |
c60fa3a7 | 5186 | rtl_verify_flow_info_1, |
028f8cc7 | 5187 | rtl_dump_bb, |
e079344a | 5188 | rtl_dump_bb_for_graph, |
c60fa3a7 | 5189 | cfg_layout_create_basic_block, |
1026363d | 5190 | cfg_layout_redirect_edge_and_branch, |
5191 | cfg_layout_redirect_edge_and_branch_force, | |
611d2ac1 | 5192 | rtl_can_remove_branch_p, |
1026363d | 5193 | cfg_layout_delete_block, |
5194 | cfg_layout_split_block, | |
5f5d4cd1 | 5195 | rtl_move_block_after, |
c60fa3a7 | 5196 | cfg_layout_can_merge_blocks_p, |
5197 | cfg_layout_merge_blocks, | |
4ee9c684 | 5198 | rtl_predict_edge, |
5199 | rtl_predicted_by_p, | |
5200 | cfg_layout_can_duplicate_bb_p, | |
5201 | cfg_layout_duplicate_bb, | |
5f5d4cd1 | 5202 | cfg_layout_split_edge, |
5203 | rtl_make_forwarder_block, | |
202bbc06 | 5204 | NULL, /* tidy_fallthru_edge */ |
5205 | rtl_force_nonfallthru, | |
4ee9c684 | 5206 | rtl_block_ends_with_call_p, |
5207 | rtl_block_ends_with_condjump_p, | |
26b12c91 | 5208 | rtl_flow_call_edges_add, |
5209 | NULL, /* execute_on_growing_pred */ | |
c50ae675 | 5210 | NULL, /* execute_on_shrinking_pred */ |
5211 | duplicate_loop_to_header_edge, /* duplicate loop for trees */ | |
5212 | rtl_lv_add_condition_to_bb, /* lv_add_condition_to_bb */ | |
5213 | NULL, /* lv_adjust_loop_header_phi*/ | |
5214 | rtl_extract_cond_bb_edges, /* extract_cond_bb_edges */ | |
9631926a | 5215 | NULL, /* flush_pending_stmts */ |
5216 | rtl_block_empty_p, /* block_empty_p */ | |
5217 | rtl_split_block_before_cond_jump, /* split_block_before_cond_jump */ | |
98193482 | 5218 | rtl_account_profile_record, |
1026363d | 5219 | }; |
23a070f3 | 5220 | |
5221 | #include "gt-cfgrtl.h" | |
62c34df8 | 5222 | |
5223 | #if __GNUC__ >= 10 | |
5224 | # pragma GCC diagnostic pop | |
5225 | #endif |