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b36d64df | 1 | /* Control flow graph manipulation code for GNU compiler. |
f1717362 | 2 | Copyright (C) 1987-2016 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" |
7c29e30e | 50 | #include "emit-rtl.h" |
94ea8568 | 51 | #include "cfgrtl.h" |
52 | #include "cfganal.h" | |
53 | #include "cfgbuild.h" | |
54 | #include "cfgcleanup.h" | |
94ea8568 | 55 | #include "bb-reorder.h" |
d7091a76 | 56 | #include "rtl-error.h" |
225e5f6f | 57 | #include "insn-attr.h" |
d53441c8 | 58 | #include "dojump.h" |
804e497b | 59 | #include "expr.h" |
c50ae675 | 60 | #include "cfgloop.h" |
77fce4cd | 61 | #include "tree-pass.h" |
397881d3 | 62 | #include "print-rtl.h" |
b36d64df | 63 | |
23a070f3 | 64 | /* Holds the interesting leading and trailing notes for the function. |
65 | Only applicable if the CFG is in cfglayout mode. */ | |
26bb3cb2 | 66 | static GTY(()) rtx_insn *cfg_layout_function_footer; |
3e75e92b | 67 | static GTY(()) rtx_insn *cfg_layout_function_header; |
23a070f3 | 68 | |
3d90435a | 69 | static rtx_insn *skip_insns_after_block (basic_block); |
23a070f3 | 70 | static void record_effective_endpoints (void); |
23a070f3 | 71 | static void fixup_reorder_chain (void); |
72 | ||
73 | void verify_insn_chain (void); | |
74 | static void fixup_fallthru_exit_predecessor (void); | |
3d90435a | 75 | static int can_delete_note_p (const rtx_note *); |
76 | static int can_delete_label_p (const rtx_code_label *); | |
4c9e08a4 | 77 | static basic_block rtl_split_edge (edge); |
5f5d4cd1 | 78 | static bool rtl_move_block_after (basic_block, basic_block); |
4c9e08a4 | 79 | static int rtl_verify_flow_info (void); |
5f5d4cd1 | 80 | static basic_block cfg_layout_split_block (basic_block, void *); |
4ee9c684 | 81 | static edge cfg_layout_redirect_edge_and_branch (edge, basic_block); |
4c9e08a4 | 82 | static basic_block cfg_layout_redirect_edge_and_branch_force (edge, basic_block); |
83 | static void cfg_layout_delete_block (basic_block); | |
84 | static void rtl_delete_block (basic_block); | |
85 | static basic_block rtl_redirect_edge_and_branch_force (edge, basic_block); | |
4ee9c684 | 86 | static edge rtl_redirect_edge_and_branch (edge, basic_block); |
5f5d4cd1 | 87 | static basic_block rtl_split_block (basic_block, void *); |
5147ec07 | 88 | static void rtl_dump_bb (FILE *, basic_block, int, int); |
4c9e08a4 | 89 | static int rtl_verify_flow_info_1 (void); |
5f5d4cd1 | 90 | static void rtl_make_forwarder_block (edge); |
b36d64df | 91 | \f |
92 | /* Return true if NOTE is not one of the ones that must be kept paired, | |
5cc577b6 | 93 | so that we may simply delete it. */ |
b36d64df | 94 | |
95 | static int | |
3d90435a | 96 | can_delete_note_p (const rtx_note *note) |
b36d64df | 97 | { |
25e880b1 | 98 | switch (NOTE_KIND (note)) |
99 | { | |
100 | case NOTE_INSN_DELETED: | |
101 | case NOTE_INSN_BASIC_BLOCK: | |
102 | case NOTE_INSN_EPILOGUE_BEG: | |
103 | return true; | |
104 | ||
105 | default: | |
106 | return false; | |
107 | } | |
b36d64df | 108 | } |
109 | ||
110 | /* True if a given label can be deleted. */ | |
111 | ||
112 | static int | |
3d90435a | 113 | can_delete_label_p (const rtx_code_label *label) |
b36d64df | 114 | { |
5cc577b6 | 115 | return (!LABEL_PRESERVE_P (label) |
116 | /* User declared labels must be preserved. */ | |
117 | && LABEL_NAME (label) == 0 | |
7a680a39 | 118 | && !in_insn_list_p (forced_labels, label)); |
b36d64df | 119 | } |
120 | ||
a2b85e40 | 121 | /* Delete INSN by patching it out. */ |
b36d64df | 122 | |
a2b85e40 | 123 | void |
26bb3cb2 | 124 | delete_insn (rtx uncast_insn) |
b36d64df | 125 | { |
26bb3cb2 | 126 | rtx_insn *insn = as_a <rtx_insn *> (uncast_insn); |
b36d64df | 127 | rtx note; |
128 | bool really_delete = true; | |
129 | ||
6d7dc5b9 | 130 | if (LABEL_P (insn)) |
b36d64df | 131 | { |
132 | /* Some labels can't be directly removed from the INSN chain, as they | |
a0c938f0 | 133 | might be references via variables, constant pool etc. |
134 | Convert them to the special NOTE_INSN_DELETED_LABEL note. */ | |
3d90435a | 135 | if (! can_delete_label_p (as_a <rtx_code_label *> (insn))) |
b36d64df | 136 | { |
137 | const char *name = LABEL_NAME (insn); | |
6de7acd5 | 138 | basic_block bb = BLOCK_FOR_INSN (insn); |
3d90435a | 139 | rtx_insn *bb_note = NEXT_INSN (insn); |
b36d64df | 140 | |
141 | really_delete = false; | |
142 | PUT_CODE (insn, NOTE); | |
ad4583d9 | 143 | NOTE_KIND (insn) = NOTE_INSN_DELETED_LABEL; |
7bd3dcc4 | 144 | NOTE_DELETED_LABEL_NAME (insn) = name; |
a2b85e40 | 145 | |
fb848efb | 146 | /* If the note following the label starts a basic block, and the |
6de7acd5 | 147 | label is a member of the same basic block, interchange the two. */ |
fb848efb | 148 | if (bb_note != NULL_RTX |
149 | && NOTE_INSN_BASIC_BLOCK_P (bb_note) | |
6de7acd5 | 150 | && bb != NULL |
151 | && bb == BLOCK_FOR_INSN (bb_note)) | |
a2b85e40 | 152 | { |
153 | reorder_insns_nobb (insn, insn, bb_note); | |
26bb3cb2 | 154 | BB_HEAD (bb) = bb_note; |
a2b85e40 | 155 | if (BB_END (bb) == bb_note) |
26bb3cb2 | 156 | BB_END (bb) = insn; |
a2b85e40 | 157 | } |
b36d64df | 158 | } |
5cc577b6 | 159 | |
a4de1c23 | 160 | remove_node_from_insn_list (insn, &nonlocal_goto_handler_labels); |
b36d64df | 161 | } |
162 | ||
163 | if (really_delete) | |
164 | { | |
e172357f | 165 | /* If this insn has already been deleted, something is very wrong. */ |
dd1286fb | 166 | gcc_assert (!insn->deleted ()); |
93ff53d3 | 167 | if (INSN_P (insn)) |
168 | df_insn_delete (insn); | |
b36d64df | 169 | remove_insn (insn); |
dd1286fb | 170 | insn->set_deleted (); |
b36d64df | 171 | } |
172 | ||
173 | /* If deleting a jump, decrement the use count of the label. Deleting | |
174 | the label itself should happen in the normal course of block merging. */ | |
19d2fe05 | 175 | if (JUMP_P (insn)) |
242dafee | 176 | { |
19d2fe05 | 177 | if (JUMP_LABEL (insn) |
178 | && LABEL_P (JUMP_LABEL (insn))) | |
179 | LABEL_NUSES (JUMP_LABEL (insn))--; | |
180 | ||
181 | /* If there are more targets, remove them too. */ | |
182 | while ((note | |
183 | = find_reg_note (insn, REG_LABEL_TARGET, NULL_RTX)) != NULL_RTX | |
6d7dc5b9 | 184 | && LABEL_P (XEXP (note, 0))) |
242dafee | 185 | { |
186 | LABEL_NUSES (XEXP (note, 0))--; | |
187 | remove_note (insn, note); | |
188 | } | |
189 | } | |
b36d64df | 190 | |
19d2fe05 | 191 | /* Also if deleting any insn that references a label as an operand. */ |
192 | while ((note = find_reg_note (insn, REG_LABEL_OPERAND, NULL_RTX)) != NULL_RTX | |
193 | && LABEL_P (XEXP (note, 0))) | |
194 | { | |
195 | LABEL_NUSES (XEXP (note, 0))--; | |
196 | remove_note (insn, note); | |
197 | } | |
198 | ||
b77639be | 199 | if (rtx_jump_table_data *table = dyn_cast <rtx_jump_table_data *> (insn)) |
b36d64df | 200 | { |
b77639be | 201 | rtvec vec = table->get_labels (); |
202 | int len = GET_NUM_ELEM (vec); | |
b36d64df | 203 | int i; |
204 | ||
205 | for (i = 0; i < len; i++) | |
fd0d7f8c | 206 | { |
b77639be | 207 | rtx label = XEXP (RTVEC_ELT (vec, i), 0); |
fd0d7f8c | 208 | |
209 | /* When deleting code in bulk (e.g. removing many unreachable | |
210 | blocks) we can delete a label that's a target of the vector | |
211 | before deleting the vector itself. */ | |
6d7dc5b9 | 212 | if (!NOTE_P (label)) |
fd0d7f8c | 213 | LABEL_NUSES (label)--; |
214 | } | |
b36d64df | 215 | } |
b36d64df | 216 | } |
217 | ||
fb20d6fa | 218 | /* Like delete_insn but also purge dead edges from BB. */ |
ebc94641 | 219 | |
a2b85e40 | 220 | void |
0c4d52cf | 221 | delete_insn_and_edges (rtx_insn *insn) |
fb20d6fa | 222 | { |
fb20d6fa | 223 | bool purge = false; |
224 | ||
ab87d1bc | 225 | if (INSN_P (insn) |
fb20d6fa | 226 | && BLOCK_FOR_INSN (insn) |
5496dbfc | 227 | && BB_END (BLOCK_FOR_INSN (insn)) == insn) |
fb20d6fa | 228 | purge = true; |
a2b85e40 | 229 | delete_insn (insn); |
fb20d6fa | 230 | if (purge) |
231 | purge_dead_edges (BLOCK_FOR_INSN (insn)); | |
fb20d6fa | 232 | } |
233 | ||
b36d64df | 234 | /* Unlink a chain of insns between START and FINISH, leaving notes |
39257eb5 | 235 | that must be paired. If CLEAR_BB is true, we set bb field for |
236 | insns that cannot be removed to NULL. */ | |
b36d64df | 237 | |
238 | void | |
39257eb5 | 239 | delete_insn_chain (rtx start, rtx finish, bool clear_bb) |
b36d64df | 240 | { |
3d90435a | 241 | rtx_insn *prev, *current; |
b36d64df | 242 | |
5cc577b6 | 243 | /* Unchain the insns one by one. It would be quicker to delete all of these |
244 | with a single unchaining, rather than one at a time, but we need to keep | |
245 | the NOTE's. */ | |
3d90435a | 246 | current = safe_as_a <rtx_insn *> (finish); |
b36d64df | 247 | while (1) |
248 | { | |
a2b85e40 | 249 | prev = PREV_INSN (current); |
3d90435a | 250 | if (NOTE_P (current) && !can_delete_note_p (as_a <rtx_note *> (current))) |
b36d64df | 251 | ; |
252 | else | |
a2b85e40 | 253 | delete_insn (current); |
b36d64df | 254 | |
dd1286fb | 255 | if (clear_bb && !current->deleted ()) |
a2b85e40 | 256 | set_block_for_insn (current, NULL); |
39257eb5 | 257 | |
a2b85e40 | 258 | if (current == start) |
b36d64df | 259 | break; |
a2b85e40 | 260 | current = prev; |
b36d64df | 261 | } |
262 | } | |
263 | \f | |
5cc577b6 | 264 | /* Create a new basic block consisting of the instructions between HEAD and END |
265 | inclusive. This function is designed to allow fast BB construction - reuses | |
266 | the note and basic block struct in BB_NOTE, if any and do not grow | |
267 | BASIC_BLOCK chain and should be used directly only by CFG construction code. | |
268 | END can be NULL in to create new empty basic block before HEAD. Both END | |
7fa55aef | 269 | and HEAD can be NULL to create basic block at the end of INSN chain. |
270 | AFTER is the basic block we should be put after. */ | |
b36d64df | 271 | |
272 | basic_block | |
3c3f97b4 | 273 | create_basic_block_structure (rtx_insn *head, rtx_insn *end, rtx_note *bb_note, |
cef3d8ad | 274 | basic_block after) |
b36d64df | 275 | { |
276 | basic_block bb; | |
277 | ||
278 | if (bb_note | |
b36d64df | 279 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL |
280 | && bb->aux == NULL) | |
281 | { | |
282 | /* If we found an existing note, thread it back onto the chain. */ | |
283 | ||
57c26b3a | 284 | rtx_insn *after; |
b36d64df | 285 | |
6d7dc5b9 | 286 | if (LABEL_P (head)) |
b36d64df | 287 | after = head; |
288 | else | |
289 | { | |
290 | after = PREV_INSN (head); | |
291 | head = bb_note; | |
292 | } | |
293 | ||
294 | if (after != bb_note && NEXT_INSN (after) != bb_note) | |
ab87d1bc | 295 | reorder_insns_nobb (bb_note, bb_note, after); |
b36d64df | 296 | } |
297 | else | |
298 | { | |
299 | /* Otherwise we must create a note and a basic block structure. */ | |
300 | ||
301 | bb = alloc_block (); | |
302 | ||
e0dde8f8 | 303 | init_rtl_bb_info (bb); |
b36d64df | 304 | if (!head && !end) |
5cc577b6 | 305 | head = end = bb_note |
306 | = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); | |
6d7dc5b9 | 307 | else if (LABEL_P (head) && end) |
b36d64df | 308 | { |
309 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); | |
310 | if (head == end) | |
311 | end = bb_note; | |
312 | } | |
313 | else | |
314 | { | |
315 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); | |
316 | head = bb_note; | |
317 | if (!end) | |
318 | end = head; | |
319 | } | |
5cc577b6 | 320 | |
b36d64df | 321 | NOTE_BASIC_BLOCK (bb_note) = bb; |
322 | } | |
323 | ||
324 | /* Always include the bb note in the block. */ | |
325 | if (NEXT_INSN (end) == bb_note) | |
326 | end = bb_note; | |
327 | ||
26bb3cb2 | 328 | BB_HEAD (bb) = head; |
329 | BB_END (bb) = end; | |
fe672ac0 | 330 | bb->index = last_basic_block_for_fn (cfun)++; |
e0dde8f8 | 331 | bb->flags = BB_NEW | BB_RTL; |
7fa55aef | 332 | link_block (bb, after); |
f64d2ca4 | 333 | SET_BASIC_BLOCK_FOR_FN (cfun, bb->index, bb); |
3072d30e | 334 | df_bb_refs_record (bb->index, false); |
ab87d1bc | 335 | update_bb_for_insn (bb); |
7562ed74 | 336 | BB_SET_PARTITION (bb, BB_UNPARTITIONED); |
b36d64df | 337 | |
338 | /* Tag the block so that we know it has been used when considering | |
339 | other basic block notes. */ | |
340 | bb->aux = bb; | |
341 | ||
342 | return bb; | |
343 | } | |
344 | ||
5cc577b6 | 345 | /* Create new basic block consisting of instructions in between HEAD and END |
0a55d497 | 346 | and place it to the BB chain after block AFTER. END can be NULL to |
347 | create a new empty basic block before HEAD. Both END and HEAD can be | |
348 | NULL to create basic block at the end of INSN chain. */ | |
b36d64df | 349 | |
c60fa3a7 | 350 | static basic_block |
351 | rtl_create_basic_block (void *headp, void *endp, basic_block after) | |
b36d64df | 352 | { |
3c3f97b4 | 353 | rtx_insn *head = (rtx_insn *) headp; |
354 | rtx_insn *end = (rtx_insn *) endp; | |
b36d64df | 355 | basic_block bb; |
b3d6de89 | 356 | |
743ff5bb | 357 | /* Grow the basic block array if needed. */ |
fe672ac0 | 358 | if ((size_t) last_basic_block_for_fn (cfun) |
359 | >= basic_block_info_for_fn (cfun)->length ()) | |
743ff5bb | 360 | { |
fe672ac0 | 361 | size_t new_size = |
362 | (last_basic_block_for_fn (cfun) | |
363 | + (last_basic_block_for_fn (cfun) + 3) / 4); | |
9ca41bd1 | 364 | vec_safe_grow_cleared (basic_block_info_for_fn (cfun), new_size); |
743ff5bb | 365 | } |
b3d6de89 | 366 | |
a28770e1 | 367 | n_basic_blocks_for_fn (cfun)++; |
b36d64df | 368 | |
f23d9a22 | 369 | bb = create_basic_block_structure (head, end, NULL, after); |
b36d64df | 370 | bb->aux = NULL; |
371 | return bb; | |
372 | } | |
c60fa3a7 | 373 | |
374 | static basic_block | |
375 | cfg_layout_create_basic_block (void *head, void *end, basic_block after) | |
376 | { | |
377 | basic_block newbb = rtl_create_basic_block (head, end, after); | |
378 | ||
c60fa3a7 | 379 | return newbb; |
380 | } | |
b36d64df | 381 | \f |
382 | /* Delete the insns in a (non-live) block. We physically delete every | |
383 | non-deleted-note insn, and update the flow graph appropriately. | |
384 | ||
385 | Return nonzero if we deleted an exception handler. */ | |
386 | ||
387 | /* ??? Preserving all such notes strikes me as wrong. It would be nice | |
388 | to post-process the stream to remove empty blocks, loops, ranges, etc. */ | |
389 | ||
5f704f9f | 390 | static void |
4c9e08a4 | 391 | rtl_delete_block (basic_block b) |
b36d64df | 392 | { |
3d90435a | 393 | rtx_insn *insn, *end; |
b36d64df | 394 | |
395 | /* If the head of this block is a CODE_LABEL, then it might be the | |
57548910 | 396 | label for an exception handler which can't be reached. We need |
397 | to remove the label from the exception_handler_label list. */ | |
5496dbfc | 398 | insn = BB_HEAD (b); |
b36d64df | 399 | |
5d65a39c | 400 | end = get_last_bb_insn (b); |
b36d64df | 401 | |
402 | /* Selectively delete the entire chain. */ | |
26bb3cb2 | 403 | BB_HEAD (b) = NULL; |
39257eb5 | 404 | delete_insn_chain (insn, end, true); |
405 | ||
3072d30e | 406 | |
407 | if (dump_file) | |
408 | fprintf (dump_file, "deleting block %d\n", b->index); | |
409 | df_bb_delete (b->index); | |
b36d64df | 410 | } |
411 | \f | |
f23d9a22 | 412 | /* Records the basic block struct in BLOCK_FOR_INSN for every insn. */ |
b36d64df | 413 | |
414 | void | |
4c9e08a4 | 415 | compute_bb_for_insn (void) |
b36d64df | 416 | { |
4c26117a | 417 | basic_block bb; |
b36d64df | 418 | |
fc00614f | 419 | FOR_EACH_BB_FN (bb, cfun) |
b36d64df | 420 | { |
3d90435a | 421 | rtx_insn *end = BB_END (bb); |
422 | rtx_insn *insn; | |
b36d64df | 423 | |
5496dbfc | 424 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) |
b36d64df | 425 | { |
ab87d1bc | 426 | BLOCK_FOR_INSN (insn) = bb; |
b36d64df | 427 | if (insn == end) |
428 | break; | |
b36d64df | 429 | } |
430 | } | |
431 | } | |
432 | ||
433 | /* Release the basic_block_for_insn array. */ | |
434 | ||
2a1990e9 | 435 | unsigned int |
4c9e08a4 | 436 | free_bb_for_insn (void) |
b36d64df | 437 | { |
3d90435a | 438 | rtx_insn *insn; |
ab87d1bc | 439 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) |
6d7dc5b9 | 440 | if (!BARRIER_P (insn)) |
ab87d1bc | 441 | BLOCK_FOR_INSN (insn) = NULL; |
2a1990e9 | 442 | return 0; |
b36d64df | 443 | } |
444 | ||
cbe8bda8 | 445 | namespace { |
446 | ||
447 | const pass_data pass_data_free_cfg = | |
448 | { | |
449 | RTL_PASS, /* type */ | |
450 | "*free_cfg", /* name */ | |
451 | OPTGROUP_NONE, /* optinfo_flags */ | |
cbe8bda8 | 452 | TV_NONE, /* tv_id */ |
453 | 0, /* properties_required */ | |
454 | 0, /* properties_provided */ | |
455 | PROP_cfg, /* properties_destroyed */ | |
456 | 0, /* todo_flags_start */ | |
457 | 0, /* todo_flags_finish */ | |
77fce4cd | 458 | }; |
459 | ||
cbe8bda8 | 460 | class pass_free_cfg : public rtl_opt_pass |
461 | { | |
462 | public: | |
9af5ce0c | 463 | pass_free_cfg (gcc::context *ctxt) |
464 | : rtl_opt_pass (pass_data_free_cfg, ctxt) | |
cbe8bda8 | 465 | {} |
466 | ||
467 | /* opt_pass methods: */ | |
65b0537f | 468 | virtual unsigned int execute (function *); |
cbe8bda8 | 469 | |
470 | }; // class pass_free_cfg | |
471 | ||
65b0537f | 472 | unsigned int |
473 | pass_free_cfg::execute (function *) | |
474 | { | |
65b0537f | 475 | /* The resource.c machinery uses DF but the CFG isn't guaranteed to be |
476 | valid at that point so it would be too late to call df_analyze. */ | |
9d463a01 | 477 | if (DELAY_SLOTS && optimize > 0 && flag_delayed_branch) |
65b0537f | 478 | { |
479 | df_note_add_problem (); | |
480 | df_analyze (); | |
481 | } | |
65b0537f | 482 | |
483 | if (crtl->has_bb_partition) | |
484 | insert_section_boundary_note (); | |
485 | ||
486 | free_bb_for_insn (); | |
487 | return 0; | |
488 | } | |
489 | ||
cbe8bda8 | 490 | } // anon namespace |
491 | ||
492 | rtl_opt_pass * | |
493 | make_pass_free_cfg (gcc::context *ctxt) | |
494 | { | |
495 | return new pass_free_cfg (ctxt); | |
496 | } | |
497 | ||
a0fee14a | 498 | /* Return RTX to emit after when we want to emit code on the entry of function. */ |
dec0d4e1 | 499 | rtx_insn * |
a0fee14a | 500 | entry_of_function (void) |
501 | { | |
a28770e1 | 502 | return (n_basic_blocks_for_fn (cfun) > NUM_FIXED_BLOCKS ? |
34154e27 | 503 | BB_HEAD (ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb) : get_insns ()); |
a0fee14a | 504 | } |
505 | ||
aa02fa19 | 506 | /* Emit INSN at the entry point of the function, ensuring that it is only |
507 | executed once per function. */ | |
508 | void | |
509 | emit_insn_at_entry (rtx insn) | |
510 | { | |
34154e27 | 511 | edge_iterator ei = ei_start (ENTRY_BLOCK_PTR_FOR_FN (cfun)->succs); |
aa02fa19 | 512 | edge e = ei_safe_edge (ei); |
1db61145 | 513 | gcc_assert (e->flags & EDGE_FALLTHRU); |
aa02fa19 | 514 | |
515 | insert_insn_on_edge (insn, e); | |
516 | commit_edge_insertions (); | |
517 | } | |
518 | ||
f41d4683 | 519 | /* Update BLOCK_FOR_INSN of insns between BEGIN and END |
48e1416a | 520 | (or BARRIER if found) and notify df of the bb change. |
f41d4683 | 521 | The insn chain range is inclusive |
522 | (i.e. both BEGIN and END will be updated. */ | |
b36d64df | 523 | |
f41d4683 | 524 | static void |
3d90435a | 525 | update_bb_for_insn_chain (rtx_insn *begin, rtx_insn *end, basic_block bb) |
b36d64df | 526 | { |
3d90435a | 527 | rtx_insn *insn; |
b36d64df | 528 | |
f41d4683 | 529 | end = NEXT_INSN (end); |
530 | for (insn = begin; insn != end; insn = NEXT_INSN (insn)) | |
a2bdd643 | 531 | if (!BARRIER_P (insn)) |
532 | df_insn_change_bb (insn, bb); | |
b36d64df | 533 | } |
f41d4683 | 534 | |
535 | /* Update BLOCK_FOR_INSN of insns in BB to BB, | |
536 | and notify df of the change. */ | |
537 | ||
538 | void | |
539 | update_bb_for_insn (basic_block bb) | |
540 | { | |
541 | update_bb_for_insn_chain (BB_HEAD (bb), BB_END (bb), bb); | |
542 | } | |
543 | ||
4a020a8c | 544 | \f |
545 | /* Like active_insn_p, except keep the return value clobber around | |
546 | even after reload. */ | |
547 | ||
548 | static bool | |
3d90435a | 549 | flow_active_insn_p (const rtx_insn *insn) |
4a020a8c | 550 | { |
551 | if (active_insn_p (insn)) | |
552 | return true; | |
553 | ||
554 | /* A clobber of the function return value exists for buggy | |
555 | programs that fail to return a value. Its effect is to | |
556 | keep the return value from being live across the entire | |
557 | function. If we allow it to be skipped, we introduce the | |
558 | possibility for register lifetime confusion. */ | |
559 | if (GET_CODE (PATTERN (insn)) == CLOBBER | |
560 | && REG_P (XEXP (PATTERN (insn), 0)) | |
561 | && REG_FUNCTION_VALUE_P (XEXP (PATTERN (insn), 0))) | |
562 | return true; | |
563 | ||
564 | return false; | |
565 | } | |
566 | ||
567 | /* Return true if the block has no effect and only forwards control flow to | |
568 | its single destination. */ | |
4a020a8c | 569 | |
570 | bool | |
bbdfcf34 | 571 | contains_no_active_insn_p (const_basic_block bb) |
4a020a8c | 572 | { |
3d90435a | 573 | rtx_insn *insn; |
4a020a8c | 574 | |
34154e27 | 575 | if (bb == EXIT_BLOCK_PTR_FOR_FN (cfun) || bb == ENTRY_BLOCK_PTR_FOR_FN (cfun) |
4a020a8c | 576 | || !single_succ_p (bb)) |
577 | return false; | |
578 | ||
bbdfcf34 | 579 | for (insn = BB_HEAD (bb); insn != BB_END (bb); insn = NEXT_INSN (insn)) |
580 | if (INSN_P (insn) && flow_active_insn_p (insn)) | |
581 | return false; | |
582 | ||
583 | return (!INSN_P (insn) | |
584 | || (JUMP_P (insn) && simplejump_p (insn)) | |
585 | || !flow_active_insn_p (insn)); | |
586 | } | |
587 | ||
588 | /* Likewise, but protect loop latches, headers and preheaders. */ | |
589 | /* FIXME: Make this a cfg hook. */ | |
590 | ||
591 | bool | |
592 | forwarder_block_p (const_basic_block bb) | |
593 | { | |
594 | if (!contains_no_active_insn_p (bb)) | |
595 | return false; | |
596 | ||
4a020a8c | 597 | /* Protect loop latches, headers and preheaders. */ |
598 | if (current_loops) | |
599 | { | |
600 | basic_block dest; | |
601 | if (bb->loop_father->header == bb) | |
602 | return false; | |
603 | dest = EDGE_SUCC (bb, 0)->dest; | |
604 | if (dest->loop_father->header == dest) | |
605 | return false; | |
606 | } | |
607 | ||
bbdfcf34 | 608 | return true; |
4a020a8c | 609 | } |
610 | ||
611 | /* Return nonzero if we can reach target from src by falling through. */ | |
cd316116 | 612 | /* FIXME: Make this a cfg hook, the result is only valid in cfgrtl mode. */ |
4a020a8c | 613 | |
614 | bool | |
615 | can_fallthru (basic_block src, basic_block target) | |
616 | { | |
3d90435a | 617 | rtx_insn *insn = BB_END (src); |
618 | rtx_insn *insn2; | |
4a020a8c | 619 | edge e; |
620 | edge_iterator ei; | |
621 | ||
34154e27 | 622 | if (target == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
4a020a8c | 623 | return true; |
624 | if (src->next_bb != target) | |
cd316116 | 625 | return false; |
626 | ||
627 | /* ??? Later we may add code to move jump tables offline. */ | |
628 | if (tablejump_p (insn, NULL, NULL)) | |
629 | return false; | |
630 | ||
4a020a8c | 631 | FOR_EACH_EDGE (e, ei, src->succs) |
34154e27 | 632 | if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) |
4a020a8c | 633 | && e->flags & EDGE_FALLTHRU) |
cd316116 | 634 | return false; |
4a020a8c | 635 | |
636 | insn2 = BB_HEAD (target); | |
cd316116 | 637 | if (!active_insn_p (insn2)) |
4a020a8c | 638 | insn2 = next_active_insn (insn2); |
639 | ||
4a020a8c | 640 | return next_active_insn (insn) == insn2; |
641 | } | |
642 | ||
643 | /* Return nonzero if we could reach target from src by falling through, | |
644 | if the target was made adjacent. If we already have a fall-through | |
645 | edge to the exit block, we can't do that. */ | |
646 | static bool | |
647 | could_fall_through (basic_block src, basic_block target) | |
648 | { | |
649 | edge e; | |
650 | edge_iterator ei; | |
651 | ||
34154e27 | 652 | if (target == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
4a020a8c | 653 | return true; |
654 | FOR_EACH_EDGE (e, ei, src->succs) | |
34154e27 | 655 | if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) |
4a020a8c | 656 | && e->flags & EDGE_FALLTHRU) |
657 | return 0; | |
658 | return true; | |
659 | } | |
b36d64df | 660 | \f |
018f0595 | 661 | /* Return the NOTE_INSN_BASIC_BLOCK of BB. */ |
61f9f451 | 662 | rtx_note * |
018f0595 | 663 | bb_note (basic_block bb) |
664 | { | |
3d90435a | 665 | rtx_insn *note; |
018f0595 | 666 | |
667 | note = BB_HEAD (bb); | |
668 | if (LABEL_P (note)) | |
669 | note = NEXT_INSN (note); | |
670 | ||
671 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (note)); | |
61f9f451 | 672 | return as_a <rtx_note *> (note); |
018f0595 | 673 | } |
674 | ||
3072d30e | 675 | /* Return the INSN immediately following the NOTE_INSN_BASIC_BLOCK |
676 | note associated with the BLOCK. */ | |
677 | ||
3d90435a | 678 | static rtx_insn * |
3072d30e | 679 | first_insn_after_basic_block_note (basic_block block) |
680 | { | |
3d90435a | 681 | rtx_insn *insn; |
3072d30e | 682 | |
683 | /* Get the first instruction in the block. */ | |
684 | insn = BB_HEAD (block); | |
685 | ||
686 | if (insn == NULL_RTX) | |
3d90435a | 687 | return NULL; |
3072d30e | 688 | if (LABEL_P (insn)) |
689 | insn = NEXT_INSN (insn); | |
690 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn)); | |
691 | ||
692 | return NEXT_INSN (insn); | |
693 | } | |
694 | ||
3ad55f68 | 695 | /* Creates a new basic block just after basic block BB by splitting |
696 | everything after specified instruction INSNP. */ | |
b36d64df | 697 | |
5f5d4cd1 | 698 | static basic_block |
4c9e08a4 | 699 | rtl_split_block (basic_block bb, void *insnp) |
b36d64df | 700 | { |
701 | basic_block new_bb; | |
3d90435a | 702 | rtx_insn *insn = (rtx_insn *) insnp; |
5f5d4cd1 | 703 | edge e; |
cd665a06 | 704 | edge_iterator ei; |
b36d64df | 705 | |
5f5d4cd1 | 706 | if (!insn) |
707 | { | |
708 | insn = first_insn_after_basic_block_note (bb); | |
709 | ||
710 | if (insn) | |
9845d120 | 711 | { |
3d90435a | 712 | rtx_insn *next = insn; |
9845d120 | 713 | |
714 | insn = PREV_INSN (insn); | |
715 | ||
716 | /* If the block contains only debug insns, insn would have | |
717 | been NULL in a non-debug compilation, and then we'd end | |
718 | up emitting a DELETED note. For -fcompare-debug | |
719 | stability, emit the note too. */ | |
720 | if (insn != BB_END (bb) | |
721 | && DEBUG_INSN_P (next) | |
722 | && DEBUG_INSN_P (BB_END (bb))) | |
723 | { | |
724 | while (next != BB_END (bb) && DEBUG_INSN_P (next)) | |
725 | next = NEXT_INSN (next); | |
726 | ||
727 | if (next == BB_END (bb)) | |
728 | emit_note_after (NOTE_INSN_DELETED, next); | |
729 | } | |
730 | } | |
5f5d4cd1 | 731 | else |
732 | insn = get_last_insn (); | |
733 | } | |
734 | ||
735 | /* We probably should check type of the insn so that we do not create | |
736 | inconsistent cfg. It is checked in verify_flow_info anyway, so do not | |
737 | bother. */ | |
738 | if (insn == BB_END (bb)) | |
739 | emit_note_after (NOTE_INSN_DELETED, insn); | |
b36d64df | 740 | |
741 | /* Create the new basic block. */ | |
5496dbfc | 742 | new_bb = create_basic_block (NEXT_INSN (insn), BB_END (bb), bb); |
7562ed74 | 743 | BB_COPY_PARTITION (new_bb, bb); |
26bb3cb2 | 744 | BB_END (bb) = insn; |
b36d64df | 745 | |
746 | /* Redirect the outgoing edges. */ | |
cd665a06 | 747 | new_bb->succs = bb->succs; |
748 | bb->succs = NULL; | |
749 | FOR_EACH_EDGE (e, ei, new_bb->succs) | |
b36d64df | 750 | e->src = new_bb; |
751 | ||
3072d30e | 752 | /* The new block starts off being dirty. */ |
753 | df_set_bb_dirty (bb); | |
5f5d4cd1 | 754 | return new_bb; |
c60fa3a7 | 755 | } |
756 | ||
8ddad41d | 757 | /* Return true if the single edge between blocks A and B is the only place |
758 | in RTL which holds some unique locus. */ | |
759 | ||
760 | static bool | |
761 | unique_locus_on_edge_between_p (basic_block a, basic_block b) | |
762 | { | |
5169661d | 763 | const location_t goto_locus = EDGE_SUCC (a, 0)->goto_locus; |
3d90435a | 764 | rtx_insn *insn, *end; |
8ddad41d | 765 | |
8e7408e3 | 766 | if (LOCATION_LOCUS (goto_locus) == UNKNOWN_LOCATION) |
8ddad41d | 767 | return false; |
768 | ||
769 | /* First scan block A backward. */ | |
770 | insn = BB_END (a); | |
771 | end = PREV_INSN (BB_HEAD (a)); | |
5169661d | 772 | while (insn != end && (!NONDEBUG_INSN_P (insn) || !INSN_HAS_LOCATION (insn))) |
8ddad41d | 773 | insn = PREV_INSN (insn); |
774 | ||
5169661d | 775 | if (insn != end && INSN_LOCATION (insn) == goto_locus) |
8ddad41d | 776 | return false; |
777 | ||
778 | /* Then scan block B forward. */ | |
779 | insn = BB_HEAD (b); | |
780 | if (insn) | |
781 | { | |
782 | end = NEXT_INSN (BB_END (b)); | |
783 | while (insn != end && !NONDEBUG_INSN_P (insn)) | |
784 | insn = NEXT_INSN (insn); | |
785 | ||
5169661d | 786 | if (insn != end && INSN_HAS_LOCATION (insn) |
787 | && INSN_LOCATION (insn) == goto_locus) | |
8ddad41d | 788 | return false; |
789 | } | |
790 | ||
791 | return true; | |
792 | } | |
793 | ||
794 | /* If the single edge between blocks A and B is the only place in RTL which | |
795 | holds some unique locus, emit a nop with that locus between the blocks. */ | |
796 | ||
797 | static void | |
798 | emit_nop_for_unique_locus_between (basic_block a, basic_block b) | |
799 | { | |
800 | if (!unique_locus_on_edge_between_p (a, b)) | |
801 | return; | |
802 | ||
26bb3cb2 | 803 | BB_END (a) = emit_insn_after_noloc (gen_nop (), BB_END (a), a); |
5169661d | 804 | INSN_LOCATION (BB_END (a)) = EDGE_SUCC (a, 0)->goto_locus; |
8ddad41d | 805 | } |
806 | ||
b36d64df | 807 | /* Blocks A and B are to be merged into a single block A. The insns |
c60fa3a7 | 808 | are already contiguous. */ |
b36d64df | 809 | |
c60fa3a7 | 810 | static void |
811 | rtl_merge_blocks (basic_block a, basic_block b) | |
b36d64df | 812 | { |
3d90435a | 813 | rtx_insn *b_head = BB_HEAD (b), *b_end = BB_END (b), *a_end = BB_END (a); |
814 | rtx_insn *del_first = NULL, *del_last = NULL; | |
815 | rtx_insn *b_debug_start = b_end, *b_debug_end = b_end; | |
18b762f0 | 816 | bool forwarder_p = (b->flags & BB_FORWARDER_BLOCK) != 0; |
b36d64df | 817 | int b_empty = 0; |
818 | ||
3072d30e | 819 | if (dump_file) |
18b762f0 | 820 | fprintf (dump_file, "Merging block %d into block %d...\n", b->index, |
821 | a->index); | |
3072d30e | 822 | |
9845d120 | 823 | while (DEBUG_INSN_P (b_end)) |
824 | b_end = PREV_INSN (b_debug_start = b_end); | |
825 | ||
b36d64df | 826 | /* If there was a CODE_LABEL beginning B, delete it. */ |
6d7dc5b9 | 827 | if (LABEL_P (b_head)) |
b36d64df | 828 | { |
829 | /* Detect basic blocks with nothing but a label. This can happen | |
830 | in particular at the end of a function. */ | |
831 | if (b_head == b_end) | |
832 | b_empty = 1; | |
5cc577b6 | 833 | |
b36d64df | 834 | del_first = del_last = b_head; |
835 | b_head = NEXT_INSN (b_head); | |
836 | } | |
837 | ||
5cc577b6 | 838 | /* Delete the basic block note and handle blocks containing just that |
839 | note. */ | |
b36d64df | 840 | if (NOTE_INSN_BASIC_BLOCK_P (b_head)) |
841 | { | |
842 | if (b_head == b_end) | |
843 | b_empty = 1; | |
844 | if (! del_last) | |
845 | del_first = b_head; | |
5cc577b6 | 846 | |
b36d64df | 847 | del_last = b_head; |
848 | b_head = NEXT_INSN (b_head); | |
849 | } | |
850 | ||
851 | /* If there was a jump out of A, delete it. */ | |
6d7dc5b9 | 852 | if (JUMP_P (a_end)) |
b36d64df | 853 | { |
3d90435a | 854 | rtx_insn *prev; |
b36d64df | 855 | |
856 | for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev)) | |
6d7dc5b9 | 857 | if (!NOTE_P (prev) |
ad4583d9 | 858 | || NOTE_INSN_BASIC_BLOCK_P (prev) |
5496dbfc | 859 | || prev == BB_HEAD (a)) |
b36d64df | 860 | break; |
861 | ||
862 | del_first = a_end; | |
863 | ||
b36d64df | 864 | /* If this was a conditional jump, we need to also delete |
865 | the insn that set cc0. */ | |
ff900b8e | 866 | if (HAVE_cc0 && only_sets_cc0_p (prev)) |
b36d64df | 867 | { |
3d90435a | 868 | rtx_insn *tmp = prev; |
5cc577b6 | 869 | |
b36d64df | 870 | prev = prev_nonnote_insn (prev); |
871 | if (!prev) | |
5496dbfc | 872 | prev = BB_HEAD (a); |
b36d64df | 873 | del_first = tmp; |
874 | } | |
b36d64df | 875 | |
876 | a_end = PREV_INSN (del_first); | |
877 | } | |
6d7dc5b9 | 878 | else if (BARRIER_P (NEXT_INSN (a_end))) |
b36d64df | 879 | del_first = NEXT_INSN (a_end); |
880 | ||
b36d64df | 881 | /* Delete everything marked above as well as crap that might be |
882 | hanging out between the two blocks. */ | |
26bb3cb2 | 883 | BB_END (a) = a_end; |
884 | BB_HEAD (b) = b_empty ? NULL : b_head; | |
39257eb5 | 885 | delete_insn_chain (del_first, del_last, true); |
b36d64df | 886 | |
36ebb5b6 | 887 | /* When not optimizing and the edge is the only place in RTL which holds |
8ddad41d | 888 | some unique locus, emit a nop with that locus in between. */ |
889 | if (!optimize) | |
890 | { | |
891 | emit_nop_for_unique_locus_between (a, b); | |
892 | a_end = BB_END (a); | |
893 | } | |
894 | ||
b36d64df | 895 | /* Reassociate the insns of B with A. */ |
896 | if (!b_empty) | |
897 | { | |
9845d120 | 898 | update_bb_for_insn_chain (a_end, b_debug_end, a); |
5cc577b6 | 899 | |
26bb3cb2 | 900 | BB_END (a) = b_debug_end; |
901 | BB_HEAD (b) = NULL; | |
9845d120 | 902 | } |
903 | else if (b_end != b_debug_end) | |
904 | { | |
905 | /* Move any deleted labels and other notes between the end of A | |
906 | and the debug insns that make up B after the debug insns, | |
907 | bringing the debug insns into A while keeping the notes after | |
908 | the end of A. */ | |
909 | if (NEXT_INSN (a_end) != b_debug_start) | |
910 | reorder_insns_nobb (NEXT_INSN (a_end), PREV_INSN (b_debug_start), | |
911 | b_debug_end); | |
912 | update_bb_for_insn_chain (b_debug_start, b_debug_end, a); | |
26bb3cb2 | 913 | BB_END (a) = b_debug_end; |
b36d64df | 914 | } |
5cc577b6 | 915 | |
3072d30e | 916 | df_bb_delete (b->index); |
18b762f0 | 917 | |
918 | /* If B was a forwarder block, propagate the locus on the edge. */ | |
81ad108c | 919 | if (forwarder_p |
920 | && LOCATION_LOCUS (EDGE_SUCC (b, 0)->goto_locus) == UNKNOWN_LOCATION) | |
18b762f0 | 921 | EDGE_SUCC (b, 0)->goto_locus = EDGE_SUCC (a, 0)->goto_locus; |
922 | ||
923 | if (dump_file) | |
924 | fprintf (dump_file, "Merged blocks %d and %d.\n", a->index, b->index); | |
b36d64df | 925 | } |
c60fa3a7 | 926 | |
3072d30e | 927 | |
c60fa3a7 | 928 | /* Return true when block A and B can be merged. */ |
5493cb9a | 929 | |
47aaf6e6 | 930 | static bool |
931 | rtl_can_merge_blocks (basic_block a, basic_block b) | |
c60fa3a7 | 932 | { |
4f18499c | 933 | /* If we are partitioning hot/cold basic blocks, we don't want to |
934 | mess up unconditional or indirect jumps that cross between hot | |
7562ed74 | 935 | and cold sections. |
936 | ||
1118aef7 | 937 | Basic block partitioning may result in some jumps that appear to |
a0c938f0 | 938 | be optimizable (or blocks that appear to be mergeable), but which really |
939 | must be left untouched (they are required to make it safely across | |
940 | partition boundaries). See the comments at the top of | |
1118aef7 | 941 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
7562ed74 | 942 | |
1897b881 | 943 | if (BB_PARTITION (a) != BB_PARTITION (b)) |
7562ed74 | 944 | return false; |
4f18499c | 945 | |
79f958cb | 946 | /* Protect the loop latches. */ |
947 | if (current_loops && b->loop_father->latch == b) | |
948 | return false; | |
949 | ||
c60fa3a7 | 950 | /* There must be exactly one edge in between the blocks. */ |
ea091dfd | 951 | return (single_succ_p (a) |
952 | && single_succ (a) == b | |
953 | && single_pred_p (b) | |
cd665a06 | 954 | && a != b |
c60fa3a7 | 955 | /* Must be simple edge. */ |
ea091dfd | 956 | && !(single_succ_edge (a)->flags & EDGE_COMPLEX) |
c60fa3a7 | 957 | && a->next_bb == b |
34154e27 | 958 | && a != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
959 | && b != EXIT_BLOCK_PTR_FOR_FN (cfun) | |
c60fa3a7 | 960 | /* If the jump insn has side effects, |
961 | we can't kill the edge. */ | |
6d7dc5b9 | 962 | && (!JUMP_P (BB_END (a)) |
18f811c9 | 963 | || (reload_completed |
5496dbfc | 964 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
c60fa3a7 | 965 | } |
b36d64df | 966 | \f |
5cc577b6 | 967 | /* Return the label in the head of basic block BLOCK. Create one if it doesn't |
968 | exist. */ | |
b36d64df | 969 | |
f9a00e9e | 970 | rtx_code_label * |
4c9e08a4 | 971 | block_label (basic_block block) |
b36d64df | 972 | { |
34154e27 | 973 | if (block == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
f9a00e9e | 974 | return NULL; |
5cc577b6 | 975 | |
6d7dc5b9 | 976 | if (!LABEL_P (BB_HEAD (block))) |
b36d64df | 977 | { |
26bb3cb2 | 978 | BB_HEAD (block) = emit_label_before (gen_label_rtx (), BB_HEAD (block)); |
b36d64df | 979 | } |
5cc577b6 | 980 | |
f9a00e9e | 981 | return as_a <rtx_code_label *> (BB_HEAD (block)); |
b36d64df | 982 | } |
983 | ||
984 | /* Attempt to perform edge redirection by replacing possibly complex jump | |
5cc577b6 | 985 | instruction by unconditional jump or removing jump completely. This can |
986 | apply only if all edges now point to the same block. The parameters and | |
987 | return values are equivalent to redirect_edge_and_branch. */ | |
b36d64df | 988 | |
4ee9c684 | 989 | edge |
c60fa3a7 | 990 | try_redirect_by_replacing_jump (edge e, basic_block target, bool in_cfglayout) |
b36d64df | 991 | { |
992 | basic_block src = e->src; | |
3d90435a | 993 | rtx_insn *insn = BB_END (src), *kill_from; |
b19beda9 | 994 | rtx set; |
b36d64df | 995 | int fallthru = 0; |
4f18499c | 996 | |
997 | /* If we are partitioning hot/cold basic blocks, we don't want to | |
998 | mess up unconditional or indirect jumps that cross between hot | |
1118aef7 | 999 | and cold sections. |
1000 | ||
1001 | Basic block partitioning may result in some jumps that appear to | |
a0c938f0 | 1002 | be optimizable (or blocks that appear to be mergeable), but which really |
1003 | must be left untouched (they are required to make it safely across | |
1004 | partition boundaries). See the comments at the top of | |
1118aef7 | 1005 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
a0c938f0 | 1006 | |
aa78dca5 | 1007 | if (BB_PARTITION (src) != BB_PARTITION (target)) |
53f8294f | 1008 | return NULL; |
4f18499c | 1009 | |
34f05bfa | 1010 | /* We can replace or remove a complex jump only when we have exactly |
1011 | two edges. Also, if we have exactly one outgoing edge, we can | |
1012 | redirect that. */ | |
1013 | if (EDGE_COUNT (src->succs) >= 3 | |
1014 | /* Verify that all targets will be TARGET. Specifically, the | |
1015 | edge that is not E must also go to TARGET. */ | |
1016 | || (EDGE_COUNT (src->succs) == 2 | |
1017 | && EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)) | |
1018 | return NULL; | |
5cc577b6 | 1019 | |
34f05bfa | 1020 | if (!onlyjump_p (insn)) |
4ee9c684 | 1021 | return NULL; |
e5562ab8 | 1022 | if ((!optimize || reload_completed) && tablejump_p (insn, NULL, NULL)) |
4ee9c684 | 1023 | return NULL; |
b36d64df | 1024 | |
1025 | /* Avoid removing branch with side effects. */ | |
1026 | set = single_set (insn); | |
1027 | if (!set || side_effects_p (set)) | |
4ee9c684 | 1028 | return NULL; |
b36d64df | 1029 | |
1030 | /* In case we zap a conditional jump, we'll need to kill | |
1031 | the cc0 setter too. */ | |
1032 | kill_from = insn; | |
ff900b8e | 1033 | if (HAVE_cc0 && reg_mentioned_p (cc0_rtx, PATTERN (insn)) |
3d5a3e76 | 1034 | && only_sets_cc0_p (PREV_INSN (insn))) |
b36d64df | 1035 | kill_from = PREV_INSN (insn); |
b36d64df | 1036 | |
1037 | /* See if we can create the fallthru edge. */ | |
c60fa3a7 | 1038 | if (in_cfglayout || can_fallthru (src, target)) |
b36d64df | 1039 | { |
450d042a | 1040 | if (dump_file) |
1041 | fprintf (dump_file, "Removing jump %i.\n", INSN_UID (insn)); | |
b36d64df | 1042 | fallthru = 1; |
1043 | ||
4a82352a | 1044 | /* Selectively unlink whole insn chain. */ |
c60fa3a7 | 1045 | if (in_cfglayout) |
1046 | { | |
3d90435a | 1047 | rtx_insn *insn = BB_FOOTER (src); |
c60fa3a7 | 1048 | |
39257eb5 | 1049 | delete_insn_chain (kill_from, BB_END (src), false); |
c60fa3a7 | 1050 | |
1051 | /* Remove barriers but keep jumptables. */ | |
1052 | while (insn) | |
1053 | { | |
6d7dc5b9 | 1054 | if (BARRIER_P (insn)) |
c60fa3a7 | 1055 | { |
1056 | if (PREV_INSN (insn)) | |
4a57a2e8 | 1057 | SET_NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); |
c60fa3a7 | 1058 | else |
943ea6fa | 1059 | BB_FOOTER (src) = NEXT_INSN (insn); |
c60fa3a7 | 1060 | if (NEXT_INSN (insn)) |
4a57a2e8 | 1061 | SET_PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); |
c60fa3a7 | 1062 | } |
6d7dc5b9 | 1063 | if (LABEL_P (insn)) |
c60fa3a7 | 1064 | break; |
1065 | insn = NEXT_INSN (insn); | |
1066 | } | |
1067 | } | |
1068 | else | |
39257eb5 | 1069 | delete_insn_chain (kill_from, PREV_INSN (BB_HEAD (target)), |
1070 | false); | |
b36d64df | 1071 | } |
5cc577b6 | 1072 | |
b36d64df | 1073 | /* If this already is simplejump, redirect it. */ |
1074 | else if (simplejump_p (insn)) | |
1075 | { | |
1076 | if (e->dest == target) | |
4ee9c684 | 1077 | return NULL; |
450d042a | 1078 | if (dump_file) |
1079 | fprintf (dump_file, "Redirecting jump %i from %i to %i.\n", | |
b3d6de89 | 1080 | INSN_UID (insn), e->dest->index, target->index); |
f9a00e9e | 1081 | if (!redirect_jump (as_a <rtx_jump_insn *> (insn), |
1082 | block_label (target), 0)) | |
8963581a | 1083 | { |
34154e27 | 1084 | gcc_assert (target == EXIT_BLOCK_PTR_FOR_FN (cfun)); |
cc636d56 | 1085 | return NULL; |
8963581a | 1086 | } |
b36d64df | 1087 | } |
5cc577b6 | 1088 | |
8963581a | 1089 | /* Cannot do anything for target exit block. */ |
34154e27 | 1090 | else if (target == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
4ee9c684 | 1091 | return NULL; |
8963581a | 1092 | |
b36d64df | 1093 | /* Or replace possibly complicated jump insn by simple jump insn. */ |
1094 | else | |
1095 | { | |
9ed997be | 1096 | rtx_code_label *target_label = block_label (target); |
3d90435a | 1097 | rtx_insn *barrier; |
1098 | rtx label; | |
c86d86ff | 1099 | rtx_jump_table_data *table; |
b36d64df | 1100 | |
1d5ad681 | 1101 | emit_jump_insn_after_noloc (targetm.gen_jump (target_label), insn); |
5496dbfc | 1102 | JUMP_LABEL (BB_END (src)) = target_label; |
b36d64df | 1103 | LABEL_NUSES (target_label)++; |
450d042a | 1104 | if (dump_file) |
1105 | fprintf (dump_file, "Replacing insn %i by jump %i\n", | |
5496dbfc | 1106 | INSN_UID (insn), INSN_UID (BB_END (src))); |
b36d64df | 1107 | |
1ed8ccdb | 1108 | |
201f6961 | 1109 | delete_insn_chain (kill_from, insn, false); |
1110 | ||
1ed8ccdb | 1111 | /* Recognize a tablejump that we are converting to a |
1112 | simple jump and remove its associated CODE_LABEL | |
1113 | and ADDR_VEC or ADDR_DIFF_VEC. */ | |
201f6961 | 1114 | if (tablejump_p (insn, &label, &table)) |
1115 | delete_insn_chain (label, table, false); | |
669f9131 | 1116 | |
5496dbfc | 1117 | barrier = next_nonnote_insn (BB_END (src)); |
6d7dc5b9 | 1118 | if (!barrier || !BARRIER_P (barrier)) |
5496dbfc | 1119 | emit_barrier_after (BB_END (src)); |
1824678b | 1120 | else |
1121 | { | |
5496dbfc | 1122 | if (barrier != NEXT_INSN (BB_END (src))) |
1824678b | 1123 | { |
1124 | /* Move the jump before barrier so that the notes | |
1125 | which originally were or were created before jump table are | |
1126 | inside the basic block. */ | |
3d90435a | 1127 | rtx_insn *new_insn = BB_END (src); |
1824678b | 1128 | |
f41d4683 | 1129 | update_bb_for_insn_chain (NEXT_INSN (BB_END (src)), |
1130 | PREV_INSN (barrier), src); | |
1824678b | 1131 | |
4a57a2e8 | 1132 | SET_NEXT_INSN (PREV_INSN (new_insn)) = NEXT_INSN (new_insn); |
1133 | SET_PREV_INSN (NEXT_INSN (new_insn)) = PREV_INSN (new_insn); | |
1824678b | 1134 | |
4a57a2e8 | 1135 | SET_NEXT_INSN (new_insn) = barrier; |
1136 | SET_NEXT_INSN (PREV_INSN (barrier)) = new_insn; | |
1824678b | 1137 | |
4a57a2e8 | 1138 | SET_PREV_INSN (new_insn) = PREV_INSN (barrier); |
1139 | SET_PREV_INSN (barrier) = new_insn; | |
1824678b | 1140 | } |
1141 | } | |
b36d64df | 1142 | } |
1143 | ||
1144 | /* Keep only one edge out and set proper flags. */ | |
ea091dfd | 1145 | if (!single_succ_p (src)) |
cd665a06 | 1146 | remove_edge (e); |
ea091dfd | 1147 | gcc_assert (single_succ_p (src)); |
cd665a06 | 1148 | |
ea091dfd | 1149 | e = single_succ_edge (src); |
b36d64df | 1150 | if (fallthru) |
1151 | e->flags = EDGE_FALLTHRU; | |
1152 | else | |
1153 | e->flags = 0; | |
5cc577b6 | 1154 | |
b36d64df | 1155 | e->probability = REG_BR_PROB_BASE; |
1156 | e->count = src->count; | |
1157 | ||
b36d64df | 1158 | if (e->dest != target) |
1159 | redirect_edge_succ (e, target); | |
4ee9c684 | 1160 | return e; |
b36d64df | 1161 | } |
1162 | ||
a8dd994c | 1163 | /* Subroutine of redirect_branch_edge that tries to patch the jump |
1164 | instruction INSN so that it reaches block NEW. Do this | |
1165 | only when it originally reached block OLD. Return true if this | |
1166 | worked or the original target wasn't OLD, return false if redirection | |
1167 | doesn't work. */ | |
1168 | ||
1169 | static bool | |
3d90435a | 1170 | patch_jump_insn (rtx_insn *insn, rtx_insn *old_label, basic_block new_bb) |
b36d64df | 1171 | { |
c86d86ff | 1172 | rtx_jump_table_data *table; |
b36d64df | 1173 | rtx tmp; |
b36d64df | 1174 | /* Recognize a tablejump and adjust all matching cases. */ |
c86d86ff | 1175 | if (tablejump_p (insn, NULL, &table)) |
b36d64df | 1176 | { |
1177 | rtvec vec; | |
1178 | int j; | |
9ed997be | 1179 | rtx_code_label *new_label = block_label (new_bb); |
b36d64df | 1180 | |
34154e27 | 1181 | if (new_bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
a8dd994c | 1182 | return false; |
b77639be | 1183 | vec = table->get_labels (); |
b36d64df | 1184 | |
1185 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
1186 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
1187 | { | |
1188 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (Pmode, new_label); | |
1189 | --LABEL_NUSES (old_label); | |
1190 | ++LABEL_NUSES (new_label); | |
1191 | } | |
1192 | ||
2358393e | 1193 | /* Handle casesi dispatch insns. */ |
b36d64df | 1194 | if ((tmp = single_set (insn)) != NULL |
1195 | && SET_DEST (tmp) == pc_rtx | |
1196 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
1197 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF | |
b49f2e4b | 1198 | && LABEL_REF_LABEL (XEXP (SET_SRC (tmp), 2)) == old_label) |
b36d64df | 1199 | { |
514b43f8 | 1200 | XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (Pmode, |
b36d64df | 1201 | new_label); |
1202 | --LABEL_NUSES (old_label); | |
1203 | ++LABEL_NUSES (new_label); | |
1204 | } | |
1205 | } | |
78f55ca8 | 1206 | else if ((tmp = extract_asm_operands (PATTERN (insn))) != NULL) |
1207 | { | |
1208 | int i, n = ASM_OPERANDS_LABEL_LENGTH (tmp); | |
9ed997be | 1209 | rtx note; |
78f55ca8 | 1210 | |
34154e27 | 1211 | if (new_bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
78f55ca8 | 1212 | return false; |
9ed997be | 1213 | rtx_code_label *new_label = block_label (new_bb); |
78f55ca8 | 1214 | |
1215 | for (i = 0; i < n; ++i) | |
1216 | { | |
1217 | rtx old_ref = ASM_OPERANDS_LABEL (tmp, i); | |
1218 | gcc_assert (GET_CODE (old_ref) == LABEL_REF); | |
1219 | if (XEXP (old_ref, 0) == old_label) | |
1220 | { | |
1221 | ASM_OPERANDS_LABEL (tmp, i) | |
1222 | = gen_rtx_LABEL_REF (Pmode, new_label); | |
1223 | --LABEL_NUSES (old_label); | |
1224 | ++LABEL_NUSES (new_label); | |
1225 | } | |
1226 | } | |
1227 | ||
1228 | if (JUMP_LABEL (insn) == old_label) | |
1229 | { | |
1230 | JUMP_LABEL (insn) = new_label; | |
1231 | note = find_reg_note (insn, REG_LABEL_TARGET, new_label); | |
1232 | if (note) | |
1233 | remove_note (insn, note); | |
1234 | } | |
1235 | else | |
1236 | { | |
1237 | note = find_reg_note (insn, REG_LABEL_TARGET, old_label); | |
1238 | if (note) | |
1239 | remove_note (insn, note); | |
1240 | if (JUMP_LABEL (insn) != new_label | |
1241 | && !find_reg_note (insn, REG_LABEL_TARGET, new_label)) | |
1242 | add_reg_note (insn, REG_LABEL_TARGET, new_label); | |
1243 | } | |
dcb172b4 | 1244 | while ((note = find_reg_note (insn, REG_LABEL_OPERAND, old_label)) |
1245 | != NULL_RTX) | |
1246 | XEXP (note, 0) = new_label; | |
78f55ca8 | 1247 | } |
b36d64df | 1248 | else |
1249 | { | |
1250 | /* ?? We may play the games with moving the named labels from | |
1251 | one basic block to the other in case only one computed_jump is | |
1252 | available. */ | |
5cc577b6 | 1253 | if (computed_jump_p (insn) |
1254 | /* A return instruction can't be redirected. */ | |
1255 | || returnjump_p (insn)) | |
a8dd994c | 1256 | return false; |
8963581a | 1257 | |
a8dd994c | 1258 | if (!currently_expanding_to_rtl || JUMP_LABEL (insn) == old_label) |
8963581a | 1259 | { |
a8dd994c | 1260 | /* If the insn doesn't go where we think, we're confused. */ |
1261 | gcc_assert (JUMP_LABEL (insn) == old_label); | |
1262 | ||
1263 | /* If the substitution doesn't succeed, die. This can happen | |
1264 | if the back end emitted unrecognizable instructions or if | |
1265 | target is exit block on some arches. */ | |
f9a00e9e | 1266 | if (!redirect_jump (as_a <rtx_jump_insn *> (insn), |
1267 | block_label (new_bb), 0)) | |
a8dd994c | 1268 | { |
34154e27 | 1269 | gcc_assert (new_bb == EXIT_BLOCK_PTR_FOR_FN (cfun)); |
a8dd994c | 1270 | return false; |
1271 | } | |
8963581a | 1272 | } |
b36d64df | 1273 | } |
a8dd994c | 1274 | return true; |
1275 | } | |
1276 | ||
1277 | ||
1278 | /* Redirect edge representing branch of (un)conditional jump or tablejump, | |
1279 | NULL on failure */ | |
1280 | static edge | |
1281 | redirect_branch_edge (edge e, basic_block target) | |
1282 | { | |
3d90435a | 1283 | rtx_insn *old_label = BB_HEAD (e->dest); |
a8dd994c | 1284 | basic_block src = e->src; |
3d90435a | 1285 | rtx_insn *insn = BB_END (src); |
a8dd994c | 1286 | |
1287 | /* We can only redirect non-fallthru edges of jump insn. */ | |
1288 | if (e->flags & EDGE_FALLTHRU) | |
1289 | return NULL; | |
1290 | else if (!JUMP_P (insn) && !currently_expanding_to_rtl) | |
1291 | return NULL; | |
1292 | ||
1293 | if (!currently_expanding_to_rtl) | |
1294 | { | |
f9a00e9e | 1295 | if (!patch_jump_insn (as_a <rtx_jump_insn *> (insn), old_label, target)) |
a8dd994c | 1296 | return NULL; |
1297 | } | |
1298 | else | |
1299 | /* When expanding this BB might actually contain multiple | |
1300 | jumps (i.e. not yet split by find_many_sub_basic_blocks). | |
1301 | Redirect all of those that match our label. */ | |
50b15e04 | 1302 | FOR_BB_INSNS (src, insn) |
f9a00e9e | 1303 | if (JUMP_P (insn) && !patch_jump_insn (as_a <rtx_jump_insn *> (insn), |
1304 | old_label, target)) | |
a8dd994c | 1305 | return NULL; |
b36d64df | 1306 | |
450d042a | 1307 | if (dump_file) |
1308 | fprintf (dump_file, "Edge %i->%i redirected to %i\n", | |
b3d6de89 | 1309 | e->src->index, e->dest->index, target->index); |
5cc577b6 | 1310 | |
b36d64df | 1311 | if (e->dest != target) |
4ee9c684 | 1312 | e = redirect_edge_succ_nodup (e, target); |
3072d30e | 1313 | |
4ee9c684 | 1314 | return e; |
c60fa3a7 | 1315 | } |
1316 | ||
aa78dca5 | 1317 | /* Called when edge E has been redirected to a new destination, |
1318 | in order to update the region crossing flag on the edge and | |
1319 | jump. */ | |
1320 | ||
1321 | static void | |
1322 | fixup_partition_crossing (edge e) | |
1323 | { | |
34154e27 | 1324 | if (e->src == ENTRY_BLOCK_PTR_FOR_FN (cfun) || e->dest |
1325 | == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
aa78dca5 | 1326 | return; |
1327 | /* If we redirected an existing edge, it may already be marked | |
1328 | crossing, even though the new src is missing a reg crossing note. | |
1329 | But make sure reg crossing note doesn't already exist before | |
1330 | inserting. */ | |
1331 | if (BB_PARTITION (e->src) != BB_PARTITION (e->dest)) | |
1332 | { | |
1333 | e->flags |= EDGE_CROSSING; | |
aa78dca5 | 1334 | if (JUMP_P (BB_END (e->src)) |
8f869004 | 1335 | && !CROSSING_JUMP_P (BB_END (e->src))) |
1336 | CROSSING_JUMP_P (BB_END (e->src)) = 1; | |
aa78dca5 | 1337 | } |
1338 | else if (BB_PARTITION (e->src) == BB_PARTITION (e->dest)) | |
1339 | { | |
1340 | e->flags &= ~EDGE_CROSSING; | |
1341 | /* Remove the section crossing note from jump at end of | |
1342 | src if it exists, and if no other successors are | |
1343 | still crossing. */ | |
8f869004 | 1344 | if (JUMP_P (BB_END (e->src)) && CROSSING_JUMP_P (BB_END (e->src))) |
aa78dca5 | 1345 | { |
1346 | bool has_crossing_succ = false; | |
1347 | edge e2; | |
1348 | edge_iterator ei; | |
1349 | FOR_EACH_EDGE (e2, ei, e->src->succs) | |
1350 | { | |
1351 | has_crossing_succ |= (e2->flags & EDGE_CROSSING); | |
1352 | if (has_crossing_succ) | |
1353 | break; | |
1354 | } | |
1355 | if (!has_crossing_succ) | |
8f869004 | 1356 | CROSSING_JUMP_P (BB_END (e->src)) = 0; |
aa78dca5 | 1357 | } |
1358 | } | |
1359 | } | |
1360 | ||
80adc5a6 | 1361 | /* Called when block BB has been reassigned to the cold partition, |
1362 | because it is now dominated by another cold block, | |
1363 | to ensure that the region crossing attributes are updated. */ | |
1364 | ||
1365 | static void | |
1366 | fixup_new_cold_bb (basic_block bb) | |
1367 | { | |
1368 | edge e; | |
1369 | edge_iterator ei; | |
1370 | ||
1371 | /* This is called when a hot bb is found to now be dominated | |
1372 | by a cold bb and therefore needs to become cold. Therefore, | |
1373 | its preds will no longer be region crossing. Any non-dominating | |
1374 | preds that were previously hot would also have become cold | |
1375 | in the caller for the same region. Any preds that were previously | |
1376 | region-crossing will be adjusted in fixup_partition_crossing. */ | |
1377 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1378 | { | |
1379 | fixup_partition_crossing (e); | |
1380 | } | |
1381 | ||
1382 | /* Possibly need to make bb's successor edges region crossing, | |
1383 | or remove stale region crossing. */ | |
1384 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1385 | { | |
1386 | /* We can't have fall-through edges across partition boundaries. | |
1387 | Note that force_nonfallthru will do any necessary partition | |
1388 | boundary fixup by calling fixup_partition_crossing itself. */ | |
1389 | if ((e->flags & EDGE_FALLTHRU) | |
1390 | && BB_PARTITION (bb) != BB_PARTITION (e->dest) | |
34154e27 | 1391 | && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
80adc5a6 | 1392 | force_nonfallthru (e); |
1393 | else | |
1394 | fixup_partition_crossing (e); | |
1395 | } | |
1396 | } | |
1397 | ||
c60fa3a7 | 1398 | /* Attempt to change code to redirect edge E to TARGET. Don't do that on |
1399 | expense of adding new instructions or reordering basic blocks. | |
1400 | ||
1401 | Function can be also called with edge destination equivalent to the TARGET. | |
1402 | Then it should try the simplifications and do nothing if none is possible. | |
1403 | ||
4ee9c684 | 1404 | Return edge representing the branch if transformation succeeded. Return NULL |
1405 | on failure. | |
1406 | We still return NULL in case E already destinated TARGET and we didn't | |
1407 | managed to simplify instruction stream. */ | |
c60fa3a7 | 1408 | |
4ee9c684 | 1409 | static edge |
f82b06e0 | 1410 | rtl_redirect_edge_and_branch (edge e, basic_block target) |
c60fa3a7 | 1411 | { |
4ee9c684 | 1412 | edge ret; |
adee86a0 | 1413 | basic_block src = e->src; |
aa78dca5 | 1414 | basic_block dest = e->dest; |
adee86a0 | 1415 | |
c60fa3a7 | 1416 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
4ee9c684 | 1417 | return NULL; |
c60fa3a7 | 1418 | |
aa78dca5 | 1419 | if (dest == target) |
4ee9c684 | 1420 | return e; |
e5562ab8 | 1421 | |
4ee9c684 | 1422 | if ((ret = try_redirect_by_replacing_jump (e, target, false)) != NULL) |
adee86a0 | 1423 | { |
3072d30e | 1424 | df_set_bb_dirty (src); |
aa78dca5 | 1425 | fixup_partition_crossing (ret); |
4ee9c684 | 1426 | return ret; |
adee86a0 | 1427 | } |
c60fa3a7 | 1428 | |
4ee9c684 | 1429 | ret = redirect_branch_edge (e, target); |
1430 | if (!ret) | |
1431 | return NULL; | |
5cc577b6 | 1432 | |
3072d30e | 1433 | df_set_bb_dirty (src); |
aa78dca5 | 1434 | fixup_partition_crossing (ret); |
4ee9c684 | 1435 | return ret; |
b36d64df | 1436 | } |
1437 | ||
aa78dca5 | 1438 | /* Emit a barrier after BB, into the footer if we are in CFGLAYOUT mode. */ |
1439 | ||
1440 | void | |
1441 | emit_barrier_after_bb (basic_block bb) | |
1442 | { | |
722334ea | 1443 | rtx_barrier *barrier = emit_barrier_after (BB_END (bb)); |
9af5ce0c | 1444 | gcc_assert (current_ir_type () == IR_RTL_CFGRTL |
aa78dca5 | 1445 | || current_ir_type () == IR_RTL_CFGLAYOUT); |
1446 | if (current_ir_type () == IR_RTL_CFGLAYOUT) | |
fb773ec9 | 1447 | { |
1448 | rtx_insn *insn = unlink_insn_chain (barrier, barrier); | |
1449 | ||
1450 | if (BB_FOOTER (bb)) | |
1451 | { | |
1452 | rtx_insn *footer_tail = BB_FOOTER (bb); | |
1453 | ||
1454 | while (NEXT_INSN (footer_tail)) | |
1455 | footer_tail = NEXT_INSN (footer_tail); | |
1456 | if (!BARRIER_P (footer_tail)) | |
1457 | { | |
1458 | SET_NEXT_INSN (footer_tail) = insn; | |
1459 | SET_PREV_INSN (insn) = footer_tail; | |
1460 | } | |
1461 | } | |
1462 | else | |
1463 | BB_FOOTER (bb) = insn; | |
1464 | } | |
aa78dca5 | 1465 | } |
1466 | ||
20dd417a | 1467 | /* Like force_nonfallthru below, but additionally performs redirection |
9cb2517e | 1468 | Used by redirect_edge_and_branch_force. JUMP_LABEL is used only |
1469 | when redirecting to the EXIT_BLOCK, it is either ret_rtx or | |
1470 | simple_return_rtx, indicating which kind of returnjump to create. | |
1471 | It should be NULL otherwise. */ | |
b36d64df | 1472 | |
4115ac36 | 1473 | basic_block |
9cb2517e | 1474 | force_nonfallthru_and_redirect (edge e, basic_block target, rtx jump_label) |
b36d64df | 1475 | { |
498d173d | 1476 | basic_block jump_block, new_bb = NULL, src = e->src; |
b36d64df | 1477 | rtx note; |
1478 | edge new_edge; | |
498d173d | 1479 | int abnormal_edge_flags = 0; |
d7ff3ab6 | 1480 | bool asm_goto_edge = false; |
9c388755 | 1481 | int loc; |
b36d64df | 1482 | |
accd6c44 | 1483 | /* In the case the last instruction is conditional jump to the next |
1484 | instruction, first redirect the jump itself and then continue | |
df07c3ae | 1485 | by creating a basic block afterwards to redirect fallthru edge. */ |
34154e27 | 1486 | if (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
1487 | && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) | |
5496dbfc | 1488 | && any_condjump_p (BB_END (e->src)) |
5496dbfc | 1489 | && JUMP_LABEL (BB_END (e->src)) == BB_HEAD (e->dest)) |
accd6c44 | 1490 | { |
1491 | rtx note; | |
d9aa52be | 1492 | edge b = unchecked_make_edge (e->src, target, 0); |
cc636d56 | 1493 | bool redirected; |
accd6c44 | 1494 | |
f9a00e9e | 1495 | redirected = redirect_jump (as_a <rtx_jump_insn *> (BB_END (e->src)), |
1496 | block_label (target), 0); | |
cc636d56 | 1497 | gcc_assert (redirected); |
a0c938f0 | 1498 | |
5496dbfc | 1499 | note = find_reg_note (BB_END (e->src), REG_BR_PROB, NULL_RTX); |
accd6c44 | 1500 | if (note) |
1501 | { | |
9eb946de | 1502 | int prob = XINT (note, 0); |
accd6c44 | 1503 | |
1504 | b->probability = prob; | |
f9d4b7f4 | 1505 | /* Update this to use GCOV_COMPUTE_SCALE. */ |
accd6c44 | 1506 | b->count = e->count * prob / REG_BR_PROB_BASE; |
1507 | e->probability -= e->probability; | |
1508 | e->count -= b->count; | |
1509 | if (e->probability < 0) | |
1510 | e->probability = 0; | |
1511 | if (e->count < 0) | |
1512 | e->count = 0; | |
1513 | } | |
1514 | } | |
1515 | ||
b36d64df | 1516 | if (e->flags & EDGE_ABNORMAL) |
498d173d | 1517 | { |
1518 | /* Irritating special case - fallthru edge to the same block as abnormal | |
1519 | edge. | |
1520 | We can't redirect abnormal edge, but we still can split the fallthru | |
4c9e08a4 | 1521 | one and create separate abnormal edge to original destination. |
498d173d | 1522 | This allows bb-reorder to make such edge non-fallthru. */ |
cc636d56 | 1523 | gcc_assert (e->dest == target); |
4ecbba1a | 1524 | abnormal_edge_flags = e->flags & ~EDGE_FALLTHRU; |
1525 | e->flags &= EDGE_FALLTHRU; | |
498d173d | 1526 | } |
cc636d56 | 1527 | else |
76cc9616 | 1528 | { |
cc636d56 | 1529 | gcc_assert (e->flags & EDGE_FALLTHRU); |
34154e27 | 1530 | if (e->src == ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
cc636d56 | 1531 | { |
1532 | /* We can't redirect the entry block. Create an empty block | |
cd665a06 | 1533 | at the start of the function which we use to add the new |
1534 | jump. */ | |
1535 | edge tmp; | |
1536 | edge_iterator ei; | |
1537 | bool found = false; | |
a0c938f0 | 1538 | |
34154e27 | 1539 | basic_block bb = create_basic_block (BB_HEAD (e->dest), NULL, |
1540 | ENTRY_BLOCK_PTR_FOR_FN (cfun)); | |
a0c938f0 | 1541 | |
cc636d56 | 1542 | /* Change the existing edge's source to be the new block, and add |
1543 | a new edge from the entry block to the new block. */ | |
1544 | e->src = bb; | |
34154e27 | 1545 | for (ei = ei_start (ENTRY_BLOCK_PTR_FOR_FN (cfun)->succs); |
1546 | (tmp = ei_safe_edge (ei)); ) | |
cd665a06 | 1547 | { |
1548 | if (tmp == e) | |
1549 | { | |
34154e27 | 1550 | ENTRY_BLOCK_PTR_FOR_FN (cfun)->succs->unordered_remove (ei.index); |
cd665a06 | 1551 | found = true; |
1552 | break; | |
1553 | } | |
1554 | else | |
1555 | ei_next (&ei); | |
1556 | } | |
a0c938f0 | 1557 | |
cd665a06 | 1558 | gcc_assert (found); |
a0c938f0 | 1559 | |
f1f41a6c | 1560 | vec_safe_push (bb->succs, e); |
34154e27 | 1561 | make_single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun), bb, |
1562 | EDGE_FALLTHRU); | |
cc636d56 | 1563 | } |
76cc9616 | 1564 | } |
1565 | ||
d7ff3ab6 | 1566 | /* If e->src ends with asm goto, see if any of the ASM_OPERANDS_LABELs |
92f67f6e | 1567 | don't point to the target or fallthru label. */ |
d7ff3ab6 | 1568 | if (JUMP_P (BB_END (e->src)) |
34154e27 | 1569 | && target != EXIT_BLOCK_PTR_FOR_FN (cfun) |
d7ff3ab6 | 1570 | && (e->flags & EDGE_FALLTHRU) |
1571 | && (note = extract_asm_operands (PATTERN (BB_END (e->src))))) | |
b36d64df | 1572 | { |
d7ff3ab6 | 1573 | int i, n = ASM_OPERANDS_LABEL_LENGTH (note); |
ca632883 | 1574 | bool adjust_jump_target = false; |
d7ff3ab6 | 1575 | |
1576 | for (i = 0; i < n; ++i) | |
92f67f6e | 1577 | { |
1578 | if (XEXP (ASM_OPERANDS_LABEL (note, i), 0) == BB_HEAD (e->dest)) | |
ca632883 | 1579 | { |
1580 | LABEL_NUSES (XEXP (ASM_OPERANDS_LABEL (note, i), 0))--; | |
1581 | XEXP (ASM_OPERANDS_LABEL (note, i), 0) = block_label (target); | |
1582 | LABEL_NUSES (XEXP (ASM_OPERANDS_LABEL (note, i), 0))++; | |
1583 | adjust_jump_target = true; | |
1584 | } | |
92f67f6e | 1585 | if (XEXP (ASM_OPERANDS_LABEL (note, i), 0) == BB_HEAD (target)) |
d7ff3ab6 | 1586 | asm_goto_edge = true; |
92f67f6e | 1587 | } |
ca632883 | 1588 | if (adjust_jump_target) |
1589 | { | |
3d90435a | 1590 | rtx_insn *insn = BB_END (e->src); |
1591 | rtx note; | |
1592 | rtx_insn *old_label = BB_HEAD (e->dest); | |
1593 | rtx_insn *new_label = BB_HEAD (target); | |
ca632883 | 1594 | |
1595 | if (JUMP_LABEL (insn) == old_label) | |
1596 | { | |
1597 | JUMP_LABEL (insn) = new_label; | |
1598 | note = find_reg_note (insn, REG_LABEL_TARGET, new_label); | |
1599 | if (note) | |
1600 | remove_note (insn, note); | |
1601 | } | |
1602 | else | |
1603 | { | |
1604 | note = find_reg_note (insn, REG_LABEL_TARGET, old_label); | |
1605 | if (note) | |
1606 | remove_note (insn, note); | |
1607 | if (JUMP_LABEL (insn) != new_label | |
1608 | && !find_reg_note (insn, REG_LABEL_TARGET, new_label)) | |
1609 | add_reg_note (insn, REG_LABEL_TARGET, new_label); | |
1610 | } | |
1611 | while ((note = find_reg_note (insn, REG_LABEL_OPERAND, old_label)) | |
1612 | != NULL_RTX) | |
1613 | XEXP (note, 0) = new_label; | |
1614 | } | |
d7ff3ab6 | 1615 | } |
1616 | ||
1617 | if (EDGE_COUNT (e->src->succs) >= 2 || abnormal_edge_flags || asm_goto_edge) | |
1618 | { | |
4cd001d5 | 1619 | rtx_insn *new_head; |
d7ff3ab6 | 1620 | gcov_type count = e->count; |
1621 | int probability = e->probability; | |
b36d64df | 1622 | /* Create the new structures. */ |
3160014e | 1623 | |
7a1fee99 | 1624 | /* If the old block ended with a tablejump, skip its table |
1625 | by searching forward from there. Otherwise start searching | |
1626 | forward from the last instruction of the old block. */ | |
c86d86ff | 1627 | rtx_jump_table_data *table; |
1628 | if (tablejump_p (BB_END (e->src), NULL, &table)) | |
4cd001d5 | 1629 | new_head = table; |
c86d86ff | 1630 | else |
4cd001d5 | 1631 | new_head = BB_END (e->src); |
1632 | new_head = NEXT_INSN (new_head); | |
3160014e | 1633 | |
4cd001d5 | 1634 | jump_block = create_basic_block (new_head, NULL, e->src); |
d7ff3ab6 | 1635 | jump_block->count = count; |
b36d64df | 1636 | jump_block->frequency = EDGE_FREQUENCY (e); |
b36d64df | 1637 | |
4f18499c | 1638 | /* Make sure new block ends up in correct hot/cold section. */ |
1639 | ||
7562ed74 | 1640 | BB_COPY_PARTITION (jump_block, e->src); |
a0c938f0 | 1641 | |
b36d64df | 1642 | /* Wire edge in. */ |
1643 | new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU); | |
d7ff3ab6 | 1644 | new_edge->probability = probability; |
1645 | new_edge->count = count; | |
b36d64df | 1646 | |
1647 | /* Redirect old edge. */ | |
1648 | redirect_edge_pred (e, jump_block); | |
1649 | e->probability = REG_BR_PROB_BASE; | |
1650 | ||
aa78dca5 | 1651 | /* If e->src was previously region crossing, it no longer is |
1652 | and the reg crossing note should be removed. */ | |
1653 | fixup_partition_crossing (new_edge); | |
1654 | ||
d7ff3ab6 | 1655 | /* If asm goto has any label refs to target's label, |
1656 | add also edge from asm goto bb to target. */ | |
1657 | if (asm_goto_edge) | |
1658 | { | |
1659 | new_edge->probability /= 2; | |
1660 | new_edge->count /= 2; | |
1661 | jump_block->count /= 2; | |
1662 | jump_block->frequency /= 2; | |
1663 | new_edge = make_edge (new_edge->src, target, | |
1664 | e->flags & ~EDGE_FALLTHRU); | |
1665 | new_edge->probability = probability - probability / 2; | |
1666 | new_edge->count = count - count / 2; | |
1667 | } | |
1668 | ||
b36d64df | 1669 | new_bb = jump_block; |
1670 | } | |
1671 | else | |
1672 | jump_block = e->src; | |
5cc577b6 | 1673 | |
8e7408e3 | 1674 | loc = e->goto_locus; |
b36d64df | 1675 | e->flags &= ~EDGE_FALLTHRU; |
34154e27 | 1676 | if (target == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
b36d64df | 1677 | { |
9cb2517e | 1678 | if (jump_label == ret_rtx) |
5da5e283 | 1679 | emit_jump_insn_after_setloc (targetm.gen_return (), |
1680 | BB_END (jump_block), loc); | |
9cb2517e | 1681 | else |
1682 | { | |
1683 | gcc_assert (jump_label == simple_return_rtx); | |
5da5e283 | 1684 | emit_jump_insn_after_setloc (targetm.gen_simple_return (), |
9cb2517e | 1685 | BB_END (jump_block), loc); |
9cb2517e | 1686 | } |
31a53363 | 1687 | set_return_jump_label (BB_END (jump_block)); |
b36d64df | 1688 | } |
1689 | else | |
1690 | { | |
9ed997be | 1691 | rtx_code_label *label = block_label (target); |
1d5ad681 | 1692 | emit_jump_insn_after_setloc (targetm.gen_jump (label), |
1693 | BB_END (jump_block), loc); | |
5496dbfc | 1694 | JUMP_LABEL (BB_END (jump_block)) = label; |
b36d64df | 1695 | LABEL_NUSES (label)++; |
1696 | } | |
5cc577b6 | 1697 | |
aa78dca5 | 1698 | /* We might be in cfg layout mode, and if so, the following routine will |
1699 | insert the barrier correctly. */ | |
1700 | emit_barrier_after_bb (jump_block); | |
b36d64df | 1701 | redirect_edge_succ_nodup (e, target); |
1702 | ||
498d173d | 1703 | if (abnormal_edge_flags) |
1704 | make_edge (src, target, abnormal_edge_flags); | |
1705 | ||
48e1416a | 1706 | df_mark_solutions_dirty (); |
aa78dca5 | 1707 | fixup_partition_crossing (e); |
b36d64df | 1708 | return new_bb; |
1709 | } | |
1710 | ||
1711 | /* Edge E is assumed to be fallthru edge. Emit needed jump instruction | |
1712 | (and possibly create new basic block) to make edge non-fallthru. | |
1713 | Return newly created BB or NULL if none. */ | |
5cc577b6 | 1714 | |
202bbc06 | 1715 | static basic_block |
1716 | rtl_force_nonfallthru (edge e) | |
b36d64df | 1717 | { |
9cb2517e | 1718 | return force_nonfallthru_and_redirect (e, e->dest, NULL_RTX); |
b36d64df | 1719 | } |
1720 | ||
1721 | /* Redirect edge even at the expense of creating new jump insn or | |
1722 | basic block. Return new basic block if created, NULL otherwise. | |
a53ff4c1 | 1723 | Conversion must be possible. */ |
b36d64df | 1724 | |
1026363d | 1725 | static basic_block |
4c9e08a4 | 1726 | rtl_redirect_edge_and_branch_force (edge e, basic_block target) |
b36d64df | 1727 | { |
5cc577b6 | 1728 | if (redirect_edge_and_branch (e, target) |
1729 | || e->dest == target) | |
b36d64df | 1730 | return NULL; |
1731 | ||
1732 | /* In case the edge redirection failed, try to force it to be non-fallthru | |
1733 | and redirect newly created simplejump. */ | |
3072d30e | 1734 | df_set_bb_dirty (e->src); |
9cb2517e | 1735 | return force_nonfallthru_and_redirect (e, target, NULL_RTX); |
b36d64df | 1736 | } |
1737 | ||
1738 | /* The given edge should potentially be a fallthru edge. If that is in | |
1739 | fact true, delete the jump and barriers that are in the way. */ | |
1740 | ||
5f5d4cd1 | 1741 | static void |
1742 | rtl_tidy_fallthru_edge (edge e) | |
b36d64df | 1743 | { |
3d90435a | 1744 | rtx_insn *q; |
5f5d4cd1 | 1745 | basic_block b = e->src, c = b->next_bb; |
1746 | ||
b36d64df | 1747 | /* ??? In a late-running flow pass, other folks may have deleted basic |
1748 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
442e3cb9 | 1749 | and the target label. They ought to be chastised and fixed. |
b36d64df | 1750 | |
1751 | We can also wind up with a sequence of undeletable labels between | |
1752 | one block and the next. | |
1753 | ||
1754 | So search through a sequence of barriers, labels, and notes for | |
1755 | the head of block C and assert that we really do fall through. */ | |
1756 | ||
5496dbfc | 1757 | for (q = NEXT_INSN (BB_END (b)); q != BB_HEAD (c); q = NEXT_INSN (q)) |
ac25a327 | 1758 | if (INSN_P (q)) |
1759 | return; | |
b36d64df | 1760 | |
1761 | /* Remove what will soon cease being the jump insn from the source block. | |
1762 | If block B consisted only of this single jump, turn it into a deleted | |
1763 | note. */ | |
5496dbfc | 1764 | q = BB_END (b); |
6d7dc5b9 | 1765 | if (JUMP_P (q) |
b36d64df | 1766 | && onlyjump_p (q) |
1767 | && (any_uncondjump_p (q) | |
ea091dfd | 1768 | || single_succ_p (b))) |
b36d64df | 1769 | { |
1f78217c | 1770 | rtx label; |
1771 | rtx_jump_table_data *table; | |
1772 | ||
1773 | if (tablejump_p (q, &label, &table)) | |
1774 | { | |
1775 | /* The label is likely mentioned in some instruction before | |
1776 | the tablejump and might not be DCEd, so turn it into | |
1777 | a note instead and move before the tablejump that is going to | |
1778 | be deleted. */ | |
1779 | const char *name = LABEL_NAME (label); | |
1780 | PUT_CODE (label, NOTE); | |
1781 | NOTE_KIND (label) = NOTE_INSN_DELETED_LABEL; | |
1782 | NOTE_DELETED_LABEL_NAME (label) = name; | |
1783 | rtx_insn *lab = safe_as_a <rtx_insn *> (label); | |
1784 | reorder_insns (lab, lab, PREV_INSN (q)); | |
1785 | delete_insn (table); | |
1786 | } | |
1787 | ||
b36d64df | 1788 | /* If this was a conditional jump, we need to also delete |
1789 | the insn that set cc0. */ | |
ff900b8e | 1790 | if (HAVE_cc0 && any_condjump_p (q) && only_sets_cc0_p (PREV_INSN (q))) |
b36d64df | 1791 | q = PREV_INSN (q); |
b36d64df | 1792 | |
1793 | q = PREV_INSN (q); | |
b36d64df | 1794 | } |
1795 | ||
1796 | /* Selectively unlink the sequence. */ | |
5496dbfc | 1797 | if (q != PREV_INSN (BB_HEAD (c))) |
39257eb5 | 1798 | delete_insn_chain (NEXT_INSN (q), PREV_INSN (BB_HEAD (c)), false); |
b36d64df | 1799 | |
1800 | e->flags |= EDGE_FALLTHRU; | |
1801 | } | |
b36d64df | 1802 | \f |
5f5d4cd1 | 1803 | /* Should move basic block BB after basic block AFTER. NIY. */ |
1804 | ||
1805 | static bool | |
1806 | rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED, | |
1807 | basic_block after ATTRIBUTE_UNUSED) | |
1808 | { | |
1809 | return false; | |
1810 | } | |
1811 | ||
aa78dca5 | 1812 | /* Locate the last bb in the same partition as START_BB. */ |
1813 | ||
1814 | static basic_block | |
1815 | last_bb_in_partition (basic_block start_bb) | |
1816 | { | |
1817 | basic_block bb; | |
34154e27 | 1818 | FOR_BB_BETWEEN (bb, start_bb, EXIT_BLOCK_PTR_FOR_FN (cfun), next_bb) |
aa78dca5 | 1819 | { |
1820 | if (BB_PARTITION (start_bb) != BB_PARTITION (bb->next_bb)) | |
1821 | return bb; | |
1822 | } | |
efee62d1 | 1823 | /* Return bb before the exit block. */ |
aa78dca5 | 1824 | return bb->prev_bb; |
1825 | } | |
1826 | ||
b36d64df | 1827 | /* Split a (typically critical) edge. Return the new block. |
a53ff4c1 | 1828 | The edge must not be abnormal. |
b36d64df | 1829 | |
1830 | ??? The code generally expects to be called on critical edges. | |
1831 | The case of a block ending in an unconditional jump to a | |
1832 | block with multiple predecessors is not handled optimally. */ | |
1833 | ||
9140e457 | 1834 | static basic_block |
4c9e08a4 | 1835 | rtl_split_edge (edge edge_in) |
b36d64df | 1836 | { |
aa78dca5 | 1837 | basic_block bb, new_bb; |
3d90435a | 1838 | rtx_insn *before; |
b36d64df | 1839 | |
1840 | /* Abnormal edges cannot be split. */ | |
cc636d56 | 1841 | gcc_assert (!(edge_in->flags & EDGE_ABNORMAL)); |
b36d64df | 1842 | |
1843 | /* We are going to place the new block in front of edge destination. | |
4a82352a | 1844 | Avoid existence of fallthru predecessors. */ |
b36d64df | 1845 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) |
1846 | { | |
7f58c05e | 1847 | edge e = find_fallthru_edge (edge_in->dest->preds); |
b36d64df | 1848 | |
1849 | if (e) | |
1850 | force_nonfallthru (e); | |
1851 | } | |
1852 | ||
588aadb7 | 1853 | /* Create the basic block note. */ |
34154e27 | 1854 | if (edge_in->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
5496dbfc | 1855 | before = BB_HEAD (edge_in->dest); |
b36d64df | 1856 | else |
3d90435a | 1857 | before = NULL; |
b36d64df | 1858 | |
9bb8a4af | 1859 | /* If this is a fall through edge to the exit block, the blocks might be |
0a55d497 | 1860 | not adjacent, and the right place is after the source. */ |
34154e27 | 1861 | if ((edge_in->flags & EDGE_FALLTHRU) |
1862 | && edge_in->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
9bb8a4af | 1863 | { |
1864 | before = NEXT_INSN (BB_END (edge_in->src)); | |
9bb8a4af | 1865 | bb = create_basic_block (before, NULL, edge_in->src); |
7562ed74 | 1866 | BB_COPY_PARTITION (bb, edge_in->src); |
9bb8a4af | 1867 | } |
1868 | else | |
065efcb1 | 1869 | { |
34154e27 | 1870 | if (edge_in->src == ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
aa78dca5 | 1871 | { |
1872 | bb = create_basic_block (before, NULL, edge_in->dest->prev_bb); | |
1873 | BB_COPY_PARTITION (bb, edge_in->dest); | |
1874 | } | |
1875 | else | |
1876 | { | |
1877 | basic_block after = edge_in->dest->prev_bb; | |
1878 | /* If this is post-bb reordering, and the edge crosses a partition | |
1879 | boundary, the new block needs to be inserted in the bb chain | |
1880 | at the end of the src partition (since we put the new bb into | |
1881 | that partition, see below). Otherwise we may end up creating | |
1882 | an extra partition crossing in the chain, which is illegal. | |
1883 | It can't go after the src, because src may have a fall-through | |
1884 | to a different block. */ | |
1885 | if (crtl->bb_reorder_complete | |
1886 | && (edge_in->flags & EDGE_CROSSING)) | |
1887 | { | |
1888 | after = last_bb_in_partition (edge_in->src); | |
33a2aaa4 | 1889 | before = get_last_bb_insn (after); |
aa78dca5 | 1890 | /* The instruction following the last bb in partition should |
1891 | be a barrier, since it cannot end in a fall-through. */ | |
1892 | gcc_checking_assert (BARRIER_P (before)); | |
1893 | before = NEXT_INSN (before); | |
1894 | } | |
1895 | bb = create_basic_block (before, NULL, after); | |
1896 | /* Put the split bb into the src partition, to avoid creating | |
1897 | a situation where a cold bb dominates a hot bb, in the case | |
1898 | where src is cold and dest is hot. The src will dominate | |
1899 | the new bb (whereas it might not have dominated dest). */ | |
1900 | BB_COPY_PARTITION (bb, edge_in->src); | |
1901 | } | |
065efcb1 | 1902 | } |
b36d64df | 1903 | |
805e22b2 | 1904 | make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU); |
b36d64df | 1905 | |
aa78dca5 | 1906 | /* Can't allow a region crossing edge to be fallthrough. */ |
1907 | if (BB_PARTITION (bb) != BB_PARTITION (edge_in->dest) | |
34154e27 | 1908 | && edge_in->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
aa78dca5 | 1909 | { |
1910 | new_bb = force_nonfallthru (single_succ_edge (bb)); | |
1911 | gcc_assert (!new_bb); | |
1912 | } | |
1913 | ||
917bbcab | 1914 | /* For non-fallthru edges, we must adjust the predecessor's |
b36d64df | 1915 | jump instruction to target our new block. */ |
1916 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1917 | { | |
cc636d56 | 1918 | edge redirected = redirect_edge_and_branch (edge_in, bb); |
1919 | gcc_assert (redirected); | |
b36d64df | 1920 | } |
1921 | else | |
dcb172b4 | 1922 | { |
34154e27 | 1923 | if (edge_in->src != ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
dcb172b4 | 1924 | { |
1925 | /* For asm goto even splitting of fallthru edge might | |
1926 | need insn patching, as other labels might point to the | |
1927 | old label. */ | |
3d90435a | 1928 | rtx_insn *last = BB_END (edge_in->src); |
dcb172b4 | 1929 | if (last |
1930 | && JUMP_P (last) | |
34154e27 | 1931 | && edge_in->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) |
dcb172b4 | 1932 | && extract_asm_operands (PATTERN (last)) != NULL_RTX |
1933 | && patch_jump_insn (last, before, bb)) | |
1934 | df_set_bb_dirty (edge_in->src); | |
1935 | } | |
1936 | redirect_edge_succ (edge_in, bb); | |
1937 | } | |
b36d64df | 1938 | |
1939 | return bb; | |
1940 | } | |
1941 | ||
1942 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1943 | The new instructions and basic blocks (if any) will not appear in the | |
1944 | CFG until commit_edge_insertions is called. */ | |
1945 | ||
1946 | void | |
4c9e08a4 | 1947 | insert_insn_on_edge (rtx pattern, edge e) |
b36d64df | 1948 | { |
1949 | /* We cannot insert instructions on an abnormal critical edge. | |
1950 | It will be easier to find the culprit if we die now. */ | |
cc636d56 | 1951 | gcc_assert (!((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e))); |
b36d64df | 1952 | |
4ee9c684 | 1953 | if (e->insns.r == NULL_RTX) |
b36d64df | 1954 | start_sequence (); |
1955 | else | |
4ee9c684 | 1956 | push_to_sequence (e->insns.r); |
b36d64df | 1957 | |
1958 | emit_insn (pattern); | |
1959 | ||
4ee9c684 | 1960 | e->insns.r = get_insns (); |
b36d64df | 1961 | end_sequence (); |
1962 | } | |
1963 | ||
1964 | /* Update the CFG for the instructions queued on edge E. */ | |
1965 | ||
a8dd994c | 1966 | void |
ca462ec0 | 1967 | commit_one_edge_insertion (edge e) |
b36d64df | 1968 | { |
3d90435a | 1969 | rtx_insn *before = NULL, *after = NULL, *insns, *tmp, *last; |
53105d88 | 1970 | basic_block bb; |
b36d64df | 1971 | |
1972 | /* Pull the insns off the edge now since the edge might go away. */ | |
ae5e6486 | 1973 | insns = e->insns.r; |
1974 | e->insns.r = NULL; | |
b36d64df | 1975 | |
53105d88 | 1976 | /* Figure out where to put these insns. If the destination has |
1977 | one predecessor, insert there. Except for the exit block. */ | |
34154e27 | 1978 | if (single_pred_p (e->dest) && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
b36d64df | 1979 | { |
53105d88 | 1980 | bb = e->dest; |
1981 | ||
1982 | /* Get the location correct wrt a code label, and "nice" wrt | |
1983 | a basic block note, and before everything else. */ | |
1984 | tmp = BB_HEAD (bb); | |
1985 | if (LABEL_P (tmp)) | |
1986 | tmp = NEXT_INSN (tmp); | |
1987 | if (NOTE_INSN_BASIC_BLOCK_P (tmp)) | |
1988 | tmp = NEXT_INSN (tmp); | |
1989 | if (tmp == BB_HEAD (bb)) | |
1990 | before = tmp; | |
1991 | else if (tmp) | |
1992 | after = PREV_INSN (tmp); | |
1993 | else | |
1994 | after = get_last_insn (); | |
1995 | } | |
fb20d6fa | 1996 | |
53105d88 | 1997 | /* If the source has one successor and the edge is not abnormal, |
8315fc61 | 1998 | insert there. Except for the entry block. |
1999 | Don't do this if the predecessor ends in a jump other than | |
2000 | unconditional simple jump. E.g. for asm goto that points all | |
2001 | its labels at the fallthru basic block, we can't insert instructions | |
2002 | before the asm goto, as the asm goto can have various of side effects, | |
2003 | and can't emit instructions after the asm goto, as it must end | |
2004 | the basic block. */ | |
53105d88 | 2005 | else if ((e->flags & EDGE_ABNORMAL) == 0 |
2006 | && single_succ_p (e->src) | |
34154e27 | 2007 | && e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
8315fc61 | 2008 | && (!JUMP_P (BB_END (e->src)) |
2009 | || simplejump_p (BB_END (e->src)))) | |
53105d88 | 2010 | { |
2011 | bb = e->src; | |
fb20d6fa | 2012 | |
53105d88 | 2013 | /* It is possible to have a non-simple jump here. Consider a target |
2014 | where some forms of unconditional jumps clobber a register. This | |
2015 | happens on the fr30 for example. | |
b36d64df | 2016 | |
53105d88 | 2017 | We know this block has a single successor, so we can just emit |
2018 | the queued insns before the jump. */ | |
2019 | if (JUMP_P (BB_END (bb))) | |
2020 | before = BB_END (bb); | |
fb20d6fa | 2021 | else |
2022 | { | |
53105d88 | 2023 | /* We'd better be fallthru, or we've lost track of what's what. */ |
2024 | gcc_assert (e->flags & EDGE_FALLTHRU); | |
4f18499c | 2025 | |
53105d88 | 2026 | after = BB_END (bb); |
b36d64df | 2027 | } |
2028 | } | |
2029 | ||
53105d88 | 2030 | /* Otherwise we must split the edge. */ |
2031 | else | |
2032 | { | |
2033 | bb = split_edge (e); | |
aa78dca5 | 2034 | |
2035 | /* If E crossed a partition boundary, we needed to make bb end in | |
2036 | a region-crossing jump, even though it was originally fallthru. */ | |
2037 | if (JUMP_P (BB_END (bb))) | |
2038 | before = BB_END (bb); | |
2039 | else | |
2040 | after = BB_END (bb); | |
53105d88 | 2041 | } |
2042 | ||
2043 | /* Now that we've found the spot, do the insertion. */ | |
b36d64df | 2044 | if (before) |
2045 | { | |
3072d30e | 2046 | emit_insn_before_noloc (insns, before, bb); |
b36d64df | 2047 | last = prev_nonnote_insn (before); |
2048 | } | |
2049 | else | |
3072d30e | 2050 | last = emit_insn_after_noloc (insns, after, bb); |
b36d64df | 2051 | |
2052 | if (returnjump_p (last)) | |
2053 | { | |
2054 | /* ??? Remove all outgoing edges from BB and add one for EXIT. | |
a0c938f0 | 2055 | This is not currently a problem because this only happens |
2056 | for the (single) epilogue, which already has a fallthru edge | |
2057 | to EXIT. */ | |
b36d64df | 2058 | |
ea091dfd | 2059 | e = single_succ_edge (bb); |
34154e27 | 2060 | gcc_assert (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) |
ea091dfd | 2061 | && single_succ_p (bb) && (e->flags & EDGE_FALLTHRU)); |
b36d64df | 2062 | |
5cc577b6 | 2063 | e->flags &= ~EDGE_FALLTHRU; |
b36d64df | 2064 | emit_barrier_after (last); |
b3d6de89 | 2065 | |
b36d64df | 2066 | if (before) |
2067 | delete_insn (before); | |
2068 | } | |
cc636d56 | 2069 | else |
2070 | gcc_assert (!JUMP_P (last)); | |
b36d64df | 2071 | } |
2072 | ||
2073 | /* Update the CFG for all queued instructions. */ | |
2074 | ||
2075 | void | |
4c9e08a4 | 2076 | commit_edge_insertions (void) |
b36d64df | 2077 | { |
b36d64df | 2078 | basic_block bb; |
2079 | ||
80adc5a6 | 2080 | /* Optimization passes that invoke this routine can cause hot blocks |
2081 | previously reached by both hot and cold blocks to become dominated only | |
2082 | by cold blocks. This will cause the verification below to fail, | |
2083 | and lead to now cold code in the hot section. In some cases this | |
2084 | may only be visible after newly unreachable blocks are deleted, | |
2085 | which will be done by fixup_partitions. */ | |
2086 | fixup_partitions (); | |
2087 | ||
382ecba7 | 2088 | checking_verify_flow_info (); |
b36d64df | 2089 | |
34154e27 | 2090 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (cfun), |
2091 | EXIT_BLOCK_PTR_FOR_FN (cfun), next_bb) | |
b36d64df | 2092 | { |
cd665a06 | 2093 | edge e; |
2094 | edge_iterator ei; | |
b36d64df | 2095 | |
cd665a06 | 2096 | FOR_EACH_EDGE (e, ei, bb->succs) |
2097 | if (e->insns.r) | |
202bbc06 | 2098 | commit_one_edge_insertion (e); |
fb20d6fa | 2099 | } |
b36d64df | 2100 | } |
2101 | \f | |
3072d30e | 2102 | |
5f5d4cd1 | 2103 | /* Print out RTL-specific basic block information (live information |
5147ec07 | 2104 | at start and end with TDF_DETAILS). FLAGS are the TDF_* masks |
2105 | documented in dumpfile.h. */ | |
b36d64df | 2106 | |
028f8cc7 | 2107 | static void |
5147ec07 | 2108 | rtl_dump_bb (FILE *outf, basic_block bb, int indent, int flags) |
b36d64df | 2109 | { |
3d90435a | 2110 | rtx_insn *insn; |
2111 | rtx_insn *last; | |
5f5d4cd1 | 2112 | char *s_indent; |
b36d64df | 2113 | |
f780cc25 | 2114 | s_indent = (char *) alloca ((size_t) indent + 1); |
4acc30e5 | 2115 | memset (s_indent, ' ', (size_t) indent); |
5f5d4cd1 | 2116 | s_indent[indent] = '\0'; |
48e1416a | 2117 | |
5147ec07 | 2118 | if (df && (flags & TDF_DETAILS)) |
3072d30e | 2119 | { |
2120 | df_dump_top (bb, outf); | |
2121 | putc ('\n', outf); | |
2122 | } | |
b36d64df | 2123 | |
4c2112a3 | 2124 | if (bb->index != ENTRY_BLOCK && bb->index != EXIT_BLOCK) |
2125 | for (insn = BB_HEAD (bb), last = NEXT_INSN (BB_END (bb)); insn != last; | |
2126 | insn = NEXT_INSN (insn)) | |
5147ec07 | 2127 | { |
ea9538fb | 2128 | if (flags & TDF_DETAILS) |
2129 | df_dump_insn_top (insn, outf); | |
5147ec07 | 2130 | if (! (flags & TDF_SLIM)) |
2131 | print_rtl_single (outf, insn); | |
2132 | else | |
2133 | dump_insn_slim (outf, insn); | |
ea9538fb | 2134 | if (flags & TDF_DETAILS) |
2135 | df_dump_insn_bottom (insn, outf); | |
5147ec07 | 2136 | } |
2137 | ||
2138 | if (df && (flags & TDF_DETAILS)) | |
3072d30e | 2139 | { |
2140 | df_dump_bottom (bb, outf); | |
2141 | putc ('\n', outf); | |
2142 | } | |
2143 | ||
b36d64df | 2144 | } |
2145 | \f | |
bec2cf98 | 2146 | /* Like dump_function_to_file, but for RTL. Print out dataflow information |
2147 | for the start of each basic block. FLAGS are the TDF_* masks documented | |
2148 | in dumpfile.h. */ | |
b36d64df | 2149 | |
2150 | void | |
e149ca56 | 2151 | print_rtl_with_bb (FILE *outf, const rtx_insn *rtx_first, int flags) |
b36d64df | 2152 | { |
e149ca56 | 2153 | const rtx_insn *tmp_rtx; |
b36d64df | 2154 | if (rtx_first == 0) |
2155 | fprintf (outf, "(nil)\n"); | |
2156 | else | |
2157 | { | |
b36d64df | 2158 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
2159 | int max_uid = get_max_uid (); | |
4c36ffe6 | 2160 | basic_block *start = XCNEWVEC (basic_block, max_uid); |
2161 | basic_block *end = XCNEWVEC (basic_block, max_uid); | |
2162 | enum bb_state *in_bb_p = XCNEWVEC (enum bb_state, max_uid); | |
4c26117a | 2163 | basic_block bb; |
2164 | ||
bec2cf98 | 2165 | /* After freeing the CFG, we still have BLOCK_FOR_INSN set on most |
2166 | insns, but the CFG is not maintained so the basic block info | |
2167 | is not reliable. Therefore it's omitted from the dumps. */ | |
2168 | if (! (cfun->curr_properties & PROP_cfg)) | |
2169 | flags &= ~TDF_BLOCKS; | |
2170 | ||
3072d30e | 2171 | if (df) |
2172 | df_dump_start (outf); | |
2173 | ||
bec2cf98 | 2174 | if (flags & TDF_BLOCKS) |
b36d64df | 2175 | { |
7a46197b | 2176 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
b36d64df | 2177 | { |
3d90435a | 2178 | rtx_insn *x; |
bec2cf98 | 2179 | |
2180 | start[INSN_UID (BB_HEAD (bb))] = bb; | |
2181 | end[INSN_UID (BB_END (bb))] = bb; | |
2182 | for (x = BB_HEAD (bb); x != NULL_RTX; x = NEXT_INSN (x)) | |
2183 | { | |
2184 | enum bb_state state = IN_MULTIPLE_BB; | |
5cc577b6 | 2185 | |
bec2cf98 | 2186 | if (in_bb_p[INSN_UID (x)] == NOT_IN_BB) |
2187 | state = IN_ONE_BB; | |
2188 | in_bb_p[INSN_UID (x)] = state; | |
b36d64df | 2189 | |
bec2cf98 | 2190 | if (x == BB_END (bb)) |
2191 | break; | |
2192 | } | |
b36d64df | 2193 | } |
2194 | } | |
2195 | ||
2196 | for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) | |
2197 | { | |
bec2cf98 | 2198 | if (flags & TDF_BLOCKS) |
2199 | { | |
2200 | bb = start[INSN_UID (tmp_rtx)]; | |
2201 | if (bb != NULL) | |
2202 | { | |
2203 | dump_bb_info (outf, bb, 0, dump_flags | TDF_COMMENT, true, false); | |
2204 | if (df && (flags & TDF_DETAILS)) | |
2205 | df_dump_top (bb, outf); | |
2206 | } | |
b36d64df | 2207 | |
bec2cf98 | 2208 | if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB |
2209 | && !NOTE_P (tmp_rtx) | |
2210 | && !BARRIER_P (tmp_rtx)) | |
2211 | fprintf (outf, ";; Insn is not within a basic block\n"); | |
2212 | else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB) | |
2213 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); | |
2214 | } | |
b36d64df | 2215 | |
ea9538fb | 2216 | if (flags & TDF_DETAILS) |
2217 | df_dump_insn_top (tmp_rtx, outf); | |
5147ec07 | 2218 | if (! (flags & TDF_SLIM)) |
2219 | print_rtl_single (outf, tmp_rtx); | |
2220 | else | |
2221 | dump_insn_slim (outf, tmp_rtx); | |
ea9538fb | 2222 | if (flags & TDF_DETAILS) |
2223 | df_dump_insn_bottom (tmp_rtx, outf); | |
b36d64df | 2224 | |
bec2cf98 | 2225 | if (flags & TDF_BLOCKS) |
2226 | { | |
2227 | bb = end[INSN_UID (tmp_rtx)]; | |
2228 | if (bb != NULL) | |
2229 | { | |
2230 | dump_bb_info (outf, bb, 0, dump_flags | TDF_COMMENT, false, true); | |
2231 | if (df && (flags & TDF_DETAILS)) | |
2232 | df_dump_bottom (bb, outf); | |
a30975d4 | 2233 | putc ('\n', outf); |
bec2cf98 | 2234 | } |
2235 | } | |
b36d64df | 2236 | } |
2237 | ||
2238 | free (start); | |
2239 | free (end); | |
2240 | free (in_bb_p); | |
2241 | } | |
b36d64df | 2242 | } |
2243 | \f | |
4a020a8c | 2244 | /* Update the branch probability of BB if a REG_BR_PROB is present. */ |
2245 | ||
f884e43f | 2246 | void |
4c9e08a4 | 2247 | update_br_prob_note (basic_block bb) |
f884e43f | 2248 | { |
2249 | rtx note; | |
6d7dc5b9 | 2250 | if (!JUMP_P (BB_END (bb))) |
f884e43f | 2251 | return; |
5496dbfc | 2252 | note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX); |
9eb946de | 2253 | if (!note || XINT (note, 0) == BRANCH_EDGE (bb)->probability) |
f884e43f | 2254 | return; |
9eb946de | 2255 | XINT (note, 0) = BRANCH_EDGE (bb)->probability; |
f884e43f | 2256 | } |
5d65a39c | 2257 | |
2258 | /* Get the last insn associated with block BB (that includes barriers and | |
2259 | tablejumps after BB). */ | |
2d63955f | 2260 | rtx_insn * |
5d65a39c | 2261 | get_last_bb_insn (basic_block bb) |
2262 | { | |
c86d86ff | 2263 | rtx_jump_table_data *table; |
2d63955f | 2264 | rtx_insn *tmp; |
2265 | rtx_insn *end = BB_END (bb); | |
5d65a39c | 2266 | |
2267 | /* Include any jump table following the basic block. */ | |
c86d86ff | 2268 | if (tablejump_p (end, NULL, &table)) |
2269 | end = table; | |
5d65a39c | 2270 | |
2271 | /* Include any barriers that may follow the basic block. */ | |
c4d13c5c | 2272 | tmp = next_nonnote_insn_bb (end); |
5d65a39c | 2273 | while (tmp && BARRIER_P (tmp)) |
2274 | { | |
2275 | end = tmp; | |
c4d13c5c | 2276 | tmp = next_nonnote_insn_bb (end); |
5d65a39c | 2277 | } |
2278 | ||
2279 | return end; | |
2280 | } | |
812ca88e | 2281 | |
80adc5a6 | 2282 | /* Sanity check partition hotness to ensure that basic blocks in |
2283 | Â the cold partition don't dominate basic blocks in the hot partition. | |
2284 | If FLAG_ONLY is true, report violations as errors. Otherwise | |
2285 | re-mark the dominated blocks as cold, since this is run after | |
2286 | cfg optimizations that may make hot blocks previously reached | |
2287 | by both hot and cold blocks now only reachable along cold paths. */ | |
2288 | ||
2289 | static vec<basic_block> | |
2290 | find_partition_fixes (bool flag_only) | |
2291 | { | |
2292 | basic_block bb; | |
2293 | vec<basic_block> bbs_in_cold_partition = vNULL; | |
2294 | vec<basic_block> bbs_to_fix = vNULL; | |
2295 | ||
2296 | /* Callers check this. */ | |
2297 | gcc_checking_assert (crtl->has_bb_partition); | |
2298 | ||
fc00614f | 2299 | FOR_EACH_BB_FN (bb, cfun) |
80adc5a6 | 2300 | if ((BB_PARTITION (bb) == BB_COLD_PARTITION)) |
2301 | bbs_in_cold_partition.safe_push (bb); | |
2302 | ||
2303 | if (bbs_in_cold_partition.is_empty ()) | |
2304 | return vNULL; | |
2305 | ||
2306 | bool dom_calculated_here = !dom_info_available_p (CDI_DOMINATORS); | |
2307 | ||
2308 | if (dom_calculated_here) | |
2309 | calculate_dominance_info (CDI_DOMINATORS); | |
2310 | ||
2311 | while (! bbs_in_cold_partition.is_empty ()) | |
2312 | { | |
2313 | bb = bbs_in_cold_partition.pop (); | |
2314 | /* Any blocks dominated by a block in the cold section | |
2315 | must also be cold. */ | |
2316 | basic_block son; | |
2317 | for (son = first_dom_son (CDI_DOMINATORS, bb); | |
2318 | son; | |
2319 | son = next_dom_son (CDI_DOMINATORS, son)) | |
2320 | { | |
2321 | /* If son is not yet cold, then mark it cold here and | |
2322 | enqueue it for further processing. */ | |
2323 | if ((BB_PARTITION (son) != BB_COLD_PARTITION)) | |
2324 | { | |
2325 | if (flag_only) | |
2326 | error ("non-cold basic block %d dominated " | |
2327 | "by a block in the cold partition (%d)", son->index, bb->index); | |
2328 | else | |
2329 | BB_SET_PARTITION (son, BB_COLD_PARTITION); | |
2330 | bbs_to_fix.safe_push (son); | |
2331 | bbs_in_cold_partition.safe_push (son); | |
2332 | } | |
2333 | } | |
2334 | } | |
2335 | ||
2336 | if (dom_calculated_here) | |
2337 | free_dominance_info (CDI_DOMINATORS); | |
2338 | ||
2339 | return bbs_to_fix; | |
2340 | } | |
2341 | ||
2342 | /* Perform cleanup on the hot/cold bb partitioning after optimization | |
2343 | passes that modify the cfg. */ | |
2344 | ||
2345 | void | |
2346 | fixup_partitions (void) | |
2347 | { | |
2348 | basic_block bb; | |
2349 | ||
2350 | if (!crtl->has_bb_partition) | |
2351 | return; | |
2352 | ||
2353 | /* Delete any blocks that became unreachable and weren't | |
2354 | already cleaned up, for example during edge forwarding | |
2355 | and convert_jumps_to_returns. This will expose more | |
2356 | opportunities for fixing the partition boundaries here. | |
2357 | Also, the calculation of the dominance graph during verification | |
2358 | will assert if there are unreachable nodes. */ | |
2359 | delete_unreachable_blocks (); | |
2360 | ||
2361 | /* If there are partitions, do a sanity check on them: A basic block in | |
2362 | Â a cold partition cannot dominate a basic block in a hot partition. | |
2363 | Fixup any that now violate this requirement, as a result of edge | |
2364 | forwarding and unreachable block deletion. Â */ | |
2365 | vec<basic_block> bbs_to_fix = find_partition_fixes (false); | |
2366 | ||
2367 | /* Do the partition fixup after all necessary blocks have been converted to | |
2368 | cold, so that we only update the region crossings the minimum number of | |
2369 | places, which can require forcing edges to be non fallthru. */ | |
2370 | while (! bbs_to_fix.is_empty ()) | |
2371 | { | |
2372 | bb = bbs_to_fix.pop (); | |
2373 | fixup_new_cold_bb (bb); | |
2374 | } | |
2375 | } | |
2376 | ||
812ca88e | 2377 | /* Verify, in the basic block chain, that there is at most one switch |
2378 | between hot/cold partitions. This condition will not be true until | |
2379 | after reorder_basic_blocks is called. */ | |
2380 | ||
4bf32a77 | 2381 | static int |
812ca88e | 2382 | verify_hot_cold_block_grouping (void) |
2383 | { | |
2384 | basic_block bb; | |
2385 | int err = 0; | |
2386 | bool switched_sections = false; | |
2387 | int current_partition = BB_UNPARTITIONED; | |
2388 | ||
aa78dca5 | 2389 | /* Even after bb reordering is complete, we go into cfglayout mode |
2390 | again (in compgoto). Ensure we don't call this before going back | |
2391 | into linearized RTL when any layout fixes would have been committed. */ | |
2392 | if (!crtl->bb_reorder_complete | |
9af5ce0c | 2393 | || current_ir_type () != IR_RTL_CFGRTL) |
4bf32a77 | 2394 | return err; |
812ca88e | 2395 | |
fc00614f | 2396 | FOR_EACH_BB_FN (bb, cfun) |
812ca88e | 2397 | { |
2398 | if (current_partition != BB_UNPARTITIONED | |
2399 | && BB_PARTITION (bb) != current_partition) | |
2400 | { | |
2401 | if (switched_sections) | |
2402 | { | |
2403 | error ("multiple hot/cold transitions found (bb %i)", | |
2404 | bb->index); | |
2405 | err = 1; | |
2406 | } | |
2407 | else | |
2408 | switched_sections = true; | |
2409 | ||
2410 | if (!crtl->has_bb_partition) | |
2411 | error ("partition found but function partition flag not set"); | |
2412 | } | |
2413 | current_partition = BB_PARTITION (bb); | |
2414 | } | |
2415 | ||
4bf32a77 | 2416 | return err; |
812ca88e | 2417 | } |
f884e43f | 2418 | \f |
b36d64df | 2419 | |
4bf32a77 | 2420 | /* Perform several checks on the edges out of each block, such as |
2421 | the consistency of the branch probabilities, the correctness | |
2422 | of hot/cold partition crossing edges, and the number of expected | |
80adc5a6 | 2423 | successor edges. Also verify that the dominance relationship |
2424 | between hot/cold blocks is sane. */ | |
5f5d4cd1 | 2425 | |
028f8cc7 | 2426 | static int |
4bf32a77 | 2427 | rtl_verify_edges (void) |
b36d64df | 2428 | { |
028f8cc7 | 2429 | int err = 0; |
d207f783 | 2430 | basic_block bb; |
b36d64df | 2431 | |
7a46197b | 2432 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
b36d64df | 2433 | { |
103dfb10 | 2434 | int n_fallthru = 0, n_branch = 0, n_abnormal_call = 0, n_sibcall = 0; |
2435 | int n_eh = 0, n_abnormal = 0; | |
e6261ab0 | 2436 | edge e, fallthru = NULL; |
cd665a06 | 2437 | edge_iterator ei; |
4bf32a77 | 2438 | rtx note; |
aa78dca5 | 2439 | bool has_crossing_edge = false; |
b36d64df | 2440 | |
e6d1500f | 2441 | if (JUMP_P (BB_END (bb)) |
5496dbfc | 2442 | && (note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX)) |
cd665a06 | 2443 | && EDGE_COUNT (bb->succs) >= 2 |
5496dbfc | 2444 | && any_condjump_p (BB_END (bb))) |
a2e42321 | 2445 | { |
9eb946de | 2446 | if (XINT (note, 0) != BRANCH_EDGE (bb)->probability |
f26d8580 | 2447 | && profile_status_for_fn (cfun) != PROFILE_ABSENT) |
a2e42321 | 2448 | { |
9eb946de | 2449 | error ("verify_flow_info: REG_BR_PROB does not match cfg %i %i", |
2450 | XINT (note, 0), BRANCH_EDGE (bb)->probability); | |
a2e42321 | 2451 | err = 1; |
2452 | } | |
2453 | } | |
4bf32a77 | 2454 | |
cd665a06 | 2455 | FOR_EACH_EDGE (e, ei, bb->succs) |
b36d64df | 2456 | { |
f59cbcbf | 2457 | bool is_crossing; |
2458 | ||
b36d64df | 2459 | if (e->flags & EDGE_FALLTHRU) |
f59cbcbf | 2460 | n_fallthru++, fallthru = e; |
2461 | ||
2462 | is_crossing = (BB_PARTITION (e->src) != BB_PARTITION (e->dest) | |
34154e27 | 2463 | && e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
2464 | && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)); | |
aa78dca5 | 2465 | has_crossing_edge |= is_crossing; |
f59cbcbf | 2466 | if (e->flags & EDGE_CROSSING) |
4f18499c | 2467 | { |
f59cbcbf | 2468 | if (!is_crossing) |
2469 | { | |
2470 | error ("EDGE_CROSSING incorrectly set across same section"); | |
2471 | err = 1; | |
2472 | } | |
2473 | if (e->flags & EDGE_FALLTHRU) | |
2474 | { | |
103dfb10 | 2475 | error ("fallthru edge crosses section boundary in bb %i", |
4f18499c | 2476 | e->src->index); |
2477 | err = 1; | |
2478 | } | |
f59cbcbf | 2479 | if (e->flags & EDGE_EH) |
2480 | { | |
103dfb10 | 2481 | error ("EH edge crosses section boundary in bb %i", |
f59cbcbf | 2482 | e->src->index); |
2483 | err = 1; | |
2484 | } | |
8f869004 | 2485 | if (JUMP_P (BB_END (bb)) && !CROSSING_JUMP_P (BB_END (bb))) |
aa78dca5 | 2486 | { |
2487 | error ("No region crossing jump at section boundary in bb %i", | |
2488 | bb->index); | |
2489 | err = 1; | |
2490 | } | |
f59cbcbf | 2491 | } |
2492 | else if (is_crossing) | |
2493 | { | |
2494 | error ("EDGE_CROSSING missing across section boundary"); | |
2495 | err = 1; | |
4f18499c | 2496 | } |
fb20d6fa | 2497 | |
7f42fe24 | 2498 | if ((e->flags & ~(EDGE_DFS_BACK |
2499 | | EDGE_CAN_FALLTHRU | |
2500 | | EDGE_IRREDUCIBLE_LOOP | |
f50b5bd0 | 2501 | | EDGE_LOOP_EXIT |
acc48fa6 | 2502 | | EDGE_CROSSING |
2503 | | EDGE_PRESERVE)) == 0) | |
fb20d6fa | 2504 | n_branch++; |
2505 | ||
2506 | if (e->flags & EDGE_ABNORMAL_CALL) | |
103dfb10 | 2507 | n_abnormal_call++; |
2508 | ||
2509 | if (e->flags & EDGE_SIBCALL) | |
2510 | n_sibcall++; | |
fb20d6fa | 2511 | |
2512 | if (e->flags & EDGE_EH) | |
2513 | n_eh++; | |
103dfb10 | 2514 | |
2515 | if (e->flags & EDGE_ABNORMAL) | |
fb20d6fa | 2516 | n_abnormal++; |
b36d64df | 2517 | } |
5cc577b6 | 2518 | |
aa78dca5 | 2519 | if (!has_crossing_edge |
8f869004 | 2520 | && JUMP_P (BB_END (bb)) |
2521 | && CROSSING_JUMP_P (BB_END (bb))) | |
aa78dca5 | 2522 | { |
2523 | print_rtl_with_bb (stderr, get_insns (), TDF_RTL | TDF_BLOCKS | TDF_DETAILS); | |
2524 | error ("Region crossing jump across same section in bb %i", | |
2525 | bb->index); | |
2526 | err = 1; | |
2527 | } | |
2528 | ||
e38def9c | 2529 | if (n_eh && !find_reg_note (BB_END (bb), REG_EH_REGION, NULL_RTX)) |
fb20d6fa | 2530 | { |
103dfb10 | 2531 | error ("missing REG_EH_REGION note at the end of bb %i", bb->index); |
fb20d6fa | 2532 | err = 1; |
2533 | } | |
e38def9c | 2534 | if (n_eh > 1) |
2535 | { | |
103dfb10 | 2536 | error ("too many exception handling edges in bb %i", bb->index); |
e38def9c | 2537 | err = 1; |
2538 | } | |
fb20d6fa | 2539 | if (n_branch |
6d7dc5b9 | 2540 | && (!JUMP_P (BB_END (bb)) |
5496dbfc | 2541 | || (n_branch > 1 && (any_uncondjump_p (BB_END (bb)) |
2542 | || any_condjump_p (BB_END (bb)))))) | |
fb20d6fa | 2543 | { |
0a81f5a0 | 2544 | error ("too many outgoing branch edges from bb %i", bb->index); |
fb20d6fa | 2545 | err = 1; |
2546 | } | |
5496dbfc | 2547 | if (n_fallthru && any_uncondjump_p (BB_END (bb))) |
fb20d6fa | 2548 | { |
103dfb10 | 2549 | error ("fallthru edge after unconditional jump in bb %i", bb->index); |
fb20d6fa | 2550 | err = 1; |
2551 | } | |
5496dbfc | 2552 | if (n_branch != 1 && any_uncondjump_p (BB_END (bb))) |
fb20d6fa | 2553 | { |
103dfb10 | 2554 | error ("wrong number of branch edges after unconditional jump" |
2555 | " in bb %i", bb->index); | |
fb20d6fa | 2556 | err = 1; |
2557 | } | |
5496dbfc | 2558 | if (n_branch != 1 && any_condjump_p (BB_END (bb)) |
8345ac1a | 2559 | && JUMP_LABEL (BB_END (bb)) != BB_HEAD (fallthru->dest)) |
fb20d6fa | 2560 | { |
103dfb10 | 2561 | error ("wrong amount of branch edges after conditional jump" |
2562 | " in bb %i", bb->index); | |
2563 | err = 1; | |
2564 | } | |
2565 | if (n_abnormal_call && !CALL_P (BB_END (bb))) | |
2566 | { | |
2567 | error ("abnormal call edges for non-call insn in bb %i", bb->index); | |
fb20d6fa | 2568 | err = 1; |
2569 | } | |
103dfb10 | 2570 | if (n_sibcall && !CALL_P (BB_END (bb))) |
fb20d6fa | 2571 | { |
103dfb10 | 2572 | error ("sibcall edges for non-call insn in bb %i", bb->index); |
fb20d6fa | 2573 | err = 1; |
2574 | } | |
103dfb10 | 2575 | if (n_abnormal > n_eh |
2576 | && !(CALL_P (BB_END (bb)) | |
2577 | && n_abnormal == n_abnormal_call + n_sibcall) | |
6d7dc5b9 | 2578 | && (!JUMP_P (BB_END (bb)) |
5496dbfc | 2579 | || any_condjump_p (BB_END (bb)) |
2580 | || any_uncondjump_p (BB_END (bb)))) | |
fb20d6fa | 2581 | { |
0a81f5a0 | 2582 | error ("abnormal edges for no purpose in bb %i", bb->index); |
fb20d6fa | 2583 | err = 1; |
2584 | } | |
4bf32a77 | 2585 | } |
db34a109 | 2586 | |
80adc5a6 | 2587 | /* If there are partitions, do a sanity check on them: A basic block in |
2588 | Â a cold partition cannot dominate a basic block in a hot partition. Â */ | |
2589 | if (crtl->has_bb_partition && !err) | |
2590 | { | |
2591 | vec<basic_block> bbs_to_fix = find_partition_fixes (true); | |
2592 | err = !bbs_to_fix.is_empty (); | |
2593 | } | |
2594 | ||
4bf32a77 | 2595 | /* Clean up. */ |
2596 | return err; | |
2597 | } | |
5cc577b6 | 2598 | |
4bf32a77 | 2599 | /* Checks on the instructions within blocks. Currently checks that each |
2600 | block starts with a basic block note, and that basic block notes and | |
2601 | control flow jumps are not found in the middle of the block. */ | |
b36d64df | 2602 | |
4bf32a77 | 2603 | static int |
2604 | rtl_verify_bb_insns (void) | |
2605 | { | |
3d90435a | 2606 | rtx_insn *x; |
4bf32a77 | 2607 | int err = 0; |
2608 | basic_block bb; | |
2609 | ||
7a46197b | 2610 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
4bf32a77 | 2611 | { |
2612 | /* Now check the header of basic | |
a0c938f0 | 2613 | block. It ought to contain optional CODE_LABEL followed |
b36d64df | 2614 | by NOTE_BASIC_BLOCK. */ |
5496dbfc | 2615 | x = BB_HEAD (bb); |
6d7dc5b9 | 2616 | if (LABEL_P (x)) |
b36d64df | 2617 | { |
5496dbfc | 2618 | if (BB_END (bb) == x) |
b36d64df | 2619 | { |
2620 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
b3d6de89 | 2621 | bb->index); |
b36d64df | 2622 | err = 1; |
2623 | } | |
5cc577b6 | 2624 | |
b36d64df | 2625 | x = NEXT_INSN (x); |
2626 | } | |
5cc577b6 | 2627 | |
b36d64df | 2628 | if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb) |
2629 | { | |
2630 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", | |
b3d6de89 | 2631 | bb->index); |
b36d64df | 2632 | err = 1; |
2633 | } | |
2634 | ||
5496dbfc | 2635 | if (BB_END (bb) == x) |
f3e2a363 | 2636 | /* Do checks for empty blocks here. */ |
5cc577b6 | 2637 | ; |
b36d64df | 2638 | else |
5cc577b6 | 2639 | for (x = NEXT_INSN (x); x; x = NEXT_INSN (x)) |
2640 | { | |
2641 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2642 | { | |
2643 | error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d", | |
b3d6de89 | 2644 | INSN_UID (x), bb->index); |
5cc577b6 | 2645 | err = 1; |
2646 | } | |
2647 | ||
5496dbfc | 2648 | if (x == BB_END (bb)) |
5cc577b6 | 2649 | break; |
b36d64df | 2650 | |
aaf52ffb | 2651 | if (control_flow_insn_p (x)) |
5cc577b6 | 2652 | { |
b3d6de89 | 2653 | error ("in basic block %d:", bb->index); |
5cc577b6 | 2654 | fatal_insn ("flow control insn inside a basic block", x); |
2655 | } | |
2656 | } | |
b36d64df | 2657 | } |
2658 | ||
4bf32a77 | 2659 | /* Clean up. */ |
2660 | return err; | |
2661 | } | |
2662 | ||
2663 | /* Verify that block pointers for instructions in basic blocks, headers and | |
2664 | footers are set appropriately. */ | |
2665 | ||
2666 | static int | |
2667 | rtl_verify_bb_pointers (void) | |
2668 | { | |
2669 | int err = 0; | |
2670 | basic_block bb; | |
2671 | ||
2672 | /* Check the general integrity of the basic blocks. */ | |
7a46197b | 2673 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
4bf32a77 | 2674 | { |
3d90435a | 2675 | rtx_insn *insn; |
4bf32a77 | 2676 | |
2677 | if (!(bb->flags & BB_RTL)) | |
2678 | { | |
2679 | error ("BB_RTL flag not set for block %d", bb->index); | |
2680 | err = 1; | |
2681 | } | |
2682 | ||
2683 | FOR_BB_INSNS (bb, insn) | |
2684 | if (BLOCK_FOR_INSN (insn) != bb) | |
2685 | { | |
2686 | error ("insn %d basic block pointer is %d, should be %d", | |
2687 | INSN_UID (insn), | |
2688 | BLOCK_FOR_INSN (insn) ? BLOCK_FOR_INSN (insn)->index : 0, | |
2689 | bb->index); | |
2690 | err = 1; | |
2691 | } | |
2692 | ||
2693 | for (insn = BB_HEADER (bb); insn; insn = NEXT_INSN (insn)) | |
2694 | if (!BARRIER_P (insn) | |
2695 | && BLOCK_FOR_INSN (insn) != NULL) | |
2696 | { | |
2697 | error ("insn %d in header of bb %d has non-NULL basic block", | |
2698 | INSN_UID (insn), bb->index); | |
2699 | err = 1; | |
2700 | } | |
2701 | for (insn = BB_FOOTER (bb); insn; insn = NEXT_INSN (insn)) | |
2702 | if (!BARRIER_P (insn) | |
2703 | && BLOCK_FOR_INSN (insn) != NULL) | |
2704 | { | |
2705 | error ("insn %d in footer of bb %d has non-NULL basic block", | |
2706 | INSN_UID (insn), bb->index); | |
2707 | err = 1; | |
2708 | } | |
2709 | } | |
812ca88e | 2710 | |
028f8cc7 | 2711 | /* Clean up. */ |
028f8cc7 | 2712 | return err; |
2713 | } | |
5cc577b6 | 2714 | |
028f8cc7 | 2715 | /* Verify the CFG and RTL consistency common for both underlying RTL and |
2716 | cfglayout RTL. | |
5cc577b6 | 2717 | |
028f8cc7 | 2718 | Currently it does following checks: |
4bf32a77 | 2719 | |
2720 | - overlapping of basic blocks | |
2721 | - insns with wrong BLOCK_FOR_INSN pointers | |
2722 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) | |
2723 | - tails of basic blocks (ensure that boundary is necessary) | |
2724 | - scans body of the basic block for JUMP_INSN, CODE_LABEL | |
2725 | and NOTE_INSN_BASIC_BLOCK | |
2726 | - verify that no fall_thru edge crosses hot/cold partition boundaries | |
2727 | - verify that there are no pending RTL branch predictions | |
80adc5a6 | 2728 | - verify that hot blocks are not dominated by cold blocks |
4bf32a77 | 2729 | |
2730 | In future it can be extended check a lot of other stuff as well | |
2731 | (reachability of basic blocks, life information, etc. etc.). */ | |
fcde5c9e | 2732 | |
028f8cc7 | 2733 | static int |
4bf32a77 | 2734 | rtl_verify_flow_info_1 (void) |
2735 | { | |
2736 | int err = 0; | |
2737 | ||
2738 | err |= rtl_verify_bb_pointers (); | |
2739 | ||
2740 | err |= rtl_verify_bb_insns (); | |
2741 | ||
2742 | err |= rtl_verify_edges (); | |
2743 | ||
4bf32a77 | 2744 | return err; |
2745 | } | |
2746 | ||
2747 | /* Walk the instruction chain and verify that bb head/end pointers | |
2748 | are correct, and that instructions are in exactly one bb and have | |
2749 | correct block pointers. */ | |
2750 | ||
2751 | static int | |
2752 | rtl_verify_bb_insn_chain (void) | |
028f8cc7 | 2753 | { |
2754 | basic_block bb; | |
4bf32a77 | 2755 | int err = 0; |
3d90435a | 2756 | rtx_insn *x; |
2757 | rtx_insn *last_head = get_last_insn (); | |
fcde5c9e | 2758 | basic_block *bb_info; |
fcde5c9e | 2759 | const int max_uid = get_max_uid (); |
2760 | ||
2761 | bb_info = XCNEWVEC (basic_block, max_uid); | |
b36d64df | 2762 | |
7a46197b | 2763 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
028f8cc7 | 2764 | { |
3d90435a | 2765 | rtx_insn *head = BB_HEAD (bb); |
2766 | rtx_insn *end = BB_END (bb); | |
cd665a06 | 2767 | |
fcde5c9e | 2768 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) |
39257eb5 | 2769 | { |
2770 | /* Verify the end of the basic block is in the INSN chain. */ | |
2771 | if (x == end) | |
2772 | break; | |
2773 | ||
4bf32a77 | 2774 | /* And that the code outside of basic blocks has NULL bb field. */ |
2775 | if (!BARRIER_P (x) | |
2776 | && BLOCK_FOR_INSN (x) != NULL) | |
2777 | { | |
2778 | error ("insn %d outside of basic blocks has non-NULL bb field", | |
2779 | INSN_UID (x)); | |
2780 | err = 1; | |
2781 | } | |
39257eb5 | 2782 | } |
fcde5c9e | 2783 | |
2784 | if (!x) | |
2785 | { | |
2786 | error ("end insn %d for block %d not found in the insn stream", | |
2787 | INSN_UID (end), bb->index); | |
2788 | err = 1; | |
2789 | } | |
2790 | ||
2791 | /* Work backwards from the end to the head of the basic block | |
2792 | to verify the head is in the RTL chain. */ | |
2793 | for (; x != NULL_RTX; x = PREV_INSN (x)) | |
d5043f32 | 2794 | { |
fcde5c9e | 2795 | /* While walking over the insn chain, verify insns appear |
2796 | in only one basic block. */ | |
2797 | if (bb_info[INSN_UID (x)] != NULL) | |
2798 | { | |
2799 | error ("insn %d is in multiple basic blocks (%d and %d)", | |
2800 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); | |
2801 | err = 1; | |
2802 | } | |
2803 | ||
2804 | bb_info[INSN_UID (x)] = bb; | |
2805 | ||
2806 | if (x == head) | |
2807 | break; | |
2808 | } | |
2809 | if (!x) | |
2810 | { | |
2811 | error ("head insn %d for block %d not found in the insn stream", | |
2812 | INSN_UID (head), bb->index); | |
d5043f32 | 2813 | err = 1; |
2814 | } | |
2815 | ||
39257eb5 | 2816 | last_head = PREV_INSN (x); |
4bf32a77 | 2817 | } |
2818 | ||
2819 | for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) | |
2820 | { | |
2821 | /* Check that the code before the first basic block has NULL | |
2822 | bb field. */ | |
2823 | if (!BARRIER_P (x) | |
2824 | && BLOCK_FOR_INSN (x) != NULL) | |
2825 | { | |
2826 | error ("insn %d outside of basic blocks has non-NULL bb field", | |
2827 | INSN_UID (x)); | |
2828 | err = 1; | |
2829 | } | |
2830 | } | |
2831 | free (bb_info); | |
2832 | ||
2833 | return err; | |
2834 | } | |
2835 | ||
2836 | /* Verify that fallthru edges point to adjacent blocks in layout order and | |
2837 | that barriers exist after non-fallthru blocks. */ | |
2838 | ||
2839 | static int | |
2840 | rtl_verify_fallthru (void) | |
2841 | { | |
2842 | basic_block bb; | |
2843 | int err = 0; | |
2844 | ||
7a46197b | 2845 | FOR_EACH_BB_REVERSE_FN (bb, cfun) |
4bf32a77 | 2846 | { |
2847 | edge e; | |
fcde5c9e | 2848 | |
7f58c05e | 2849 | e = find_fallthru_edge (bb->succs); |
028f8cc7 | 2850 | if (!e) |
2851 | { | |
3d90435a | 2852 | rtx_insn *insn; |
028f8cc7 | 2853 | |
2854 | /* Ensure existence of barrier in BB with no fallthru edges. */ | |
d2b48f0c | 2855 | for (insn = NEXT_INSN (BB_END (bb)); ; insn = NEXT_INSN (insn)) |
2856 | { | |
2857 | if (!insn || NOTE_INSN_BASIC_BLOCK_P (insn)) | |
028f8cc7 | 2858 | { |
2859 | error ("missing barrier after block %i", bb->index); | |
2860 | err = 1; | |
2861 | break; | |
2862 | } | |
d2b48f0c | 2863 | if (BARRIER_P (insn)) |
2864 | break; | |
2865 | } | |
028f8cc7 | 2866 | } |
34154e27 | 2867 | else if (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
2868 | && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
a0c938f0 | 2869 | { |
3d90435a | 2870 | rtx_insn *insn; |
028f8cc7 | 2871 | |
2872 | if (e->src->next_bb != e->dest) | |
2873 | { | |
2874 | error | |
2875 | ("verify_flow_info: Incorrect blocks for fallthru %i->%i", | |
2876 | e->src->index, e->dest->index); | |
2877 | err = 1; | |
2878 | } | |
2879 | else | |
5496dbfc | 2880 | for (insn = NEXT_INSN (BB_END (e->src)); insn != BB_HEAD (e->dest); |
028f8cc7 | 2881 | insn = NEXT_INSN (insn)) |
ac7d3688 | 2882 | if (BARRIER_P (insn) || INSN_P (insn)) |
028f8cc7 | 2883 | { |
2884 | error ("verify_flow_info: Incorrect fallthru %i->%i", | |
2885 | e->src->index, e->dest->index); | |
2886 | fatal_insn ("wrong insn in the fallthru edge", insn); | |
2887 | err = 1; | |
2888 | } | |
a0c938f0 | 2889 | } |
028f8cc7 | 2890 | } |
b36d64df | 2891 | |
4bf32a77 | 2892 | return err; |
2893 | } | |
2894 | ||
2895 | /* Verify that blocks are laid out in consecutive order. While walking the | |
2896 | instructions, verify that all expected instructions are inside the basic | |
2897 | blocks, and that all returns are followed by barriers. */ | |
2898 | ||
2899 | static int | |
2900 | rtl_verify_bb_layout (void) | |
2901 | { | |
2902 | basic_block bb; | |
2903 | int err = 0; | |
3d90435a | 2904 | rtx_insn *x; |
4bf32a77 | 2905 | int num_bb_notes; |
3d90435a | 2906 | rtx_insn * const rtx_first = get_insns (); |
34154e27 | 2907 | basic_block last_bb_seen = ENTRY_BLOCK_PTR_FOR_FN (cfun), curr_bb = NULL; |
fcde5c9e | 2908 | |
b36d64df | 2909 | num_bb_notes = 0; |
34154e27 | 2910 | last_bb_seen = ENTRY_BLOCK_PTR_FOR_FN (cfun); |
4c26117a | 2911 | |
5cc577b6 | 2912 | for (x = rtx_first; x; x = NEXT_INSN (x)) |
b36d64df | 2913 | { |
2914 | if (NOTE_INSN_BASIC_BLOCK_P (x)) | |
2915 | { | |
3c0a32c9 | 2916 | bb = NOTE_BASIC_BLOCK (x); |
5cc577b6 | 2917 | |
b36d64df | 2918 | num_bb_notes++; |
4c26117a | 2919 | if (bb != last_bb_seen->next_bb) |
028f8cc7 | 2920 | internal_error ("basic blocks not laid down consecutively"); |
b36d64df | 2921 | |
028f8cc7 | 2922 | curr_bb = last_bb_seen = bb; |
b36d64df | 2923 | } |
2924 | ||
028f8cc7 | 2925 | if (!curr_bb) |
b36d64df | 2926 | { |
2927 | switch (GET_CODE (x)) | |
2928 | { | |
2929 | case BARRIER: | |
2930 | case NOTE: | |
2931 | break; | |
2932 | ||
2933 | case CODE_LABEL: | |
91f71fa3 | 2934 | /* An ADDR_VEC is placed outside any basic block. */ |
b36d64df | 2935 | if (NEXT_INSN (x) |
971ba038 | 2936 | && JUMP_TABLE_DATA_P (NEXT_INSN (x))) |
5cc577b6 | 2937 | x = NEXT_INSN (x); |
b36d64df | 2938 | |
2939 | /* But in any case, non-deletable labels can appear anywhere. */ | |
2940 | break; | |
2941 | ||
2942 | default: | |
cb8bacb6 | 2943 | fatal_insn ("insn outside basic block", x); |
b36d64df | 2944 | } |
2945 | } | |
2946 | ||
345f9e8c | 2947 | if (JUMP_P (x) |
b36d64df | 2948 | && returnjump_p (x) && ! condjump_p (x) |
8fcc0f14 | 2949 | && ! (next_nonnote_insn (x) && BARRIER_P (next_nonnote_insn (x)))) |
cb8bacb6 | 2950 | fatal_insn ("return not followed by barrier", x); |
4bf32a77 | 2951 | |
5496dbfc | 2952 | if (curr_bb && x == BB_END (curr_bb)) |
028f8cc7 | 2953 | curr_bb = NULL; |
b36d64df | 2954 | } |
2955 | ||
a28770e1 | 2956 | if (num_bb_notes != n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS) |
b36d64df | 2957 | internal_error |
b3d6de89 | 2958 | ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)", |
a28770e1 | 2959 | num_bb_notes, n_basic_blocks_for_fn (cfun)); |
b36d64df | 2960 | |
028f8cc7 | 2961 | return err; |
b36d64df | 2962 | } |
4bf32a77 | 2963 | |
2964 | /* Verify the CFG and RTL consistency common for both underlying RTL and | |
2965 | cfglayout RTL, plus consistency checks specific to linearized RTL mode. | |
2966 | ||
2967 | Currently it does following checks: | |
2968 | - all checks of rtl_verify_flow_info_1 | |
2969 | - test head/end pointers | |
2970 | - check that blocks are laid out in consecutive order | |
2971 | - check that all insns are in the basic blocks | |
2972 | (except the switch handling code, barriers and notes) | |
2973 | - check that all returns are followed by barriers | |
80adc5a6 | 2974 | - check that all fallthru edge points to the adjacent blocks |
2975 | - verify that there is a single hot/cold partition boundary after bbro */ | |
4bf32a77 | 2976 | |
2977 | static int | |
2978 | rtl_verify_flow_info (void) | |
2979 | { | |
2980 | int err = 0; | |
2981 | ||
2982 | err |= rtl_verify_flow_info_1 (); | |
2983 | ||
2984 | err |= rtl_verify_bb_insn_chain (); | |
2985 | ||
2986 | err |= rtl_verify_fallthru (); | |
2987 | ||
2988 | err |= rtl_verify_bb_layout (); | |
2989 | ||
aa78dca5 | 2990 | err |= verify_hot_cold_block_grouping (); |
2991 | ||
4bf32a77 | 2992 | return err; |
2993 | } | |
b36d64df | 2994 | \f |
4a82352a | 2995 | /* Assume that the preceding pass has possibly eliminated jump instructions |
b36d64df | 2996 | or converted the unconditional jumps. Eliminate the edges from CFG. |
2997 | Return true if any edges are eliminated. */ | |
2998 | ||
2999 | bool | |
4c9e08a4 | 3000 | purge_dead_edges (basic_block bb) |
b36d64df | 3001 | { |
cd665a06 | 3002 | edge e; |
3d90435a | 3003 | rtx_insn *insn = BB_END (bb); |
3004 | rtx note; | |
b36d64df | 3005 | bool purged = false; |
cd665a06 | 3006 | bool found; |
3007 | edge_iterator ei; | |
b36d64df | 3008 | |
9845d120 | 3009 | if (DEBUG_INSN_P (insn) && insn != BB_HEAD (bb)) |
3010 | do | |
3011 | insn = PREV_INSN (insn); | |
3012 | while ((DEBUG_INSN_P (insn) || NOTE_P (insn)) && insn != BB_HEAD (bb)); | |
3013 | ||
11808932 | 3014 | /* If this instruction cannot trap, remove REG_EH_REGION notes. */ |
6d7dc5b9 | 3015 | if (NONJUMP_INSN_P (insn) |
11808932 | 3016 | && (note = find_reg_note (insn, REG_EH_REGION, NULL))) |
3017 | { | |
3018 | rtx eqnote; | |
3019 | ||
3020 | if (! may_trap_p (PATTERN (insn)) | |
3021 | || ((eqnote = find_reg_equal_equiv_note (insn)) | |
3022 | && ! may_trap_p (XEXP (eqnote, 0)))) | |
3023 | remove_note (insn, note); | |
3024 | } | |
3025 | ||
f178f44b | 3026 | /* Cleanup abnormal edges caused by exceptions or non-local gotos. */ |
cd665a06 | 3027 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
f178f44b | 3028 | { |
e38def9c | 3029 | bool remove = false; |
3030 | ||
04166d08 | 3031 | /* There are three types of edges we need to handle correctly here: EH |
3032 | edges, abnormal call EH edges, and abnormal call non-EH edges. The | |
3033 | latter can appear when nonlocal gotos are used. */ | |
e38def9c | 3034 | if (e->flags & EDGE_ABNORMAL_CALL) |
f178f44b | 3035 | { |
e38def9c | 3036 | if (!CALL_P (insn)) |
3037 | remove = true; | |
3038 | else if (can_nonlocal_goto (insn)) | |
3039 | ; | |
3040 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) | |
3041 | ; | |
4c0315d0 | 3042 | else if (flag_tm && find_reg_note (insn, REG_TM, NULL)) |
3043 | ; | |
e38def9c | 3044 | else |
3045 | remove = true; | |
f178f44b | 3046 | } |
e38def9c | 3047 | else if (e->flags & EDGE_EH) |
3048 | remove = !can_throw_internal (insn); | |
3049 | ||
3050 | if (remove) | |
f178f44b | 3051 | { |
e38def9c | 3052 | remove_edge (e); |
3053 | df_set_bb_dirty (bb); | |
3054 | purged = true; | |
f178f44b | 3055 | } |
3056 | else | |
e38def9c | 3057 | ei_next (&ei); |
f178f44b | 3058 | } |
5cc577b6 | 3059 | |
6d7dc5b9 | 3060 | if (JUMP_P (insn)) |
b36d64df | 3061 | { |
3062 | rtx note; | |
3063 | edge b,f; | |
cd665a06 | 3064 | edge_iterator ei; |
5cc577b6 | 3065 | |
b36d64df | 3066 | /* We do care only about conditional jumps and simplejumps. */ |
3067 | if (!any_condjump_p (insn) | |
3068 | && !returnjump_p (insn) | |
3069 | && !simplejump_p (insn)) | |
461eeb14 | 3070 | return purged; |
5cc577b6 | 3071 | |
a2e42321 | 3072 | /* Branch probability/prediction notes are defined only for |
3073 | condjumps. We've possibly turned condjump into simplejump. */ | |
3074 | if (simplejump_p (insn)) | |
3075 | { | |
3076 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
3077 | if (note) | |
3078 | remove_note (insn, note); | |
3079 | while ((note = find_reg_note (insn, REG_BR_PRED, NULL))) | |
3080 | remove_note (insn, note); | |
3081 | } | |
3082 | ||
cd665a06 | 3083 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
b36d64df | 3084 | { |
4270b4b9 | 3085 | /* Avoid abnormal flags to leak from computed jumps turned |
3086 | into simplejumps. */ | |
db34a109 | 3087 | |
a0fb7382 | 3088 | e->flags &= ~EDGE_ABNORMAL; |
4270b4b9 | 3089 | |
14abf923 | 3090 | /* See if this edge is one we should keep. */ |
3091 | if ((e->flags & EDGE_FALLTHRU) && any_condjump_p (insn)) | |
3092 | /* A conditional jump can fall through into the next | |
3093 | block, so we should keep the edge. */ | |
cd665a06 | 3094 | { |
3095 | ei_next (&ei); | |
3096 | continue; | |
3097 | } | |
34154e27 | 3098 | else if (e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) |
5496dbfc | 3099 | && BB_HEAD (e->dest) == JUMP_LABEL (insn)) |
14abf923 | 3100 | /* If the destination block is the target of the jump, |
3101 | keep the edge. */ | |
cd665a06 | 3102 | { |
3103 | ei_next (&ei); | |
3104 | continue; | |
3105 | } | |
34154e27 | 3106 | else if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) |
3107 | && returnjump_p (insn)) | |
14abf923 | 3108 | /* If the destination block is the exit block, and this |
3109 | instruction is a return, then keep the edge. */ | |
cd665a06 | 3110 | { |
3111 | ei_next (&ei); | |
3112 | continue; | |
3113 | } | |
14abf923 | 3114 | else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) |
3115 | /* Keep the edges that correspond to exceptions thrown by | |
1b64239d | 3116 | this instruction and rematerialize the EDGE_ABNORMAL |
3117 | flag we just cleared above. */ | |
3118 | { | |
3119 | e->flags |= EDGE_ABNORMAL; | |
cd665a06 | 3120 | ei_next (&ei); |
1b64239d | 3121 | continue; |
3122 | } | |
5cc577b6 | 3123 | |
14abf923 | 3124 | /* We do not need this edge. */ |
3072d30e | 3125 | df_set_bb_dirty (bb); |
b36d64df | 3126 | purged = true; |
3127 | remove_edge (e); | |
3128 | } | |
5cc577b6 | 3129 | |
cd665a06 | 3130 | if (EDGE_COUNT (bb->succs) == 0 || !purged) |
461eeb14 | 3131 | return purged; |
5cc577b6 | 3132 | |
450d042a | 3133 | if (dump_file) |
3134 | fprintf (dump_file, "Purged edges from bb %i\n", bb->index); | |
5cc577b6 | 3135 | |
b36d64df | 3136 | if (!optimize) |
3137 | return purged; | |
3138 | ||
3139 | /* Redistribute probabilities. */ | |
ea091dfd | 3140 | if (single_succ_p (bb)) |
b36d64df | 3141 | { |
ea091dfd | 3142 | single_succ_edge (bb)->probability = REG_BR_PROB_BASE; |
3143 | single_succ_edge (bb)->count = bb->count; | |
db34a109 | 3144 | } |
b36d64df | 3145 | else |
3146 | { | |
3147 | note = find_reg_note (insn, REG_BR_PROB, NULL); | |
3148 | if (!note) | |
3149 | return purged; | |
5cc577b6 | 3150 | |
b36d64df | 3151 | b = BRANCH_EDGE (bb); |
3152 | f = FALLTHRU_EDGE (bb); | |
9eb946de | 3153 | b->probability = XINT (note, 0); |
b36d64df | 3154 | f->probability = REG_BR_PROB_BASE - b->probability; |
f9d4b7f4 | 3155 | /* Update these to use GCOV_COMPUTE_SCALE. */ |
b36d64df | 3156 | b->count = bb->count * b->probability / REG_BR_PROB_BASE; |
3157 | f->count = bb->count * f->probability / REG_BR_PROB_BASE; | |
3158 | } | |
5cc577b6 | 3159 | |
b36d64df | 3160 | return purged; |
3161 | } | |
6d7dc5b9 | 3162 | else if (CALL_P (insn) && SIBLING_CALL_P (insn)) |
bf4311e9 | 3163 | { |
3164 | /* First, there should not be any EH or ABCALL edges resulting | |
3165 | from non-local gotos and the like. If there were, we shouldn't | |
3166 | have created the sibcall in the first place. Second, there | |
3167 | should of course never have been a fallthru edge. */ | |
ea091dfd | 3168 | gcc_assert (single_succ_p (bb)); |
3169 | gcc_assert (single_succ_edge (bb)->flags | |
3170 | == (EDGE_SIBCALL | EDGE_ABNORMAL)); | |
bf4311e9 | 3171 | |
3172 | return 0; | |
3173 | } | |
b36d64df | 3174 | |
b36d64df | 3175 | /* If we don't see a jump insn, we don't know exactly why the block would |
3176 | have been broken at this point. Look for a simple, non-fallthru edge, | |
3177 | as these are only created by conditional branches. If we find such an | |
3178 | edge we know that there used to be a jump here and can then safely | |
3179 | remove all non-fallthru edges. */ | |
cd665a06 | 3180 | found = false; |
3181 | FOR_EACH_EDGE (e, ei, bb->succs) | |
3182 | if (! (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU))) | |
3183 | { | |
3184 | found = true; | |
3185 | break; | |
3186 | } | |
5cc577b6 | 3187 | |
cd665a06 | 3188 | if (!found) |
b36d64df | 3189 | return purged; |
5cc577b6 | 3190 | |
6e81a369 | 3191 | /* Remove all but the fake and fallthru edges. The fake edge may be |
3192 | the only successor for this block in the case of noreturn | |
3193 | calls. */ | |
cd665a06 | 3194 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
b36d64df | 3195 | { |
6e81a369 | 3196 | if (!(e->flags & (EDGE_FALLTHRU | EDGE_FAKE))) |
461eeb14 | 3197 | { |
3072d30e | 3198 | df_set_bb_dirty (bb); |
461eeb14 | 3199 | remove_edge (e); |
3200 | purged = true; | |
3201 | } | |
cd665a06 | 3202 | else |
3203 | ei_next (&ei); | |
b36d64df | 3204 | } |
5cc577b6 | 3205 | |
ea091dfd | 3206 | gcc_assert (single_succ_p (bb)); |
5cc577b6 | 3207 | |
ea091dfd | 3208 | single_succ_edge (bb)->probability = REG_BR_PROB_BASE; |
3209 | single_succ_edge (bb)->count = bb->count; | |
b36d64df | 3210 | |
450d042a | 3211 | if (dump_file) |
3212 | fprintf (dump_file, "Purged non-fallthru edges from bb %i\n", | |
b3d6de89 | 3213 | bb->index); |
b36d64df | 3214 | return purged; |
3215 | } | |
3216 | ||
5cc577b6 | 3217 | /* Search all basic blocks for potentially dead edges and purge them. Return |
3218 | true if some edge has been eliminated. */ | |
b36d64df | 3219 | |
3220 | bool | |
94ee50e8 | 3221 | purge_all_dead_edges (void) |
b36d64df | 3222 | { |
4c26117a | 3223 | int purged = false; |
4c26117a | 3224 | basic_block bb; |
0922c912 | 3225 | |
fc00614f | 3226 | FOR_EACH_BB_FN (bb, cfun) |
0922c912 | 3227 | { |
4c26117a | 3228 | bool purged_here = purge_dead_edges (bb); |
5cc577b6 | 3229 | |
0922c912 | 3230 | purged |= purged_here; |
0922c912 | 3231 | } |
5cc577b6 | 3232 | |
b36d64df | 3233 | return purged; |
3234 | } | |
1026363d | 3235 | |
54f21e20 | 3236 | /* This is used by a few passes that emit some instructions after abnormal |
3237 | calls, moving the basic block's end, while they in fact do want to emit | |
3238 | them on the fallthru edge. Look for abnormal call edges, find backward | |
3239 | the call in the block and insert the instructions on the edge instead. | |
3240 | ||
3241 | Similarly, handle instructions throwing exceptions internally. | |
3242 | ||
3243 | Return true when instructions have been found and inserted on edges. */ | |
3244 | ||
3245 | bool | |
3246 | fixup_abnormal_edges (void) | |
3247 | { | |
3248 | bool inserted = false; | |
3249 | basic_block bb; | |
3250 | ||
fc00614f | 3251 | FOR_EACH_BB_FN (bb, cfun) |
54f21e20 | 3252 | { |
3253 | edge e; | |
3254 | edge_iterator ei; | |
3255 | ||
3256 | /* Look for cases we are interested in - calls or instructions causing | |
3257 | exceptions. */ | |
3258 | FOR_EACH_EDGE (e, ei, bb->succs) | |
3259 | if ((e->flags & EDGE_ABNORMAL_CALL) | |
3260 | || ((e->flags & (EDGE_ABNORMAL | EDGE_EH)) | |
3261 | == (EDGE_ABNORMAL | EDGE_EH))) | |
3262 | break; | |
3263 | ||
3264 | if (e && !CALL_P (BB_END (bb)) && !can_throw_internal (BB_END (bb))) | |
3265 | { | |
3d90435a | 3266 | rtx_insn *insn; |
54f21e20 | 3267 | |
3268 | /* Get past the new insns generated. Allow notes, as the insns | |
3269 | may be already deleted. */ | |
3270 | insn = BB_END (bb); | |
3271 | while ((NONJUMP_INSN_P (insn) || NOTE_P (insn)) | |
3272 | && !can_throw_internal (insn) | |
3273 | && insn != BB_HEAD (bb)) | |
3274 | insn = PREV_INSN (insn); | |
3275 | ||
3276 | if (CALL_P (insn) || can_throw_internal (insn)) | |
3277 | { | |
3d90435a | 3278 | rtx_insn *stop, *next; |
54f21e20 | 3279 | |
3280 | e = find_fallthru_edge (bb->succs); | |
3281 | ||
3282 | stop = NEXT_INSN (BB_END (bb)); | |
26bb3cb2 | 3283 | BB_END (bb) = insn; |
54f21e20 | 3284 | |
3285 | for (insn = NEXT_INSN (insn); insn != stop; insn = next) | |
3286 | { | |
3287 | next = NEXT_INSN (insn); | |
3288 | if (INSN_P (insn)) | |
3289 | { | |
3290 | delete_insn (insn); | |
3291 | ||
3292 | /* Sometimes there's still the return value USE. | |
3293 | If it's placed after a trapping call (i.e. that | |
3294 | call is the last insn anyway), we have no fallthru | |
3295 | edge. Simply delete this use and don't try to insert | |
3296 | on the non-existent edge. */ | |
3297 | if (GET_CODE (PATTERN (insn)) != USE) | |
3298 | { | |
3299 | /* We're not deleting it, we're moving it. */ | |
dd1286fb | 3300 | insn->set_undeleted (); |
4a57a2e8 | 3301 | SET_PREV_INSN (insn) = NULL_RTX; |
3302 | SET_NEXT_INSN (insn) = NULL_RTX; | |
54f21e20 | 3303 | |
3304 | insert_insn_on_edge (insn, e); | |
3305 | inserted = true; | |
3306 | } | |
3307 | } | |
3308 | else if (!BARRIER_P (insn)) | |
3309 | set_block_for_insn (insn, NULL); | |
3310 | } | |
3311 | } | |
3312 | ||
3313 | /* It may be that we don't find any trapping insn. In this | |
3314 | case we discovered quite late that the insn that had been | |
3315 | marked as can_throw_internal in fact couldn't trap at all. | |
3316 | So we should in fact delete the EH edges out of the block. */ | |
3317 | else | |
3318 | purge_dead_edges (bb); | |
3319 | } | |
3320 | } | |
3321 | ||
3322 | return inserted; | |
3323 | } | |
23a070f3 | 3324 | \f |
3325 | /* Cut the insns from FIRST to LAST out of the insns stream. */ | |
3326 | ||
aa935352 | 3327 | rtx_insn * |
3e75e92b | 3328 | unlink_insn_chain (rtx_insn *first, rtx_insn *last) |
23a070f3 | 3329 | { |
aa935352 | 3330 | rtx_insn *prevfirst = PREV_INSN (first); |
3331 | rtx_insn *nextlast = NEXT_INSN (last); | |
23a070f3 | 3332 | |
4a57a2e8 | 3333 | SET_PREV_INSN (first) = NULL; |
3334 | SET_NEXT_INSN (last) = NULL; | |
23a070f3 | 3335 | if (prevfirst) |
4a57a2e8 | 3336 | SET_NEXT_INSN (prevfirst) = nextlast; |
23a070f3 | 3337 | if (nextlast) |
4a57a2e8 | 3338 | SET_PREV_INSN (nextlast) = prevfirst; |
23a070f3 | 3339 | else |
3340 | set_last_insn (prevfirst); | |
3341 | if (!prevfirst) | |
3342 | set_first_insn (nextlast); | |
3e75e92b | 3343 | return first; |
23a070f3 | 3344 | } |
3345 | \f | |
3346 | /* Skip over inter-block insns occurring after BB which are typically | |
3347 | associated with BB (e.g., barriers). If there are any such insns, | |
3348 | we return the last one. Otherwise, we return the end of BB. */ | |
3349 | ||
3d90435a | 3350 | static rtx_insn * |
23a070f3 | 3351 | skip_insns_after_block (basic_block bb) |
3352 | { | |
3d90435a | 3353 | rtx_insn *insn, *last_insn, *next_head, *prev; |
23a070f3 | 3354 | |
3d90435a | 3355 | next_head = NULL; |
34154e27 | 3356 | if (bb->next_bb != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
23a070f3 | 3357 | next_head = BB_HEAD (bb->next_bb); |
3358 | ||
3359 | for (last_insn = insn = BB_END (bb); (insn = NEXT_INSN (insn)) != 0; ) | |
3360 | { | |
3361 | if (insn == next_head) | |
3362 | break; | |
3363 | ||
3364 | switch (GET_CODE (insn)) | |
3365 | { | |
3366 | case BARRIER: | |
3367 | last_insn = insn; | |
3368 | continue; | |
3369 | ||
3370 | case NOTE: | |
3371 | switch (NOTE_KIND (insn)) | |
3372 | { | |
3373 | case NOTE_INSN_BLOCK_END: | |
3374 | gcc_unreachable (); | |
3375 | continue; | |
3376 | default: | |
3377 | continue; | |
3378 | break; | |
3379 | } | |
3380 | break; | |
3381 | ||
3382 | case CODE_LABEL: | |
3383 | if (NEXT_INSN (insn) | |
3384 | && JUMP_TABLE_DATA_P (NEXT_INSN (insn))) | |
3385 | { | |
3386 | insn = NEXT_INSN (insn); | |
3387 | last_insn = insn; | |
3388 | continue; | |
3389 | } | |
3390 | break; | |
3391 | ||
3392 | default: | |
3393 | break; | |
3394 | } | |
3395 | ||
3396 | break; | |
3397 | } | |
3398 | ||
3399 | /* It is possible to hit contradictory sequence. For instance: | |
3400 | ||
3401 | jump_insn | |
3402 | NOTE_INSN_BLOCK_BEG | |
3403 | barrier | |
3404 | ||
3405 | Where barrier belongs to jump_insn, but the note does not. This can be | |
3406 | created by removing the basic block originally following | |
3407 | NOTE_INSN_BLOCK_BEG. In such case reorder the notes. */ | |
3408 | ||
3409 | for (insn = last_insn; insn != BB_END (bb); insn = prev) | |
3410 | { | |
3411 | prev = PREV_INSN (insn); | |
3412 | if (NOTE_P (insn)) | |
3413 | switch (NOTE_KIND (insn)) | |
3414 | { | |
3415 | case NOTE_INSN_BLOCK_END: | |
3416 | gcc_unreachable (); | |
3417 | break; | |
3418 | case NOTE_INSN_DELETED: | |
3419 | case NOTE_INSN_DELETED_LABEL: | |
3420 | case NOTE_INSN_DELETED_DEBUG_LABEL: | |
3421 | continue; | |
3422 | default: | |
3423 | reorder_insns (insn, insn, last_insn); | |
3424 | } | |
3425 | } | |
3426 | ||
3427 | return last_insn; | |
3428 | } | |
3429 | ||
3430 | /* Locate or create a label for a given basic block. */ | |
3431 | ||
9ed997be | 3432 | static rtx_insn * |
23a070f3 | 3433 | label_for_bb (basic_block bb) |
3434 | { | |
9ed997be | 3435 | rtx_insn *label = BB_HEAD (bb); |
23a070f3 | 3436 | |
3437 | if (!LABEL_P (label)) | |
3438 | { | |
3439 | if (dump_file) | |
3440 | fprintf (dump_file, "Emitting label for block %d\n", bb->index); | |
3441 | ||
3442 | label = block_label (bb); | |
3443 | } | |
3444 | ||
3445 | return label; | |
3446 | } | |
3447 | ||
3448 | /* Locate the effective beginning and end of the insn chain for each | |
3449 | block, as defined by skip_insns_after_block above. */ | |
3450 | ||
3451 | static void | |
3452 | record_effective_endpoints (void) | |
3453 | { | |
3d90435a | 3454 | rtx_insn *next_insn; |
23a070f3 | 3455 | basic_block bb; |
3d90435a | 3456 | rtx_insn *insn; |
23a070f3 | 3457 | |
3458 | for (insn = get_insns (); | |
3459 | insn | |
3460 | && NOTE_P (insn) | |
3461 | && NOTE_KIND (insn) != NOTE_INSN_BASIC_BLOCK; | |
3462 | insn = NEXT_INSN (insn)) | |
3463 | continue; | |
3464 | /* No basic blocks at all? */ | |
3465 | gcc_assert (insn); | |
3466 | ||
3467 | if (PREV_INSN (insn)) | |
3468 | cfg_layout_function_header = | |
3469 | unlink_insn_chain (get_insns (), PREV_INSN (insn)); | |
3470 | else | |
3e75e92b | 3471 | cfg_layout_function_header = NULL; |
23a070f3 | 3472 | |
3473 | next_insn = get_insns (); | |
fc00614f | 3474 | FOR_EACH_BB_FN (bb, cfun) |
23a070f3 | 3475 | { |
3d90435a | 3476 | rtx_insn *end; |
23a070f3 | 3477 | |
3478 | if (PREV_INSN (BB_HEAD (bb)) && next_insn != BB_HEAD (bb)) | |
26bb3cb2 | 3479 | BB_HEADER (bb) = unlink_insn_chain (next_insn, |
a684cb04 | 3480 | PREV_INSN (BB_HEAD (bb))); |
23a070f3 | 3481 | end = skip_insns_after_block (bb); |
3482 | if (NEXT_INSN (BB_END (bb)) && BB_END (bb) != end) | |
943ea6fa | 3483 | BB_FOOTER (bb) = unlink_insn_chain (NEXT_INSN (BB_END (bb)), end); |
23a070f3 | 3484 | next_insn = NEXT_INSN (BB_END (bb)); |
3485 | } | |
3486 | ||
3487 | cfg_layout_function_footer = next_insn; | |
3488 | if (cfg_layout_function_footer) | |
3489 | cfg_layout_function_footer = unlink_insn_chain (cfg_layout_function_footer, get_last_insn ()); | |
3490 | } | |
3491 | \f | |
cbe8bda8 | 3492 | namespace { |
3493 | ||
3494 | const pass_data pass_data_into_cfg_layout_mode = | |
3495 | { | |
3496 | RTL_PASS, /* type */ | |
3497 | "into_cfglayout", /* name */ | |
3498 | OPTGROUP_NONE, /* optinfo_flags */ | |
cbe8bda8 | 3499 | TV_CFG, /* tv_id */ |
3500 | 0, /* properties_required */ | |
3501 | PROP_cfglayout, /* properties_provided */ | |
3502 | 0, /* properties_destroyed */ | |
3503 | 0, /* todo_flags_start */ | |
3504 | 0, /* todo_flags_finish */ | |
23a070f3 | 3505 | }; |
3506 | ||
cbe8bda8 | 3507 | class pass_into_cfg_layout_mode : public rtl_opt_pass |
3508 | { | |
3509 | public: | |
9af5ce0c | 3510 | pass_into_cfg_layout_mode (gcc::context *ctxt) |
3511 | : rtl_opt_pass (pass_data_into_cfg_layout_mode, ctxt) | |
cbe8bda8 | 3512 | {} |
3513 | ||
3514 | /* opt_pass methods: */ | |
65b0537f | 3515 | virtual unsigned int execute (function *) |
3516 | { | |
3517 | cfg_layout_initialize (0); | |
3518 | return 0; | |
3519 | } | |
cbe8bda8 | 3520 | |
3521 | }; // class pass_into_cfg_layout_mode | |
3522 | ||
3523 | } // anon namespace | |
3524 | ||
3525 | rtl_opt_pass * | |
3526 | make_pass_into_cfg_layout_mode (gcc::context *ctxt) | |
3527 | { | |
3528 | return new pass_into_cfg_layout_mode (ctxt); | |
3529 | } | |
3530 | ||
3531 | namespace { | |
3532 | ||
3533 | const pass_data pass_data_outof_cfg_layout_mode = | |
3534 | { | |
3535 | RTL_PASS, /* type */ | |
3536 | "outof_cfglayout", /* name */ | |
3537 | OPTGROUP_NONE, /* optinfo_flags */ | |
cbe8bda8 | 3538 | TV_CFG, /* tv_id */ |
3539 | 0, /* properties_required */ | |
3540 | 0, /* properties_provided */ | |
3541 | PROP_cfglayout, /* properties_destroyed */ | |
3542 | 0, /* todo_flags_start */ | |
3543 | 0, /* todo_flags_finish */ | |
23a070f3 | 3544 | }; |
cbe8bda8 | 3545 | |
3546 | class pass_outof_cfg_layout_mode : public rtl_opt_pass | |
3547 | { | |
3548 | public: | |
9af5ce0c | 3549 | pass_outof_cfg_layout_mode (gcc::context *ctxt) |
3550 | : rtl_opt_pass (pass_data_outof_cfg_layout_mode, ctxt) | |
cbe8bda8 | 3551 | {} |
3552 | ||
3553 | /* opt_pass methods: */ | |
65b0537f | 3554 | virtual unsigned int execute (function *); |
cbe8bda8 | 3555 | |
3556 | }; // class pass_outof_cfg_layout_mode | |
3557 | ||
65b0537f | 3558 | unsigned int |
3559 | pass_outof_cfg_layout_mode::execute (function *fun) | |
3560 | { | |
3561 | basic_block bb; | |
3562 | ||
3563 | FOR_EACH_BB_FN (bb, fun) | |
3564 | if (bb->next_bb != EXIT_BLOCK_PTR_FOR_FN (fun)) | |
3565 | bb->aux = bb->next_bb; | |
3566 | ||
3567 | cfg_layout_finalize (); | |
3568 | ||
3569 | return 0; | |
3570 | } | |
3571 | ||
cbe8bda8 | 3572 | } // anon namespace |
3573 | ||
3574 | rtl_opt_pass * | |
3575 | make_pass_outof_cfg_layout_mode (gcc::context *ctxt) | |
3576 | { | |
3577 | return new pass_outof_cfg_layout_mode (ctxt); | |
3578 | } | |
23a070f3 | 3579 | \f |
3580 | ||
3581 | /* Link the basic blocks in the correct order, compacting the basic | |
3582 | block queue while at it. If STAY_IN_CFGLAYOUT_MODE is false, this | |
3583 | function also clears the basic block header and footer fields. | |
3584 | ||
3585 | This function is usually called after a pass (e.g. tracer) finishes | |
3586 | some transformations while in cfglayout mode. The required sequence | |
3587 | of the basic blocks is in a linked list along the bb->aux field. | |
3588 | This functions re-links the basic block prev_bb and next_bb pointers | |
4a020a8c | 3589 | accordingly, and it compacts and renumbers the blocks. |
3590 | ||
3591 | FIXME: This currently works only for RTL, but the only RTL-specific | |
3592 | bits are the STAY_IN_CFGLAYOUT_MODE bits. The tracer pass was moved | |
3593 | to GIMPLE a long time ago, but it doesn't relink the basic block | |
3594 | chain. It could do that (to give better initial RTL) if this function | |
3595 | is made IR-agnostic (and moved to cfganal.c or cfg.c while at it). */ | |
23a070f3 | 3596 | |
3597 | void | |
3598 | relink_block_chain (bool stay_in_cfglayout_mode) | |
3599 | { | |
3600 | basic_block bb, prev_bb; | |
3601 | int index; | |
3602 | ||
3603 | /* Maybe dump the re-ordered sequence. */ | |
3604 | if (dump_file) | |
3605 | { | |
3606 | fprintf (dump_file, "Reordered sequence:\n"); | |
34154e27 | 3607 | for (bb = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb, index = |
3608 | NUM_FIXED_BLOCKS; | |
23a070f3 | 3609 | bb; |
3610 | bb = (basic_block) bb->aux, index++) | |
3611 | { | |
3612 | fprintf (dump_file, " %i ", index); | |
3613 | if (get_bb_original (bb)) | |
3614 | fprintf (dump_file, "duplicate of %i ", | |
3615 | get_bb_original (bb)->index); | |
3616 | else if (forwarder_block_p (bb) | |
3617 | && !LABEL_P (BB_HEAD (bb))) | |
3618 | fprintf (dump_file, "compensation "); | |
3619 | else | |
3620 | fprintf (dump_file, "bb %i ", bb->index); | |
3621 | fprintf (dump_file, " [%i]\n", bb->frequency); | |
3622 | } | |
3623 | } | |
3624 | ||
3625 | /* Now reorder the blocks. */ | |
34154e27 | 3626 | prev_bb = ENTRY_BLOCK_PTR_FOR_FN (cfun); |
3627 | bb = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb; | |
23a070f3 | 3628 | for (; bb; prev_bb = bb, bb = (basic_block) bb->aux) |
3629 | { | |
3630 | bb->prev_bb = prev_bb; | |
3631 | prev_bb->next_bb = bb; | |
3632 | } | |
34154e27 | 3633 | prev_bb->next_bb = EXIT_BLOCK_PTR_FOR_FN (cfun); |
3634 | EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb = prev_bb; | |
23a070f3 | 3635 | |
3636 | /* Then, clean up the aux fields. */ | |
ed7d889a | 3637 | FOR_ALL_BB_FN (bb, cfun) |
23a070f3 | 3638 | { |
3639 | bb->aux = NULL; | |
3640 | if (!stay_in_cfglayout_mode) | |
26bb3cb2 | 3641 | BB_HEADER (bb) = BB_FOOTER (bb) = NULL; |
23a070f3 | 3642 | } |
3643 | ||
3644 | /* Maybe reset the original copy tables, they are not valid anymore | |
3645 | when we renumber the basic blocks in compact_blocks. If we are | |
3646 | are going out of cfglayout mode, don't re-allocate the tables. */ | |
3647 | free_original_copy_tables (); | |
3648 | if (stay_in_cfglayout_mode) | |
3649 | initialize_original_copy_tables (); | |
3650 | ||
3651 | /* Finally, put basic_block_info in the new order. */ | |
3652 | compact_blocks (); | |
3653 | } | |
3654 | \f | |
3655 | ||
3656 | /* Given a reorder chain, rearrange the code to match. */ | |
3657 | ||
3658 | static void | |
3659 | fixup_reorder_chain (void) | |
3660 | { | |
3661 | basic_block bb; | |
3e75e92b | 3662 | rtx_insn *insn = NULL; |
23a070f3 | 3663 | |
3664 | if (cfg_layout_function_header) | |
3665 | { | |
3666 | set_first_insn (cfg_layout_function_header); | |
3667 | insn = cfg_layout_function_header; | |
3668 | while (NEXT_INSN (insn)) | |
3669 | insn = NEXT_INSN (insn); | |
3670 | } | |
3671 | ||
3672 | /* First do the bulk reordering -- rechain the blocks without regard to | |
3673 | the needed changes to jumps and labels. */ | |
3674 | ||
34154e27 | 3675 | for (bb = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb; bb; bb = (basic_block) |
3676 | bb->aux) | |
23a070f3 | 3677 | { |
3678 | if (BB_HEADER (bb)) | |
3679 | { | |
3680 | if (insn) | |
4a57a2e8 | 3681 | SET_NEXT_INSN (insn) = BB_HEADER (bb); |
23a070f3 | 3682 | else |
3683 | set_first_insn (BB_HEADER (bb)); | |
4a57a2e8 | 3684 | SET_PREV_INSN (BB_HEADER (bb)) = insn; |
23a070f3 | 3685 | insn = BB_HEADER (bb); |
3686 | while (NEXT_INSN (insn)) | |
3687 | insn = NEXT_INSN (insn); | |
3688 | } | |
3689 | if (insn) | |
4a57a2e8 | 3690 | SET_NEXT_INSN (insn) = BB_HEAD (bb); |
23a070f3 | 3691 | else |
3692 | set_first_insn (BB_HEAD (bb)); | |
4a57a2e8 | 3693 | SET_PREV_INSN (BB_HEAD (bb)) = insn; |
23a070f3 | 3694 | insn = BB_END (bb); |
3695 | if (BB_FOOTER (bb)) | |
3696 | { | |
4a57a2e8 | 3697 | SET_NEXT_INSN (insn) = BB_FOOTER (bb); |
3698 | SET_PREV_INSN (BB_FOOTER (bb)) = insn; | |
23a070f3 | 3699 | while (NEXT_INSN (insn)) |
3700 | insn = NEXT_INSN (insn); | |
3701 | } | |
3702 | } | |
3703 | ||
4a57a2e8 | 3704 | SET_NEXT_INSN (insn) = cfg_layout_function_footer; |
23a070f3 | 3705 | if (cfg_layout_function_footer) |
4a57a2e8 | 3706 | SET_PREV_INSN (cfg_layout_function_footer) = insn; |
23a070f3 | 3707 | |
3708 | while (NEXT_INSN (insn)) | |
3709 | insn = NEXT_INSN (insn); | |
3710 | ||
3711 | set_last_insn (insn); | |
382ecba7 | 3712 | if (flag_checking) |
3713 | verify_insn_chain (); | |
23a070f3 | 3714 | |
3715 | /* Now add jumps and labels as needed to match the blocks new | |
c38b28e7 | 3716 | outgoing edges. */ |
23a070f3 | 3717 | |
c38b28e7 | 3718 | for (bb = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb; bb ; bb = (basic_block) |
3719 | bb->aux) | |
23a070f3 | 3720 | { |
3721 | edge e_fall, e_taken, e; | |
3d90435a | 3722 | rtx_insn *bb_end_insn; |
23a070f3 | 3723 | rtx ret_label = NULL_RTX; |
aa78dca5 | 3724 | basic_block nb; |
23a070f3 | 3725 | edge_iterator ei; |
3726 | ||
3727 | if (EDGE_COUNT (bb->succs) == 0) | |
3728 | continue; | |
3729 | ||
3730 | /* Find the old fallthru edge, and another non-EH edge for | |
3731 | a taken jump. */ | |
3732 | e_taken = e_fall = NULL; | |
3733 | ||
3734 | FOR_EACH_EDGE (e, ei, bb->succs) | |
3735 | if (e->flags & EDGE_FALLTHRU) | |
3736 | e_fall = e; | |
3737 | else if (! (e->flags & EDGE_EH)) | |
3738 | e_taken = e; | |
3739 | ||
3740 | bb_end_insn = BB_END (bb); | |
f9a00e9e | 3741 | if (rtx_jump_insn *bb_end_jump = dyn_cast <rtx_jump_insn *> (bb_end_insn)) |
23a070f3 | 3742 | { |
f9a00e9e | 3743 | ret_label = JUMP_LABEL (bb_end_jump); |
3744 | if (any_condjump_p (bb_end_jump)) | |
23a070f3 | 3745 | { |
3746 | /* This might happen if the conditional jump has side | |
3747 | effects and could therefore not be optimized away. | |
3748 | Make the basic block to end with a barrier in order | |
3749 | to prevent rtl_verify_flow_info from complaining. */ | |
3750 | if (!e_fall) | |
3751 | { | |
f9a00e9e | 3752 | gcc_assert (!onlyjump_p (bb_end_jump) |
3753 | || returnjump_p (bb_end_jump) | |
3b649e5d | 3754 | || (e_taken->flags & EDGE_CROSSING)); |
f9a00e9e | 3755 | emit_barrier_after (bb_end_jump); |
23a070f3 | 3756 | continue; |
3757 | } | |
3758 | ||
3759 | /* If the old fallthru is still next, nothing to do. */ | |
3760 | if (bb->aux == e_fall->dest | |
34154e27 | 3761 | || e_fall->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
23a070f3 | 3762 | continue; |
3763 | ||
3764 | /* The degenerated case of conditional jump jumping to the next | |
3765 | instruction can happen for jumps with side effects. We need | |
3766 | to construct a forwarder block and this will be done just | |
3767 | fine by force_nonfallthru below. */ | |
3768 | if (!e_taken) | |
3769 | ; | |
3770 | ||
3771 | /* There is another special case: if *neither* block is next, | |
3772 | such as happens at the very end of a function, then we'll | |
3773 | need to add a new unconditional jump. Choose the taken | |
3774 | edge based on known or assumed probability. */ | |
3775 | else if (bb->aux != e_taken->dest) | |
3776 | { | |
f9a00e9e | 3777 | rtx note = find_reg_note (bb_end_jump, REG_BR_PROB, 0); |
23a070f3 | 3778 | |
3779 | if (note | |
9eb946de | 3780 | && XINT (note, 0) < REG_BR_PROB_BASE / 2 |
f9a00e9e | 3781 | && invert_jump (bb_end_jump, |
34154e27 | 3782 | (e_fall->dest |
3783 | == EXIT_BLOCK_PTR_FOR_FN (cfun) | |
23a070f3 | 3784 | ? NULL_RTX |
3785 | : label_for_bb (e_fall->dest)), 0)) | |
3786 | { | |
3787 | e_fall->flags &= ~EDGE_FALLTHRU; | |
3788 | gcc_checking_assert (could_fall_through | |
3789 | (e_taken->src, e_taken->dest)); | |
3790 | e_taken->flags |= EDGE_FALLTHRU; | |
3791 | update_br_prob_note (bb); | |
3792 | e = e_fall, e_fall = e_taken, e_taken = e; | |
3793 | } | |
3794 | } | |
3795 | ||
3796 | /* If the "jumping" edge is a crossing edge, and the fall | |
3797 | through edge is non-crossing, leave things as they are. */ | |
3798 | else if ((e_taken->flags & EDGE_CROSSING) | |
3799 | && !(e_fall->flags & EDGE_CROSSING)) | |
3800 | continue; | |
3801 | ||
3802 | /* Otherwise we can try to invert the jump. This will | |
3803 | basically never fail, however, keep up the pretense. */ | |
f9a00e9e | 3804 | else if (invert_jump (bb_end_jump, |
34154e27 | 3805 | (e_fall->dest |
3806 | == EXIT_BLOCK_PTR_FOR_FN (cfun) | |
23a070f3 | 3807 | ? NULL_RTX |
3808 | : label_for_bb (e_fall->dest)), 0)) | |
3809 | { | |
3810 | e_fall->flags &= ~EDGE_FALLTHRU; | |
3811 | gcc_checking_assert (could_fall_through | |
3812 | (e_taken->src, e_taken->dest)); | |
3813 | e_taken->flags |= EDGE_FALLTHRU; | |
3814 | update_br_prob_note (bb); | |
3815 | if (LABEL_NUSES (ret_label) == 0 | |
3816 | && single_pred_p (e_taken->dest)) | |
3817 | delete_insn (ret_label); | |
3818 | continue; | |
3819 | } | |
3820 | } | |
3821 | else if (extract_asm_operands (PATTERN (bb_end_insn)) != NULL) | |
3822 | { | |
3823 | /* If the old fallthru is still next or if | |
3824 | asm goto doesn't have a fallthru (e.g. when followed by | |
3825 | __builtin_unreachable ()), nothing to do. */ | |
3826 | if (! e_fall | |
3827 | || bb->aux == e_fall->dest | |
34154e27 | 3828 | || e_fall->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
23a070f3 | 3829 | continue; |
3830 | ||
3831 | /* Otherwise we'll have to use the fallthru fixup below. */ | |
3832 | } | |
3833 | else | |
3834 | { | |
3835 | /* Otherwise we have some return, switch or computed | |
3836 | jump. In the 99% case, there should not have been a | |
3837 | fallthru edge. */ | |
3838 | gcc_assert (returnjump_p (bb_end_insn) || !e_fall); | |
3839 | continue; | |
3840 | } | |
3841 | } | |
3842 | else | |
3843 | { | |
3844 | /* No fallthru implies a noreturn function with EH edges, or | |
3845 | something similarly bizarre. In any case, we don't need to | |
3846 | do anything. */ | |
3847 | if (! e_fall) | |
3848 | continue; | |
3849 | ||
3850 | /* If the fallthru block is still next, nothing to do. */ | |
3851 | if (bb->aux == e_fall->dest) | |
3852 | continue; | |
3853 | ||
3854 | /* A fallthru to exit block. */ | |
34154e27 | 3855 | if (e_fall->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
23a070f3 | 3856 | continue; |
3857 | } | |
3858 | ||
3859 | /* We got here if we need to add a new jump insn. | |
3860 | Note force_nonfallthru can delete E_FALL and thus we have to | |
3861 | save E_FALL->src prior to the call to force_nonfallthru. */ | |
23a070f3 | 3862 | nb = force_nonfallthru_and_redirect (e_fall, e_fall->dest, ret_label); |
3863 | if (nb) | |
3864 | { | |
3865 | nb->aux = bb->aux; | |
3866 | bb->aux = nb; | |
3867 | /* Don't process this new block. */ | |
3868 | bb = nb; | |
23a070f3 | 3869 | } |
3870 | } | |
3871 | ||
3872 | relink_block_chain (/*stay_in_cfglayout_mode=*/false); | |
3873 | ||
c38b28e7 | 3874 | /* Annoying special case - jump around dead jumptables left in the code. */ |
fc00614f | 3875 | FOR_EACH_BB_FN (bb, cfun) |
23a070f3 | 3876 | { |
3877 | edge e = find_fallthru_edge (bb->succs); | |
3878 | ||
c38b28e7 | 3879 | if (e && !can_fallthru (e->src, e->dest)) |
3880 | force_nonfallthru (e); | |
23a070f3 | 3881 | } |
3882 | ||
3883 | /* Ensure goto_locus from edges has some instructions with that locus | |
3884 | in RTL. */ | |
3885 | if (!optimize) | |
fc00614f | 3886 | FOR_EACH_BB_FN (bb, cfun) |
23a070f3 | 3887 | { |
3888 | edge e; | |
3889 | edge_iterator ei; | |
3890 | ||
3891 | FOR_EACH_EDGE (e, ei, bb->succs) | |
8e7408e3 | 3892 | if (LOCATION_LOCUS (e->goto_locus) != UNKNOWN_LOCATION |
5169661d | 3893 | && !(e->flags & EDGE_ABNORMAL)) |
23a070f3 | 3894 | { |
3895 | edge e2; | |
3896 | edge_iterator ei2; | |
3897 | basic_block dest, nb; | |
3d90435a | 3898 | rtx_insn *end; |
23a070f3 | 3899 | |
3900 | insn = BB_END (e->src); | |
3901 | end = PREV_INSN (BB_HEAD (e->src)); | |
3902 | while (insn != end | |
5169661d | 3903 | && (!NONDEBUG_INSN_P (insn) || !INSN_HAS_LOCATION (insn))) |
23a070f3 | 3904 | insn = PREV_INSN (insn); |
3905 | if (insn != end | |
5169661d | 3906 | && INSN_LOCATION (insn) == e->goto_locus) |
23a070f3 | 3907 | continue; |
3908 | if (simplejump_p (BB_END (e->src)) | |
5169661d | 3909 | && !INSN_HAS_LOCATION (BB_END (e->src))) |
23a070f3 | 3910 | { |
5169661d | 3911 | INSN_LOCATION (BB_END (e->src)) = e->goto_locus; |
23a070f3 | 3912 | continue; |
3913 | } | |
3914 | dest = e->dest; | |
34154e27 | 3915 | if (dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
23a070f3 | 3916 | { |
3917 | /* Non-fallthru edges to the exit block cannot be split. */ | |
3918 | if (!(e->flags & EDGE_FALLTHRU)) | |
3919 | continue; | |
3920 | } | |
3921 | else | |
3922 | { | |
3923 | insn = BB_HEAD (dest); | |
3924 | end = NEXT_INSN (BB_END (dest)); | |
3925 | while (insn != end && !NONDEBUG_INSN_P (insn)) | |
3926 | insn = NEXT_INSN (insn); | |
5169661d | 3927 | if (insn != end && INSN_HAS_LOCATION (insn) |
3928 | && INSN_LOCATION (insn) == e->goto_locus) | |
23a070f3 | 3929 | continue; |
3930 | } | |
3931 | nb = split_edge (e); | |
3932 | if (!INSN_P (BB_END (nb))) | |
26bb3cb2 | 3933 | BB_END (nb) = emit_insn_after_noloc (gen_nop (), BB_END (nb), |
a684cb04 | 3934 | nb); |
5169661d | 3935 | INSN_LOCATION (BB_END (nb)) = e->goto_locus; |
23a070f3 | 3936 | |
3937 | /* If there are other incoming edges to the destination block | |
3938 | with the same goto locus, redirect them to the new block as | |
3939 | well, this can prevent other such blocks from being created | |
3940 | in subsequent iterations of the loop. */ | |
3941 | for (ei2 = ei_start (dest->preds); (e2 = ei_safe_edge (ei2)); ) | |
8e7408e3 | 3942 | if (LOCATION_LOCUS (e2->goto_locus) != UNKNOWN_LOCATION |
23a070f3 | 3943 | && !(e2->flags & (EDGE_ABNORMAL | EDGE_FALLTHRU)) |
5169661d | 3944 | && e->goto_locus == e2->goto_locus) |
23a070f3 | 3945 | redirect_edge_and_branch (e2, nb); |
3946 | else | |
3947 | ei_next (&ei2); | |
3948 | } | |
3949 | } | |
3950 | } | |
3951 | \f | |
3952 | /* Perform sanity checks on the insn chain. | |
3953 | 1. Check that next/prev pointers are consistent in both the forward and | |
3954 | reverse direction. | |
3955 | 2. Count insns in chain, going both directions, and check if equal. | |
3956 | 3. Check that get_last_insn () returns the actual end of chain. */ | |
3957 | ||
3958 | DEBUG_FUNCTION void | |
3959 | verify_insn_chain (void) | |
3960 | { | |
3d90435a | 3961 | rtx_insn *x, *prevx, *nextx; |
23a070f3 | 3962 | int insn_cnt1, insn_cnt2; |
3963 | ||
3964 | for (prevx = NULL, insn_cnt1 = 1, x = get_insns (); | |
3965 | x != 0; | |
3966 | prevx = x, insn_cnt1++, x = NEXT_INSN (x)) | |
3967 | gcc_assert (PREV_INSN (x) == prevx); | |
3968 | ||
3969 | gcc_assert (prevx == get_last_insn ()); | |
3970 | ||
3971 | for (nextx = NULL, insn_cnt2 = 1, x = get_last_insn (); | |
3972 | x != 0; | |
3973 | nextx = x, insn_cnt2++, x = PREV_INSN (x)) | |
3974 | gcc_assert (NEXT_INSN (x) == nextx); | |
3975 | ||
3976 | gcc_assert (insn_cnt1 == insn_cnt2); | |
3977 | } | |
3978 | \f | |
3979 | /* If we have assembler epilogues, the block falling through to exit must | |
3980 | be the last one in the reordered chain when we reach final. Ensure | |
3981 | that this condition is met. */ | |
3982 | static void | |
3983 | fixup_fallthru_exit_predecessor (void) | |
3984 | { | |
3985 | edge e; | |
3986 | basic_block bb = NULL; | |
3987 | ||
3988 | /* This transformation is not valid before reload, because we might | |
3989 | separate a call from the instruction that copies the return | |
3990 | value. */ | |
3991 | gcc_assert (reload_completed); | |
3992 | ||
34154e27 | 3993 | e = find_fallthru_edge (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds); |
23a070f3 | 3994 | if (e) |
3995 | bb = e->src; | |
3996 | ||
3997 | if (bb && bb->aux) | |
3998 | { | |
34154e27 | 3999 | basic_block c = ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb; |
23a070f3 | 4000 | |
4001 | /* If the very first block is the one with the fall-through exit | |
4002 | edge, we have to split that block. */ | |
4003 | if (c == bb) | |
4004 | { | |
4302d619 | 4005 | bb = split_block_after_labels (bb)->dest; |
23a070f3 | 4006 | bb->aux = c->aux; |
4007 | c->aux = bb; | |
943ea6fa | 4008 | BB_FOOTER (bb) = BB_FOOTER (c); |
4009 | BB_FOOTER (c) = NULL; | |
23a070f3 | 4010 | } |
4011 | ||
4012 | while (c->aux != bb) | |
4013 | c = (basic_block) c->aux; | |
4014 | ||
4015 | c->aux = bb->aux; | |
4016 | while (c->aux) | |
4017 | c = (basic_block) c->aux; | |
4018 | ||
4019 | c->aux = bb; | |
4020 | bb->aux = NULL; | |
4021 | } | |
4022 | } | |
4023 | ||
4024 | /* In case there are more than one fallthru predecessors of exit, force that | |
4025 | there is only one. */ | |
4026 | ||
4027 | static void | |
4028 | force_one_exit_fallthru (void) | |
4029 | { | |
4030 | edge e, predecessor = NULL; | |
4031 | bool more = false; | |
4032 | edge_iterator ei; | |
4033 | basic_block forwarder, bb; | |
4034 | ||
34154e27 | 4035 | FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds) |
23a070f3 | 4036 | if (e->flags & EDGE_FALLTHRU) |
4037 | { | |
4038 | if (predecessor == NULL) | |
4039 | predecessor = e; | |
4040 | else | |
4041 | { | |
4042 | more = true; | |
4043 | break; | |
4044 | } | |
4045 | } | |
4046 | ||
4047 | if (!more) | |
4048 | return; | |
4049 | ||
4050 | /* Exit has several fallthru predecessors. Create a forwarder block for | |
4051 | them. */ | |
4052 | forwarder = split_edge (predecessor); | |
34154e27 | 4053 | for (ei = ei_start (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds); |
4054 | (e = ei_safe_edge (ei)); ) | |
23a070f3 | 4055 | { |
4056 | if (e->src == forwarder | |
4057 | || !(e->flags & EDGE_FALLTHRU)) | |
4058 | ei_next (&ei); | |
4059 | else | |
4060 | redirect_edge_and_branch_force (e, forwarder); | |
4061 | } | |
4062 | ||
4063 | /* Fix up the chain of blocks -- make FORWARDER immediately precede the | |
4064 | exit block. */ | |
fc00614f | 4065 | FOR_EACH_BB_FN (bb, cfun) |
23a070f3 | 4066 | { |
4067 | if (bb->aux == NULL && bb != forwarder) | |
4068 | { | |
4069 | bb->aux = forwarder; | |
4070 | break; | |
4071 | } | |
4072 | } | |
4073 | } | |
4074 | \f | |
4075 | /* Return true in case it is possible to duplicate the basic block BB. */ | |
4076 | ||
4077 | static bool | |
4078 | cfg_layout_can_duplicate_bb_p (const_basic_block bb) | |
4079 | { | |
4080 | /* Do not attempt to duplicate tablejumps, as we need to unshare | |
4081 | the dispatch table. This is difficult to do, as the instructions | |
4082 | computing jump destination may be hoisted outside the basic block. */ | |
4083 | if (tablejump_p (BB_END (bb), NULL, NULL)) | |
4084 | return false; | |
4085 | ||
4086 | /* Do not duplicate blocks containing insns that can't be copied. */ | |
4087 | if (targetm.cannot_copy_insn_p) | |
4088 | { | |
3d90435a | 4089 | rtx_insn *insn = BB_HEAD (bb); |
23a070f3 | 4090 | while (1) |
4091 | { | |
4092 | if (INSN_P (insn) && targetm.cannot_copy_insn_p (insn)) | |
4093 | return false; | |
4094 | if (insn == BB_END (bb)) | |
4095 | break; | |
4096 | insn = NEXT_INSN (insn); | |
4097 | } | |
4098 | } | |
4099 | ||
4100 | return true; | |
4101 | } | |
4102 | ||
aa935352 | 4103 | rtx_insn * |
baa294b4 | 4104 | duplicate_insn_chain (rtx_insn *from, rtx_insn *to) |
23a070f3 | 4105 | { |
baa294b4 | 4106 | rtx_insn *insn, *next, *copy; |
cef3d8ad | 4107 | rtx_note *last; |
23a070f3 | 4108 | |
4109 | /* Avoid updating of boundaries of previous basic block. The | |
4110 | note will get removed from insn stream in fixup. */ | |
4111 | last = emit_note (NOTE_INSN_DELETED); | |
4112 | ||
4113 | /* Create copy at the end of INSN chain. The chain will | |
4114 | be reordered later. */ | |
4115 | for (insn = from; insn != NEXT_INSN (to); insn = NEXT_INSN (insn)) | |
4116 | { | |
4117 | switch (GET_CODE (insn)) | |
4118 | { | |
4119 | case DEBUG_INSN: | |
4120 | /* Don't duplicate label debug insns. */ | |
4121 | if (TREE_CODE (INSN_VAR_LOCATION_DECL (insn)) == LABEL_DECL) | |
4122 | break; | |
4123 | /* FALLTHRU */ | |
4124 | case INSN: | |
4125 | case CALL_INSN: | |
4126 | case JUMP_INSN: | |
23a070f3 | 4127 | copy = emit_copy_of_insn_after (insn, get_last_insn ()); |
4128 | if (JUMP_P (insn) && JUMP_LABEL (insn) != NULL_RTX | |
4129 | && ANY_RETURN_P (JUMP_LABEL (insn))) | |
4130 | JUMP_LABEL (copy) = JUMP_LABEL (insn); | |
4131 | maybe_copy_prologue_epilogue_insn (insn, copy); | |
4132 | break; | |
4133 | ||
91f71fa3 | 4134 | case JUMP_TABLE_DATA: |
4135 | /* Avoid copying of dispatch tables. We never duplicate | |
4136 | tablejumps, so this can hit only in case the table got | |
4137 | moved far from original jump. | |
4138 | Avoid copying following barrier as well if any | |
4139 | (and debug insns in between). */ | |
4140 | for (next = NEXT_INSN (insn); | |
4141 | next != NEXT_INSN (to); | |
4142 | next = NEXT_INSN (next)) | |
4143 | if (!DEBUG_INSN_P (next)) | |
4144 | break; | |
4145 | if (next != NEXT_INSN (to) && BARRIER_P (next)) | |
4146 | insn = next; | |
4147 | break; | |
4148 | ||
23a070f3 | 4149 | case CODE_LABEL: |
4150 | break; | |
4151 | ||
4152 | case BARRIER: | |
4153 | emit_barrier (); | |
4154 | break; | |
4155 | ||
4156 | case NOTE: | |
4157 | switch (NOTE_KIND (insn)) | |
4158 | { | |
4159 | /* In case prologue is empty and function contain label | |
4160 | in first BB, we may want to copy the block. */ | |
4161 | case NOTE_INSN_PROLOGUE_END: | |
4162 | ||
4163 | case NOTE_INSN_DELETED: | |
4164 | case NOTE_INSN_DELETED_LABEL: | |
4165 | case NOTE_INSN_DELETED_DEBUG_LABEL: | |
4166 | /* No problem to strip these. */ | |
4167 | case NOTE_INSN_FUNCTION_BEG: | |
4168 | /* There is always just single entry to function. */ | |
4169 | case NOTE_INSN_BASIC_BLOCK: | |
aa78dca5 | 4170 | /* We should only switch text sections once. */ |
4171 | case NOTE_INSN_SWITCH_TEXT_SECTIONS: | |
23a070f3 | 4172 | break; |
4173 | ||
4174 | case NOTE_INSN_EPILOGUE_BEG: | |
97354ae4 | 4175 | case NOTE_INSN_UPDATE_SJLJ_CONTEXT: |
cef3d8ad | 4176 | emit_note_copy (as_a <rtx_note *> (insn)); |
23a070f3 | 4177 | break; |
4178 | ||
4179 | default: | |
4180 | /* All other notes should have already been eliminated. */ | |
4181 | gcc_unreachable (); | |
4182 | } | |
4183 | break; | |
4184 | default: | |
4185 | gcc_unreachable (); | |
4186 | } | |
4187 | } | |
4188 | insn = NEXT_INSN (last); | |
4189 | delete_insn (last); | |
baa294b4 | 4190 | return insn; |
23a070f3 | 4191 | } |
4192 | ||
4193 | /* Create a duplicate of the basic block BB. */ | |
4194 | ||
4195 | static basic_block | |
4196 | cfg_layout_duplicate_bb (basic_block bb) | |
4197 | { | |
3d90435a | 4198 | rtx_insn *insn; |
23a070f3 | 4199 | basic_block new_bb; |
4200 | ||
4201 | insn = duplicate_insn_chain (BB_HEAD (bb), BB_END (bb)); | |
4202 | new_bb = create_basic_block (insn, | |
4203 | insn ? get_last_insn () : NULL, | |
34154e27 | 4204 | EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb); |
23a070f3 | 4205 | |
4206 | BB_COPY_PARTITION (new_bb, bb); | |
4207 | if (BB_HEADER (bb)) | |
4208 | { | |
4209 | insn = BB_HEADER (bb); | |
4210 | while (NEXT_INSN (insn)) | |
4211 | insn = NEXT_INSN (insn); | |
4212 | insn = duplicate_insn_chain (BB_HEADER (bb), insn); | |
4213 | if (insn) | |
26bb3cb2 | 4214 | BB_HEADER (new_bb) = unlink_insn_chain (insn, get_last_insn ()); |
23a070f3 | 4215 | } |
4216 | ||
4217 | if (BB_FOOTER (bb)) | |
4218 | { | |
4219 | insn = BB_FOOTER (bb); | |
4220 | while (NEXT_INSN (insn)) | |
4221 | insn = NEXT_INSN (insn); | |
4222 | insn = duplicate_insn_chain (BB_FOOTER (bb), insn); | |
4223 | if (insn) | |
943ea6fa | 4224 | BB_FOOTER (new_bb) = unlink_insn_chain (insn, get_last_insn ()); |
23a070f3 | 4225 | } |
4226 | ||
4227 | return new_bb; | |
4228 | } | |
4229 | ||
4230 | \f | |
4231 | /* Main entry point to this module - initialize the datastructures for | |
4232 | CFG layout changes. It keeps LOOPS up-to-date if not null. | |
4233 | ||
4234 | FLAGS is a set of additional flags to pass to cleanup_cfg(). */ | |
4235 | ||
4236 | void | |
4237 | cfg_layout_initialize (unsigned int flags) | |
4238 | { | |
a4de1c23 | 4239 | rtx_insn_list *x; |
23a070f3 | 4240 | basic_block bb; |
4241 | ||
e22c35e9 | 4242 | /* Once bb partitioning is complete, cfg layout mode should not be |
4243 | re-entered. Entering cfg layout mode may require fixups. As an | |
4244 | example, if edge forwarding performed when optimizing the cfg | |
4245 | layout required moving a block from the hot to the cold | |
4246 | section. This would create an illegal partitioning unless some | |
4247 | manual fixup was performed. */ | |
4248 | gcc_assert (!(crtl->bb_reorder_complete | |
4249 | && flag_reorder_blocks_and_partition)); | |
e31c70b9 | 4250 | |
23a070f3 | 4251 | initialize_original_copy_tables (); |
4252 | ||
4253 | cfg_layout_rtl_register_cfg_hooks (); | |
4254 | ||
4255 | record_effective_endpoints (); | |
4256 | ||
4257 | /* Make sure that the targets of non local gotos are marked. */ | |
6e16e157 | 4258 | for (x = nonlocal_goto_handler_labels; x; x = x->next ()) |
23a070f3 | 4259 | { |
a4de1c23 | 4260 | bb = BLOCK_FOR_INSN (x->insn ()); |
23a070f3 | 4261 | bb->flags |= BB_NON_LOCAL_GOTO_TARGET; |
4262 | } | |
4263 | ||
4264 | cleanup_cfg (CLEANUP_CFGLAYOUT | flags); | |
4265 | } | |
4266 | ||
4267 | /* Splits superblocks. */ | |
4268 | void | |
4269 | break_superblocks (void) | |
4270 | { | |
4271 | sbitmap superblocks; | |
4272 | bool need = false; | |
4273 | basic_block bb; | |
4274 | ||
fe672ac0 | 4275 | superblocks = sbitmap_alloc (last_basic_block_for_fn (cfun)); |
53c5d9d4 | 4276 | bitmap_clear (superblocks); |
23a070f3 | 4277 | |
fc00614f | 4278 | FOR_EACH_BB_FN (bb, cfun) |
23a070f3 | 4279 | if (bb->flags & BB_SUPERBLOCK) |
4280 | { | |
4281 | bb->flags &= ~BB_SUPERBLOCK; | |
08b7917c | 4282 | bitmap_set_bit (superblocks, bb->index); |
23a070f3 | 4283 | need = true; |
4284 | } | |
4285 | ||
4286 | if (need) | |
4287 | { | |
4288 | rebuild_jump_labels (get_insns ()); | |
4289 | find_many_sub_basic_blocks (superblocks); | |
4290 | } | |
4291 | ||
4292 | free (superblocks); | |
4293 | } | |
4294 | ||
4295 | /* Finalize the changes: reorder insn list according to the sequence specified | |
c38b28e7 | 4296 | by aux pointers, enter compensation code, rebuild scope forest. */ |
23a070f3 | 4297 | |
4298 | void | |
4299 | cfg_layout_finalize (void) | |
4300 | { | |
382ecba7 | 4301 | checking_verify_flow_info (); |
f3c921eb | 4302 | free_dominance_info (CDI_DOMINATORS); |
23a070f3 | 4303 | force_one_exit_fallthru (); |
4304 | rtl_register_cfg_hooks (); | |
cf3a33c8 | 4305 | if (reload_completed && !targetm.have_epilogue ()) |
23a070f3 | 4306 | fixup_fallthru_exit_predecessor (); |
4307 | fixup_reorder_chain (); | |
4308 | ||
c38b28e7 | 4309 | rebuild_jump_labels (get_insns ()); |
4310 | delete_dead_jumptables (); | |
4311 | ||
382ecba7 | 4312 | if (flag_checking) |
4313 | verify_insn_chain (); | |
4314 | checking_verify_flow_info (); | |
23a070f3 | 4315 | } |
4316 | ||
54f21e20 | 4317 | |
1026363d | 4318 | /* Same as split_block but update cfg_layout structures. */ |
5f5d4cd1 | 4319 | |
4320 | static basic_block | |
4c9e08a4 | 4321 | cfg_layout_split_block (basic_block bb, void *insnp) |
1026363d | 4322 | { |
f780cc25 | 4323 | rtx insn = (rtx) insnp; |
5f5d4cd1 | 4324 | basic_block new_bb = rtl_split_block (bb, insn); |
1026363d | 4325 | |
943ea6fa | 4326 | BB_FOOTER (new_bb) = BB_FOOTER (bb); |
4327 | BB_FOOTER (bb) = NULL; | |
1026363d | 4328 | |
5f5d4cd1 | 4329 | return new_bb; |
1026363d | 4330 | } |
4331 | ||
1026363d | 4332 | /* Redirect Edge to DEST. */ |
4ee9c684 | 4333 | static edge |
4c9e08a4 | 4334 | cfg_layout_redirect_edge_and_branch (edge e, basic_block dest) |
1026363d | 4335 | { |
4336 | basic_block src = e->src; | |
4ee9c684 | 4337 | edge ret; |
1026363d | 4338 | |
c60fa3a7 | 4339 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) |
4ee9c684 | 4340 | return NULL; |
c60fa3a7 | 4341 | |
e5562ab8 | 4342 | if (e->dest == dest) |
4ee9c684 | 4343 | return e; |
c60fa3a7 | 4344 | |
34154e27 | 4345 | if (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
4ee9c684 | 4346 | && (ret = try_redirect_by_replacing_jump (e, dest, true))) |
adee86a0 | 4347 | { |
3072d30e | 4348 | df_set_bb_dirty (src); |
4ee9c684 | 4349 | return ret; |
adee86a0 | 4350 | } |
c60fa3a7 | 4351 | |
34154e27 | 4352 | if (e->src == ENTRY_BLOCK_PTR_FOR_FN (cfun) |
c60fa3a7 | 4353 | && (e->flags & EDGE_FALLTHRU) && !(e->flags & EDGE_COMPLEX)) |
4354 | { | |
450d042a | 4355 | if (dump_file) |
4356 | fprintf (dump_file, "Redirecting entry edge from bb %i to %i\n", | |
c60fa3a7 | 4357 | e->src->index, dest->index); |
4358 | ||
3072d30e | 4359 | df_set_bb_dirty (e->src); |
c60fa3a7 | 4360 | redirect_edge_succ (e, dest); |
4ee9c684 | 4361 | return e; |
c60fa3a7 | 4362 | } |
4363 | ||
1026363d | 4364 | /* Redirect_edge_and_branch may decide to turn branch into fallthru edge |
4365 | in the case the basic block appears to be in sequence. Avoid this | |
4366 | transformation. */ | |
4367 | ||
1026363d | 4368 | if (e->flags & EDGE_FALLTHRU) |
4369 | { | |
4370 | /* Redirect any branch edges unified with the fallthru one. */ | |
6d7dc5b9 | 4371 | if (JUMP_P (BB_END (src)) |
b9de5542 | 4372 | && label_is_jump_target_p (BB_HEAD (e->dest), |
4373 | BB_END (src))) | |
1026363d | 4374 | { |
cc636d56 | 4375 | edge redirected; |
a0c938f0 | 4376 | |
450d042a | 4377 | if (dump_file) |
4378 | fprintf (dump_file, "Fallthru edge unified with branch " | |
b9de5542 | 4379 | "%i->%i redirected to %i\n", |
4380 | e->src->index, e->dest->index, dest->index); | |
4381 | e->flags &= ~EDGE_FALLTHRU; | |
cc636d56 | 4382 | redirected = redirect_branch_edge (e, dest); |
4383 | gcc_assert (redirected); | |
d5321455 | 4384 | redirected->flags |= EDGE_FALLTHRU; |
4385 | df_set_bb_dirty (redirected->src); | |
4386 | return redirected; | |
1026363d | 4387 | } |
4388 | /* In case we are redirecting fallthru edge to the branch edge | |
a0c938f0 | 4389 | of conditional jump, remove it. */ |
cd665a06 | 4390 | if (EDGE_COUNT (src->succs) == 2) |
1026363d | 4391 | { |
9ea57afb | 4392 | /* Find the edge that is different from E. */ |
4393 | edge s = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e); | |
cd665a06 | 4394 | |
1026363d | 4395 | if (s->dest == dest |
5496dbfc | 4396 | && any_condjump_p (BB_END (src)) |
4397 | && onlyjump_p (BB_END (src))) | |
4398 | delete_insn (BB_END (src)); | |
1026363d | 4399 | } |
450d042a | 4400 | if (dump_file) |
6d31b223 | 4401 | fprintf (dump_file, "Redirecting fallthru edge %i->%i to %i\n", |
c60fa3a7 | 4402 | e->src->index, e->dest->index, dest->index); |
d5321455 | 4403 | ret = redirect_edge_succ_nodup (e, dest); |
1026363d | 4404 | } |
4405 | else | |
c60fa3a7 | 4406 | ret = redirect_branch_edge (e, dest); |
1026363d | 4407 | |
4408 | /* We don't want simplejumps in the insn stream during cfglayout. */ | |
cc636d56 | 4409 | gcc_assert (!simplejump_p (BB_END (src))); |
1026363d | 4410 | |
3072d30e | 4411 | df_set_bb_dirty (src); |
1026363d | 4412 | return ret; |
4413 | } | |
4414 | ||
4415 | /* Simple wrapper as we always can redirect fallthru edges. */ | |
4416 | static basic_block | |
4c9e08a4 | 4417 | cfg_layout_redirect_edge_and_branch_force (edge e, basic_block dest) |
1026363d | 4418 | { |
cc636d56 | 4419 | edge redirected = cfg_layout_redirect_edge_and_branch (e, dest); |
4420 | ||
4421 | gcc_assert (redirected); | |
1026363d | 4422 | return NULL; |
4423 | } | |
4424 | ||
5f5d4cd1 | 4425 | /* Same as delete_basic_block but update cfg_layout structures. */ |
4426 | ||
1026363d | 4427 | static void |
4c9e08a4 | 4428 | cfg_layout_delete_block (basic_block bb) |
1026363d | 4429 | { |
3d90435a | 4430 | rtx_insn *insn, *next, *prev = PREV_INSN (BB_HEAD (bb)), *remaints; |
26bb3cb2 | 4431 | rtx_insn **to; |
1026363d | 4432 | |
43e94e51 | 4433 | if (BB_HEADER (bb)) |
1026363d | 4434 | { |
5496dbfc | 4435 | next = BB_HEAD (bb); |
1026363d | 4436 | if (prev) |
4a57a2e8 | 4437 | SET_NEXT_INSN (prev) = BB_HEADER (bb); |
1026363d | 4438 | else |
43e94e51 | 4439 | set_first_insn (BB_HEADER (bb)); |
4a57a2e8 | 4440 | SET_PREV_INSN (BB_HEADER (bb)) = prev; |
43e94e51 | 4441 | insn = BB_HEADER (bb); |
1026363d | 4442 | while (NEXT_INSN (insn)) |
4443 | insn = NEXT_INSN (insn); | |
4a57a2e8 | 4444 | SET_NEXT_INSN (insn) = next; |
4445 | SET_PREV_INSN (next) = insn; | |
1026363d | 4446 | } |
5496dbfc | 4447 | next = NEXT_INSN (BB_END (bb)); |
43e94e51 | 4448 | if (BB_FOOTER (bb)) |
1026363d | 4449 | { |
43e94e51 | 4450 | insn = BB_FOOTER (bb); |
c60fa3a7 | 4451 | while (insn) |
4452 | { | |
6d7dc5b9 | 4453 | if (BARRIER_P (insn)) |
c60fa3a7 | 4454 | { |
4455 | if (PREV_INSN (insn)) | |
4a57a2e8 | 4456 | SET_NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); |
c60fa3a7 | 4457 | else |
943ea6fa | 4458 | BB_FOOTER (bb) = NEXT_INSN (insn); |
c60fa3a7 | 4459 | if (NEXT_INSN (insn)) |
4a57a2e8 | 4460 | SET_PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); |
c60fa3a7 | 4461 | } |
6d7dc5b9 | 4462 | if (LABEL_P (insn)) |
c60fa3a7 | 4463 | break; |
4464 | insn = NEXT_INSN (insn); | |
4465 | } | |
43e94e51 | 4466 | if (BB_FOOTER (bb)) |
c60fa3a7 | 4467 | { |
5496dbfc | 4468 | insn = BB_END (bb); |
4a57a2e8 | 4469 | SET_NEXT_INSN (insn) = BB_FOOTER (bb); |
4470 | SET_PREV_INSN (BB_FOOTER (bb)) = insn; | |
c60fa3a7 | 4471 | while (NEXT_INSN (insn)) |
4472 | insn = NEXT_INSN (insn); | |
4a57a2e8 | 4473 | SET_NEXT_INSN (insn) = next; |
c60fa3a7 | 4474 | if (next) |
4a57a2e8 | 4475 | SET_PREV_INSN (next) = insn; |
c60fa3a7 | 4476 | else |
4477 | set_last_insn (insn); | |
4478 | } | |
1026363d | 4479 | } |
34154e27 | 4480 | if (bb->next_bb != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
26bb3cb2 | 4481 | to = &BB_HEADER (bb->next_bb); |
1026363d | 4482 | else |
4483 | to = &cfg_layout_function_footer; | |
7a22afab | 4484 | |
1026363d | 4485 | rtl_delete_block (bb); |
4486 | ||
4487 | if (prev) | |
4488 | prev = NEXT_INSN (prev); | |
4c9e08a4 | 4489 | else |
1026363d | 4490 | prev = get_insns (); |
4491 | if (next) | |
4492 | next = PREV_INSN (next); | |
4c9e08a4 | 4493 | else |
1026363d | 4494 | next = get_last_insn (); |
4495 | ||
4496 | if (next && NEXT_INSN (next) != prev) | |
4497 | { | |
4498 | remaints = unlink_insn_chain (prev, next); | |
4499 | insn = remaints; | |
4500 | while (NEXT_INSN (insn)) | |
4501 | insn = NEXT_INSN (insn); | |
4a57a2e8 | 4502 | SET_NEXT_INSN (insn) = *to; |
1026363d | 4503 | if (*to) |
4a57a2e8 | 4504 | SET_PREV_INSN (*to) = insn; |
1026363d | 4505 | *to = remaints; |
4506 | } | |
4507 | } | |
4508 | ||
139c3f48 | 4509 | /* Return true when blocks A and B can be safely merged. */ |
47aaf6e6 | 4510 | |
c60fa3a7 | 4511 | static bool |
47aaf6e6 | 4512 | cfg_layout_can_merge_blocks_p (basic_block a, basic_block b) |
c60fa3a7 | 4513 | { |
4f18499c | 4514 | /* If we are partitioning hot/cold basic blocks, we don't want to |
4515 | mess up unconditional or indirect jumps that cross between hot | |
7562ed74 | 4516 | and cold sections. |
4517 | ||
1118aef7 | 4518 | Basic block partitioning may result in some jumps that appear to |
a0c938f0 | 4519 | be optimizable (or blocks that appear to be mergeable), but which really |
4520 | must be left untouched (they are required to make it safely across | |
4521 | partition boundaries). See the comments at the top of | |
1118aef7 | 4522 | bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ |
4523 | ||
1897b881 | 4524 | if (BB_PARTITION (a) != BB_PARTITION (b)) |
7562ed74 | 4525 | return false; |
4f18499c | 4526 | |
79f958cb | 4527 | /* Protect the loop latches. */ |
4528 | if (current_loops && b->loop_father->latch == b) | |
4529 | return false; | |
4530 | ||
d945554e | 4531 | /* If we would end up moving B's instructions, make sure it doesn't fall |
4532 | through into the exit block, since we cannot recover from a fallthrough | |
4533 | edge into the exit block occurring in the middle of a function. */ | |
4534 | if (NEXT_INSN (BB_END (a)) != BB_HEAD (b)) | |
4535 | { | |
4536 | edge e = find_fallthru_edge (b->succs); | |
34154e27 | 4537 | if (e && e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
d945554e | 4538 | return false; |
4539 | } | |
4540 | ||
c60fa3a7 | 4541 | /* There must be exactly one edge in between the blocks. */ |
ea091dfd | 4542 | return (single_succ_p (a) |
4543 | && single_succ (a) == b | |
4544 | && single_pred_p (b) == 1 | |
cd665a06 | 4545 | && a != b |
c60fa3a7 | 4546 | /* Must be simple edge. */ |
ea091dfd | 4547 | && !(single_succ_edge (a)->flags & EDGE_COMPLEX) |
34154e27 | 4548 | && a != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
4549 | && b != EXIT_BLOCK_PTR_FOR_FN (cfun) | |
4aaec180 | 4550 | /* If the jump insn has side effects, we can't kill the edge. |
4551 | When not optimizing, try_redirect_by_replacing_jump will | |
4552 | not allow us to redirect an edge by replacing a table jump. */ | |
6d7dc5b9 | 4553 | && (!JUMP_P (BB_END (a)) |
4aaec180 | 4554 | || ((!optimize || reload_completed) |
5496dbfc | 4555 | ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); |
c60fa3a7 | 4556 | } |
4557 | ||
a53ff4c1 | 4558 | /* Merge block A and B. The blocks must be mergeable. */ |
4559 | ||
c60fa3a7 | 4560 | static void |
4561 | cfg_layout_merge_blocks (basic_block a, basic_block b) | |
4562 | { | |
18b762f0 | 4563 | bool forwarder_p = (b->flags & BB_FORWARDER_BLOCK) != 0; |
3d90435a | 4564 | rtx_insn *insn; |
18b762f0 | 4565 | |
1b4345f7 | 4566 | gcc_checking_assert (cfg_layout_can_merge_blocks_p (a, b)); |
c60fa3a7 | 4567 | |
3072d30e | 4568 | if (dump_file) |
18b762f0 | 4569 | fprintf (dump_file, "Merging block %d into block %d...\n", b->index, |
4570 | a->index); | |
3072d30e | 4571 | |
c60fa3a7 | 4572 | /* If there was a CODE_LABEL beginning B, delete it. */ |
6d7dc5b9 | 4573 | if (LABEL_P (BB_HEAD (b))) |
7b07eae7 | 4574 | { |
7b07eae7 | 4575 | delete_insn (BB_HEAD (b)); |
4576 | } | |
c60fa3a7 | 4577 | |
4578 | /* We should have fallthru edge in a, or we can do dummy redirection to get | |
4579 | it cleaned up. */ | |
6d7dc5b9 | 4580 | if (JUMP_P (BB_END (a))) |
cd665a06 | 4581 | try_redirect_by_replacing_jump (EDGE_SUCC (a, 0), b, true); |
cc636d56 | 4582 | gcc_assert (!JUMP_P (BB_END (a))); |
c60fa3a7 | 4583 | |
36ebb5b6 | 4584 | /* When not optimizing and the edge is the only place in RTL which holds |
9c388755 | 4585 | some unique locus, emit a nop with that locus in between. */ |
8ddad41d | 4586 | if (!optimize) |
4587 | emit_nop_for_unique_locus_between (a, b); | |
9c388755 | 4588 | |
eda57d74 | 4589 | /* Move things from b->footer after a->footer. */ |
4590 | if (BB_FOOTER (b)) | |
c60fa3a7 | 4591 | { |
eda57d74 | 4592 | if (!BB_FOOTER (a)) |
943ea6fa | 4593 | BB_FOOTER (a) = BB_FOOTER (b); |
eda57d74 | 4594 | else |
4595 | { | |
3d90435a | 4596 | rtx_insn *last = BB_FOOTER (a); |
eda57d74 | 4597 | |
4598 | while (NEXT_INSN (last)) | |
4599 | last = NEXT_INSN (last); | |
4a57a2e8 | 4600 | SET_NEXT_INSN (last) = BB_FOOTER (b); |
4601 | SET_PREV_INSN (BB_FOOTER (b)) = last; | |
eda57d74 | 4602 | } |
943ea6fa | 4603 | BB_FOOTER (b) = NULL; |
eda57d74 | 4604 | } |
4605 | ||
4606 | /* Move things from b->header before a->footer. | |
4607 | Note that this may include dead tablejump data, but we don't clean | |
4608 | those up until we go out of cfglayout mode. */ | |
4609 | if (BB_HEADER (b)) | |
4610 | { | |
4611 | if (! BB_FOOTER (a)) | |
943ea6fa | 4612 | BB_FOOTER (a) = BB_HEADER (b); |
eda57d74 | 4613 | else |
4614 | { | |
3d90435a | 4615 | rtx_insn *last = BB_HEADER (b); |
eda57d74 | 4616 | |
4617 | while (NEXT_INSN (last)) | |
4618 | last = NEXT_INSN (last); | |
4a57a2e8 | 4619 | SET_NEXT_INSN (last) = BB_FOOTER (a); |
4620 | SET_PREV_INSN (BB_FOOTER (a)) = last; | |
943ea6fa | 4621 | BB_FOOTER (a) = BB_HEADER (b); |
eda57d74 | 4622 | } |
26bb3cb2 | 4623 | BB_HEADER (b) = NULL; |
c60fa3a7 | 4624 | } |
4625 | ||
4626 | /* In the case basic blocks are not adjacent, move them around. */ | |
5496dbfc | 4627 | if (NEXT_INSN (BB_END (a)) != BB_HEAD (b)) |
c60fa3a7 | 4628 | { |
d4afc00c | 4629 | insn = unlink_insn_chain (BB_HEAD (b), BB_END (b)); |
f41d4683 | 4630 | |
d4afc00c | 4631 | emit_insn_after_noloc (insn, BB_END (a), a); |
c60fa3a7 | 4632 | } |
4633 | /* Otherwise just re-associate the instructions. */ | |
4634 | else | |
4635 | { | |
5496dbfc | 4636 | insn = BB_HEAD (b); |
26bb3cb2 | 4637 | BB_END (a) = BB_END (b); |
c60fa3a7 | 4638 | } |
4639 | ||
d4afc00c | 4640 | /* emit_insn_after_noloc doesn't call df_insn_change_bb. |
4641 | We need to explicitly call. */ | |
4642 | update_bb_for_insn_chain (insn, BB_END (b), a); | |
4643 | ||
4644 | /* Skip possible DELETED_LABEL insn. */ | |
4645 | if (!NOTE_INSN_BASIC_BLOCK_P (insn)) | |
4646 | insn = NEXT_INSN (insn); | |
4647 | gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn)); | |
26bb3cb2 | 4648 | BB_HEAD (b) = BB_END (b) = NULL; |
d4afc00c | 4649 | delete_insn (insn); |
4650 | ||
3072d30e | 4651 | df_bb_delete (b->index); |
4652 | ||
18b762f0 | 4653 | /* If B was a forwarder block, propagate the locus on the edge. */ |
8e7408e3 | 4654 | if (forwarder_p |
81ad108c | 4655 | && LOCATION_LOCUS (EDGE_SUCC (b, 0)->goto_locus) == UNKNOWN_LOCATION) |
18b762f0 | 4656 | EDGE_SUCC (b, 0)->goto_locus = EDGE_SUCC (a, 0)->goto_locus; |
4657 | ||
450d042a | 4658 | if (dump_file) |
18b762f0 | 4659 | fprintf (dump_file, "Merged blocks %d and %d.\n", a->index, b->index); |
c60fa3a7 | 4660 | } |
4661 | ||
4662 | /* Split edge E. */ | |
5f5d4cd1 | 4663 | |
c60fa3a7 | 4664 | static basic_block |
4665 | cfg_layout_split_edge (edge e) | |
4666 | { | |
c60fa3a7 | 4667 | basic_block new_bb = |
34154e27 | 4668 | create_basic_block (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun) |
5496dbfc | 4669 | ? NEXT_INSN (BB_END (e->src)) : get_insns (), |
c60fa3a7 | 4670 | NULL_RTX, e->src); |
4671 | ||
34154e27 | 4672 | if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
e1b2b77c | 4673 | BB_COPY_PARTITION (new_bb, e->src); |
4674 | else | |
4675 | BB_COPY_PARTITION (new_bb, e->dest); | |
3bdc4312 | 4676 | make_edge (new_bb, e->dest, EDGE_FALLTHRU); |
c60fa3a7 | 4677 | redirect_edge_and_branch_force (e, new_bb); |
4678 | ||
4679 | return new_bb; | |
4680 | } | |
4681 | ||
5f5d4cd1 | 4682 | /* Do postprocessing after making a forwarder block joined by edge FALLTHRU. */ |
4683 | ||
4684 | static void | |
4685 | rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED) | |
4686 | { | |
4687 | } | |
4688 | ||
9631926a | 4689 | /* Return true if BB contains only labels or non-executable |
4690 | instructions. */ | |
4691 | ||
4692 | static bool | |
4693 | rtl_block_empty_p (basic_block bb) | |
4694 | { | |
3d90435a | 4695 | rtx_insn *insn; |
9631926a | 4696 | |
34154e27 | 4697 | if (bb == ENTRY_BLOCK_PTR_FOR_FN (cfun) |
4698 | || bb == EXIT_BLOCK_PTR_FOR_FN (cfun)) | |
9631926a | 4699 | return true; |
4700 | ||
4701 | FOR_BB_INSNS (bb, insn) | |
4702 | if (NONDEBUG_INSN_P (insn) && !any_uncondjump_p (insn)) | |
4703 | return false; | |
4704 | ||
4705 | return true; | |
4706 | } | |
4707 | ||
4708 | /* Split a basic block if it ends with a conditional branch and if | |
4709 | the other part of the block is not empty. */ | |
4710 | ||
4711 | static basic_block | |
4712 | rtl_split_block_before_cond_jump (basic_block bb) | |
4713 | { | |
3d90435a | 4714 | rtx_insn *insn; |
4715 | rtx_insn *split_point = NULL; | |
4716 | rtx_insn *last = NULL; | |
9631926a | 4717 | bool found_code = false; |
4718 | ||
4719 | FOR_BB_INSNS (bb, insn) | |
4720 | { | |
4721 | if (any_condjump_p (insn)) | |
4722 | split_point = last; | |
4723 | else if (NONDEBUG_INSN_P (insn)) | |
4724 | found_code = true; | |
4725 | last = insn; | |
4726 | } | |
4727 | ||
4728 | /* Did not find everything. */ | |
4729 | if (found_code && split_point) | |
4730 | return split_block (bb, split_point)->dest; | |
4731 | else | |
4732 | return NULL; | |
4733 | } | |
4734 | ||
4ee9c684 | 4735 | /* Return 1 if BB ends with a call, possibly followed by some |
4736 | instructions that must stay with the call, 0 otherwise. */ | |
4737 | ||
4738 | static bool | |
47aaf6e6 | 4739 | rtl_block_ends_with_call_p (basic_block bb) |
4ee9c684 | 4740 | { |
3d90435a | 4741 | rtx_insn *insn = BB_END (bb); |
4ee9c684 | 4742 | |
6d7dc5b9 | 4743 | while (!CALL_P (insn) |
4ee9c684 | 4744 | && insn != BB_HEAD (bb) |
f69dfa18 | 4745 | && (keep_with_call_p (insn) |
9845d120 | 4746 | || NOTE_P (insn) |
4747 | || DEBUG_INSN_P (insn))) | |
4ee9c684 | 4748 | insn = PREV_INSN (insn); |
6d7dc5b9 | 4749 | return (CALL_P (insn)); |
4ee9c684 | 4750 | } |
4751 | ||
4752 | /* Return 1 if BB ends with a conditional branch, 0 otherwise. */ | |
4753 | ||
4754 | static bool | |
5493cb9a | 4755 | rtl_block_ends_with_condjump_p (const_basic_block bb) |
4ee9c684 | 4756 | { |
4757 | return any_condjump_p (BB_END (bb)); | |
4758 | } | |
4759 | ||
4760 | /* Return true if we need to add fake edge to exit. | |
4761 | Helper function for rtl_flow_call_edges_add. */ | |
4762 | ||
4763 | static bool | |
3d90435a | 4764 | need_fake_edge_p (const rtx_insn *insn) |
4ee9c684 | 4765 | { |
4766 | if (!INSN_P (insn)) | |
4767 | return false; | |
4768 | ||
6d7dc5b9 | 4769 | if ((CALL_P (insn) |
4ee9c684 | 4770 | && !SIBLING_CALL_P (insn) |
4771 | && !find_reg_note (insn, REG_NORETURN, NULL) | |
9c2a0c05 | 4772 | && !(RTL_CONST_OR_PURE_CALL_P (insn)))) |
4ee9c684 | 4773 | return true; |
4774 | ||
4775 | return ((GET_CODE (PATTERN (insn)) == ASM_OPERANDS | |
4776 | && MEM_VOLATILE_P (PATTERN (insn))) | |
4777 | || (GET_CODE (PATTERN (insn)) == PARALLEL | |
4778 | && asm_noperands (insn) != -1 | |
4779 | && MEM_VOLATILE_P (XVECEXP (PATTERN (insn), 0, 0))) | |
4780 | || GET_CODE (PATTERN (insn)) == ASM_INPUT); | |
4781 | } | |
4782 | ||
4783 | /* Add fake edges to the function exit for any non constant and non noreturn | |
4784 | calls, volatile inline assembly in the bitmap of blocks specified by | |
4785 | BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks | |
4786 | that were split. | |
4787 | ||
4788 | The goal is to expose cases in which entering a basic block does not imply | |
4789 | that all subsequent instructions must be executed. */ | |
4790 | ||
4791 | static int | |
4792 | rtl_flow_call_edges_add (sbitmap blocks) | |
4793 | { | |
4794 | int i; | |
4795 | int blocks_split = 0; | |
fe672ac0 | 4796 | int last_bb = last_basic_block_for_fn (cfun); |
4ee9c684 | 4797 | bool check_last_block = false; |
4798 | ||
a28770e1 | 4799 | if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS) |
4ee9c684 | 4800 | return 0; |
4801 | ||
4802 | if (! blocks) | |
4803 | check_last_block = true; | |
4804 | else | |
34154e27 | 4805 | check_last_block = bitmap_bit_p (blocks, |
4806 | EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb->index); | |
4ee9c684 | 4807 | |
4808 | /* In the last basic block, before epilogue generation, there will be | |
4809 | a fallthru edge to EXIT. Special care is required if the last insn | |
4810 | of the last basic block is a call because make_edge folds duplicate | |
4811 | edges, which would result in the fallthru edge also being marked | |
4812 | fake, which would result in the fallthru edge being removed by | |
4813 | remove_fake_edges, which would result in an invalid CFG. | |
4814 | ||
4815 | Moreover, we can't elide the outgoing fake edge, since the block | |
4816 | profiler needs to take this into account in order to solve the minimal | |
4817 | spanning tree in the case that the call doesn't return. | |
4818 | ||
4819 | Handle this by adding a dummy instruction in a new last basic block. */ | |
4820 | if (check_last_block) | |
4821 | { | |
34154e27 | 4822 | basic_block bb = EXIT_BLOCK_PTR_FOR_FN (cfun)->prev_bb; |
3d90435a | 4823 | rtx_insn *insn = BB_END (bb); |
4ee9c684 | 4824 | |
4825 | /* Back up past insns that must be kept in the same block as a call. */ | |
4826 | while (insn != BB_HEAD (bb) | |
4827 | && keep_with_call_p (insn)) | |
4828 | insn = PREV_INSN (insn); | |
4829 | ||
4830 | if (need_fake_edge_p (insn)) | |
4831 | { | |
4832 | edge e; | |
4833 | ||
34154e27 | 4834 | e = find_edge (bb, EXIT_BLOCK_PTR_FOR_FN (cfun)); |
c6356c17 | 4835 | if (e) |
4836 | { | |
18b42941 | 4837 | insert_insn_on_edge (gen_use (const0_rtx), e); |
c6356c17 | 4838 | commit_edge_insertions (); |
4839 | } | |
4ee9c684 | 4840 | } |
4841 | } | |
4842 | ||
4843 | /* Now add fake edges to the function exit for any non constant | |
4844 | calls since there is no way that we can determine if they will | |
4845 | return or not... */ | |
4846 | ||
4d2e5d52 | 4847 | for (i = NUM_FIXED_BLOCKS; i < last_bb; i++) |
4ee9c684 | 4848 | { |
f5a6b05f | 4849 | basic_block bb = BASIC_BLOCK_FOR_FN (cfun, i); |
3d90435a | 4850 | rtx_insn *insn; |
4851 | rtx_insn *prev_insn; | |
4ee9c684 | 4852 | |
4853 | if (!bb) | |
4854 | continue; | |
4855 | ||
08b7917c | 4856 | if (blocks && !bitmap_bit_p (blocks, i)) |
4ee9c684 | 4857 | continue; |
4858 | ||
4859 | for (insn = BB_END (bb); ; insn = prev_insn) | |
4860 | { | |
4861 | prev_insn = PREV_INSN (insn); | |
4862 | if (need_fake_edge_p (insn)) | |
4863 | { | |
4864 | edge e; | |
3d90435a | 4865 | rtx_insn *split_at_insn = insn; |
4ee9c684 | 4866 | |
4867 | /* Don't split the block between a call and an insn that should | |
a0c938f0 | 4868 | remain in the same block as the call. */ |
6d7dc5b9 | 4869 | if (CALL_P (insn)) |
4ee9c684 | 4870 | while (split_at_insn != BB_END (bb) |
4871 | && keep_with_call_p (NEXT_INSN (split_at_insn))) | |
4872 | split_at_insn = NEXT_INSN (split_at_insn); | |
4873 | ||
4874 | /* The handling above of the final block before the epilogue | |
a0c938f0 | 4875 | should be enough to verify that there is no edge to the exit |
4ee9c684 | 4876 | block in CFG already. Calling make_edge in such case would |
4877 | cause us to mark that edge as fake and remove it later. */ | |
4878 | ||
382ecba7 | 4879 | if (flag_checking && split_at_insn == BB_END (bb)) |
cd665a06 | 4880 | { |
34154e27 | 4881 | e = find_edge (bb, EXIT_BLOCK_PTR_FOR_FN (cfun)); |
c6356c17 | 4882 | gcc_assert (e == NULL); |
cd665a06 | 4883 | } |
4ee9c684 | 4884 | |
4885 | /* Note that the following may create a new basic block | |
4886 | and renumber the existing basic blocks. */ | |
4887 | if (split_at_insn != BB_END (bb)) | |
4888 | { | |
4889 | e = split_block (bb, split_at_insn); | |
4890 | if (e) | |
4891 | blocks_split++; | |
4892 | } | |
4893 | ||
34154e27 | 4894 | make_edge (bb, EXIT_BLOCK_PTR_FOR_FN (cfun), EDGE_FAKE); |
4ee9c684 | 4895 | } |
4896 | ||
4897 | if (insn == BB_HEAD (bb)) | |
4898 | break; | |
4899 | } | |
4900 | } | |
4901 | ||
4902 | if (blocks_split) | |
4903 | verify_flow_info (); | |
4904 | ||
4905 | return blocks_split; | |
4906 | } | |
4907 | ||
c50ae675 | 4908 | /* Add COMP_RTX as a condition at end of COND_BB. FIRST_HEAD is |
d90dbd3e | 4909 | the conditional branch target, SECOND_HEAD should be the fall-thru |
c50ae675 | 4910 | there is no need to handle this here the loop versioning code handles |
4911 | this. the reason for SECON_HEAD is that it is needed for condition | |
4912 | in trees, and this should be of the same type since it is a hook. */ | |
4913 | static void | |
4914 | rtl_lv_add_condition_to_bb (basic_block first_head , | |
a0c938f0 | 4915 | basic_block second_head ATTRIBUTE_UNUSED, |
4916 | basic_block cond_bb, void *comp_rtx) | |
c50ae675 | 4917 | { |
f9a00e9e | 4918 | rtx_code_label *label; |
3d90435a | 4919 | rtx_insn *seq, *jump; |
c50ae675 | 4920 | rtx op0 = XEXP ((rtx)comp_rtx, 0); |
4921 | rtx op1 = XEXP ((rtx)comp_rtx, 1); | |
4922 | enum rtx_code comp = GET_CODE ((rtx)comp_rtx); | |
3754d046 | 4923 | machine_mode mode; |
c50ae675 | 4924 | |
4925 | ||
4926 | label = block_label (first_head); | |
4927 | mode = GET_MODE (op0); | |
4928 | if (mode == VOIDmode) | |
4929 | mode = GET_MODE (op1); | |
4930 | ||
4931 | start_sequence (); | |
4932 | op0 = force_operand (op0, NULL_RTX); | |
4933 | op1 = force_operand (op1, NULL_RTX); | |
f9a00e9e | 4934 | do_compare_rtx_and_jump (op0, op1, comp, 0, mode, NULL_RTX, NULL, label, -1); |
c50ae675 | 4935 | jump = get_last_insn (); |
4936 | JUMP_LABEL (jump) = label; | |
4937 | LABEL_NUSES (label)++; | |
4938 | seq = get_insns (); | |
4939 | end_sequence (); | |
4940 | ||
3ad55f68 | 4941 | /* Add the new cond, in the new head. */ |
9af5ce0c | 4942 | emit_insn_after (seq, BB_END (cond_bb)); |
c50ae675 | 4943 | } |
4944 | ||
4945 | ||
4946 | /* Given a block B with unconditional branch at its end, get the | |
4947 | store the return the branch edge and the fall-thru edge in | |
4948 | BRANCH_EDGE and FALLTHRU_EDGE respectively. */ | |
4949 | static void | |
4950 | rtl_extract_cond_bb_edges (basic_block b, edge *branch_edge, | |
4951 | edge *fallthru_edge) | |
4952 | { | |
4953 | edge e = EDGE_SUCC (b, 0); | |
4954 | ||
4955 | if (e->flags & EDGE_FALLTHRU) | |
4956 | { | |
4957 | *fallthru_edge = e; | |
4958 | *branch_edge = EDGE_SUCC (b, 1); | |
4959 | } | |
4960 | else | |
4961 | { | |
4962 | *branch_edge = e; | |
4963 | *fallthru_edge = EDGE_SUCC (b, 1); | |
4964 | } | |
4965 | } | |
4966 | ||
e0dde8f8 | 4967 | void |
4968 | init_rtl_bb_info (basic_block bb) | |
4969 | { | |
43e94e51 | 4970 | gcc_assert (!bb->il.x.rtl); |
4971 | bb->il.x.head_ = NULL; | |
25a27413 | 4972 | bb->il.x.rtl = ggc_cleared_alloc<rtl_bb_info> (); |
e0dde8f8 | 4973 | } |
4974 | ||
611d2ac1 | 4975 | /* Returns true if it is possible to remove edge E by redirecting |
4976 | it to the destination of the other edge from E->src. */ | |
4977 | ||
4978 | static bool | |
5493cb9a | 4979 | rtl_can_remove_branch_p (const_edge e) |
611d2ac1 | 4980 | { |
5493cb9a | 4981 | const_basic_block src = e->src; |
4982 | const_basic_block target = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest; | |
3d90435a | 4983 | const rtx_insn *insn = BB_END (src); |
4984 | rtx set; | |
611d2ac1 | 4985 | |
4986 | /* The conditions are taken from try_redirect_by_replacing_jump. */ | |
34154e27 | 4987 | if (target == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
611d2ac1 | 4988 | return false; |
4989 | ||
4990 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) | |
4991 | return false; | |
4992 | ||
aa78dca5 | 4993 | if (BB_PARTITION (src) != BB_PARTITION (target)) |
611d2ac1 | 4994 | return false; |
4995 | ||
4996 | if (!onlyjump_p (insn) | |
4997 | || tablejump_p (insn, NULL, NULL)) | |
4998 | return false; | |
4999 | ||
5000 | set = single_set (insn); | |
5001 | if (!set || side_effects_p (set)) | |
5002 | return false; | |
5003 | ||
5004 | return true; | |
5005 | } | |
5006 | ||
0a55d497 | 5007 | static basic_block |
5008 | rtl_duplicate_bb (basic_block bb) | |
5009 | { | |
5010 | bb = cfg_layout_duplicate_bb (bb); | |
5011 | bb->aux = NULL; | |
5012 | return bb; | |
5013 | } | |
5014 | ||
98193482 | 5015 | /* Do book-keeping of basic block BB for the profile consistency checker. |
5016 | If AFTER_PASS is 0, do pre-pass accounting, or if AFTER_PASS is 1 | |
5017 | then do post-pass accounting. Store the counting in RECORD. */ | |
5018 | static void | |
5019 | rtl_account_profile_record (basic_block bb, int after_pass, | |
5020 | struct profile_record *record) | |
5021 | { | |
3d90435a | 5022 | rtx_insn *insn; |
98193482 | 5023 | FOR_BB_INSNS (bb, insn) |
5024 | if (INSN_P (insn)) | |
5025 | { | |
5026 | record->size[after_pass] | |
5027 | += insn_rtx_cost (PATTERN (insn), false); | |
f26d8580 | 5028 | if (profile_status_for_fn (cfun) == PROFILE_READ) |
98193482 | 5029 | record->time[after_pass] |
5030 | += insn_rtx_cost (PATTERN (insn), true) * bb->count; | |
f26d8580 | 5031 | else if (profile_status_for_fn (cfun) == PROFILE_GUESSED) |
98193482 | 5032 | record->time[after_pass] |
5033 | += insn_rtx_cost (PATTERN (insn), true) * bb->frequency; | |
5034 | } | |
5035 | } | |
5036 | ||
1026363d | 5037 | /* Implementation of CFG manipulation for linearized RTL. */ |
5038 | struct cfg_hooks rtl_cfg_hooks = { | |
5f5d4cd1 | 5039 | "rtl", |
1026363d | 5040 | rtl_verify_flow_info, |
028f8cc7 | 5041 | rtl_dump_bb, |
e079344a | 5042 | rtl_dump_bb_for_graph, |
c60fa3a7 | 5043 | rtl_create_basic_block, |
1026363d | 5044 | rtl_redirect_edge_and_branch, |
5045 | rtl_redirect_edge_and_branch_force, | |
611d2ac1 | 5046 | rtl_can_remove_branch_p, |
1026363d | 5047 | rtl_delete_block, |
5048 | rtl_split_block, | |
5f5d4cd1 | 5049 | rtl_move_block_after, |
c60fa3a7 | 5050 | rtl_can_merge_blocks, /* can_merge_blocks_p */ |
5051 | rtl_merge_blocks, | |
4ee9c684 | 5052 | rtl_predict_edge, |
5053 | rtl_predicted_by_p, | |
0a55d497 | 5054 | cfg_layout_can_duplicate_bb_p, |
5055 | rtl_duplicate_bb, | |
5f5d4cd1 | 5056 | rtl_split_edge, |
5057 | rtl_make_forwarder_block, | |
4ee9c684 | 5058 | rtl_tidy_fallthru_edge, |
202bbc06 | 5059 | rtl_force_nonfallthru, |
4ee9c684 | 5060 | rtl_block_ends_with_call_p, |
5061 | rtl_block_ends_with_condjump_p, | |
26b12c91 | 5062 | rtl_flow_call_edges_add, |
5063 | NULL, /* execute_on_growing_pred */ | |
c50ae675 | 5064 | NULL, /* execute_on_shrinking_pred */ |
5065 | NULL, /* duplicate loop for trees */ | |
5066 | NULL, /* lv_add_condition_to_bb */ | |
5067 | NULL, /* lv_adjust_loop_header_phi*/ | |
5068 | NULL, /* extract_cond_bb_edges */ | |
9631926a | 5069 | NULL, /* flush_pending_stmts */ |
5070 | rtl_block_empty_p, /* block_empty_p */ | |
5071 | rtl_split_block_before_cond_jump, /* split_block_before_cond_jump */ | |
98193482 | 5072 | rtl_account_profile_record, |
1026363d | 5073 | }; |
5074 | ||
5075 | /* Implementation of CFG manipulation for cfg layout RTL, where | |
5076 | basic block connected via fallthru edges does not have to be adjacent. | |
5077 | This representation will hopefully become the default one in future | |
5078 | version of the compiler. */ | |
4ee9c684 | 5079 | |
1026363d | 5080 | struct cfg_hooks cfg_layout_rtl_cfg_hooks = { |
5f5d4cd1 | 5081 | "cfglayout mode", |
c60fa3a7 | 5082 | rtl_verify_flow_info_1, |
028f8cc7 | 5083 | rtl_dump_bb, |
e079344a | 5084 | rtl_dump_bb_for_graph, |
c60fa3a7 | 5085 | cfg_layout_create_basic_block, |
1026363d | 5086 | cfg_layout_redirect_edge_and_branch, |
5087 | cfg_layout_redirect_edge_and_branch_force, | |
611d2ac1 | 5088 | rtl_can_remove_branch_p, |
1026363d | 5089 | cfg_layout_delete_block, |
5090 | cfg_layout_split_block, | |
5f5d4cd1 | 5091 | rtl_move_block_after, |
c60fa3a7 | 5092 | cfg_layout_can_merge_blocks_p, |
5093 | cfg_layout_merge_blocks, | |
4ee9c684 | 5094 | rtl_predict_edge, |
5095 | rtl_predicted_by_p, | |
5096 | cfg_layout_can_duplicate_bb_p, | |
5097 | cfg_layout_duplicate_bb, | |
5f5d4cd1 | 5098 | cfg_layout_split_edge, |
5099 | rtl_make_forwarder_block, | |
202bbc06 | 5100 | NULL, /* tidy_fallthru_edge */ |
5101 | rtl_force_nonfallthru, | |
4ee9c684 | 5102 | rtl_block_ends_with_call_p, |
5103 | rtl_block_ends_with_condjump_p, | |
26b12c91 | 5104 | rtl_flow_call_edges_add, |
5105 | NULL, /* execute_on_growing_pred */ | |
c50ae675 | 5106 | NULL, /* execute_on_shrinking_pred */ |
5107 | duplicate_loop_to_header_edge, /* duplicate loop for trees */ | |
5108 | rtl_lv_add_condition_to_bb, /* lv_add_condition_to_bb */ | |
5109 | NULL, /* lv_adjust_loop_header_phi*/ | |
5110 | rtl_extract_cond_bb_edges, /* extract_cond_bb_edges */ | |
9631926a | 5111 | NULL, /* flush_pending_stmts */ |
5112 | rtl_block_empty_p, /* block_empty_p */ | |
5113 | rtl_split_block_before_cond_jump, /* split_block_before_cond_jump */ | |
98193482 | 5114 | rtl_account_profile_record, |
1026363d | 5115 | }; |
23a070f3 | 5116 | |
5117 | #include "gt-cfgrtl.h" |