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610d2478 | 1 | /* CPU mode switching |
6fb5fa3c | 2 | Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007 |
610d2478 SB |
3 | Free Software Foundation, Inc. |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it under | |
8 | the terms of the GNU General Public License as published by the Free | |
9dcd6f09 | 9 | Software Foundation; either version 3, or (at your option) any later |
610d2478 SB |
10 | version. |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
610d2478 SB |
20 | |
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
24 | #include "tm.h" | |
25 | #include "rtl.h" | |
26 | #include "regs.h" | |
27 | #include "hard-reg-set.h" | |
28 | #include "flags.h" | |
29 | #include "real.h" | |
30 | #include "insn-config.h" | |
31 | #include "recog.h" | |
32 | #include "basic-block.h" | |
33 | #include "output.h" | |
34 | #include "tm_p.h" | |
35 | #include "function.h" | |
ef330312 PB |
36 | #include "tree-pass.h" |
37 | #include "timevar.h" | |
6fb5fa3c | 38 | #include "df.h" |
610d2478 SB |
39 | |
40 | /* We want target macros for the mode switching code to be able to refer | |
41 | to instruction attribute values. */ | |
42 | #include "insn-attr.h" | |
43 | ||
44 | #ifdef OPTIMIZE_MODE_SWITCHING | |
45 | ||
46 | /* The algorithm for setting the modes consists of scanning the insn list | |
47 | and finding all the insns which require a specific mode. Each insn gets | |
48 | a unique struct seginfo element. These structures are inserted into a list | |
49 | for each basic block. For each entity, there is an array of bb_info over | |
50 | the flow graph basic blocks (local var 'bb_info'), and contains a list | |
51 | of all insns within that basic block, in the order they are encountered. | |
52 | ||
53 | For each entity, any basic block WITHOUT any insns requiring a specific | |
54 | mode are given a single entry, without a mode. (Each basic block | |
55 | in the flow graph must have at least one entry in the segment table.) | |
56 | ||
57 | The LCM algorithm is then run over the flow graph to determine where to | |
58 | place the sets to the highest-priority value in respect of first the first | |
59 | insn in any one block. Any adjustments required to the transparency | |
60 | vectors are made, then the next iteration starts for the next-lower | |
61 | priority mode, till for each entity all modes are exhausted. | |
62 | ||
63 | More details are located in the code for optimize_mode_switching(). */ | |
64 | \f | |
65 | /* This structure contains the information for each insn which requires | |
66 | either single or double mode to be set. | |
67 | MODE is the mode this insn must be executed in. | |
68 | INSN_PTR is the insn to be executed (may be the note that marks the | |
69 | beginning of a basic block). | |
70 | BBNUM is the flow graph basic block this insn occurs in. | |
71 | NEXT is the next insn in the same basic block. */ | |
72 | struct seginfo | |
73 | { | |
74 | int mode; | |
75 | rtx insn_ptr; | |
76 | int bbnum; | |
77 | struct seginfo *next; | |
78 | HARD_REG_SET regs_live; | |
79 | }; | |
80 | ||
81 | struct bb_info | |
82 | { | |
83 | struct seginfo *seginfo; | |
84 | int computing; | |
85 | }; | |
86 | ||
87 | /* These bitmaps are used for the LCM algorithm. */ | |
88 | ||
89 | static sbitmap *antic; | |
90 | static sbitmap *transp; | |
91 | static sbitmap *comp; | |
92 | ||
93 | static struct seginfo * new_seginfo (int, rtx, int, HARD_REG_SET); | |
94 | static void add_seginfo (struct bb_info *, struct seginfo *); | |
408bed3c | 95 | static void reg_dies (rtx, HARD_REG_SET *); |
7bc980e1 | 96 | static void reg_becomes_live (rtx, const_rtx, void *); |
610d2478 SB |
97 | static void make_preds_opaque (basic_block, int); |
98 | \f | |
99 | ||
100 | /* This function will allocate a new BBINFO structure, initialized | |
101 | with the MODE, INSN, and basic block BB parameters. */ | |
102 | ||
103 | static struct seginfo * | |
104 | new_seginfo (int mode, rtx insn, int bb, HARD_REG_SET regs_live) | |
105 | { | |
106 | struct seginfo *ptr; | |
5ed6ace5 | 107 | ptr = XNEW (struct seginfo); |
610d2478 SB |
108 | ptr->mode = mode; |
109 | ptr->insn_ptr = insn; | |
110 | ptr->bbnum = bb; | |
111 | ptr->next = NULL; | |
112 | COPY_HARD_REG_SET (ptr->regs_live, regs_live); | |
113 | return ptr; | |
114 | } | |
115 | ||
116 | /* Add a seginfo element to the end of a list. | |
117 | HEAD is a pointer to the list beginning. | |
118 | INFO is the structure to be linked in. */ | |
119 | ||
120 | static void | |
121 | add_seginfo (struct bb_info *head, struct seginfo *info) | |
122 | { | |
123 | struct seginfo *ptr; | |
124 | ||
125 | if (head->seginfo == NULL) | |
126 | head->seginfo = info; | |
127 | else | |
128 | { | |
129 | ptr = head->seginfo; | |
130 | while (ptr->next != NULL) | |
131 | ptr = ptr->next; | |
132 | ptr->next = info; | |
133 | } | |
134 | } | |
135 | ||
136 | /* Make all predecessors of basic block B opaque, recursively, till we hit | |
137 | some that are already non-transparent, or an edge where aux is set; that | |
138 | denotes that a mode set is to be done on that edge. | |
139 | J is the bit number in the bitmaps that corresponds to the entity that | |
140 | we are currently handling mode-switching for. */ | |
141 | ||
142 | static void | |
143 | make_preds_opaque (basic_block b, int j) | |
144 | { | |
145 | edge e; | |
146 | edge_iterator ei; | |
147 | ||
148 | FOR_EACH_EDGE (e, ei, b->preds) | |
149 | { | |
150 | basic_block pb = e->src; | |
151 | ||
152 | if (e->aux || ! TEST_BIT (transp[pb->index], j)) | |
153 | continue; | |
154 | ||
155 | RESET_BIT (transp[pb->index], j); | |
156 | make_preds_opaque (pb, j); | |
157 | } | |
158 | } | |
159 | ||
160 | /* Record in LIVE that register REG died. */ | |
161 | ||
162 | static void | |
408bed3c | 163 | reg_dies (rtx reg, HARD_REG_SET *live) |
610d2478 | 164 | { |
09e18274 | 165 | int regno; |
610d2478 SB |
166 | |
167 | if (!REG_P (reg)) | |
168 | return; | |
169 | ||
170 | regno = REGNO (reg); | |
171 | if (regno < FIRST_PSEUDO_REGISTER) | |
09e18274 | 172 | remove_from_hard_reg_set (live, GET_MODE (reg), regno); |
610d2478 SB |
173 | } |
174 | ||
175 | /* Record in LIVE that register REG became live. | |
176 | This is called via note_stores. */ | |
177 | ||
178 | static void | |
7bc980e1 | 179 | reg_becomes_live (rtx reg, const_rtx setter ATTRIBUTE_UNUSED, void *live) |
610d2478 | 180 | { |
09e18274 | 181 | int regno; |
610d2478 SB |
182 | |
183 | if (GET_CODE (reg) == SUBREG) | |
184 | reg = SUBREG_REG (reg); | |
185 | ||
186 | if (!REG_P (reg)) | |
187 | return; | |
188 | ||
189 | regno = REGNO (reg); | |
190 | if (regno < FIRST_PSEUDO_REGISTER) | |
09e18274 | 191 | add_to_hard_reg_set ((HARD_REG_SET *) live, GET_MODE (reg), regno); |
610d2478 SB |
192 | } |
193 | ||
194 | /* Make sure if MODE_ENTRY is defined the MODE_EXIT is defined | |
195 | and vice versa. */ | |
196 | #if defined (MODE_ENTRY) != defined (MODE_EXIT) | |
197 | #error "Both MODE_ENTRY and MODE_EXIT must be defined" | |
198 | #endif | |
199 | ||
200 | #if defined (MODE_ENTRY) && defined (MODE_EXIT) | |
201 | /* Split the fallthrough edge to the exit block, so that we can note | |
202 | that there NORMAL_MODE is required. Return the new block if it's | |
203 | inserted before the exit block. Otherwise return null. */ | |
204 | ||
205 | static basic_block | |
206 | create_pre_exit (int n_entities, int *entity_map, const int *num_modes) | |
207 | { | |
208 | edge eg; | |
209 | edge_iterator ei; | |
210 | basic_block pre_exit; | |
211 | ||
212 | /* The only non-call predecessor at this stage is a block with a | |
213 | fallthrough edge; there can be at most one, but there could be | |
214 | none at all, e.g. when exit is called. */ | |
215 | pre_exit = 0; | |
216 | FOR_EACH_EDGE (eg, ei, EXIT_BLOCK_PTR->preds) | |
217 | if (eg->flags & EDGE_FALLTHRU) | |
218 | { | |
219 | basic_block src_bb = eg->src; | |
610d2478 SB |
220 | rtx last_insn, ret_reg; |
221 | ||
222 | gcc_assert (!pre_exit); | |
223 | /* If this function returns a value at the end, we have to | |
224 | insert the final mode switch before the return value copy | |
225 | to its hard register. */ | |
226 | if (EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 1 | |
227 | && NONJUMP_INSN_P ((last_insn = BB_END (src_bb))) | |
228 | && GET_CODE (PATTERN (last_insn)) == USE | |
229 | && GET_CODE ((ret_reg = XEXP (PATTERN (last_insn), 0))) == REG) | |
230 | { | |
231 | int ret_start = REGNO (ret_reg); | |
232 | int nregs = hard_regno_nregs[ret_start][GET_MODE (ret_reg)]; | |
233 | int ret_end = ret_start + nregs; | |
234 | int short_block = 0; | |
235 | int maybe_builtin_apply = 0; | |
236 | int forced_late_switch = 0; | |
237 | rtx before_return_copy; | |
238 | ||
239 | do | |
240 | { | |
241 | rtx return_copy = PREV_INSN (last_insn); | |
242 | rtx return_copy_pat, copy_reg; | |
243 | int copy_start, copy_num; | |
244 | int j; | |
245 | ||
246 | if (INSN_P (return_copy)) | |
247 | { | |
89ab4659 KK |
248 | return_copy_pat = PATTERN (return_copy); |
249 | switch (GET_CODE (return_copy_pat)) | |
07288ab0 | 250 | { |
89ab4659 KK |
251 | case USE: |
252 | /* Skip __builtin_apply pattern. */ | |
253 | if (GET_CODE (XEXP (return_copy_pat, 0)) == REG | |
254 | && (FUNCTION_VALUE_REGNO_P | |
255 | (REGNO (XEXP (return_copy_pat, 0))))) | |
256 | { | |
257 | maybe_builtin_apply = 1; | |
258 | last_insn = return_copy; | |
259 | continue; | |
260 | } | |
261 | break; | |
262 | ||
263 | case ASM_OPERANDS: | |
264 | /* Skip barrier insns. */ | |
265 | if (!MEM_VOLATILE_P (return_copy_pat)) | |
266 | break; | |
267 | ||
268 | /* Fall through. */ | |
269 | ||
270 | case ASM_INPUT: | |
271 | case UNSPEC_VOLATILE: | |
07288ab0 KK |
272 | last_insn = return_copy; |
273 | continue; | |
89ab4659 KK |
274 | |
275 | default: | |
276 | break; | |
07288ab0 | 277 | } |
89ab4659 | 278 | |
610d2478 SB |
279 | /* If the return register is not (in its entirety) |
280 | likely spilled, the return copy might be | |
281 | partially or completely optimized away. */ | |
282 | return_copy_pat = single_set (return_copy); | |
283 | if (!return_copy_pat) | |
284 | { | |
285 | return_copy_pat = PATTERN (return_copy); | |
286 | if (GET_CODE (return_copy_pat) != CLOBBER) | |
287 | break; | |
6fb5fa3c DB |
288 | else if (!optimize) |
289 | { | |
290 | /* This might be (clobber (reg [<result>])) | |
291 | when not optimizing. Then check if | |
292 | the previous insn is the clobber for | |
293 | the return register. */ | |
294 | copy_reg = SET_DEST (return_copy_pat); | |
295 | if (GET_CODE (copy_reg) == REG | |
296 | && !HARD_REGISTER_NUM_P (REGNO (copy_reg))) | |
297 | { | |
298 | if (INSN_P (PREV_INSN (return_copy))) | |
299 | { | |
300 | return_copy = PREV_INSN (return_copy); | |
301 | return_copy_pat = PATTERN (return_copy); | |
302 | if (GET_CODE (return_copy_pat) != CLOBBER) | |
303 | break; | |
304 | } | |
305 | } | |
306 | } | |
610d2478 SB |
307 | } |
308 | copy_reg = SET_DEST (return_copy_pat); | |
309 | if (GET_CODE (copy_reg) == REG) | |
310 | copy_start = REGNO (copy_reg); | |
311 | else if (GET_CODE (copy_reg) == SUBREG | |
312 | && GET_CODE (SUBREG_REG (copy_reg)) == REG) | |
313 | copy_start = REGNO (SUBREG_REG (copy_reg)); | |
314 | else | |
315 | break; | |
316 | if (copy_start >= FIRST_PSEUDO_REGISTER) | |
317 | break; | |
318 | copy_num | |
319 | = hard_regno_nregs[copy_start][GET_MODE (copy_reg)]; | |
320 | ||
321 | /* If the return register is not likely spilled, - as is | |
322 | the case for floating point on SH4 - then it might | |
323 | be set by an arithmetic operation that needs a | |
324 | different mode than the exit block. */ | |
325 | for (j = n_entities - 1; j >= 0; j--) | |
326 | { | |
327 | int e = entity_map[j]; | |
328 | int mode = MODE_NEEDED (e, return_copy); | |
329 | ||
330 | if (mode != num_modes[e] && mode != MODE_EXIT (e)) | |
331 | break; | |
332 | } | |
333 | if (j >= 0) | |
334 | { | |
335 | /* For the SH4, floating point loads depend on fpscr, | |
336 | thus we might need to put the final mode switch | |
337 | after the return value copy. That is still OK, | |
338 | because a floating point return value does not | |
339 | conflict with address reloads. */ | |
340 | if (copy_start >= ret_start | |
341 | && copy_start + copy_num <= ret_end | |
342 | && OBJECT_P (SET_SRC (return_copy_pat))) | |
343 | forced_late_switch = 1; | |
344 | break; | |
345 | } | |
346 | ||
347 | if (copy_start >= ret_start | |
348 | && copy_start + copy_num <= ret_end) | |
349 | nregs -= copy_num; | |
350 | else if (!maybe_builtin_apply | |
351 | || !FUNCTION_VALUE_REGNO_P (copy_start)) | |
352 | break; | |
353 | last_insn = return_copy; | |
354 | } | |
355 | /* ??? Exception handling can lead to the return value | |
356 | copy being already separated from the return value use, | |
357 | as in unwind-dw2.c . | |
358 | Similarly, conditionally returning without a value, | |
359 | and conditionally using builtin_return can lead to an | |
360 | isolated use. */ | |
361 | if (return_copy == BB_HEAD (src_bb)) | |
362 | { | |
363 | short_block = 1; | |
364 | break; | |
365 | } | |
366 | last_insn = return_copy; | |
367 | } | |
368 | while (nregs); | |
369 | ||
370 | /* If we didn't see a full return value copy, verify that there | |
371 | is a plausible reason for this. If some, but not all of the | |
372 | return register is likely spilled, we can expect that there | |
373 | is a copy for the likely spilled part. */ | |
374 | gcc_assert (!nregs | |
375 | || forced_late_switch | |
376 | || short_block | |
377 | || !(CLASS_LIKELY_SPILLED_P | |
378 | (REGNO_REG_CLASS (ret_start))) | |
379 | || (nregs | |
380 | != hard_regno_nregs[ret_start][GET_MODE (ret_reg)]) | |
381 | /* For multi-hard-register floating point | |
382 | values, sometimes the likely-spilled part | |
383 | is ordinarily copied first, then the other | |
384 | part is set with an arithmetic operation. | |
385 | This doesn't actually cause reload | |
386 | failures, so let it pass. */ | |
387 | || (GET_MODE_CLASS (GET_MODE (ret_reg)) != MODE_INT | |
388 | && nregs != 1)); | |
389 | ||
390 | if (INSN_P (last_insn)) | |
391 | { | |
392 | before_return_copy | |
393 | = emit_note_before (NOTE_INSN_DELETED, last_insn); | |
394 | /* Instructions preceding LAST_INSN in the same block might | |
395 | require a different mode than MODE_EXIT, so if we might | |
396 | have such instructions, keep them in a separate block | |
397 | from pre_exit. */ | |
398 | if (last_insn != BB_HEAD (src_bb)) | |
399 | src_bb = split_block (src_bb, | |
400 | PREV_INSN (before_return_copy))->dest; | |
401 | } | |
402 | else | |
403 | before_return_copy = last_insn; | |
404 | pre_exit = split_block (src_bb, before_return_copy)->src; | |
405 | } | |
406 | else | |
407 | { | |
408 | pre_exit = split_edge (eg); | |
610d2478 SB |
409 | } |
410 | } | |
411 | ||
412 | return pre_exit; | |
413 | } | |
414 | #endif | |
415 | ||
416 | /* Find all insns that need a particular mode setting, and insert the | |
417 | necessary mode switches. Return true if we did work. */ | |
418 | ||
7399bcb0 | 419 | static int |
10d22567 | 420 | optimize_mode_switching (void) |
610d2478 SB |
421 | { |
422 | rtx insn; | |
423 | int e; | |
424 | basic_block bb; | |
425 | int need_commit = 0; | |
426 | sbitmap *kill; | |
427 | struct edge_list *edge_list; | |
428 | static const int num_modes[] = NUM_MODES_FOR_MODE_SWITCHING; | |
429 | #define N_ENTITIES ARRAY_SIZE (num_modes) | |
430 | int entity_map[N_ENTITIES]; | |
431 | struct bb_info *bb_info[N_ENTITIES]; | |
432 | int i, j; | |
433 | int n_entities; | |
434 | int max_num_modes = 0; | |
435 | bool emited = false; | |
436 | basic_block post_entry ATTRIBUTE_UNUSED, pre_exit ATTRIBUTE_UNUSED; | |
437 | ||
610d2478 SB |
438 | for (e = N_ENTITIES - 1, n_entities = 0; e >= 0; e--) |
439 | if (OPTIMIZE_MODE_SWITCHING (e)) | |
440 | { | |
441 | int entry_exit_extra = 0; | |
442 | ||
443 | /* Create the list of segments within each basic block. | |
444 | If NORMAL_MODE is defined, allow for two extra | |
445 | blocks split from the entry and exit block. */ | |
446 | #if defined (MODE_ENTRY) && defined (MODE_EXIT) | |
447 | entry_exit_extra = 3; | |
448 | #endif | |
449 | bb_info[n_entities] | |
60ec1aa4 | 450 | = XCNEWVEC (struct bb_info, last_basic_block + entry_exit_extra); |
610d2478 SB |
451 | entity_map[n_entities++] = e; |
452 | if (num_modes[e] > max_num_modes) | |
453 | max_num_modes = num_modes[e]; | |
454 | } | |
455 | ||
456 | if (! n_entities) | |
457 | return 0; | |
458 | ||
459 | #if defined (MODE_ENTRY) && defined (MODE_EXIT) | |
460 | /* Split the edge from the entry block, so that we can note that | |
461 | there NORMAL_MODE is supplied. */ | |
462 | post_entry = split_edge (single_succ_edge (ENTRY_BLOCK_PTR)); | |
463 | pre_exit = create_pre_exit (n_entities, entity_map, num_modes); | |
464 | #endif | |
465 | ||
6fb5fa3c DB |
466 | df_analyze (); |
467 | ||
610d2478 SB |
468 | /* Create the bitmap vectors. */ |
469 | ||
470 | antic = sbitmap_vector_alloc (last_basic_block, n_entities); | |
471 | transp = sbitmap_vector_alloc (last_basic_block, n_entities); | |
472 | comp = sbitmap_vector_alloc (last_basic_block, n_entities); | |
473 | ||
474 | sbitmap_vector_ones (transp, last_basic_block); | |
475 | ||
476 | for (j = n_entities - 1; j >= 0; j--) | |
477 | { | |
478 | int e = entity_map[j]; | |
479 | int no_mode = num_modes[e]; | |
480 | struct bb_info *info = bb_info[j]; | |
481 | ||
482 | /* Determine what the first use (if any) need for a mode of entity E is. | |
483 | This will be the mode that is anticipatable for this block. | |
484 | Also compute the initial transparency settings. */ | |
485 | FOR_EACH_BB (bb) | |
486 | { | |
487 | struct seginfo *ptr; | |
488 | int last_mode = no_mode; | |
489 | HARD_REG_SET live_now; | |
490 | ||
6fb5fa3c | 491 | REG_SET_TO_HARD_REG_SET (live_now, df_get_live_in (bb)); |
24c2fde2 RH |
492 | |
493 | /* Pretend the mode is clobbered across abnormal edges. */ | |
494 | { | |
495 | edge_iterator ei; | |
496 | edge e; | |
497 | FOR_EACH_EDGE (e, ei, bb->preds) | |
498 | if (e->flags & EDGE_COMPLEX) | |
499 | break; | |
500 | if (e) | |
650a59ef R |
501 | { |
502 | ptr = new_seginfo (no_mode, BB_HEAD (bb), bb->index, live_now); | |
503 | add_seginfo (info + bb->index, ptr); | |
504 | RESET_BIT (transp[bb->index], j); | |
505 | } | |
24c2fde2 RH |
506 | } |
507 | ||
610d2478 SB |
508 | for (insn = BB_HEAD (bb); |
509 | insn != NULL && insn != NEXT_INSN (BB_END (bb)); | |
510 | insn = NEXT_INSN (insn)) | |
511 | { | |
512 | if (INSN_P (insn)) | |
513 | { | |
514 | int mode = MODE_NEEDED (e, insn); | |
515 | rtx link; | |
516 | ||
517 | if (mode != no_mode && mode != last_mode) | |
518 | { | |
519 | last_mode = mode; | |
520 | ptr = new_seginfo (mode, insn, bb->index, live_now); | |
521 | add_seginfo (info + bb->index, ptr); | |
522 | RESET_BIT (transp[bb->index], j); | |
523 | } | |
524 | #ifdef MODE_AFTER | |
525 | last_mode = MODE_AFTER (last_mode, insn); | |
526 | #endif | |
527 | /* Update LIVE_NOW. */ | |
528 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) | |
529 | if (REG_NOTE_KIND (link) == REG_DEAD) | |
408bed3c | 530 | reg_dies (XEXP (link, 0), &live_now); |
610d2478 SB |
531 | |
532 | note_stores (PATTERN (insn), reg_becomes_live, &live_now); | |
533 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) | |
534 | if (REG_NOTE_KIND (link) == REG_UNUSED) | |
408bed3c | 535 | reg_dies (XEXP (link, 0), &live_now); |
610d2478 SB |
536 | } |
537 | } | |
538 | ||
539 | info[bb->index].computing = last_mode; | |
540 | /* Check for blocks without ANY mode requirements. */ | |
541 | if (last_mode == no_mode) | |
542 | { | |
543 | ptr = new_seginfo (no_mode, BB_END (bb), bb->index, live_now); | |
544 | add_seginfo (info + bb->index, ptr); | |
545 | } | |
546 | } | |
547 | #if defined (MODE_ENTRY) && defined (MODE_EXIT) | |
548 | { | |
549 | int mode = MODE_ENTRY (e); | |
550 | ||
551 | if (mode != no_mode) | |
552 | { | |
553 | bb = post_entry; | |
554 | ||
555 | /* By always making this nontransparent, we save | |
556 | an extra check in make_preds_opaque. We also | |
557 | need this to avoid confusing pre_edge_lcm when | |
558 | antic is cleared but transp and comp are set. */ | |
559 | RESET_BIT (transp[bb->index], j); | |
560 | ||
561 | /* Insert a fake computing definition of MODE into entry | |
562 | blocks which compute no mode. This represents the mode on | |
563 | entry. */ | |
564 | info[bb->index].computing = mode; | |
565 | ||
566 | if (pre_exit) | |
567 | info[pre_exit->index].seginfo->mode = MODE_EXIT (e); | |
568 | } | |
569 | } | |
570 | #endif /* NORMAL_MODE */ | |
571 | } | |
572 | ||
573 | kill = sbitmap_vector_alloc (last_basic_block, n_entities); | |
574 | for (i = 0; i < max_num_modes; i++) | |
575 | { | |
576 | int current_mode[N_ENTITIES]; | |
577 | sbitmap *delete; | |
578 | sbitmap *insert; | |
579 | ||
580 | /* Set the anticipatable and computing arrays. */ | |
581 | sbitmap_vector_zero (antic, last_basic_block); | |
582 | sbitmap_vector_zero (comp, last_basic_block); | |
583 | for (j = n_entities - 1; j >= 0; j--) | |
584 | { | |
585 | int m = current_mode[j] = MODE_PRIORITY_TO_MODE (entity_map[j], i); | |
586 | struct bb_info *info = bb_info[j]; | |
587 | ||
588 | FOR_EACH_BB (bb) | |
589 | { | |
590 | if (info[bb->index].seginfo->mode == m) | |
591 | SET_BIT (antic[bb->index], j); | |
592 | ||
593 | if (info[bb->index].computing == m) | |
594 | SET_BIT (comp[bb->index], j); | |
595 | } | |
596 | } | |
597 | ||
598 | /* Calculate the optimal locations for the | |
599 | placement mode switches to modes with priority I. */ | |
600 | ||
601 | FOR_EACH_BB (bb) | |
602 | sbitmap_not (kill[bb->index], transp[bb->index]); | |
10d22567 | 603 | edge_list = pre_edge_lcm (n_entities, transp, comp, antic, |
610d2478 SB |
604 | kill, &insert, &delete); |
605 | ||
606 | for (j = n_entities - 1; j >= 0; j--) | |
607 | { | |
608 | /* Insert all mode sets that have been inserted by lcm. */ | |
609 | int no_mode = num_modes[entity_map[j]]; | |
610 | ||
611 | /* Wherever we have moved a mode setting upwards in the flow graph, | |
612 | the blocks between the new setting site and the now redundant | |
613 | computation ceases to be transparent for any lower-priority | |
614 | mode of the same entity. First set the aux field of each | |
615 | insertion site edge non-transparent, then propagate the new | |
616 | non-transparency from the redundant computation upwards till | |
617 | we hit an insertion site or an already non-transparent block. */ | |
618 | for (e = NUM_EDGES (edge_list) - 1; e >= 0; e--) | |
619 | { | |
620 | edge eg = INDEX_EDGE (edge_list, e); | |
621 | int mode; | |
622 | basic_block src_bb; | |
623 | HARD_REG_SET live_at_edge; | |
624 | rtx mode_set; | |
625 | ||
626 | eg->aux = 0; | |
627 | ||
628 | if (! TEST_BIT (insert[e], j)) | |
629 | continue; | |
630 | ||
631 | eg->aux = (void *)1; | |
632 | ||
633 | mode = current_mode[j]; | |
634 | src_bb = eg->src; | |
635 | ||
6fb5fa3c | 636 | REG_SET_TO_HARD_REG_SET (live_at_edge, df_get_live_out (src_bb)); |
610d2478 SB |
637 | |
638 | start_sequence (); | |
639 | EMIT_MODE_SET (entity_map[j], mode, live_at_edge); | |
640 | mode_set = get_insns (); | |
641 | end_sequence (); | |
642 | ||
643 | /* Do not bother to insert empty sequence. */ | |
644 | if (mode_set == NULL_RTX) | |
645 | continue; | |
646 | ||
650a59ef R |
647 | /* We should not get an abnormal edge here. */ |
648 | gcc_assert (! (eg->flags & EDGE_ABNORMAL)); | |
649 | ||
650 | need_commit = 1; | |
651 | insert_insn_on_edge (mode_set, eg); | |
610d2478 SB |
652 | } |
653 | ||
654 | FOR_EACH_BB_REVERSE (bb) | |
655 | if (TEST_BIT (delete[bb->index], j)) | |
656 | { | |
657 | make_preds_opaque (bb, j); | |
658 | /* Cancel the 'deleted' mode set. */ | |
659 | bb_info[j][bb->index].seginfo->mode = no_mode; | |
660 | } | |
661 | } | |
662 | ||
663 | sbitmap_vector_free (delete); | |
664 | sbitmap_vector_free (insert); | |
665 | clear_aux_for_edges (); | |
666 | free_edge_list (edge_list); | |
667 | } | |
668 | ||
669 | /* Now output the remaining mode sets in all the segments. */ | |
670 | for (j = n_entities - 1; j >= 0; j--) | |
671 | { | |
672 | int no_mode = num_modes[entity_map[j]]; | |
673 | ||
674 | FOR_EACH_BB_REVERSE (bb) | |
675 | { | |
676 | struct seginfo *ptr, *next; | |
677 | for (ptr = bb_info[j][bb->index].seginfo; ptr; ptr = next) | |
678 | { | |
679 | next = ptr->next; | |
680 | if (ptr->mode != no_mode) | |
681 | { | |
682 | rtx mode_set; | |
683 | ||
684 | start_sequence (); | |
685 | EMIT_MODE_SET (entity_map[j], ptr->mode, ptr->regs_live); | |
686 | mode_set = get_insns (); | |
687 | end_sequence (); | |
688 | ||
689 | /* Insert MODE_SET only if it is nonempty. */ | |
690 | if (mode_set != NULL_RTX) | |
691 | { | |
692 | emited = true; | |
a38e7aa5 | 693 | if (NOTE_INSN_BASIC_BLOCK_P (ptr->insn_ptr)) |
610d2478 SB |
694 | emit_insn_after (mode_set, ptr->insn_ptr); |
695 | else | |
696 | emit_insn_before (mode_set, ptr->insn_ptr); | |
697 | } | |
698 | } | |
699 | ||
700 | free (ptr); | |
701 | } | |
702 | } | |
703 | ||
704 | free (bb_info[j]); | |
705 | } | |
706 | ||
707 | /* Finished. Free up all the things we've allocated. */ | |
610d2478 SB |
708 | sbitmap_vector_free (kill); |
709 | sbitmap_vector_free (antic); | |
710 | sbitmap_vector_free (transp); | |
711 | sbitmap_vector_free (comp); | |
712 | ||
713 | if (need_commit) | |
714 | commit_edge_insertions (); | |
715 | ||
716 | #if defined (MODE_ENTRY) && defined (MODE_EXIT) | |
717 | cleanup_cfg (CLEANUP_NO_INSN_DEL); | |
718 | #else | |
719 | if (!need_commit && !emited) | |
720 | return 0; | |
721 | #endif | |
722 | ||
610d2478 SB |
723 | return 1; |
724 | } | |
ef330312 | 725 | |
610d2478 | 726 | #endif /* OPTIMIZE_MODE_SWITCHING */ |
ef330312 PB |
727 | \f |
728 | static bool | |
729 | gate_mode_switching (void) | |
730 | { | |
731 | #ifdef OPTIMIZE_MODE_SWITCHING | |
732 | return true; | |
733 | #else | |
734 | return false; | |
735 | #endif | |
736 | } | |
737 | ||
c2924966 | 738 | static unsigned int |
ef330312 PB |
739 | rest_of_handle_mode_switching (void) |
740 | { | |
741 | #ifdef OPTIMIZE_MODE_SWITCHING | |
10d22567 | 742 | optimize_mode_switching (); |
ef330312 | 743 | #endif /* OPTIMIZE_MODE_SWITCHING */ |
c2924966 | 744 | return 0; |
ef330312 PB |
745 | } |
746 | ||
747 | ||
748 | struct tree_opt_pass pass_mode_switching = | |
749 | { | |
defb77dc | 750 | "mode-sw", /* name */ |
ef330312 PB |
751 | gate_mode_switching, /* gate */ |
752 | rest_of_handle_mode_switching, /* execute */ | |
753 | NULL, /* sub */ | |
754 | NULL, /* next */ | |
755 | 0, /* static_pass_number */ | |
756 | TV_MODE_SWITCH, /* tv_id */ | |
757 | 0, /* properties_required */ | |
758 | 0, /* properties_provided */ | |
759 | 0, /* properties_destroyed */ | |
760 | 0, /* todo_flags_start */ | |
6fb5fa3c | 761 | TODO_df_finish | |
defb77dc | 762 | TODO_dump_func, /* todo_flags_finish */ |
ef330312 PB |
763 | 0 /* letter */ |
764 | }; |