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2f138c1c | 1 | /* CPU mode switching |
711789cc | 2 | Copyright (C) 1998-2013 Free Software Foundation, Inc. |
2f138c1c | 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 |
2f138c1c | 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/>. */ | |
2f138c1c | 19 | |
20 | #include "config.h" | |
21 | #include "system.h" | |
22 | #include "coretypes.h" | |
23 | #include "tm.h" | |
e1ce1485 | 24 | #include "target.h" |
2f138c1c | 25 | #include "rtl.h" |
26 | #include "regs.h" | |
27 | #include "hard-reg-set.h" | |
28 | #include "flags.h" | |
2f138c1c | 29 | #include "insn-config.h" |
30 | #include "recog.h" | |
31 | #include "basic-block.h" | |
2f138c1c | 32 | #include "tm_p.h" |
33 | #include "function.h" | |
77fce4cd | 34 | #include "tree-pass.h" |
3072d30e | 35 | #include "df.h" |
06f9d6ef | 36 | #include "emit-rtl.h" |
2f138c1c | 37 | |
38 | /* We want target macros for the mode switching code to be able to refer | |
39 | to instruction attribute values. */ | |
40 | #include "insn-attr.h" | |
41 | ||
42 | #ifdef OPTIMIZE_MODE_SWITCHING | |
43 | ||
44 | /* The algorithm for setting the modes consists of scanning the insn list | |
45 | and finding all the insns which require a specific mode. Each insn gets | |
46 | a unique struct seginfo element. These structures are inserted into a list | |
47 | for each basic block. For each entity, there is an array of bb_info over | |
48 | the flow graph basic blocks (local var 'bb_info'), and contains a list | |
49 | of all insns within that basic block, in the order they are encountered. | |
50 | ||
51 | For each entity, any basic block WITHOUT any insns requiring a specific | |
52 | mode are given a single entry, without a mode. (Each basic block | |
53 | in the flow graph must have at least one entry in the segment table.) | |
54 | ||
55 | The LCM algorithm is then run over the flow graph to determine where to | |
56 | place the sets to the highest-priority value in respect of first the first | |
57 | insn in any one block. Any adjustments required to the transparency | |
58 | vectors are made, then the next iteration starts for the next-lower | |
59 | priority mode, till for each entity all modes are exhausted. | |
60 | ||
61 | More details are located in the code for optimize_mode_switching(). */ | |
62 | \f | |
63 | /* This structure contains the information for each insn which requires | |
64 | either single or double mode to be set. | |
65 | MODE is the mode this insn must be executed in. | |
66 | INSN_PTR is the insn to be executed (may be the note that marks the | |
67 | beginning of a basic block). | |
68 | BBNUM is the flow graph basic block this insn occurs in. | |
69 | NEXT is the next insn in the same basic block. */ | |
70 | struct seginfo | |
71 | { | |
72 | int mode; | |
73 | rtx insn_ptr; | |
74 | int bbnum; | |
75 | struct seginfo *next; | |
76 | HARD_REG_SET regs_live; | |
77 | }; | |
78 | ||
79 | struct bb_info | |
80 | { | |
81 | struct seginfo *seginfo; | |
82 | int computing; | |
83 | }; | |
84 | ||
85 | /* These bitmaps are used for the LCM algorithm. */ | |
86 | ||
87 | static sbitmap *antic; | |
88 | static sbitmap *transp; | |
89 | static sbitmap *comp; | |
90 | ||
91 | static struct seginfo * new_seginfo (int, rtx, int, HARD_REG_SET); | |
92 | static void add_seginfo (struct bb_info *, struct seginfo *); | |
0ff4fe1d | 93 | static void reg_dies (rtx, HARD_REG_SET *); |
81a410b1 | 94 | static void reg_becomes_live (rtx, const_rtx, void *); |
2f138c1c | 95 | static void make_preds_opaque (basic_block, int); |
96 | \f | |
97 | ||
98 | /* This function will allocate a new BBINFO structure, initialized | |
99 | with the MODE, INSN, and basic block BB parameters. */ | |
100 | ||
101 | static struct seginfo * | |
102 | new_seginfo (int mode, rtx insn, int bb, HARD_REG_SET regs_live) | |
103 | { | |
104 | struct seginfo *ptr; | |
4c36ffe6 | 105 | ptr = XNEW (struct seginfo); |
2f138c1c | 106 | ptr->mode = mode; |
107 | ptr->insn_ptr = insn; | |
108 | ptr->bbnum = bb; | |
109 | ptr->next = NULL; | |
110 | COPY_HARD_REG_SET (ptr->regs_live, regs_live); | |
111 | return ptr; | |
112 | } | |
113 | ||
114 | /* Add a seginfo element to the end of a list. | |
115 | HEAD is a pointer to the list beginning. | |
116 | INFO is the structure to be linked in. */ | |
117 | ||
118 | static void | |
119 | add_seginfo (struct bb_info *head, struct seginfo *info) | |
120 | { | |
121 | struct seginfo *ptr; | |
122 | ||
123 | if (head->seginfo == NULL) | |
124 | head->seginfo = info; | |
125 | else | |
126 | { | |
127 | ptr = head->seginfo; | |
128 | while (ptr->next != NULL) | |
129 | ptr = ptr->next; | |
130 | ptr->next = info; | |
131 | } | |
132 | } | |
133 | ||
134 | /* Make all predecessors of basic block B opaque, recursively, till we hit | |
135 | some that are already non-transparent, or an edge where aux is set; that | |
136 | denotes that a mode set is to be done on that edge. | |
137 | J is the bit number in the bitmaps that corresponds to the entity that | |
138 | we are currently handling mode-switching for. */ | |
139 | ||
140 | static void | |
141 | make_preds_opaque (basic_block b, int j) | |
142 | { | |
143 | edge e; | |
144 | edge_iterator ei; | |
145 | ||
146 | FOR_EACH_EDGE (e, ei, b->preds) | |
147 | { | |
148 | basic_block pb = e->src; | |
149 | ||
08b7917c | 150 | if (e->aux || ! bitmap_bit_p (transp[pb->index], j)) |
2f138c1c | 151 | continue; |
152 | ||
08b7917c | 153 | bitmap_clear_bit (transp[pb->index], j); |
2f138c1c | 154 | make_preds_opaque (pb, j); |
155 | } | |
156 | } | |
157 | ||
158 | /* Record in LIVE that register REG died. */ | |
159 | ||
160 | static void | |
0ff4fe1d | 161 | reg_dies (rtx reg, HARD_REG_SET *live) |
2f138c1c | 162 | { |
a2c6f0b7 | 163 | int regno; |
2f138c1c | 164 | |
165 | if (!REG_P (reg)) | |
166 | return; | |
167 | ||
168 | regno = REGNO (reg); | |
169 | if (regno < FIRST_PSEUDO_REGISTER) | |
a2c6f0b7 | 170 | remove_from_hard_reg_set (live, GET_MODE (reg), regno); |
2f138c1c | 171 | } |
172 | ||
173 | /* Record in LIVE that register REG became live. | |
174 | This is called via note_stores. */ | |
175 | ||
176 | static void | |
81a410b1 | 177 | reg_becomes_live (rtx reg, const_rtx setter ATTRIBUTE_UNUSED, void *live) |
2f138c1c | 178 | { |
a2c6f0b7 | 179 | int regno; |
2f138c1c | 180 | |
181 | if (GET_CODE (reg) == SUBREG) | |
182 | reg = SUBREG_REG (reg); | |
183 | ||
184 | if (!REG_P (reg)) | |
185 | return; | |
186 | ||
187 | regno = REGNO (reg); | |
188 | if (regno < FIRST_PSEUDO_REGISTER) | |
a2c6f0b7 | 189 | add_to_hard_reg_set ((HARD_REG_SET *) live, GET_MODE (reg), regno); |
2f138c1c | 190 | } |
191 | ||
192 | /* Make sure if MODE_ENTRY is defined the MODE_EXIT is defined | |
193 | and vice versa. */ | |
194 | #if defined (MODE_ENTRY) != defined (MODE_EXIT) | |
195 | #error "Both MODE_ENTRY and MODE_EXIT must be defined" | |
196 | #endif | |
197 | ||
198 | #if defined (MODE_ENTRY) && defined (MODE_EXIT) | |
199 | /* Split the fallthrough edge to the exit block, so that we can note | |
200 | that there NORMAL_MODE is required. Return the new block if it's | |
201 | inserted before the exit block. Otherwise return null. */ | |
202 | ||
203 | static basic_block | |
204 | create_pre_exit (int n_entities, int *entity_map, const int *num_modes) | |
205 | { | |
206 | edge eg; | |
207 | edge_iterator ei; | |
208 | basic_block pre_exit; | |
209 | ||
210 | /* The only non-call predecessor at this stage is a block with a | |
211 | fallthrough edge; there can be at most one, but there could be | |
212 | none at all, e.g. when exit is called. */ | |
213 | pre_exit = 0; | |
214 | FOR_EACH_EDGE (eg, ei, EXIT_BLOCK_PTR->preds) | |
215 | if (eg->flags & EDGE_FALLTHRU) | |
216 | { | |
217 | basic_block src_bb = eg->src; | |
2f138c1c | 218 | rtx last_insn, ret_reg; |
219 | ||
220 | gcc_assert (!pre_exit); | |
221 | /* If this function returns a value at the end, we have to | |
222 | insert the final mode switch before the return value copy | |
223 | to its hard register. */ | |
224 | if (EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 1 | |
225 | && NONJUMP_INSN_P ((last_insn = BB_END (src_bb))) | |
226 | && GET_CODE (PATTERN (last_insn)) == USE | |
227 | && GET_CODE ((ret_reg = XEXP (PATTERN (last_insn), 0))) == REG) | |
228 | { | |
229 | int ret_start = REGNO (ret_reg); | |
230 | int nregs = hard_regno_nregs[ret_start][GET_MODE (ret_reg)]; | |
231 | int ret_end = ret_start + nregs; | |
232 | int short_block = 0; | |
233 | int maybe_builtin_apply = 0; | |
234 | int forced_late_switch = 0; | |
235 | rtx before_return_copy; | |
236 | ||
237 | do | |
238 | { | |
239 | rtx return_copy = PREV_INSN (last_insn); | |
240 | rtx return_copy_pat, copy_reg; | |
241 | int copy_start, copy_num; | |
242 | int j; | |
243 | ||
8c94ea57 | 244 | if (NONDEBUG_INSN_P (return_copy)) |
2f138c1c | 245 | { |
1915b15f | 246 | /* When using SJLJ exceptions, the call to the |
247 | unregister function is inserted between the | |
248 | clobber of the return value and the copy. | |
249 | We do not want to split the block before this | |
250 | or any other call; if we have not found the | |
251 | copy yet, the copy must have been deleted. */ | |
252 | if (CALL_P (return_copy)) | |
253 | { | |
254 | short_block = 1; | |
255 | break; | |
256 | } | |
646857a5 | 257 | return_copy_pat = PATTERN (return_copy); |
258 | switch (GET_CODE (return_copy_pat)) | |
8801c4fd | 259 | { |
646857a5 | 260 | case USE: |
261 | /* Skip __builtin_apply pattern. */ | |
262 | if (GET_CODE (XEXP (return_copy_pat, 0)) == REG | |
e1ce1485 | 263 | && (targetm.calls.function_value_regno_p |
646857a5 | 264 | (REGNO (XEXP (return_copy_pat, 0))))) |
265 | { | |
266 | maybe_builtin_apply = 1; | |
267 | last_insn = return_copy; | |
268 | continue; | |
269 | } | |
270 | break; | |
271 | ||
272 | case ASM_OPERANDS: | |
273 | /* Skip barrier insns. */ | |
274 | if (!MEM_VOLATILE_P (return_copy_pat)) | |
275 | break; | |
276 | ||
277 | /* Fall through. */ | |
278 | ||
279 | case ASM_INPUT: | |
280 | case UNSPEC_VOLATILE: | |
8801c4fd | 281 | last_insn = return_copy; |
282 | continue; | |
646857a5 | 283 | |
284 | default: | |
285 | break; | |
8801c4fd | 286 | } |
646857a5 | 287 | |
2f138c1c | 288 | /* If the return register is not (in its entirety) |
289 | likely spilled, the return copy might be | |
290 | partially or completely optimized away. */ | |
291 | return_copy_pat = single_set (return_copy); | |
292 | if (!return_copy_pat) | |
293 | { | |
294 | return_copy_pat = PATTERN (return_copy); | |
295 | if (GET_CODE (return_copy_pat) != CLOBBER) | |
296 | break; | |
3072d30e | 297 | else if (!optimize) |
298 | { | |
299 | /* This might be (clobber (reg [<result>])) | |
300 | when not optimizing. Then check if | |
301 | the previous insn is the clobber for | |
302 | the return register. */ | |
303 | copy_reg = SET_DEST (return_copy_pat); | |
304 | if (GET_CODE (copy_reg) == REG | |
305 | && !HARD_REGISTER_NUM_P (REGNO (copy_reg))) | |
306 | { | |
307 | if (INSN_P (PREV_INSN (return_copy))) | |
308 | { | |
309 | return_copy = PREV_INSN (return_copy); | |
310 | return_copy_pat = PATTERN (return_copy); | |
311 | if (GET_CODE (return_copy_pat) != CLOBBER) | |
312 | break; | |
313 | } | |
314 | } | |
315 | } | |
2f138c1c | 316 | } |
317 | copy_reg = SET_DEST (return_copy_pat); | |
318 | if (GET_CODE (copy_reg) == REG) | |
319 | copy_start = REGNO (copy_reg); | |
320 | else if (GET_CODE (copy_reg) == SUBREG | |
321 | && GET_CODE (SUBREG_REG (copy_reg)) == REG) | |
322 | copy_start = REGNO (SUBREG_REG (copy_reg)); | |
323 | else | |
419e5c35 | 324 | { |
325 | /* When control reaches end of non-void function, | |
326 | there are no return copy insns at all. This | |
327 | avoids an ice on that invalid function. */ | |
328 | if (ret_start + nregs == ret_end) | |
329 | short_block = 1; | |
330 | break; | |
331 | } | |
3f988ca9 | 332 | if (!targetm.calls.function_value_regno_p (copy_start)) |
319b2f49 | 333 | { |
334 | last_insn = return_copy; | |
335 | continue; | |
336 | } | |
2f138c1c | 337 | copy_num |
338 | = hard_regno_nregs[copy_start][GET_MODE (copy_reg)]; | |
339 | ||
340 | /* If the return register is not likely spilled, - as is | |
341 | the case for floating point on SH4 - then it might | |
342 | be set by an arithmetic operation that needs a | |
343 | different mode than the exit block. */ | |
344 | for (j = n_entities - 1; j >= 0; j--) | |
345 | { | |
346 | int e = entity_map[j]; | |
347 | int mode = MODE_NEEDED (e, return_copy); | |
348 | ||
349 | if (mode != num_modes[e] && mode != MODE_EXIT (e)) | |
350 | break; | |
351 | } | |
352 | if (j >= 0) | |
353 | { | |
9cb7855c | 354 | /* __builtin_return emits a sequence of loads to all |
355 | return registers. One of them might require | |
356 | another mode than MODE_EXIT, even if it is | |
357 | unrelated to the return value, so we want to put | |
358 | the final mode switch after it. */ | |
359 | if (maybe_builtin_apply | |
360 | && targetm.calls.function_value_regno_p | |
361 | (copy_start)) | |
362 | forced_late_switch = 1; | |
363 | ||
2f138c1c | 364 | /* For the SH4, floating point loads depend on fpscr, |
365 | thus we might need to put the final mode switch | |
366 | after the return value copy. That is still OK, | |
367 | because a floating point return value does not | |
368 | conflict with address reloads. */ | |
369 | if (copy_start >= ret_start | |
370 | && copy_start + copy_num <= ret_end | |
371 | && OBJECT_P (SET_SRC (return_copy_pat))) | |
372 | forced_late_switch = 1; | |
373 | break; | |
374 | } | |
375 | ||
376 | if (copy_start >= ret_start | |
377 | && copy_start + copy_num <= ret_end) | |
378 | nregs -= copy_num; | |
379 | else if (!maybe_builtin_apply | |
e1ce1485 | 380 | || !targetm.calls.function_value_regno_p |
381 | (copy_start)) | |
2f138c1c | 382 | break; |
383 | last_insn = return_copy; | |
384 | } | |
385 | /* ??? Exception handling can lead to the return value | |
386 | copy being already separated from the return value use, | |
387 | as in unwind-dw2.c . | |
388 | Similarly, conditionally returning without a value, | |
389 | and conditionally using builtin_return can lead to an | |
390 | isolated use. */ | |
391 | if (return_copy == BB_HEAD (src_bb)) | |
392 | { | |
393 | short_block = 1; | |
394 | break; | |
395 | } | |
396 | last_insn = return_copy; | |
397 | } | |
398 | while (nregs); | |
48e1416a | 399 | |
2f138c1c | 400 | /* If we didn't see a full return value copy, verify that there |
401 | is a plausible reason for this. If some, but not all of the | |
402 | return register is likely spilled, we can expect that there | |
403 | is a copy for the likely spilled part. */ | |
404 | gcc_assert (!nregs | |
405 | || forced_late_switch | |
406 | || short_block | |
24dd0668 | 407 | || !(targetm.class_likely_spilled_p |
2f138c1c | 408 | (REGNO_REG_CLASS (ret_start))) |
409 | || (nregs | |
410 | != hard_regno_nregs[ret_start][GET_MODE (ret_reg)]) | |
411 | /* For multi-hard-register floating point | |
412 | values, sometimes the likely-spilled part | |
413 | is ordinarily copied first, then the other | |
414 | part is set with an arithmetic operation. | |
415 | This doesn't actually cause reload | |
416 | failures, so let it pass. */ | |
417 | || (GET_MODE_CLASS (GET_MODE (ret_reg)) != MODE_INT | |
418 | && nregs != 1)); | |
48e1416a | 419 | |
2f138c1c | 420 | if (INSN_P (last_insn)) |
421 | { | |
422 | before_return_copy | |
423 | = emit_note_before (NOTE_INSN_DELETED, last_insn); | |
424 | /* Instructions preceding LAST_INSN in the same block might | |
425 | require a different mode than MODE_EXIT, so if we might | |
426 | have such instructions, keep them in a separate block | |
427 | from pre_exit. */ | |
428 | if (last_insn != BB_HEAD (src_bb)) | |
429 | src_bb = split_block (src_bb, | |
430 | PREV_INSN (before_return_copy))->dest; | |
431 | } | |
432 | else | |
433 | before_return_copy = last_insn; | |
434 | pre_exit = split_block (src_bb, before_return_copy)->src; | |
435 | } | |
436 | else | |
437 | { | |
438 | pre_exit = split_edge (eg); | |
2f138c1c | 439 | } |
440 | } | |
441 | ||
442 | return pre_exit; | |
443 | } | |
444 | #endif | |
445 | ||
446 | /* Find all insns that need a particular mode setting, and insert the | |
447 | necessary mode switches. Return true if we did work. */ | |
448 | ||
9d31a126 | 449 | static int |
3f5be5f4 | 450 | optimize_mode_switching (void) |
2f138c1c | 451 | { |
452 | rtx insn; | |
453 | int e; | |
454 | basic_block bb; | |
455 | int need_commit = 0; | |
456 | sbitmap *kill; | |
457 | struct edge_list *edge_list; | |
458 | static const int num_modes[] = NUM_MODES_FOR_MODE_SWITCHING; | |
459 | #define N_ENTITIES ARRAY_SIZE (num_modes) | |
460 | int entity_map[N_ENTITIES]; | |
461 | struct bb_info *bb_info[N_ENTITIES]; | |
462 | int i, j; | |
463 | int n_entities; | |
464 | int max_num_modes = 0; | |
9d75589a | 465 | bool emitted ATTRIBUTE_UNUSED = false; |
2f138c1c | 466 | basic_block post_entry ATTRIBUTE_UNUSED, pre_exit ATTRIBUTE_UNUSED; |
467 | ||
2f138c1c | 468 | for (e = N_ENTITIES - 1, n_entities = 0; e >= 0; e--) |
469 | if (OPTIMIZE_MODE_SWITCHING (e)) | |
470 | { | |
471 | int entry_exit_extra = 0; | |
472 | ||
473 | /* Create the list of segments within each basic block. | |
474 | If NORMAL_MODE is defined, allow for two extra | |
475 | blocks split from the entry and exit block. */ | |
476 | #if defined (MODE_ENTRY) && defined (MODE_EXIT) | |
477 | entry_exit_extra = 3; | |
478 | #endif | |
479 | bb_info[n_entities] | |
613768ea | 480 | = XCNEWVEC (struct bb_info, last_basic_block + entry_exit_extra); |
2f138c1c | 481 | entity_map[n_entities++] = e; |
482 | if (num_modes[e] > max_num_modes) | |
483 | max_num_modes = num_modes[e]; | |
484 | } | |
485 | ||
486 | if (! n_entities) | |
487 | return 0; | |
488 | ||
489 | #if defined (MODE_ENTRY) && defined (MODE_EXIT) | |
490 | /* Split the edge from the entry block, so that we can note that | |
491 | there NORMAL_MODE is supplied. */ | |
492 | post_entry = split_edge (single_succ_edge (ENTRY_BLOCK_PTR)); | |
493 | pre_exit = create_pre_exit (n_entities, entity_map, num_modes); | |
494 | #endif | |
495 | ||
3072d30e | 496 | df_analyze (); |
497 | ||
2f138c1c | 498 | /* Create the bitmap vectors. */ |
499 | ||
500 | antic = sbitmap_vector_alloc (last_basic_block, n_entities); | |
501 | transp = sbitmap_vector_alloc (last_basic_block, n_entities); | |
502 | comp = sbitmap_vector_alloc (last_basic_block, n_entities); | |
503 | ||
53c5d9d4 | 504 | bitmap_vector_ones (transp, last_basic_block); |
2f138c1c | 505 | |
506 | for (j = n_entities - 1; j >= 0; j--) | |
507 | { | |
508 | int e = entity_map[j]; | |
509 | int no_mode = num_modes[e]; | |
510 | struct bb_info *info = bb_info[j]; | |
511 | ||
512 | /* Determine what the first use (if any) need for a mode of entity E is. | |
513 | This will be the mode that is anticipatable for this block. | |
514 | Also compute the initial transparency settings. */ | |
515 | FOR_EACH_BB (bb) | |
516 | { | |
517 | struct seginfo *ptr; | |
518 | int last_mode = no_mode; | |
aadec354 | 519 | bool any_set_required = false; |
2f138c1c | 520 | HARD_REG_SET live_now; |
521 | ||
3072d30e | 522 | REG_SET_TO_HARD_REG_SET (live_now, df_get_live_in (bb)); |
37430745 | 523 | |
524 | /* Pretend the mode is clobbered across abnormal edges. */ | |
525 | { | |
526 | edge_iterator ei; | |
527 | edge e; | |
528 | FOR_EACH_EDGE (e, ei, bb->preds) | |
529 | if (e->flags & EDGE_COMPLEX) | |
530 | break; | |
531 | if (e) | |
9e236a59 | 532 | { |
533 | ptr = new_seginfo (no_mode, BB_HEAD (bb), bb->index, live_now); | |
534 | add_seginfo (info + bb->index, ptr); | |
08b7917c | 535 | bitmap_clear_bit (transp[bb->index], j); |
9e236a59 | 536 | } |
37430745 | 537 | } |
538 | ||
50b15e04 | 539 | FOR_BB_INSNS (bb, insn) |
2f138c1c | 540 | { |
541 | if (INSN_P (insn)) | |
542 | { | |
543 | int mode = MODE_NEEDED (e, insn); | |
544 | rtx link; | |
545 | ||
546 | if (mode != no_mode && mode != last_mode) | |
547 | { | |
aadec354 | 548 | any_set_required = true; |
2f138c1c | 549 | last_mode = mode; |
550 | ptr = new_seginfo (mode, insn, bb->index, live_now); | |
551 | add_seginfo (info + bb->index, ptr); | |
08b7917c | 552 | bitmap_clear_bit (transp[bb->index], j); |
2f138c1c | 553 | } |
554 | #ifdef MODE_AFTER | |
7bc8959a | 555 | last_mode = MODE_AFTER (e, last_mode, insn); |
2f138c1c | 556 | #endif |
557 | /* Update LIVE_NOW. */ | |
558 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) | |
559 | if (REG_NOTE_KIND (link) == REG_DEAD) | |
0ff4fe1d | 560 | reg_dies (XEXP (link, 0), &live_now); |
2f138c1c | 561 | |
562 | note_stores (PATTERN (insn), reg_becomes_live, &live_now); | |
563 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) | |
564 | if (REG_NOTE_KIND (link) == REG_UNUSED) | |
0ff4fe1d | 565 | reg_dies (XEXP (link, 0), &live_now); |
2f138c1c | 566 | } |
567 | } | |
568 | ||
569 | info[bb->index].computing = last_mode; | |
aadec354 | 570 | /* Check for blocks without ANY mode requirements. |
571 | N.B. because of MODE_AFTER, last_mode might still be different | |
572 | from no_mode. */ | |
573 | if (!any_set_required) | |
2f138c1c | 574 | { |
575 | ptr = new_seginfo (no_mode, BB_END (bb), bb->index, live_now); | |
576 | add_seginfo (info + bb->index, ptr); | |
577 | } | |
578 | } | |
579 | #if defined (MODE_ENTRY) && defined (MODE_EXIT) | |
580 | { | |
581 | int mode = MODE_ENTRY (e); | |
582 | ||
583 | if (mode != no_mode) | |
584 | { | |
585 | bb = post_entry; | |
586 | ||
587 | /* By always making this nontransparent, we save | |
588 | an extra check in make_preds_opaque. We also | |
589 | need this to avoid confusing pre_edge_lcm when | |
590 | antic is cleared but transp and comp are set. */ | |
08b7917c | 591 | bitmap_clear_bit (transp[bb->index], j); |
2f138c1c | 592 | |
593 | /* Insert a fake computing definition of MODE into entry | |
594 | blocks which compute no mode. This represents the mode on | |
595 | entry. */ | |
596 | info[bb->index].computing = mode; | |
597 | ||
598 | if (pre_exit) | |
599 | info[pre_exit->index].seginfo->mode = MODE_EXIT (e); | |
600 | } | |
601 | } | |
602 | #endif /* NORMAL_MODE */ | |
603 | } | |
604 | ||
605 | kill = sbitmap_vector_alloc (last_basic_block, n_entities); | |
606 | for (i = 0; i < max_num_modes; i++) | |
607 | { | |
608 | int current_mode[N_ENTITIES]; | |
9ce37fa7 | 609 | sbitmap *del; |
2f138c1c | 610 | sbitmap *insert; |
611 | ||
612 | /* Set the anticipatable and computing arrays. */ | |
53c5d9d4 | 613 | bitmap_vector_clear (antic, last_basic_block); |
614 | bitmap_vector_clear (comp, last_basic_block); | |
2f138c1c | 615 | for (j = n_entities - 1; j >= 0; j--) |
616 | { | |
617 | int m = current_mode[j] = MODE_PRIORITY_TO_MODE (entity_map[j], i); | |
618 | struct bb_info *info = bb_info[j]; | |
619 | ||
620 | FOR_EACH_BB (bb) | |
621 | { | |
622 | if (info[bb->index].seginfo->mode == m) | |
08b7917c | 623 | bitmap_set_bit (antic[bb->index], j); |
2f138c1c | 624 | |
625 | if (info[bb->index].computing == m) | |
08b7917c | 626 | bitmap_set_bit (comp[bb->index], j); |
2f138c1c | 627 | } |
628 | } | |
629 | ||
630 | /* Calculate the optimal locations for the | |
631 | placement mode switches to modes with priority I. */ | |
632 | ||
633 | FOR_EACH_BB (bb) | |
53c5d9d4 | 634 | bitmap_not (kill[bb->index], transp[bb->index]); |
3f5be5f4 | 635 | edge_list = pre_edge_lcm (n_entities, transp, comp, antic, |
9ce37fa7 | 636 | kill, &insert, &del); |
2f138c1c | 637 | |
638 | for (j = n_entities - 1; j >= 0; j--) | |
639 | { | |
640 | /* Insert all mode sets that have been inserted by lcm. */ | |
641 | int no_mode = num_modes[entity_map[j]]; | |
642 | ||
643 | /* Wherever we have moved a mode setting upwards in the flow graph, | |
644 | the blocks between the new setting site and the now redundant | |
645 | computation ceases to be transparent for any lower-priority | |
646 | mode of the same entity. First set the aux field of each | |
647 | insertion site edge non-transparent, then propagate the new | |
648 | non-transparency from the redundant computation upwards till | |
649 | we hit an insertion site or an already non-transparent block. */ | |
650 | for (e = NUM_EDGES (edge_list) - 1; e >= 0; e--) | |
651 | { | |
652 | edge eg = INDEX_EDGE (edge_list, e); | |
653 | int mode; | |
654 | basic_block src_bb; | |
655 | HARD_REG_SET live_at_edge; | |
656 | rtx mode_set; | |
657 | ||
658 | eg->aux = 0; | |
659 | ||
08b7917c | 660 | if (! bitmap_bit_p (insert[e], j)) |
2f138c1c | 661 | continue; |
662 | ||
663 | eg->aux = (void *)1; | |
664 | ||
665 | mode = current_mode[j]; | |
666 | src_bb = eg->src; | |
667 | ||
3072d30e | 668 | REG_SET_TO_HARD_REG_SET (live_at_edge, df_get_live_out (src_bb)); |
2f138c1c | 669 | |
670 | start_sequence (); | |
671 | EMIT_MODE_SET (entity_map[j], mode, live_at_edge); | |
672 | mode_set = get_insns (); | |
673 | end_sequence (); | |
674 | ||
675 | /* Do not bother to insert empty sequence. */ | |
676 | if (mode_set == NULL_RTX) | |
677 | continue; | |
678 | ||
9e236a59 | 679 | /* We should not get an abnormal edge here. */ |
680 | gcc_assert (! (eg->flags & EDGE_ABNORMAL)); | |
681 | ||
682 | need_commit = 1; | |
683 | insert_insn_on_edge (mode_set, eg); | |
2f138c1c | 684 | } |
685 | ||
686 | FOR_EACH_BB_REVERSE (bb) | |
08b7917c | 687 | if (bitmap_bit_p (del[bb->index], j)) |
2f138c1c | 688 | { |
689 | make_preds_opaque (bb, j); | |
690 | /* Cancel the 'deleted' mode set. */ | |
691 | bb_info[j][bb->index].seginfo->mode = no_mode; | |
692 | } | |
693 | } | |
694 | ||
9ce37fa7 | 695 | sbitmap_vector_free (del); |
2f138c1c | 696 | sbitmap_vector_free (insert); |
697 | clear_aux_for_edges (); | |
698 | free_edge_list (edge_list); | |
699 | } | |
700 | ||
701 | /* Now output the remaining mode sets in all the segments. */ | |
702 | for (j = n_entities - 1; j >= 0; j--) | |
703 | { | |
704 | int no_mode = num_modes[entity_map[j]]; | |
705 | ||
706 | FOR_EACH_BB_REVERSE (bb) | |
707 | { | |
708 | struct seginfo *ptr, *next; | |
709 | for (ptr = bb_info[j][bb->index].seginfo; ptr; ptr = next) | |
710 | { | |
711 | next = ptr->next; | |
712 | if (ptr->mode != no_mode) | |
713 | { | |
714 | rtx mode_set; | |
715 | ||
716 | start_sequence (); | |
717 | EMIT_MODE_SET (entity_map[j], ptr->mode, ptr->regs_live); | |
718 | mode_set = get_insns (); | |
719 | end_sequence (); | |
720 | ||
721 | /* Insert MODE_SET only if it is nonempty. */ | |
722 | if (mode_set != NULL_RTX) | |
723 | { | |
9d75589a | 724 | emitted = true; |
ad4583d9 | 725 | if (NOTE_INSN_BASIC_BLOCK_P (ptr->insn_ptr)) |
2f138c1c | 726 | emit_insn_after (mode_set, ptr->insn_ptr); |
727 | else | |
728 | emit_insn_before (mode_set, ptr->insn_ptr); | |
729 | } | |
730 | } | |
731 | ||
732 | free (ptr); | |
733 | } | |
734 | } | |
735 | ||
736 | free (bb_info[j]); | |
737 | } | |
738 | ||
739 | /* Finished. Free up all the things we've allocated. */ | |
2f138c1c | 740 | sbitmap_vector_free (kill); |
741 | sbitmap_vector_free (antic); | |
742 | sbitmap_vector_free (transp); | |
743 | sbitmap_vector_free (comp); | |
744 | ||
745 | if (need_commit) | |
746 | commit_edge_insertions (); | |
747 | ||
748 | #if defined (MODE_ENTRY) && defined (MODE_EXIT) | |
749 | cleanup_cfg (CLEANUP_NO_INSN_DEL); | |
750 | #else | |
9d75589a | 751 | if (!need_commit && !emitted) |
2f138c1c | 752 | return 0; |
753 | #endif | |
754 | ||
2f138c1c | 755 | return 1; |
756 | } | |
77fce4cd | 757 | |
2f138c1c | 758 | #endif /* OPTIMIZE_MODE_SWITCHING */ |
77fce4cd | 759 | \f |
760 | static bool | |
761 | gate_mode_switching (void) | |
762 | { | |
763 | #ifdef OPTIMIZE_MODE_SWITCHING | |
764 | return true; | |
765 | #else | |
766 | return false; | |
767 | #endif | |
768 | } | |
769 | ||
2a1990e9 | 770 | static unsigned int |
77fce4cd | 771 | rest_of_handle_mode_switching (void) |
772 | { | |
773 | #ifdef OPTIMIZE_MODE_SWITCHING | |
3f5be5f4 | 774 | optimize_mode_switching (); |
77fce4cd | 775 | #endif /* OPTIMIZE_MODE_SWITCHING */ |
2a1990e9 | 776 | return 0; |
77fce4cd | 777 | } |
778 | ||
779 | ||
20099e35 | 780 | struct rtl_opt_pass pass_mode_switching = |
77fce4cd | 781 | { |
20099e35 | 782 | { |
783 | RTL_PASS, | |
b85ccd2c | 784 | "mode_sw", /* name */ |
c7875731 | 785 | OPTGROUP_NONE, /* optinfo_flags */ |
77fce4cd | 786 | gate_mode_switching, /* gate */ |
787 | rest_of_handle_mode_switching, /* execute */ | |
788 | NULL, /* sub */ | |
789 | NULL, /* next */ | |
790 | 0, /* static_pass_number */ | |
791 | TV_MODE_SWITCH, /* tv_id */ | |
792 | 0, /* properties_required */ | |
793 | 0, /* properties_provided */ | |
794 | 0, /* properties_destroyed */ | |
795 | 0, /* todo_flags_start */ | |
0806b508 | 796 | TODO_df_finish | TODO_verify_rtl_sharing | |
771e2890 | 797 | 0 /* todo_flags_finish */ |
20099e35 | 798 | } |
77fce4cd | 799 | }; |