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bd58420c RK |
1 | /* Instruction scheduling pass. |
2 | Copyright (C) 1992 Free Software Foundation, Inc. | |
3 | Contributed by Michael Tiemann (tiemann@cygnus.com) | |
4 | Enhanced by, and currently maintained by, Jim Wilson (wilson@cygnus.com) | |
5 | ||
6 | This file is part of GNU CC. | |
7 | ||
8 | GNU CC is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2, or (at your option) | |
11 | any later version. | |
12 | ||
13 | GNU CC is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with GNU CC; see the file COPYING. If not, write to | |
20 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
21 | ||
22 | /* Instruction scheduling pass. | |
23 | ||
24 | This pass implements list scheduling within basic blocks. It is | |
25 | run after flow analysis, but before register allocation. The | |
26 | scheduler works as follows: | |
27 | ||
28 | We compute insn priorities based on data dependencies. Flow | |
29 | analysis only creates a fraction of the data-dependencies we must | |
30 | observe: namely, only those dependencies which the combiner can be | |
31 | expected to use. For this pass, we must therefore create the | |
32 | remaining dependencies we need to observe: register dependencies, | |
33 | memory dependencies, dependencies to keep function calls in order, | |
34 | and the dependence between a conditional branch and the setting of | |
35 | condition codes are all dealt with here. | |
36 | ||
37 | The scheduler first traverses the data flow graph, starting with | |
38 | the last instruction, and proceeding to the first, assigning | |
39 | values to insn_priority as it goes. This sorts the instructions | |
40 | topologically by data dependence. | |
41 | ||
42 | Once priorities have been established, we order the insns using | |
43 | list scheduling. This works as follows: starting with a list of | |
44 | all the ready insns, and sorted according to priority number, we | |
45 | schedule the insn from the end of the list by placing its | |
46 | predecessors in the list according to their priority order. We | |
47 | consider this insn scheduled by setting the pointer to the "end" of | |
48 | the list to point to the previous insn. When an insn has no | |
49 | predecessors, we also add it to the ready list. When all insns down | |
50 | to the lowest priority have been scheduled, the critical path of the | |
51 | basic block has been made as short as possible. The remaining insns | |
52 | are then scheduled in remaining slots. | |
53 | ||
54 | The following list shows the order in which we want to break ties: | |
55 | ||
56 | 1. choose insn with lowest conflict cost, ties broken by | |
57 | 2. choose insn with the longest path to end of bb, ties broken by | |
58 | 3. choose insn that kills the most registers, ties broken by | |
59 | 4. choose insn that conflicts with the most ready insns, or finally | |
60 | 5. choose insn with lowest UID. | |
61 | ||
62 | Memory references complicate matters. Only if we can be certain | |
63 | that memory references are not part of the data dependency graph | |
64 | (via true, anti, or output dependence), can we move operations past | |
65 | memory references. To first approximation, reads can be done | |
66 | independently, while writes introduce dependencies. Better | |
67 | approximations will yield fewer dependencies. | |
68 | ||
69 | Dependencies set up by memory references are treated in exactly the | |
70 | same way as other dependencies, by using LOG_LINKS. | |
71 | ||
72 | Having optimized the critical path, we may have also unduly | |
73 | extended the lifetimes of some registers. If an operation requires | |
74 | that constants be loaded into registers, it is certainly desirable | |
75 | to load those constants as early as necessary, but no earlier. | |
76 | I.e., it will not do to load up a bunch of registers at the | |
77 | beginning of a basic block only to use them at the end, if they | |
78 | could be loaded later, since this may result in excessive register | |
79 | utilization. | |
80 | ||
81 | Note that since branches are never in basic blocks, but only end | |
82 | basic blocks, this pass will not do any branch scheduling. But | |
83 | that is ok, since we can use GNU's delayed branch scheduling | |
84 | pass to take care of this case. | |
85 | ||
86 | Also note that no further optimizations based on algebraic identities | |
87 | are performed, so this pass would be a good one to perform instruction | |
88 | splitting, such as breaking up a multiply instruction into shifts | |
89 | and adds where that is profitable. | |
90 | ||
91 | Given the memory aliasing analysis that this pass should perform, | |
92 | it should be possible to remove redundant stores to memory, and to | |
93 | load values from registers instead of hitting memory. | |
94 | ||
95 | This pass must update information that subsequent passes expect to be | |
96 | correct. Namely: reg_n_refs, reg_n_sets, reg_n_deaths, | |
97 | reg_n_calls_crossed, and reg_live_length. Also, basic_block_head, | |
98 | basic_block_end. | |
99 | ||
100 | The information in the line number notes is carefully retained by this | |
101 | pass. All other NOTE insns are grouped in their same relative order at | |
102 | the beginning of basic blocks that have been scheduled. */ | |
103 | \f | |
104 | #include <stdio.h> | |
105 | #include "config.h" | |
106 | #include "rtl.h" | |
107 | #include "basic-block.h" | |
108 | #include "regs.h" | |
109 | #include "hard-reg-set.h" | |
110 | #include "flags.h" | |
111 | #include "insn-config.h" | |
112 | #include "insn-attr.h" | |
113 | ||
114 | /* Arrays set up by scheduling for the same respective purposes as | |
115 | similar-named arrays set up by flow analysis. We work with these | |
116 | arrays during the scheduling pass so we can compare values against | |
117 | unscheduled code. | |
118 | ||
119 | Values of these arrays are copied at the end of this pass into the | |
120 | arrays set up by flow analysis. */ | |
121 | static short *sched_reg_n_deaths; | |
122 | static int *sched_reg_n_calls_crossed; | |
123 | static int *sched_reg_live_length; | |
124 | ||
125 | /* Element N is the next insn that sets (hard or pseudo) register | |
126 | N within the current basic block; or zero, if there is no | |
127 | such insn. Needed for new registers which may be introduced | |
128 | by splitting insns. */ | |
129 | static rtx *reg_last_uses; | |
130 | static rtx *reg_last_sets; | |
131 | ||
132 | /* Vector indexed by INSN_UID giving the original ordering of the insns. */ | |
133 | static int *insn_luid; | |
134 | #define INSN_LUID(INSN) (insn_luid[INSN_UID (INSN)]) | |
135 | ||
136 | /* Vector indexed by INSN_UID giving each instruction a priority. */ | |
137 | static int *insn_priority; | |
138 | #define INSN_PRIORITY(INSN) (insn_priority[INSN_UID (INSN)]) | |
139 | ||
c3de4fe6 JW |
140 | static short *insn_costs; |
141 | #define INSN_COST(INSN) insn_costs[INSN_UID (INSN)] | |
142 | ||
bd58420c RK |
143 | #define DONE_PRIORITY -1 |
144 | #define MAX_PRIORITY 0x7fffffff | |
145 | #define TAIL_PRIORITY 0x7ffffffe | |
146 | #define LAUNCH_PRIORITY 0x7f000001 | |
147 | #define DONE_PRIORITY_P(INSN) (INSN_PRIORITY (INSN) < 0) | |
148 | #define LOW_PRIORITY_P(INSN) ((INSN_PRIORITY (INSN) & 0x7f000000) == 0) | |
149 | ||
b4ac57ab | 150 | /* Vector indexed by INSN_UID giving number of insns referring to this insn. */ |
bd58420c RK |
151 | static int *insn_ref_count; |
152 | #define INSN_REF_COUNT(INSN) (insn_ref_count[INSN_UID (INSN)]) | |
153 | ||
154 | /* Vector indexed by INSN_UID giving line-number note in effect for each | |
155 | insn. For line-number notes, this indicates whether the note may be | |
156 | reused. */ | |
157 | static rtx *line_note; | |
158 | #define LINE_NOTE(INSN) (line_note[INSN_UID (INSN)]) | |
159 | ||
160 | /* Vector indexed by basic block number giving the starting line-number | |
161 | for each basic block. */ | |
162 | static rtx *line_note_head; | |
163 | ||
164 | /* List of important notes we must keep around. This is a pointer to the | |
165 | last element in the list. */ | |
166 | static rtx note_list; | |
167 | ||
168 | /* Regsets telling whether a given register is live or dead before the last | |
169 | scheduled insn. Must scan the instructions once before scheduling to | |
170 | determine what registers are live or dead at the end of the block. */ | |
171 | static regset bb_dead_regs; | |
172 | static regset bb_live_regs; | |
173 | ||
174 | /* Regset telling whether a given register is live after the insn currently | |
175 | being scheduled. Before processing an insn, this is equal to bb_live_regs | |
6dc42e49 | 176 | above. This is used so that we can find registers that are newly born/dead |
bd58420c RK |
177 | after processing an insn. */ |
178 | static regset old_live_regs; | |
179 | ||
180 | /* The chain of REG_DEAD notes. REG_DEAD notes are removed from all insns | |
181 | during the initial scan and reused later. If there are not exactly as | |
182 | many REG_DEAD notes in the post scheduled code as there were in the | |
183 | prescheduled code then we trigger an abort because this indicates a bug. */ | |
184 | static rtx dead_notes; | |
185 | ||
186 | /* Queues, etc. */ | |
187 | ||
188 | /* An instruction is ready to be scheduled when all insns following it | |
189 | have already been scheduled. It is important to ensure that all | |
190 | insns which use its result will not be executed until its result | |
191 | has been computed. We maintain three lists (conceptually): | |
192 | ||
193 | (1) a "Ready" list of unscheduled, uncommitted insns | |
194 | (2) a "Scheduled" list of scheduled insns | |
195 | (3) a "Pending" list of insns which can be scheduled, but | |
196 | for stalls. | |
197 | ||
198 | Insns move from the "Ready" list to the "Pending" list when | |
199 | all insns following them have been scheduled. | |
200 | ||
201 | Insns move from the "Pending" list to the "Scheduled" list | |
202 | when there is sufficient space in the pipeline to prevent | |
203 | stalls between the insn and scheduled insns which use it. | |
204 | ||
205 | The "Pending" list acts as a buffer to prevent insns | |
206 | from avalanching. | |
207 | ||
208 | The "Ready" list is implemented by the variable `ready'. | |
209 | The "Pending" list are the insns in the LOG_LINKS of ready insns. | |
210 | The "Scheduled" list is the new insn chain built by this pass. */ | |
211 | ||
212 | /* Implement a circular buffer from which instructions are issued. */ | |
213 | #define Q_SIZE 128 | |
214 | static rtx insn_queue[Q_SIZE]; | |
215 | static int q_ptr = 0; | |
216 | static int q_size = 0; | |
217 | #define NEXT_Q(X) (((X)+1) & (Q_SIZE-1)) | |
218 | #define NEXT_Q_AFTER(X,C) (((X)+C) & (Q_SIZE-1)) | |
6dab9d41 | 219 | |
bd58420c RK |
220 | /* Forward declarations. */ |
221 | static void sched_analyze_2 (); | |
222 | static void schedule_block (); | |
223 | ||
224 | /* Main entry point of this file. */ | |
225 | void schedule_insns (); | |
226 | \f | |
227 | #define SIZE_FOR_MODE(X) (GET_MODE_SIZE (GET_MODE (X))) | |
228 | ||
229 | /* Vector indexed by N giving the initial (unchanging) value known | |
230 | for pseudo-register N. */ | |
231 | static rtx *reg_known_value; | |
232 | ||
233 | /* Indicates number of valid entries in reg_known_value. */ | |
234 | static int reg_known_value_size; | |
235 | ||
236 | static rtx | |
237 | canon_rtx (x) | |
238 | rtx x; | |
239 | { | |
240 | if (GET_CODE (x) == REG && REGNO (x) >= FIRST_PSEUDO_REGISTER | |
241 | && REGNO (x) <= reg_known_value_size) | |
242 | return reg_known_value[REGNO (x)]; | |
243 | else if (GET_CODE (x) == PLUS) | |
244 | { | |
245 | rtx x0 = canon_rtx (XEXP (x, 0)); | |
246 | rtx x1 = canon_rtx (XEXP (x, 1)); | |
247 | ||
248 | if (x0 != XEXP (x, 0) || x1 != XEXP (x, 1)) | |
249 | { | |
250 | /* We can tolerate LO_SUMs being offset here; these | |
251 | rtl are used for nothing other than comparisons. */ | |
252 | if (GET_CODE (x0) == CONST_INT) | |
253 | return plus_constant_for_output (x1, INTVAL (x0)); | |
254 | else if (GET_CODE (x1) == CONST_INT) | |
255 | return plus_constant_for_output (x0, INTVAL (x1)); | |
256 | return gen_rtx (PLUS, GET_MODE (x), x0, x1); | |
257 | } | |
258 | } | |
259 | return x; | |
260 | } | |
261 | ||
262 | /* Set up all info needed to perform alias analysis on memory references. */ | |
263 | ||
264 | void | |
265 | init_alias_analysis () | |
266 | { | |
267 | int maxreg = max_reg_num (); | |
268 | rtx insn; | |
269 | rtx note; | |
270 | rtx set; | |
271 | ||
272 | reg_known_value_size = maxreg; | |
273 | ||
274 | reg_known_value | |
275 | = (rtx *) oballoc ((maxreg-FIRST_PSEUDO_REGISTER) * sizeof (rtx)) | |
276 | - FIRST_PSEUDO_REGISTER; | |
277 | bzero (reg_known_value+FIRST_PSEUDO_REGISTER, | |
278 | (maxreg-FIRST_PSEUDO_REGISTER) * sizeof (rtx)); | |
279 | ||
280 | /* Fill in the entries with known constant values. */ | |
281 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) | |
282 | if ((set = single_set (insn)) != 0 | |
283 | && GET_CODE (SET_DEST (set)) == REG | |
284 | && REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER | |
285 | && (((note = find_reg_note (insn, REG_EQUAL, 0)) != 0 | |
286 | && reg_n_sets[REGNO (SET_DEST (set))] == 1) | |
fb3821f7 | 287 | || (note = find_reg_note (insn, REG_EQUIV, NULL_RTX)) != 0) |
bd58420c RK |
288 | && GET_CODE (XEXP (note, 0)) != EXPR_LIST) |
289 | reg_known_value[REGNO (SET_DEST (set))] = XEXP (note, 0); | |
290 | ||
291 | /* Fill in the remaining entries. */ | |
292 | while (--maxreg >= FIRST_PSEUDO_REGISTER) | |
293 | if (reg_known_value[maxreg] == 0) | |
294 | reg_known_value[maxreg] = regno_reg_rtx[maxreg]; | |
295 | } | |
296 | ||
297 | /* Return 1 if X and Y are identical-looking rtx's. | |
298 | ||
299 | We use the data in reg_known_value above to see if two registers with | |
300 | different numbers are, in fact, equivalent. */ | |
301 | ||
302 | static int | |
303 | rtx_equal_for_memref_p (x, y) | |
304 | rtx x, y; | |
305 | { | |
306 | register int i; | |
307 | register int j; | |
308 | register enum rtx_code code; | |
309 | register char *fmt; | |
310 | ||
311 | if (x == 0 && y == 0) | |
312 | return 1; | |
313 | if (x == 0 || y == 0) | |
314 | return 0; | |
315 | x = canon_rtx (x); | |
316 | y = canon_rtx (y); | |
317 | ||
318 | if (x == y) | |
319 | return 1; | |
320 | ||
321 | code = GET_CODE (x); | |
322 | /* Rtx's of different codes cannot be equal. */ | |
323 | if (code != GET_CODE (y)) | |
324 | return 0; | |
325 | ||
326 | /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. | |
327 | (REG:SI x) and (REG:HI x) are NOT equivalent. */ | |
328 | ||
329 | if (GET_MODE (x) != GET_MODE (y)) | |
330 | return 0; | |
331 | ||
332 | /* REG, LABEL_REF, and SYMBOL_REF can be compared nonrecursively. */ | |
333 | ||
334 | if (code == REG) | |
335 | return REGNO (x) == REGNO (y); | |
336 | if (code == LABEL_REF) | |
337 | return XEXP (x, 0) == XEXP (y, 0); | |
338 | if (code == SYMBOL_REF) | |
339 | return XSTR (x, 0) == XSTR (y, 0); | |
340 | ||
341 | /* Compare the elements. If any pair of corresponding elements | |
342 | fail to match, return 0 for the whole things. */ | |
343 | ||
344 | fmt = GET_RTX_FORMAT (code); | |
345 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
346 | { | |
347 | switch (fmt[i]) | |
348 | { | |
fb3821f7 CH |
349 | case 'w': |
350 | if (XWINT (x, i) != XWINT (y, i)) | |
351 | return 0; | |
352 | break; | |
353 | ||
bd58420c RK |
354 | case 'n': |
355 | case 'i': | |
356 | if (XINT (x, i) != XINT (y, i)) | |
357 | return 0; | |
358 | break; | |
359 | ||
360 | case 'V': | |
361 | case 'E': | |
362 | /* Two vectors must have the same length. */ | |
363 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
364 | return 0; | |
365 | ||
366 | /* And the corresponding elements must match. */ | |
367 | for (j = 0; j < XVECLEN (x, i); j++) | |
368 | if (rtx_equal_for_memref_p (XVECEXP (x, i, j), XVECEXP (y, i, j)) == 0) | |
369 | return 0; | |
370 | break; | |
371 | ||
372 | case 'e': | |
373 | if (rtx_equal_for_memref_p (XEXP (x, i), XEXP (y, i)) == 0) | |
374 | return 0; | |
375 | break; | |
376 | ||
377 | case 'S': | |
378 | case 's': | |
379 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
380 | return 0; | |
381 | break; | |
382 | ||
383 | case 'u': | |
384 | /* These are just backpointers, so they don't matter. */ | |
385 | break; | |
386 | ||
387 | case '0': | |
388 | break; | |
389 | ||
390 | /* It is believed that rtx's at this level will never | |
391 | contain anything but integers and other rtx's, | |
392 | except for within LABEL_REFs and SYMBOL_REFs. */ | |
393 | default: | |
394 | abort (); | |
395 | } | |
396 | } | |
397 | return 1; | |
398 | } | |
399 | ||
400 | /* Given an rtx X, find a SYMBOL_REF or LABEL_REF within | |
401 | X and return it, or return 0 if none found. */ | |
402 | ||
403 | static rtx | |
404 | find_symbolic_term (x) | |
405 | rtx x; | |
406 | { | |
407 | register int i; | |
408 | register enum rtx_code code; | |
409 | register char *fmt; | |
410 | ||
411 | code = GET_CODE (x); | |
412 | if (code == SYMBOL_REF || code == LABEL_REF) | |
413 | return x; | |
414 | if (GET_RTX_CLASS (code) == 'o') | |
415 | return 0; | |
416 | ||
417 | fmt = GET_RTX_FORMAT (code); | |
418 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
419 | { | |
420 | rtx t; | |
421 | ||
422 | if (fmt[i] == 'e') | |
423 | { | |
424 | t = find_symbolic_term (XEXP (x, i)); | |
425 | if (t != 0) | |
426 | return t; | |
427 | } | |
428 | else if (fmt[i] == 'E') | |
429 | break; | |
430 | } | |
431 | return 0; | |
432 | } | |
433 | ||
434 | /* Return nonzero if X and Y (memory addresses) could reference the | |
435 | same location in memory. C is an offset accumulator. When | |
436 | C is nonzero, we are testing aliases between X and Y + C. | |
437 | XSIZE is the size in bytes of the X reference, | |
438 | similarly YSIZE is the size in bytes for Y. | |
439 | ||
440 | If XSIZE or YSIZE is zero, we do not know the amount of memory being | |
441 | referenced (the reference was BLKmode), so make the most pessimistic | |
442 | assumptions. | |
443 | ||
444 | We recognize the following cases of non-conflicting memory: | |
445 | ||
446 | (1) addresses involving the frame pointer cannot conflict | |
447 | with addresses involving static variables. | |
448 | (2) static variables with different addresses cannot conflict. | |
449 | ||
6dc42e49 | 450 | Nice to notice that varying addresses cannot conflict with fp if no |
bd58420c RK |
451 | local variables had their addresses taken, but that's too hard now. */ |
452 | ||
453 | static int | |
454 | memrefs_conflict_p (xsize, x, ysize, y, c) | |
455 | rtx x, y; | |
456 | int xsize, ysize; | |
fb3821f7 | 457 | HOST_WIDE_INT c; |
bd58420c RK |
458 | { |
459 | if (GET_CODE (x) == HIGH) | |
460 | x = XEXP (x, 0); | |
461 | else if (GET_CODE (x) == LO_SUM) | |
462 | x = XEXP (x, 1); | |
463 | else | |
464 | x = canon_rtx (x); | |
465 | if (GET_CODE (y) == HIGH) | |
466 | y = XEXP (y, 0); | |
467 | else if (GET_CODE (y) == LO_SUM) | |
468 | y = XEXP (y, 1); | |
469 | else | |
470 | y = canon_rtx (y); | |
471 | ||
472 | if (rtx_equal_for_memref_p (x, y)) | |
473 | return (xsize == 0 || ysize == 0 || | |
474 | (c >= 0 && xsize > c) || (c < 0 && ysize+c > 0)); | |
475 | ||
476 | if (y == frame_pointer_rtx || y == stack_pointer_rtx) | |
477 | { | |
478 | rtx t = y; | |
479 | int tsize = ysize; | |
480 | y = x; ysize = xsize; | |
481 | x = t; xsize = tsize; | |
482 | } | |
483 | ||
484 | if (x == frame_pointer_rtx || x == stack_pointer_rtx) | |
485 | { | |
486 | rtx y1; | |
487 | ||
488 | if (CONSTANT_P (y)) | |
489 | return 0; | |
490 | ||
491 | if (GET_CODE (y) == PLUS | |
492 | && canon_rtx (XEXP (y, 0)) == x | |
493 | && (y1 = canon_rtx (XEXP (y, 1))) | |
494 | && GET_CODE (y1) == CONST_INT) | |
495 | { | |
496 | c += INTVAL (y1); | |
497 | return (xsize == 0 || ysize == 0 | |
498 | || (c >= 0 && xsize > c) || (c < 0 && ysize+c > 0)); | |
499 | } | |
500 | ||
501 | if (GET_CODE (y) == PLUS | |
502 | && (y1 = canon_rtx (XEXP (y, 0))) | |
503 | && CONSTANT_P (y1)) | |
504 | return 0; | |
505 | ||
506 | return 1; | |
507 | } | |
508 | ||
509 | if (GET_CODE (x) == PLUS) | |
510 | { | |
6dc42e49 RS |
511 | /* The fact that X is canonicalized means that this |
512 | PLUS rtx is canonicalized. */ | |
bd58420c RK |
513 | rtx x0 = XEXP (x, 0); |
514 | rtx x1 = XEXP (x, 1); | |
515 | ||
516 | if (GET_CODE (y) == PLUS) | |
517 | { | |
6dc42e49 RS |
518 | /* The fact that Y is canonicalized means that this |
519 | PLUS rtx is canonicalized. */ | |
bd58420c RK |
520 | rtx y0 = XEXP (y, 0); |
521 | rtx y1 = XEXP (y, 1); | |
522 | ||
523 | if (rtx_equal_for_memref_p (x1, y1)) | |
524 | return memrefs_conflict_p (xsize, x0, ysize, y0, c); | |
525 | if (rtx_equal_for_memref_p (x0, y0)) | |
526 | return memrefs_conflict_p (xsize, x1, ysize, y1, c); | |
527 | if (GET_CODE (x1) == CONST_INT) | |
528 | if (GET_CODE (y1) == CONST_INT) | |
529 | return memrefs_conflict_p (xsize, x0, ysize, y0, | |
530 | c - INTVAL (x1) + INTVAL (y1)); | |
531 | else | |
532 | return memrefs_conflict_p (xsize, x0, ysize, y, c - INTVAL (x1)); | |
533 | else if (GET_CODE (y1) == CONST_INT) | |
534 | return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1)); | |
535 | ||
536 | /* Handle case where we cannot understand iteration operators, | |
537 | but we notice that the base addresses are distinct objects. */ | |
538 | x = find_symbolic_term (x); | |
539 | if (x == 0) | |
540 | return 1; | |
541 | y = find_symbolic_term (y); | |
542 | if (y == 0) | |
543 | return 1; | |
544 | return rtx_equal_for_memref_p (x, y); | |
545 | } | |
546 | else if (GET_CODE (x1) == CONST_INT) | |
547 | return memrefs_conflict_p (xsize, x0, ysize, y, c - INTVAL (x1)); | |
548 | } | |
549 | else if (GET_CODE (y) == PLUS) | |
550 | { | |
6dc42e49 RS |
551 | /* The fact that Y is canonicalized means that this |
552 | PLUS rtx is canonicalized. */ | |
bd58420c RK |
553 | rtx y0 = XEXP (y, 0); |
554 | rtx y1 = XEXP (y, 1); | |
555 | ||
556 | if (GET_CODE (y1) == CONST_INT) | |
557 | return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1)); | |
558 | else | |
559 | return 1; | |
560 | } | |
561 | ||
562 | if (GET_CODE (x) == GET_CODE (y)) | |
563 | switch (GET_CODE (x)) | |
564 | { | |
565 | case MULT: | |
566 | { | |
567 | /* Handle cases where we expect the second operands to be the | |
568 | same, and check only whether the first operand would conflict | |
569 | or not. */ | |
570 | rtx x0, y0; | |
571 | rtx x1 = canon_rtx (XEXP (x, 1)); | |
572 | rtx y1 = canon_rtx (XEXP (y, 1)); | |
573 | if (! rtx_equal_for_memref_p (x1, y1)) | |
574 | return 1; | |
575 | x0 = canon_rtx (XEXP (x, 0)); | |
576 | y0 = canon_rtx (XEXP (y, 0)); | |
577 | if (rtx_equal_for_memref_p (x0, y0)) | |
578 | return (xsize == 0 || ysize == 0 | |
579 | || (c >= 0 && xsize > c) || (c < 0 && ysize+c > 0)); | |
580 | ||
581 | /* Can't properly adjust our sizes. */ | |
582 | if (GET_CODE (x1) != CONST_INT) | |
583 | return 1; | |
584 | xsize /= INTVAL (x1); | |
585 | ysize /= INTVAL (x1); | |
586 | c /= INTVAL (x1); | |
587 | return memrefs_conflict_p (xsize, x0, ysize, y0, c); | |
588 | } | |
589 | } | |
590 | ||
591 | if (CONSTANT_P (x)) | |
592 | { | |
593 | if (GET_CODE (x) == CONST_INT && GET_CODE (y) == CONST_INT) | |
594 | { | |
595 | c += (INTVAL (y) - INTVAL (x)); | |
596 | return (xsize == 0 || ysize == 0 | |
597 | || (c >= 0 && xsize > c) || (c < 0 && ysize+c > 0)); | |
598 | } | |
599 | ||
600 | if (GET_CODE (x) == CONST) | |
601 | { | |
602 | if (GET_CODE (y) == CONST) | |
603 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), | |
604 | ysize, canon_rtx (XEXP (y, 0)), c); | |
605 | else | |
606 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), | |
607 | ysize, y, c); | |
608 | } | |
609 | if (GET_CODE (y) == CONST) | |
610 | return memrefs_conflict_p (xsize, x, ysize, | |
611 | canon_rtx (XEXP (y, 0)), c); | |
612 | ||
613 | if (CONSTANT_P (y)) | |
614 | return (rtx_equal_for_memref_p (x, y) | |
615 | && (xsize == 0 || ysize == 0 | |
616 | || (c >= 0 && xsize > c) || (c < 0 && ysize+c > 0))); | |
617 | ||
618 | return 1; | |
619 | } | |
620 | return 1; | |
621 | } | |
622 | ||
623 | /* Functions to compute memory dependencies. | |
624 | ||
625 | Since we process the insns in execution order, we can build tables | |
626 | to keep track of what registers are fixed (and not aliased), what registers | |
627 | are varying in known ways, and what registers are varying in unknown | |
628 | ways. | |
629 | ||
630 | If both memory references are volatile, then there must always be a | |
631 | dependence between the two references, since their order can not be | |
632 | changed. A volatile and non-volatile reference can be interchanged | |
633 | though. | |
634 | ||
635 | A MEM_IN_STRUCT reference at a varying address can never conflict with a | |
636 | non-MEM_IN_STRUCT reference at a fixed address. */ | |
637 | ||
638 | /* Read dependence: X is read after read in MEM takes place. There can | |
639 | only be a dependence here if both reads are volatile. */ | |
640 | ||
641 | int | |
642 | read_dependence (mem, x) | |
643 | rtx mem; | |
644 | rtx x; | |
645 | { | |
646 | return MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem); | |
647 | } | |
648 | ||
649 | /* True dependence: X is read after store in MEM takes place. */ | |
650 | ||
651 | int | |
652 | true_dependence (mem, x) | |
653 | rtx mem; | |
654 | rtx x; | |
655 | { | |
1f6fc4de JW |
656 | /* If X is an unchanging read, then it can't possibly conflict with any |
657 | non-unchanging store. It may conflict with an unchanging write though, | |
658 | because there may be a single store to this address to initialize it. | |
659 | Just fall through to the code below to resolve the case where we have | |
660 | both an unchanging read and an unchanging write. This won't handle all | |
661 | cases optimally, but the possible performance loss should be | |
662 | negligible. */ | |
663 | if (RTX_UNCHANGING_P (x) && ! RTX_UNCHANGING_P (mem)) | |
bd58420c RK |
664 | return 0; |
665 | ||
666 | return ((MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) | |
667 | || (memrefs_conflict_p (SIZE_FOR_MODE (mem), XEXP (mem, 0), | |
668 | SIZE_FOR_MODE (x), XEXP (x, 0), 0) | |
669 | && ! (MEM_IN_STRUCT_P (mem) && rtx_addr_varies_p (mem) | |
670 | && ! MEM_IN_STRUCT_P (x) && ! rtx_addr_varies_p (x)) | |
671 | && ! (MEM_IN_STRUCT_P (x) && rtx_addr_varies_p (x) | |
672 | && ! MEM_IN_STRUCT_P (mem) && ! rtx_addr_varies_p (mem)))); | |
673 | } | |
674 | ||
675 | /* Anti dependence: X is written after read in MEM takes place. */ | |
676 | ||
677 | int | |
678 | anti_dependence (mem, x) | |
679 | rtx mem; | |
680 | rtx x; | |
681 | { | |
1f6fc4de JW |
682 | /* If MEM is an unchanging read, then it can't possibly conflict with |
683 | the store to X, because there is at most one store to MEM, and it must | |
684 | have occured somewhere before MEM. */ | |
bd58420c RK |
685 | if (RTX_UNCHANGING_P (mem)) |
686 | return 0; | |
687 | ||
688 | return ((MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) | |
689 | || (memrefs_conflict_p (SIZE_FOR_MODE (mem), XEXP (mem, 0), | |
690 | SIZE_FOR_MODE (x), XEXP (x, 0), 0) | |
691 | && ! (MEM_IN_STRUCT_P (mem) && rtx_addr_varies_p (mem) | |
692 | && ! MEM_IN_STRUCT_P (x) && ! rtx_addr_varies_p (x)) | |
693 | && ! (MEM_IN_STRUCT_P (x) && rtx_addr_varies_p (x) | |
694 | && ! MEM_IN_STRUCT_P (mem) && ! rtx_addr_varies_p (mem)))); | |
695 | } | |
696 | ||
697 | /* Output dependence: X is written after store in MEM takes place. */ | |
698 | ||
699 | int | |
700 | output_dependence (mem, x) | |
701 | rtx mem; | |
702 | rtx x; | |
703 | { | |
704 | return ((MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) | |
705 | || (memrefs_conflict_p (SIZE_FOR_MODE (mem), XEXP (mem, 0), | |
706 | SIZE_FOR_MODE (x), XEXP (x, 0), 0) | |
707 | && ! (MEM_IN_STRUCT_P (mem) && rtx_addr_varies_p (mem) | |
708 | && ! MEM_IN_STRUCT_P (x) && ! rtx_addr_varies_p (x)) | |
709 | && ! (MEM_IN_STRUCT_P (x) && rtx_addr_varies_p (x) | |
710 | && ! MEM_IN_STRUCT_P (mem) && ! rtx_addr_varies_p (mem)))); | |
711 | } | |
712 | \f | |
6dab9d41 RS |
713 | /* Helper functions for instruction scheduling. */ |
714 | ||
715 | /* Add ELEM wrapped in an INSN_LIST with reg note kind DEP_TYPE to the | |
716 | LOG_LINKS of INSN, if not already there. DEP_TYPE indicates the type | |
717 | of dependence that this link represents. */ | |
718 | ||
719 | void | |
720 | add_dependence (insn, elem, dep_type) | |
721 | rtx insn; | |
722 | rtx elem; | |
723 | enum reg_note dep_type; | |
724 | { | |
725 | rtx link, next; | |
726 | ||
727 | /* Don't depend an insn on itself. */ | |
728 | if (insn == elem) | |
729 | return; | |
730 | ||
731 | /* If elem is part of a sequence that must be scheduled together, then | |
732 | make the dependence point to the last insn of the sequence. | |
733 | When HAVE_cc0, it is possible for NOTEs to exist between users and | |
734 | setters of the condition codes, so we must skip past notes here. | |
735 | Otherwise, NOTEs are impossible here. */ | |
736 | ||
737 | next = NEXT_INSN (elem); | |
738 | ||
739 | #ifdef HAVE_cc0 | |
740 | while (next && GET_CODE (next) == NOTE) | |
741 | next = NEXT_INSN (next); | |
742 | #endif | |
743 | ||
744 | if (next && SCHED_GROUP_P (next)) | |
745 | { | |
746 | /* Notes will never intervene here though, so don't bother checking | |
747 | for them. */ | |
748 | while (NEXT_INSN (next) && SCHED_GROUP_P (NEXT_INSN (next))) | |
749 | next = NEXT_INSN (next); | |
750 | ||
751 | /* Again, don't depend an insn on itself. */ | |
752 | if (insn == next) | |
753 | return; | |
754 | ||
755 | /* Make the dependence to NEXT, the last insn of the group, instead | |
756 | of the original ELEM. */ | |
757 | elem = next; | |
758 | } | |
759 | ||
760 | /* Check that we don't already have this dependence. */ | |
761 | for (link = LOG_LINKS (insn); link; link = XEXP (link, 1)) | |
762 | if (XEXP (link, 0) == elem) | |
763 | { | |
764 | /* If this is a more restrictive type of dependence than the existing | |
765 | one, then change the existing dependence to this type. */ | |
766 | if ((int) dep_type < (int) REG_NOTE_KIND (link)) | |
767 | PUT_REG_NOTE_KIND (link, dep_type); | |
768 | return; | |
769 | } | |
770 | /* Might want to check one level of transitivity to save conses. */ | |
771 | ||
772 | link = rtx_alloc (INSN_LIST); | |
773 | /* Insn dependency, not data dependency. */ | |
774 | PUT_REG_NOTE_KIND (link, dep_type); | |
775 | XEXP (link, 0) = elem; | |
776 | XEXP (link, 1) = LOG_LINKS (insn); | |
777 | LOG_LINKS (insn) = link; | |
778 | } | |
779 | ||
780 | /* Remove ELEM wrapped in an INSN_LIST from the LOG_LINKS | |
781 | of INSN. Abort if not found. */ | |
782 | void | |
783 | remove_dependence (insn, elem) | |
784 | rtx insn; | |
785 | rtx elem; | |
786 | { | |
787 | rtx prev, link; | |
788 | int found = 0; | |
789 | ||
790 | for (prev = 0, link = LOG_LINKS (insn); link; | |
791 | prev = link, link = XEXP (link, 1)) | |
792 | { | |
793 | if (XEXP (link, 0) == elem) | |
794 | { | |
795 | if (prev) | |
796 | XEXP (prev, 1) = XEXP (link, 1); | |
797 | else | |
798 | LOG_LINKS (insn) = XEXP (link, 1); | |
799 | found = 1; | |
800 | } | |
801 | } | |
802 | ||
803 | if (! found) | |
804 | abort (); | |
805 | return; | |
806 | } | |
807 | \f | |
bd58420c RK |
808 | #ifndef INSN_SCHEDULING |
809 | void schedule_insns () {} | |
810 | #else | |
811 | #ifndef __GNUC__ | |
812 | #define __inline | |
813 | #endif | |
814 | ||
815 | /* Computation of memory dependencies. */ | |
816 | ||
817 | /* The *_insns and *_mems are paired lists. Each pending memory operation | |
818 | will have a pointer to the MEM rtx on one list and a pointer to the | |
819 | containing insn on the other list in the same place in the list. */ | |
820 | ||
821 | /* We can't use add_dependence like the old code did, because a single insn | |
822 | may have multiple memory accesses, and hence needs to be on the list | |
823 | once for each memory access. Add_dependence won't let you add an insn | |
824 | to a list more than once. */ | |
825 | ||
826 | /* An INSN_LIST containing all insns with pending read operations. */ | |
827 | static rtx pending_read_insns; | |
828 | ||
829 | /* An EXPR_LIST containing all MEM rtx's which are pending reads. */ | |
830 | static rtx pending_read_mems; | |
831 | ||
832 | /* An INSN_LIST containing all insns with pending write operations. */ | |
833 | static rtx pending_write_insns; | |
834 | ||
835 | /* An EXPR_LIST containing all MEM rtx's which are pending writes. */ | |
836 | static rtx pending_write_mems; | |
837 | ||
838 | /* Indicates the combined length of the two pending lists. We must prevent | |
839 | these lists from ever growing too large since the number of dependencies | |
840 | produced is at least O(N*N), and execution time is at least O(4*N*N), as | |
841 | a function of the length of these pending lists. */ | |
842 | ||
843 | static int pending_lists_length; | |
844 | ||
845 | /* An INSN_LIST containing all INSN_LISTs allocated but currently unused. */ | |
846 | ||
847 | static rtx unused_insn_list; | |
848 | ||
849 | /* An EXPR_LIST containing all EXPR_LISTs allocated but currently unused. */ | |
850 | ||
851 | static rtx unused_expr_list; | |
852 | ||
853 | /* The last insn upon which all memory references must depend. | |
854 | This is an insn which flushed the pending lists, creating a dependency | |
855 | between it and all previously pending memory references. This creates | |
856 | a barrier (or a checkpoint) which no memory reference is allowed to cross. | |
857 | ||
858 | This includes all non constant CALL_INSNs. When we do interprocedural | |
859 | alias analysis, this restriction can be relaxed. | |
860 | This may also be an INSN that writes memory if the pending lists grow | |
861 | too large. */ | |
862 | ||
863 | static rtx last_pending_memory_flush; | |
864 | ||
865 | /* The last function call we have seen. All hard regs, and, of course, | |
866 | the last function call, must depend on this. */ | |
867 | ||
868 | static rtx last_function_call; | |
869 | ||
870 | /* The LOG_LINKS field of this is a list of insns which use a pseudo register | |
871 | that does not already cross a call. We create dependencies between each | |
872 | of those insn and the next call insn, to ensure that they won't cross a call | |
873 | after scheduling is done. */ | |
874 | ||
875 | static rtx sched_before_next_call; | |
876 | ||
877 | /* Pointer to the last instruction scheduled. Used by rank_for_schedule, | |
878 | so that insns independent of the last scheduled insn will be preferred | |
879 | over dependent instructions. */ | |
880 | ||
881 | static rtx last_scheduled_insn; | |
882 | ||
883 | /* Process an insn's memory dependencies. There are four kinds of | |
884 | dependencies: | |
885 | ||
886 | (0) read dependence: read follows read | |
887 | (1) true dependence: read follows write | |
888 | (2) anti dependence: write follows read | |
889 | (3) output dependence: write follows write | |
890 | ||
891 | We are careful to build only dependencies which actually exist, and | |
892 | use transitivity to avoid building too many links. */ | |
893 | \f | |
894 | /* Return the INSN_LIST containing INSN in LIST, or NULL | |
895 | if LIST does not contain INSN. */ | |
896 | ||
897 | __inline static rtx | |
898 | find_insn_list (insn, list) | |
899 | rtx insn; | |
900 | rtx list; | |
901 | { | |
902 | while (list) | |
903 | { | |
904 | if (XEXP (list, 0) == insn) | |
905 | return list; | |
906 | list = XEXP (list, 1); | |
907 | } | |
908 | return 0; | |
909 | } | |
910 | ||
911 | /* Compute cost of executing INSN. This is the number of virtual | |
912 | cycles taken between instruction issue and instruction results. */ | |
913 | ||
914 | __inline static int | |
915 | insn_cost (insn) | |
916 | rtx insn; | |
917 | { | |
918 | register int cost; | |
919 | ||
c3de4fe6 JW |
920 | if (INSN_COST (insn)) |
921 | return INSN_COST (insn); | |
922 | ||
bd58420c RK |
923 | recog_memoized (insn); |
924 | ||
925 | /* A USE insn, or something else we don't need to understand. | |
926 | We can't pass these directly to result_ready_cost because it will trigger | |
927 | a fatal error for unrecognizable insns. */ | |
928 | if (INSN_CODE (insn) < 0) | |
c3de4fe6 JW |
929 | { |
930 | INSN_COST (insn) = 1; | |
931 | return 1; | |
932 | } | |
bd58420c RK |
933 | else |
934 | { | |
935 | cost = result_ready_cost (insn); | |
936 | ||
937 | if (cost < 1) | |
938 | cost = 1; | |
939 | ||
c3de4fe6 | 940 | INSN_COST (insn) = cost; |
bd58420c RK |
941 | return cost; |
942 | } | |
943 | } | |
944 | ||
945 | /* Compute the priority number for INSN. */ | |
946 | ||
947 | static int | |
948 | priority (insn) | |
949 | rtx insn; | |
950 | { | |
951 | if (insn && GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
952 | { | |
953 | int prev_priority; | |
954 | int max_priority; | |
955 | int this_priority = INSN_PRIORITY (insn); | |
956 | rtx prev; | |
957 | ||
958 | if (this_priority > 0) | |
959 | return this_priority; | |
960 | ||
961 | max_priority = 1; | |
962 | ||
963 | /* Nonzero if these insns must be scheduled together. */ | |
964 | if (SCHED_GROUP_P (insn)) | |
965 | { | |
966 | prev = insn; | |
967 | while (SCHED_GROUP_P (prev)) | |
968 | { | |
969 | prev = PREV_INSN (prev); | |
970 | INSN_REF_COUNT (prev) += 1; | |
971 | } | |
972 | } | |
973 | ||
974 | for (prev = LOG_LINKS (insn); prev; prev = XEXP (prev, 1)) | |
975 | { | |
976 | rtx x = XEXP (prev, 0); | |
977 | ||
978 | /* A dependence pointing to a note is always obsolete, because | |
979 | sched_analyze_insn will have created any necessary new dependences | |
980 | which replace it. Notes can be created when instructions are | |
981 | deleted by insn splitting, or by register allocation. */ | |
982 | if (GET_CODE (x) == NOTE) | |
983 | { | |
984 | remove_dependence (insn, x); | |
985 | continue; | |
986 | } | |
987 | ||
988 | /* This priority calculation was chosen because it results in the | |
989 | least instruction movement, and does not hurt the performance | |
990 | of the resulting code compared to the old algorithm. | |
991 | This makes the sched algorithm more stable, which results | |
992 | in better code, because there is less register pressure, | |
993 | cross jumping is more likely to work, and debugging is easier. | |
994 | ||
995 | When all instructions have a latency of 1, there is no need to | |
996 | move any instructions. Subtracting one here ensures that in such | |
997 | cases all instructions will end up with a priority of one, and | |
998 | hence no scheduling will be done. | |
999 | ||
1000 | The original code did not subtract the one, and added the | |
1001 | insn_cost of the current instruction to its priority (e.g. | |
1002 | move the insn_cost call down to the end). */ | |
1003 | ||
1004 | if (REG_NOTE_KIND (prev) == 0) | |
1005 | /* Data dependence. */ | |
1006 | prev_priority = priority (x) + insn_cost (x) - 1; | |
1007 | else | |
1008 | /* Anti or output dependence. Don't add the latency of this | |
1009 | insn's result, because it isn't being used. */ | |
1010 | prev_priority = priority (x); | |
1011 | ||
1012 | if (prev_priority > max_priority) | |
1013 | max_priority = prev_priority; | |
1014 | INSN_REF_COUNT (x) += 1; | |
1015 | } | |
1016 | ||
1017 | INSN_PRIORITY (insn) = max_priority; | |
1018 | return INSN_PRIORITY (insn); | |
1019 | } | |
1020 | return 0; | |
1021 | } | |
1022 | \f | |
1023 | /* Remove all INSN_LISTs and EXPR_LISTs from the pending lists and add | |
1024 | them to the unused_*_list variables, so that they can be reused. */ | |
1025 | ||
1026 | static void | |
1027 | free_pending_lists () | |
1028 | { | |
1029 | register rtx link, prev_link; | |
1030 | ||
1031 | if (pending_read_insns) | |
1032 | { | |
1033 | prev_link = pending_read_insns; | |
1034 | link = XEXP (prev_link, 1); | |
1035 | ||
1036 | while (link) | |
1037 | { | |
1038 | prev_link = link; | |
1039 | link = XEXP (link, 1); | |
1040 | } | |
1041 | ||
1042 | XEXP (prev_link, 1) = unused_insn_list; | |
1043 | unused_insn_list = pending_read_insns; | |
1044 | pending_read_insns = 0; | |
1045 | } | |
1046 | ||
1047 | if (pending_write_insns) | |
1048 | { | |
1049 | prev_link = pending_write_insns; | |
1050 | link = XEXP (prev_link, 1); | |
1051 | ||
1052 | while (link) | |
1053 | { | |
1054 | prev_link = link; | |
1055 | link = XEXP (link, 1); | |
1056 | } | |
1057 | ||
1058 | XEXP (prev_link, 1) = unused_insn_list; | |
1059 | unused_insn_list = pending_write_insns; | |
1060 | pending_write_insns = 0; | |
1061 | } | |
1062 | ||
1063 | if (pending_read_mems) | |
1064 | { | |
1065 | prev_link = pending_read_mems; | |
1066 | link = XEXP (prev_link, 1); | |
1067 | ||
1068 | while (link) | |
1069 | { | |
1070 | prev_link = link; | |
1071 | link = XEXP (link, 1); | |
1072 | } | |
1073 | ||
1074 | XEXP (prev_link, 1) = unused_expr_list; | |
1075 | unused_expr_list = pending_read_mems; | |
1076 | pending_read_mems = 0; | |
1077 | } | |
1078 | ||
1079 | if (pending_write_mems) | |
1080 | { | |
1081 | prev_link = pending_write_mems; | |
1082 | link = XEXP (prev_link, 1); | |
1083 | ||
1084 | while (link) | |
1085 | { | |
1086 | prev_link = link; | |
1087 | link = XEXP (link, 1); | |
1088 | } | |
1089 | ||
1090 | XEXP (prev_link, 1) = unused_expr_list; | |
1091 | unused_expr_list = pending_write_mems; | |
1092 | pending_write_mems = 0; | |
1093 | } | |
1094 | } | |
1095 | ||
1096 | /* Add an INSN and MEM reference pair to a pending INSN_LIST and MEM_LIST. | |
1097 | The MEM is a memory reference contained within INSN, which we are saving | |
1098 | so that we can do memory aliasing on it. */ | |
1099 | ||
1100 | static void | |
1101 | add_insn_mem_dependence (insn_list, mem_list, insn, mem) | |
1102 | rtx *insn_list, *mem_list, insn, mem; | |
1103 | { | |
1104 | register rtx link; | |
1105 | ||
1106 | if (unused_insn_list) | |
1107 | { | |
1108 | link = unused_insn_list; | |
1109 | unused_insn_list = XEXP (link, 1); | |
1110 | } | |
1111 | else | |
1112 | link = rtx_alloc (INSN_LIST); | |
1113 | XEXP (link, 0) = insn; | |
1114 | XEXP (link, 1) = *insn_list; | |
1115 | *insn_list = link; | |
1116 | ||
1117 | if (unused_expr_list) | |
1118 | { | |
1119 | link = unused_expr_list; | |
1120 | unused_expr_list = XEXP (link, 1); | |
1121 | } | |
1122 | else | |
1123 | link = rtx_alloc (EXPR_LIST); | |
1124 | XEXP (link, 0) = mem; | |
1125 | XEXP (link, 1) = *mem_list; | |
1126 | *mem_list = link; | |
1127 | ||
1128 | pending_lists_length++; | |
1129 | } | |
1130 | \f | |
1131 | /* Make a dependency between every memory reference on the pending lists | |
1132 | and INSN, thus flushing the pending lists. */ | |
1133 | ||
1134 | static void | |
1135 | flush_pending_lists (insn) | |
1136 | rtx insn; | |
1137 | { | |
1138 | rtx link; | |
1139 | ||
1140 | while (pending_read_insns) | |
1141 | { | |
1142 | add_dependence (insn, XEXP (pending_read_insns, 0), REG_DEP_ANTI); | |
1143 | ||
1144 | link = pending_read_insns; | |
1145 | pending_read_insns = XEXP (pending_read_insns, 1); | |
1146 | XEXP (link, 1) = unused_insn_list; | |
1147 | unused_insn_list = link; | |
1148 | ||
1149 | link = pending_read_mems; | |
1150 | pending_read_mems = XEXP (pending_read_mems, 1); | |
1151 | XEXP (link, 1) = unused_expr_list; | |
1152 | unused_expr_list = link; | |
1153 | } | |
1154 | while (pending_write_insns) | |
1155 | { | |
1156 | add_dependence (insn, XEXP (pending_write_insns, 0), REG_DEP_ANTI); | |
1157 | ||
1158 | link = pending_write_insns; | |
1159 | pending_write_insns = XEXP (pending_write_insns, 1); | |
1160 | XEXP (link, 1) = unused_insn_list; | |
1161 | unused_insn_list = link; | |
1162 | ||
1163 | link = pending_write_mems; | |
1164 | pending_write_mems = XEXP (pending_write_mems, 1); | |
1165 | XEXP (link, 1) = unused_expr_list; | |
1166 | unused_expr_list = link; | |
1167 | } | |
1168 | pending_lists_length = 0; | |
1169 | ||
1170 | if (last_pending_memory_flush) | |
1171 | add_dependence (insn, last_pending_memory_flush, REG_DEP_ANTI); | |
1172 | ||
1173 | last_pending_memory_flush = insn; | |
1174 | } | |
1175 | ||
1176 | /* Analyze a single SET or CLOBBER rtx, X, creating all dependencies generated | |
1177 | by the write to the destination of X, and reads of everything mentioned. */ | |
1178 | ||
1179 | static void | |
1180 | sched_analyze_1 (x, insn) | |
1181 | rtx x; | |
1182 | rtx insn; | |
1183 | { | |
1184 | register int regno; | |
1185 | register rtx dest = SET_DEST (x); | |
1186 | ||
1187 | if (dest == 0) | |
1188 | return; | |
1189 | ||
1190 | while (GET_CODE (dest) == STRICT_LOW_PART || GET_CODE (dest) == SUBREG | |
1191 | || GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SIGN_EXTRACT) | |
1192 | { | |
1193 | if (GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SIGN_EXTRACT) | |
1194 | { | |
1195 | /* The second and third arguments are values read by this insn. */ | |
1196 | sched_analyze_2 (XEXP (dest, 1), insn); | |
1197 | sched_analyze_2 (XEXP (dest, 2), insn); | |
1198 | } | |
1199 | dest = SUBREG_REG (dest); | |
1200 | } | |
1201 | ||
1202 | if (GET_CODE (dest) == REG) | |
1203 | { | |
1204 | register int offset, bit, i; | |
1205 | ||
1206 | regno = REGNO (dest); | |
1207 | ||
1208 | /* A hard reg in a wide mode may really be multiple registers. | |
1209 | If so, mark all of them just like the first. */ | |
1210 | if (regno < FIRST_PSEUDO_REGISTER) | |
1211 | { | |
1212 | i = HARD_REGNO_NREGS (regno, GET_MODE (dest)); | |
1213 | while (--i >= 0) | |
1214 | { | |
1215 | rtx u; | |
1216 | ||
1217 | for (u = reg_last_uses[regno+i]; u; u = XEXP (u, 1)) | |
1218 | add_dependence (insn, XEXP (u, 0), REG_DEP_ANTI); | |
1219 | reg_last_uses[regno + i] = 0; | |
1220 | if (reg_last_sets[regno + i]) | |
1221 | add_dependence (insn, reg_last_sets[regno + i], | |
1222 | REG_DEP_OUTPUT); | |
1223 | reg_last_sets[regno + i] = insn; | |
1224 | if ((call_used_regs[i] || global_regs[i]) | |
1225 | && last_function_call) | |
1226 | /* Function calls clobber all call_used regs. */ | |
1227 | add_dependence (insn, last_function_call, REG_DEP_ANTI); | |
1228 | } | |
1229 | } | |
1230 | else | |
1231 | { | |
1232 | rtx u; | |
1233 | ||
1234 | for (u = reg_last_uses[regno]; u; u = XEXP (u, 1)) | |
1235 | add_dependence (insn, XEXP (u, 0), REG_DEP_ANTI); | |
1236 | reg_last_uses[regno] = 0; | |
1237 | if (reg_last_sets[regno]) | |
1238 | add_dependence (insn, reg_last_sets[regno], REG_DEP_OUTPUT); | |
1239 | reg_last_sets[regno] = insn; | |
1240 | ||
1241 | /* Don't let it cross a call after scheduling if it doesn't | |
1242 | already cross one. */ | |
1243 | if (reg_n_calls_crossed[regno] == 0 && last_function_call) | |
1244 | add_dependence (insn, last_function_call, REG_DEP_ANTI); | |
1245 | } | |
1246 | } | |
1247 | else if (GET_CODE (dest) == MEM) | |
1248 | { | |
1249 | /* Writing memory. */ | |
1250 | ||
1251 | if (pending_lists_length > 32) | |
1252 | { | |
1253 | /* Flush all pending reads and writes to prevent the pending lists | |
1254 | from getting any larger. Insn scheduling runs too slowly when | |
1255 | these lists get long. The number 32 was chosen because it | |
6dc42e49 | 1256 | seems like a reasonable number. When compiling GCC with itself, |
bd58420c RK |
1257 | this flush occurs 8 times for sparc, and 10 times for m88k using |
1258 | the number 32. */ | |
1259 | flush_pending_lists (insn); | |
1260 | } | |
1261 | else | |
1262 | { | |
1263 | rtx pending, pending_mem; | |
1264 | ||
1265 | pending = pending_read_insns; | |
1266 | pending_mem = pending_read_mems; | |
1267 | while (pending) | |
1268 | { | |
1269 | /* If a dependency already exists, don't create a new one. */ | |
1270 | if (! find_insn_list (XEXP (pending, 0), LOG_LINKS (insn))) | |
1271 | if (anti_dependence (XEXP (pending_mem, 0), dest, insn)) | |
1272 | add_dependence (insn, XEXP (pending, 0), REG_DEP_ANTI); | |
1273 | ||
1274 | pending = XEXP (pending, 1); | |
1275 | pending_mem = XEXP (pending_mem, 1); | |
1276 | } | |
1277 | ||
1278 | pending = pending_write_insns; | |
1279 | pending_mem = pending_write_mems; | |
1280 | while (pending) | |
1281 | { | |
1282 | /* If a dependency already exists, don't create a new one. */ | |
1283 | if (! find_insn_list (XEXP (pending, 0), LOG_LINKS (insn))) | |
1284 | if (output_dependence (XEXP (pending_mem, 0), dest)) | |
1285 | add_dependence (insn, XEXP (pending, 0), REG_DEP_OUTPUT); | |
1286 | ||
1287 | pending = XEXP (pending, 1); | |
1288 | pending_mem = XEXP (pending_mem, 1); | |
1289 | } | |
1290 | ||
1291 | if (last_pending_memory_flush) | |
1292 | add_dependence (insn, last_pending_memory_flush, REG_DEP_ANTI); | |
1293 | ||
1294 | add_insn_mem_dependence (&pending_write_insns, &pending_write_mems, | |
1295 | insn, dest); | |
1296 | } | |
1297 | sched_analyze_2 (XEXP (dest, 0), insn); | |
1298 | } | |
1299 | ||
1300 | /* Analyze reads. */ | |
1301 | if (GET_CODE (x) == SET) | |
1302 | sched_analyze_2 (SET_SRC (x), insn); | |
bd58420c RK |
1303 | } |
1304 | ||
1305 | /* Analyze the uses of memory and registers in rtx X in INSN. */ | |
1306 | ||
1307 | static void | |
1308 | sched_analyze_2 (x, insn) | |
1309 | rtx x; | |
1310 | rtx insn; | |
1311 | { | |
1312 | register int i; | |
1313 | register int j; | |
1314 | register enum rtx_code code; | |
1315 | register char *fmt; | |
1316 | ||
1317 | if (x == 0) | |
1318 | return; | |
1319 | ||
1320 | code = GET_CODE (x); | |
1321 | ||
b85b8af2 | 1322 | switch (code) |
bd58420c | 1323 | { |
b85b8af2 JW |
1324 | case CONST_INT: |
1325 | case CONST_DOUBLE: | |
1326 | case SYMBOL_REF: | |
1327 | case CONST: | |
1328 | case LABEL_REF: | |
1329 | /* Ignore constants. Note that we must handle CONST_DOUBLE here | |
1330 | because it may have a cc0_rtx in its CONST_DOUBLE_CHAIN field, but | |
1331 | this does not mean that this insn is using cc0. */ | |
bd58420c | 1332 | return; |
bd58420c | 1333 | |
b85b8af2 JW |
1334 | #ifdef HAVE_cc0 |
1335 | case CC0: | |
1336 | { | |
a3ee5899 | 1337 | rtx link, prev; |
bd58420c | 1338 | |
a3ee5899 | 1339 | /* There may be a note before this insn now, but all notes will |
ea3fa5f7 | 1340 | be removed before we actually try to schedule the insns, so |
a3ee5899 JW |
1341 | it won't cause a problem later. We must avoid it here though. */ |
1342 | ||
d21d2fb8 | 1343 | /* User of CC0 depends on immediately preceding insn. */ |
b85b8af2 | 1344 | SCHED_GROUP_P (insn) = 1; |
bd58420c | 1345 | |
a3ee5899 JW |
1346 | /* Make a copy of all dependencies on the immediately previous insn, |
1347 | and add to this insn. This is so that all the dependencies will | |
1348 | apply to the group. */ | |
1349 | ||
1350 | prev = PREV_INSN (insn); | |
1351 | while (GET_CODE (prev) == NOTE) | |
1352 | prev = PREV_INSN (prev); | |
bd58420c | 1353 | |
a3ee5899 | 1354 | for (link = LOG_LINKS (prev); link; link = XEXP (link, 1)) |
b85b8af2 | 1355 | add_dependence (insn, XEXP (link, 0), GET_MODE (link)); |
bd58420c | 1356 | |
b85b8af2 JW |
1357 | return; |
1358 | } | |
1359 | #endif | |
bd58420c | 1360 | |
b85b8af2 JW |
1361 | case REG: |
1362 | { | |
1363 | int regno = REGNO (x); | |
1364 | if (regno < FIRST_PSEUDO_REGISTER) | |
1365 | { | |
1366 | int i; | |
1367 | ||
1368 | i = HARD_REGNO_NREGS (regno, GET_MODE (x)); | |
1369 | while (--i >= 0) | |
1370 | { | |
1371 | reg_last_uses[regno + i] | |
1372 | = gen_rtx (INSN_LIST, VOIDmode, | |
1373 | insn, reg_last_uses[regno + i]); | |
1374 | if (reg_last_sets[regno + i]) | |
1375 | add_dependence (insn, reg_last_sets[regno + i], 0); | |
1376 | if ((call_used_regs[regno + i] || global_regs[regno + i]) | |
1377 | && last_function_call) | |
1378 | /* Function calls clobber all call_used regs. */ | |
1379 | add_dependence (insn, last_function_call, REG_DEP_ANTI); | |
1380 | } | |
1381 | } | |
1382 | else | |
1383 | { | |
1384 | reg_last_uses[regno] | |
1385 | = gen_rtx (INSN_LIST, VOIDmode, insn, reg_last_uses[regno]); | |
1386 | if (reg_last_sets[regno]) | |
1387 | add_dependence (insn, reg_last_sets[regno], 0); | |
1388 | ||
1389 | /* If the register does not already cross any calls, then add this | |
1390 | insn to the sched_before_next_call list so that it will still | |
1391 | not cross calls after scheduling. */ | |
1392 | if (reg_n_calls_crossed[regno] == 0) | |
1393 | add_dependence (sched_before_next_call, insn, REG_DEP_ANTI); | |
1394 | } | |
1395 | return; | |
1396 | } | |
bd58420c | 1397 | |
b85b8af2 JW |
1398 | case MEM: |
1399 | { | |
1400 | /* Reading memory. */ | |
1401 | ||
1f6fc4de JW |
1402 | rtx pending, pending_mem; |
1403 | ||
1404 | pending = pending_read_insns; | |
1405 | pending_mem = pending_read_mems; | |
1406 | while (pending) | |
b85b8af2 | 1407 | { |
1f6fc4de JW |
1408 | /* If a dependency already exists, don't create a new one. */ |
1409 | if (! find_insn_list (XEXP (pending, 0), LOG_LINKS (insn))) | |
1410 | if (read_dependence (XEXP (pending_mem, 0), x)) | |
1411 | add_dependence (insn, XEXP (pending, 0), REG_DEP_ANTI); | |
b85b8af2 | 1412 | |
1f6fc4de JW |
1413 | pending = XEXP (pending, 1); |
1414 | pending_mem = XEXP (pending_mem, 1); | |
1415 | } | |
b85b8af2 | 1416 | |
1f6fc4de JW |
1417 | pending = pending_write_insns; |
1418 | pending_mem = pending_write_mems; | |
1419 | while (pending) | |
1420 | { | |
1421 | /* If a dependency already exists, don't create a new one. */ | |
1422 | if (! find_insn_list (XEXP (pending, 0), LOG_LINKS (insn))) | |
1423 | if (true_dependence (XEXP (pending_mem, 0), x)) | |
1424 | add_dependence (insn, XEXP (pending, 0), 0); | |
b85b8af2 | 1425 | |
1f6fc4de JW |
1426 | pending = XEXP (pending, 1); |
1427 | pending_mem = XEXP (pending_mem, 1); | |
1428 | } | |
1429 | if (last_pending_memory_flush) | |
1430 | add_dependence (insn, last_pending_memory_flush, REG_DEP_ANTI); | |
b85b8af2 | 1431 | |
1f6fc4de JW |
1432 | /* Always add these dependencies to pending_reads, since |
1433 | this insn may be followed by a write. */ | |
1434 | add_insn_mem_dependence (&pending_read_insns, &pending_read_mems, | |
1435 | insn, x); | |
b85b8af2 | 1436 | |
b85b8af2 JW |
1437 | /* Take advantage of tail recursion here. */ |
1438 | sched_analyze_2 (XEXP (x, 0), insn); | |
1439 | return; | |
1440 | } | |
bd58420c | 1441 | |
b85b8af2 JW |
1442 | case ASM_OPERANDS: |
1443 | case ASM_INPUT: | |
1444 | case UNSPEC_VOLATILE: | |
c3de4fe6 | 1445 | case TRAP_IF: |
b85b8af2 JW |
1446 | { |
1447 | rtx u; | |
1448 | ||
1449 | /* Traditional and volatile asm instructions must be considered to use | |
1450 | and clobber all hard registers and all of memory. So must | |
c3de4fe6 JW |
1451 | TRAP_IF and UNSPEC_VOLATILE operations. */ |
1452 | if (code != ASM_OPERANDS || MEM_VOLATILE_P (x)) | |
b85b8af2 JW |
1453 | { |
1454 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
1455 | { | |
1456 | for (u = reg_last_uses[i]; u; u = XEXP (u, 1)) | |
1457 | if (GET_CODE (PATTERN (XEXP (u, 0))) != USE) | |
1458 | add_dependence (insn, XEXP (u, 0), REG_DEP_ANTI); | |
1459 | reg_last_uses[i] = 0; | |
1460 | if (reg_last_sets[i] | |
1461 | && GET_CODE (PATTERN (reg_last_sets[i])) != USE) | |
1462 | add_dependence (insn, reg_last_sets[i], 0); | |
1463 | reg_last_sets[i] = insn; | |
1464 | } | |
1465 | ||
1466 | flush_pending_lists (insn); | |
1467 | } | |
1468 | ||
1469 | /* For all ASM_OPERANDS, we must traverse the vector of input operands. | |
1470 | We can not just fall through here since then we would be confused | |
1471 | by the ASM_INPUT rtx inside ASM_OPERANDS, which do not indicate | |
1472 | traditional asms unlike their normal usage. */ | |
1473 | ||
1474 | if (code == ASM_OPERANDS) | |
1475 | { | |
1476 | for (j = 0; j < ASM_OPERANDS_INPUT_LENGTH (x); j++) | |
1477 | sched_analyze_2 (ASM_OPERANDS_INPUT (x, j), insn); | |
1478 | return; | |
1479 | } | |
1480 | break; | |
1481 | } | |
bd58420c | 1482 | |
b85b8af2 JW |
1483 | case PRE_DEC: |
1484 | case POST_DEC: | |
1485 | case PRE_INC: | |
1486 | case POST_INC: | |
1487 | /* These read and modify the result; just consider them writes. */ | |
1488 | sched_analyze_1 (x, insn); | |
bd58420c RK |
1489 | return; |
1490 | } | |
1491 | ||
bd58420c RK |
1492 | /* Other cases: walk the insn. */ |
1493 | fmt = GET_RTX_FORMAT (code); | |
1494 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1495 | { | |
1496 | if (fmt[i] == 'e') | |
1497 | sched_analyze_2 (XEXP (x, i), insn); | |
1498 | else if (fmt[i] == 'E') | |
1499 | for (j = 0; j < XVECLEN (x, i); j++) | |
1500 | sched_analyze_2 (XVECEXP (x, i, j), insn); | |
1501 | } | |
1502 | } | |
1503 | ||
1504 | /* Analyze an INSN with pattern X to find all dependencies. */ | |
1505 | ||
1506 | static void | |
1507 | sched_analyze_insn (x, insn) | |
1508 | rtx x, insn; | |
1509 | { | |
1510 | register RTX_CODE code = GET_CODE (x); | |
1511 | rtx link; | |
1512 | ||
1513 | if (code == SET || code == CLOBBER) | |
1514 | sched_analyze_1 (x, insn); | |
1515 | else if (code == PARALLEL) | |
1516 | { | |
1517 | register int i; | |
1518 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
1519 | { | |
1520 | code = GET_CODE (XVECEXP (x, 0, i)); | |
1521 | if (code == SET || code == CLOBBER) | |
1522 | sched_analyze_1 (XVECEXP (x, 0, i), insn); | |
1523 | else | |
1524 | sched_analyze_2 (XVECEXP (x, 0, i), insn); | |
1525 | } | |
1526 | } | |
1527 | else | |
1528 | sched_analyze_2 (x, insn); | |
1529 | ||
bd58420c RK |
1530 | /* Handle function calls. */ |
1531 | if (GET_CODE (insn) == CALL_INSN) | |
1532 | { | |
1533 | rtx dep_insn; | |
1534 | rtx prev_dep_insn; | |
1535 | ||
1536 | /* When scheduling instructions, we make sure calls don't lose their | |
1537 | accompanying USE insns by depending them one on another in order. */ | |
1538 | ||
1539 | prev_dep_insn = insn; | |
1540 | dep_insn = PREV_INSN (insn); | |
1541 | while (GET_CODE (dep_insn) == INSN | |
1542 | && GET_CODE (PATTERN (dep_insn)) == USE) | |
1543 | { | |
1544 | SCHED_GROUP_P (prev_dep_insn) = 1; | |
1545 | ||
1546 | /* Make a copy of all dependencies on dep_insn, and add to insn. | |
1547 | This is so that all of the dependencies will apply to the | |
1548 | group. */ | |
1549 | ||
1550 | for (link = LOG_LINKS (dep_insn); link; link = XEXP (link, 1)) | |
1551 | add_dependence (insn, XEXP (link, 0), GET_MODE (link)); | |
1552 | ||
1553 | prev_dep_insn = dep_insn; | |
1554 | dep_insn = PREV_INSN (dep_insn); | |
1555 | } | |
1556 | } | |
1557 | } | |
1558 | ||
1559 | /* Analyze every insn between HEAD and TAIL inclusive, creating LOG_LINKS | |
1560 | for every dependency. */ | |
1561 | ||
1562 | static int | |
1563 | sched_analyze (head, tail) | |
1564 | rtx head, tail; | |
1565 | { | |
1566 | register rtx insn; | |
1567 | register int n_insns = 0; | |
1568 | register rtx u; | |
1569 | register int luid = 0; | |
1570 | ||
1571 | for (insn = head; ; insn = NEXT_INSN (insn)) | |
1572 | { | |
1573 | INSN_LUID (insn) = luid++; | |
1574 | ||
1575 | if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN) | |
1576 | { | |
1577 | sched_analyze_insn (PATTERN (insn), insn); | |
1578 | n_insns += 1; | |
1579 | } | |
1580 | else if (GET_CODE (insn) == CALL_INSN) | |
1581 | { | |
1582 | rtx dest = 0; | |
1583 | rtx x; | |
1584 | register int i; | |
1585 | ||
1586 | /* Any instruction using a hard register which may get clobbered | |
1587 | by a call needs to be marked as dependent on this call. | |
1588 | This prevents a use of a hard return reg from being moved | |
1589 | past a void call (i.e. it does not explicitly set the hard | |
1590 | return reg). */ | |
1591 | ||
1592 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
1593 | if (call_used_regs[i] || global_regs[i]) | |
1594 | { | |
1595 | for (u = reg_last_uses[i]; u; u = XEXP (u, 1)) | |
1596 | if (GET_CODE (PATTERN (XEXP (u, 0))) != USE) | |
1597 | add_dependence (insn, XEXP (u, 0), REG_DEP_ANTI); | |
1598 | reg_last_uses[i] = 0; | |
1599 | if (reg_last_sets[i] | |
1600 | && GET_CODE (PATTERN (reg_last_sets[i])) != USE) | |
1601 | add_dependence (insn, reg_last_sets[i], REG_DEP_ANTI); | |
1602 | reg_last_sets[i] = insn; | |
1603 | /* Insn, being a CALL_INSN, magically depends on | |
1604 | `last_function_call' already. */ | |
1605 | } | |
1606 | ||
1607 | /* For each insn which shouldn't cross a call, add a dependence | |
1608 | between that insn and this call insn. */ | |
1609 | x = LOG_LINKS (sched_before_next_call); | |
1610 | while (x) | |
1611 | { | |
1612 | add_dependence (insn, XEXP (x, 0), REG_DEP_ANTI); | |
1613 | x = XEXP (x, 1); | |
1614 | } | |
1615 | LOG_LINKS (sched_before_next_call) = 0; | |
1616 | ||
1617 | sched_analyze_insn (PATTERN (insn), insn); | |
1618 | ||
1619 | /* We don't need to flush memory for a function call which does | |
1620 | not involve memory. */ | |
1621 | if (! CONST_CALL_P (insn)) | |
1622 | { | |
1623 | /* In the absence of interprocedural alias analysis, | |
1624 | we must flush all pending reads and writes, and | |
1625 | start new dependencies starting from here. */ | |
1626 | flush_pending_lists (insn); | |
1627 | } | |
1628 | ||
1629 | /* Depend this function call (actually, the user of this | |
1630 | function call) on all hard register clobberage. */ | |
1631 | last_function_call = insn; | |
1632 | n_insns += 1; | |
1633 | } | |
1634 | ||
1635 | if (insn == tail) | |
1636 | return n_insns; | |
1637 | } | |
1638 | } | |
1639 | \f | |
1640 | /* Called when we see a set of a register. If death is true, then we are | |
1641 | scanning backwards. Mark that register as unborn. If nobody says | |
1642 | otherwise, that is how things will remain. If death is false, then we | |
1643 | are scanning forwards. Mark that register as being born. */ | |
1644 | ||
1645 | static void | |
1646 | sched_note_set (b, x, death) | |
1647 | int b; | |
1648 | rtx x; | |
1649 | int death; | |
1650 | { | |
1651 | register int regno, j; | |
1652 | register rtx reg = SET_DEST (x); | |
1653 | int subreg_p = 0; | |
1654 | ||
1655 | if (reg == 0) | |
1656 | return; | |
1657 | ||
1658 | while (GET_CODE (reg) == SUBREG || GET_CODE (reg) == STRICT_LOW_PART | |
1659 | || GET_CODE (reg) == SIGN_EXTRACT || GET_CODE (reg) == ZERO_EXTRACT) | |
1660 | { | |
1661 | /* Must treat modification of just one hardware register of a multi-reg | |
1662 | value or just a byte field of a register exactly the same way that | |
1663 | mark_set_1 in flow.c does. */ | |
1664 | if (GET_CODE (reg) == ZERO_EXTRACT | |
1665 | || GET_CODE (reg) == SIGN_EXTRACT | |
1666 | || (GET_CODE (reg) == SUBREG | |
1667 | && REG_SIZE (SUBREG_REG (reg)) > REG_SIZE (reg))) | |
1668 | subreg_p = 1; | |
1669 | ||
1670 | reg = SUBREG_REG (reg); | |
1671 | } | |
1672 | ||
1673 | if (GET_CODE (reg) != REG) | |
1674 | return; | |
1675 | ||
1676 | /* Global registers are always live, so the code below does not apply | |
1677 | to them. */ | |
1678 | ||
1679 | regno = REGNO (reg); | |
1680 | if (regno >= FIRST_PSEUDO_REGISTER || ! global_regs[regno]) | |
1681 | { | |
1682 | register int offset = regno / REGSET_ELT_BITS; | |
fb3821f7 CH |
1683 | register REGSET_ELT_TYPE bit |
1684 | = (REGSET_ELT_TYPE) 1 << (regno % REGSET_ELT_BITS); | |
bd58420c RK |
1685 | |
1686 | if (death) | |
1687 | { | |
1688 | /* If we only set part of the register, then this set does not | |
1689 | kill it. */ | |
1690 | if (subreg_p) | |
1691 | return; | |
1692 | ||
1693 | /* Try killing this register. */ | |
1694 | if (regno < FIRST_PSEUDO_REGISTER) | |
1695 | { | |
1696 | int j = HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
1697 | while (--j >= 0) | |
1698 | { | |
1699 | offset = (regno + j) / REGSET_ELT_BITS; | |
fb3821f7 | 1700 | bit = (REGSET_ELT_TYPE) 1 << ((regno + j) % REGSET_ELT_BITS); |
bd58420c RK |
1701 | |
1702 | bb_live_regs[offset] &= ~bit; | |
1703 | bb_dead_regs[offset] |= bit; | |
1704 | } | |
1705 | } | |
1706 | else | |
1707 | { | |
1708 | bb_live_regs[offset] &= ~bit; | |
1709 | bb_dead_regs[offset] |= bit; | |
1710 | } | |
1711 | } | |
1712 | else | |
1713 | { | |
1714 | /* Make the register live again. */ | |
1715 | if (regno < FIRST_PSEUDO_REGISTER) | |
1716 | { | |
1717 | int j = HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
1718 | while (--j >= 0) | |
1719 | { | |
1720 | offset = (regno + j) / REGSET_ELT_BITS; | |
fb3821f7 | 1721 | bit = (REGSET_ELT_TYPE) 1 << ((regno + j) % REGSET_ELT_BITS); |
bd58420c RK |
1722 | |
1723 | bb_live_regs[offset] |= bit; | |
1724 | bb_dead_regs[offset] &= ~bit; | |
1725 | } | |
1726 | } | |
1727 | else | |
1728 | { | |
1729 | bb_live_regs[offset] |= bit; | |
1730 | bb_dead_regs[offset] &= ~bit; | |
1731 | } | |
1732 | } | |
1733 | } | |
1734 | } | |
1735 | \f | |
1736 | /* Macros and functions for keeping the priority queue sorted, and | |
1737 | dealing with queueing and unqueueing of instructions. */ | |
1738 | ||
1739 | #define SCHED_SORT(READY, NEW_READY, OLD_READY) \ | |
1740 | do { if ((NEW_READY) - (OLD_READY) == 1) \ | |
1741 | swap_sort (READY, NEW_READY); \ | |
1742 | else if ((NEW_READY) - (OLD_READY) > 1) \ | |
1743 | qsort (READY, NEW_READY, sizeof (rtx), rank_for_schedule); } \ | |
1744 | while (0) | |
1745 | ||
1746 | /* Returns a positive value if y is preferred; returns a negative value if | |
1747 | x is preferred. Should never return 0, since that will make the sort | |
1748 | unstable. */ | |
1749 | ||
1750 | static int | |
1751 | rank_for_schedule (x, y) | |
1752 | rtx *x, *y; | |
1753 | { | |
1754 | rtx tmp = *y; | |
1755 | rtx tmp2 = *x; | |
1756 | rtx tmp_dep, tmp2_dep; | |
1757 | int tmp_class, tmp2_class; | |
1758 | int value; | |
1759 | ||
1760 | /* Choose the instruction with the highest priority, if different. */ | |
1761 | if (value = INSN_PRIORITY (tmp) - INSN_PRIORITY (tmp2)) | |
1762 | return value; | |
1763 | ||
1764 | if (last_scheduled_insn) | |
1765 | { | |
1766 | /* Classify the instructions into three classes: | |
1767 | 1) Data dependent on last schedule insn. | |
1768 | 2) Anti/Output dependent on last scheduled insn. | |
1769 | 3) Independent of last scheduled insn, or has latency of one. | |
1770 | Choose the insn from the highest numbered class if different. */ | |
1771 | tmp_dep = find_insn_list (tmp, LOG_LINKS (last_scheduled_insn)); | |
1772 | if (tmp_dep == 0 || insn_cost (tmp) == 1) | |
1773 | tmp_class = 3; | |
1774 | else if (REG_NOTE_KIND (tmp_dep) == 0) | |
1775 | tmp_class = 1; | |
1776 | else | |
1777 | tmp_class = 2; | |
1778 | ||
1779 | tmp2_dep = find_insn_list (tmp2, LOG_LINKS (last_scheduled_insn)); | |
1780 | if (tmp2_dep == 0 || insn_cost (tmp2) == 1) | |
1781 | tmp2_class = 3; | |
1782 | else if (REG_NOTE_KIND (tmp2_dep) == 0) | |
1783 | tmp2_class = 1; | |
1784 | else | |
1785 | tmp2_class = 2; | |
1786 | ||
1787 | if (value = tmp_class - tmp2_class) | |
1788 | return value; | |
1789 | } | |
1790 | ||
1791 | /* If insns are equally good, sort by INSN_LUID (original insn order), | |
1792 | so that we make the sort stable. This minimizes instruction movement, | |
1793 | thus minimizing sched's effect on debugging and cross-jumping. */ | |
1794 | return INSN_LUID (tmp) - INSN_LUID (tmp2); | |
1795 | } | |
1796 | ||
1797 | /* Resort the array A in which only element at index N may be out of order. */ | |
1798 | ||
1799 | __inline static void | |
1800 | swap_sort (a, n) | |
1801 | rtx *a; | |
1802 | int n; | |
1803 | { | |
1804 | rtx insn = a[n-1]; | |
1805 | int i = n-2; | |
1806 | ||
1807 | while (i >= 0 && rank_for_schedule (a+i, &insn) >= 0) | |
1808 | { | |
1809 | a[i+1] = a[i]; | |
1810 | i -= 1; | |
1811 | } | |
1812 | a[i+1] = insn; | |
1813 | } | |
1814 | ||
1815 | static int max_priority; | |
1816 | ||
1817 | /* Add INSN to the insn queue so that it fires at least N_CYCLES | |
1818 | before the currently executing insn. */ | |
1819 | ||
1820 | __inline static void | |
1821 | queue_insn (insn, n_cycles) | |
1822 | rtx insn; | |
1823 | int n_cycles; | |
1824 | { | |
1825 | int next_q = NEXT_Q_AFTER (q_ptr, n_cycles); | |
1826 | NEXT_INSN (insn) = insn_queue[next_q]; | |
1827 | insn_queue[next_q] = insn; | |
1828 | q_size += 1; | |
1829 | } | |
1830 | ||
1831 | /* Return nonzero if PAT is the pattern of an insn which makes a | |
1832 | register live. */ | |
1833 | ||
1834 | __inline static int | |
1835 | birthing_insn_p (pat) | |
1836 | rtx pat; | |
1837 | { | |
1838 | int j; | |
1839 | ||
1840 | if (reload_completed == 1) | |
1841 | return 0; | |
1842 | ||
1843 | if (GET_CODE (pat) == SET | |
1844 | && GET_CODE (SET_DEST (pat)) == REG) | |
1845 | { | |
1846 | rtx dest = SET_DEST (pat); | |
1847 | int i = REGNO (dest); | |
1848 | int offset = i / REGSET_ELT_BITS; | |
fb3821f7 | 1849 | REGSET_ELT_TYPE bit = (REGSET_ELT_TYPE) 1 << (i % REGSET_ELT_BITS); |
bd58420c RK |
1850 | |
1851 | /* It would be more accurate to use refers_to_regno_p or | |
1852 | reg_mentioned_p to determine when the dest is not live before this | |
1853 | insn. */ | |
1854 | ||
1855 | if (bb_live_regs[offset] & bit) | |
1856 | return (reg_n_sets[i] == 1); | |
1857 | ||
1858 | return 0; | |
1859 | } | |
1860 | if (GET_CODE (pat) == PARALLEL) | |
1861 | { | |
1862 | for (j = 0; j < XVECLEN (pat, 0); j++) | |
1863 | if (birthing_insn_p (XVECEXP (pat, 0, j))) | |
1864 | return 1; | |
1865 | } | |
1866 | return 0; | |
1867 | } | |
1868 | ||
1869 | /* If PREV is an insn which is immediately ready to execute, return 1, | |
1870 | otherwise return 0. We may adjust its priority if that will help shorten | |
1871 | register lifetimes. */ | |
1872 | ||
1873 | static int | |
1874 | launch_link (prev) | |
1875 | rtx prev; | |
1876 | { | |
1877 | rtx pat = PATTERN (prev); | |
1878 | rtx note; | |
1879 | /* MAX of (a) number of cycles needed by prev | |
1880 | (b) number of cycles before needed resources are free. */ | |
1881 | int n_cycles = insn_cost (prev); | |
1882 | int n_deaths = 0; | |
1883 | ||
1884 | /* Trying to shorten register lives after reload has completed | |
1885 | is useless and wrong. It gives inaccurate schedules. */ | |
1886 | if (reload_completed == 0) | |
1887 | { | |
1888 | for (note = REG_NOTES (prev); note; note = XEXP (note, 1)) | |
1889 | if (REG_NOTE_KIND (note) == REG_DEAD) | |
1890 | n_deaths += 1; | |
1891 | ||
1892 | /* Defer scheduling insns which kill registers, since that | |
1893 | shortens register lives. Prefer scheduling insns which | |
1894 | make registers live for the same reason. */ | |
1895 | switch (n_deaths) | |
1896 | { | |
1897 | default: | |
1898 | INSN_PRIORITY (prev) >>= 3; | |
1899 | break; | |
1900 | case 3: | |
1901 | INSN_PRIORITY (prev) >>= 2; | |
1902 | break; | |
1903 | case 2: | |
1904 | case 1: | |
1905 | INSN_PRIORITY (prev) >>= 1; | |
1906 | break; | |
1907 | case 0: | |
1908 | if (birthing_insn_p (pat)) | |
1909 | { | |
1910 | int max = max_priority; | |
1911 | ||
1912 | if (max > INSN_PRIORITY (prev)) | |
1913 | INSN_PRIORITY (prev) = max; | |
1914 | } | |
1915 | break; | |
1916 | } | |
1917 | } | |
1918 | ||
1919 | if (n_cycles <= 1) | |
1920 | return 1; | |
1921 | queue_insn (prev, n_cycles); | |
1922 | return 0; | |
1923 | } | |
1924 | ||
1925 | /* INSN is the "currently executing insn". Launch each insn which was | |
1926 | waiting on INSN (in the backwards dataflow sense). READY is a | |
1927 | vector of insns which are ready to fire. N_READY is the number of | |
1928 | elements in READY. */ | |
1929 | ||
1930 | static int | |
1931 | launch_links (insn, ready, n_ready) | |
1932 | rtx insn; | |
1933 | rtx *ready; | |
1934 | int n_ready; | |
1935 | { | |
1936 | rtx link; | |
1937 | int new_ready = n_ready; | |
1938 | ||
1939 | if (LOG_LINKS (insn) == 0) | |
1940 | return n_ready; | |
1941 | ||
1942 | /* This is used by the function launch_link above. */ | |
1943 | if (n_ready > 0) | |
1944 | max_priority = MAX (INSN_PRIORITY (ready[0]), INSN_PRIORITY (insn)); | |
1945 | else | |
1946 | max_priority = INSN_PRIORITY (insn); | |
1947 | ||
1948 | for (link = LOG_LINKS (insn); link != 0; link = XEXP (link, 1)) | |
1949 | { | |
1950 | rtx prev = XEXP (link, 0); | |
1951 | ||
1952 | if ((INSN_REF_COUNT (prev) -= 1) == 0 && launch_link (prev)) | |
1953 | ready[new_ready++] = prev; | |
1954 | } | |
1955 | ||
1956 | return new_ready; | |
1957 | } | |
1958 | ||
1959 | /* Add a REG_DEAD note for REG to INSN, reusing a REG_DEAD note from the | |
1960 | dead_notes list. */ | |
1961 | ||
1962 | static void | |
1963 | create_reg_dead_note (reg, insn) | |
1964 | rtx reg, insn; | |
1965 | { | |
1966 | rtx link = dead_notes; | |
1967 | ||
1968 | if (link == 0) | |
1969 | /* In theory, we should not end up with more REG_DEAD reg notes than we | |
1970 | started with. In practice, this can occur as the result of bugs in | |
1971 | flow, combine and/or sched. */ | |
1972 | { | |
1973 | #if 1 | |
1974 | abort (); | |
1975 | #else | |
1976 | link = rtx_alloc (EXPR_LIST); | |
1977 | PUT_REG_NOTE_KIND (link, REG_DEAD); | |
1978 | #endif | |
1979 | } | |
1980 | else | |
1981 | dead_notes = XEXP (dead_notes, 1); | |
1982 | ||
1983 | XEXP (link, 0) = reg; | |
1984 | XEXP (link, 1) = REG_NOTES (insn); | |
1985 | REG_NOTES (insn) = link; | |
1986 | } | |
1987 | ||
1988 | /* Subroutine on attach_deaths_insn--handles the recursive search | |
1989 | through INSN. If SET_P is true, then x is being modified by the insn. */ | |
1990 | ||
1991 | static void | |
1992 | attach_deaths (x, insn, set_p) | |
1993 | rtx x; | |
1994 | rtx insn; | |
1995 | int set_p; | |
1996 | { | |
1997 | register int i; | |
1998 | register int j; | |
1999 | register enum rtx_code code; | |
2000 | register char *fmt; | |
2001 | ||
2002 | if (x == 0) | |
2003 | return; | |
2004 | ||
2005 | code = GET_CODE (x); | |
2006 | ||
2007 | switch (code) | |
2008 | { | |
2009 | case CONST_INT: | |
2010 | case CONST_DOUBLE: | |
2011 | case LABEL_REF: | |
2012 | case SYMBOL_REF: | |
2013 | case CONST: | |
2014 | case CODE_LABEL: | |
2015 | case PC: | |
2016 | case CC0: | |
2017 | /* Get rid of the easy cases first. */ | |
2018 | return; | |
2019 | ||
2020 | case REG: | |
2021 | { | |
2022 | /* If the register dies in this insn, queue that note, and mark | |
2023 | this register as needing to die. */ | |
2024 | /* This code is very similar to mark_used_1 (if set_p is false) | |
2025 | and mark_set_1 (if set_p is true) in flow.c. */ | |
2026 | ||
2027 | register int regno = REGNO (x); | |
2028 | register int offset = regno / REGSET_ELT_BITS; | |
fb3821f7 CH |
2029 | register REGSET_ELT_TYPE bit |
2030 | = (REGSET_ELT_TYPE) 1 << (regno % REGSET_ELT_BITS); | |
2031 | REGSET_ELT_TYPE all_needed = (old_live_regs[offset] & bit); | |
2032 | REGSET_ELT_TYPE some_needed = (old_live_regs[offset] & bit); | |
bd58420c RK |
2033 | |
2034 | if (set_p) | |
2035 | return; | |
2036 | ||
2037 | if (regno < FIRST_PSEUDO_REGISTER) | |
2038 | { | |
2039 | int n; | |
2040 | ||
2041 | n = HARD_REGNO_NREGS (regno, GET_MODE (x)); | |
2042 | while (--n > 0) | |
2043 | { | |
2044 | some_needed |= (old_live_regs[(regno + n) / REGSET_ELT_BITS] | |
fb3821f7 CH |
2045 | & ((REGSET_ELT_TYPE) 1 |
2046 | << ((regno + n) % REGSET_ELT_BITS))); | |
bd58420c | 2047 | all_needed &= (old_live_regs[(regno + n) / REGSET_ELT_BITS] |
fb3821f7 CH |
2048 | & ((REGSET_ELT_TYPE) 1 |
2049 | << ((regno + n) % REGSET_ELT_BITS))); | |
bd58420c RK |
2050 | } |
2051 | } | |
2052 | ||
2053 | /* If it wasn't live before we started, then add a REG_DEAD note. | |
2054 | We must check the previous lifetime info not the current info, | |
2055 | because we may have to execute this code several times, e.g. | |
2056 | once for a clobber (which doesn't add a note) and later | |
2057 | for a use (which does add a note). | |
2058 | ||
2059 | Always make the register live. We must do this even if it was | |
2060 | live before, because this may be an insn which sets and uses | |
2061 | the same register, in which case the register has already been | |
2062 | killed, so we must make it live again. | |
2063 | ||
2064 | Global registers are always live, and should never have a REG_DEAD | |
2065 | note added for them, so none of the code below applies to them. */ | |
2066 | ||
2067 | if (regno >= FIRST_PSEUDO_REGISTER || ! global_regs[regno]) | |
2068 | { | |
2069 | /* Never add REG_DEAD notes for the FRAME_POINTER_REGNUM or the | |
2070 | STACK_POINTER_REGNUM, since these are always considered to be | |
2071 | live. Similarly for ARG_POINTER_REGNUM if it is fixed. */ | |
2072 | if (regno != FRAME_POINTER_REGNUM | |
2073 | #if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM | |
2074 | && ! (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) | |
bd58420c RK |
2075 | #endif |
2076 | && regno != STACK_POINTER_REGNUM) | |
2077 | { | |
2078 | if (! all_needed && ! dead_or_set_p (insn, x)) | |
2079 | { | |
2080 | /* If none of the words in X is needed, make a REG_DEAD | |
2081 | note. Otherwise, we must make partial REG_DEAD | |
2082 | notes. */ | |
2083 | if (! some_needed) | |
2084 | create_reg_dead_note (x, insn); | |
2085 | else | |
2086 | { | |
2087 | int i; | |
2088 | ||
2089 | /* Don't make a REG_DEAD note for a part of a | |
2090 | register that is set in the insn. */ | |
2091 | for (i = HARD_REGNO_NREGS (regno, GET_MODE (x)) - 1; | |
2092 | i >= 0; i--) | |
2093 | if ((old_live_regs[(regno + i) / REGSET_ELT_BITS] | |
fb3821f7 CH |
2094 | & ((REGSET_ELT_TYPE) 1 |
2095 | << ((regno +i) % REGSET_ELT_BITS))) == 0 | |
bd58420c RK |
2096 | && ! dead_or_set_regno_p (insn, regno + i)) |
2097 | create_reg_dead_note (gen_rtx (REG, word_mode, | |
2098 | regno + i), | |
2099 | insn); | |
2100 | } | |
2101 | } | |
2102 | } | |
2103 | ||
2104 | if (regno < FIRST_PSEUDO_REGISTER) | |
2105 | { | |
2106 | int j = HARD_REGNO_NREGS (regno, GET_MODE (x)); | |
2107 | while (--j >= 0) | |
2108 | { | |
2109 | offset = (regno + j) / REGSET_ELT_BITS; | |
fb3821f7 CH |
2110 | bit |
2111 | = (REGSET_ELT_TYPE) 1 << ((regno + j) % REGSET_ELT_BITS); | |
bd58420c RK |
2112 | |
2113 | bb_dead_regs[offset] &= ~bit; | |
2114 | bb_live_regs[offset] |= bit; | |
2115 | } | |
2116 | } | |
2117 | else | |
2118 | { | |
2119 | bb_dead_regs[offset] &= ~bit; | |
2120 | bb_live_regs[offset] |= bit; | |
2121 | } | |
2122 | } | |
2123 | return; | |
2124 | } | |
2125 | ||
2126 | case MEM: | |
2127 | /* Handle tail-recursive case. */ | |
2128 | attach_deaths (XEXP (x, 0), insn, 0); | |
2129 | return; | |
2130 | ||
2131 | case SUBREG: | |
2132 | case STRICT_LOW_PART: | |
2133 | /* These two cases preserve the value of SET_P, so handle them | |
2134 | separately. */ | |
2135 | attach_deaths (XEXP (x, 0), insn, set_p); | |
2136 | return; | |
2137 | ||
2138 | case ZERO_EXTRACT: | |
2139 | case SIGN_EXTRACT: | |
2140 | /* This case preserves the value of SET_P for the first operand, but | |
2141 | clears it for the other two. */ | |
2142 | attach_deaths (XEXP (x, 0), insn, set_p); | |
2143 | attach_deaths (XEXP (x, 1), insn, 0); | |
2144 | attach_deaths (XEXP (x, 2), insn, 0); | |
2145 | return; | |
2146 | ||
2147 | default: | |
2148 | /* Other cases: walk the insn. */ | |
2149 | fmt = GET_RTX_FORMAT (code); | |
2150 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
2151 | { | |
2152 | if (fmt[i] == 'e') | |
2153 | attach_deaths (XEXP (x, i), insn, 0); | |
2154 | else if (fmt[i] == 'E') | |
2155 | for (j = 0; j < XVECLEN (x, i); j++) | |
2156 | attach_deaths (XVECEXP (x, i, j), insn, 0); | |
2157 | } | |
2158 | } | |
2159 | } | |
2160 | ||
2161 | /* After INSN has executed, add register death notes for each register | |
2162 | that is dead after INSN. */ | |
2163 | ||
2164 | static void | |
2165 | attach_deaths_insn (insn) | |
2166 | rtx insn; | |
2167 | { | |
2168 | rtx x = PATTERN (insn); | |
2169 | register RTX_CODE code = GET_CODE (x); | |
2170 | ||
2171 | if (code == SET) | |
2172 | { | |
2173 | attach_deaths (SET_SRC (x), insn, 0); | |
2174 | ||
2175 | /* A register might die here even if it is the destination, e.g. | |
2176 | it is the target of a volatile read and is otherwise unused. | |
2177 | Hence we must always call attach_deaths for the SET_DEST. */ | |
2178 | attach_deaths (SET_DEST (x), insn, 1); | |
2179 | } | |
2180 | else if (code == PARALLEL) | |
2181 | { | |
2182 | register int i; | |
2183 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
2184 | { | |
2185 | code = GET_CODE (XVECEXP (x, 0, i)); | |
2186 | if (code == SET) | |
2187 | { | |
2188 | attach_deaths (SET_SRC (XVECEXP (x, 0, i)), insn, 0); | |
2189 | ||
2190 | attach_deaths (SET_DEST (XVECEXP (x, 0, i)), insn, 1); | |
2191 | } | |
2192 | else if (code == CLOBBER) | |
2193 | attach_deaths (XEXP (XVECEXP (x, 0, i), 0), insn, 1); | |
2194 | else | |
2195 | attach_deaths (XVECEXP (x, 0, i), insn, 0); | |
2196 | } | |
2197 | } | |
2198 | else if (code == CLOBBER) | |
2199 | attach_deaths (XEXP (x, 0), insn, 1); | |
2200 | else | |
2201 | attach_deaths (x, insn, 0); | |
2202 | } | |
2203 | ||
2204 | /* Delete notes beginning with INSN and maybe put them in the chain | |
2205 | of notes ended by NOTE_LIST. | |
2206 | Returns the insn following the notes. */ | |
2207 | ||
2208 | static rtx | |
2209 | unlink_notes (insn, tail) | |
2210 | rtx insn, tail; | |
2211 | { | |
2212 | rtx prev = PREV_INSN (insn); | |
2213 | ||
2214 | while (insn != tail && GET_CODE (insn) == NOTE) | |
2215 | { | |
2216 | rtx next = NEXT_INSN (insn); | |
2217 | /* Delete the note from its current position. */ | |
2218 | if (prev) | |
2219 | NEXT_INSN (prev) = next; | |
2220 | if (next) | |
2221 | PREV_INSN (next) = prev; | |
2222 | ||
2223 | if (write_symbols != NO_DEBUG && NOTE_LINE_NUMBER (insn) > 0) | |
2224 | /* Record line-number notes so they can be reused. */ | |
2225 | LINE_NOTE (insn) = insn; | |
2226 | else | |
2227 | { | |
2228 | /* Insert the note at the end of the notes list. */ | |
2229 | PREV_INSN (insn) = note_list; | |
2230 | if (note_list) | |
2231 | NEXT_INSN (note_list) = insn; | |
2232 | note_list = insn; | |
2233 | } | |
2234 | ||
2235 | insn = next; | |
2236 | } | |
2237 | return insn; | |
2238 | } | |
2239 | ||
2240 | /* Data structure for keeping track of register information | |
2241 | during that register's life. */ | |
2242 | ||
2243 | struct sometimes | |
2244 | { | |
2245 | short offset; short bit; | |
2246 | short live_length; short calls_crossed; | |
2247 | }; | |
2248 | ||
2249 | /* Constructor for `sometimes' data structure. */ | |
2250 | ||
2251 | static int | |
2252 | new_sometimes_live (regs_sometimes_live, offset, bit, sometimes_max) | |
2253 | struct sometimes *regs_sometimes_live; | |
2254 | int offset, bit; | |
2255 | int sometimes_max; | |
2256 | { | |
2257 | register struct sometimes *p; | |
2258 | register int regno = offset * REGSET_ELT_BITS + bit; | |
2259 | int i; | |
2260 | ||
2261 | /* There should never be a register greater than max_regno here. If there | |
2262 | is, it means that a define_split has created a new pseudo reg. This | |
2263 | is not allowed, since there will not be flow info available for any | |
2264 | new register, so catch the error here. */ | |
2265 | if (regno >= max_regno) | |
2266 | abort (); | |
2267 | ||
2268 | p = ®s_sometimes_live[sometimes_max]; | |
2269 | p->offset = offset; | |
2270 | p->bit = bit; | |
2271 | p->live_length = 0; | |
2272 | p->calls_crossed = 0; | |
2273 | sometimes_max++; | |
2274 | return sometimes_max; | |
2275 | } | |
2276 | ||
2277 | /* Count lengths of all regs we are currently tracking, | |
2278 | and find new registers no longer live. */ | |
2279 | ||
2280 | static void | |
2281 | finish_sometimes_live (regs_sometimes_live, sometimes_max) | |
2282 | struct sometimes *regs_sometimes_live; | |
2283 | int sometimes_max; | |
2284 | { | |
2285 | int i; | |
2286 | ||
2287 | for (i = 0; i < sometimes_max; i++) | |
2288 | { | |
2289 | register struct sometimes *p = ®s_sometimes_live[i]; | |
2290 | int regno; | |
2291 | ||
2292 | regno = p->offset * REGSET_ELT_BITS + p->bit; | |
2293 | ||
2294 | sched_reg_live_length[regno] += p->live_length; | |
2295 | sched_reg_n_calls_crossed[regno] += p->calls_crossed; | |
2296 | } | |
2297 | } | |
2298 | ||
2299 | /* Use modified list scheduling to rearrange insns in basic block | |
2300 | B. FILE, if nonzero, is where we dump interesting output about | |
2301 | this pass. */ | |
2302 | ||
2303 | static void | |
2304 | schedule_block (b, file) | |
2305 | int b; | |
2306 | FILE *file; | |
2307 | { | |
2308 | rtx insn, last; | |
2309 | rtx last_note = 0; | |
2310 | rtx *ready, link; | |
2311 | int i, j, n_ready = 0, new_ready, n_insns = 0; | |
2312 | int sched_n_insns = 0; | |
2313 | #define NEED_NOTHING 0 | |
2314 | #define NEED_HEAD 1 | |
2315 | #define NEED_TAIL 2 | |
2316 | int new_needs; | |
2317 | ||
2318 | /* HEAD and TAIL delimit the region being scheduled. */ | |
2319 | rtx head = basic_block_head[b]; | |
2320 | rtx tail = basic_block_end[b]; | |
2321 | /* PREV_HEAD and NEXT_TAIL are the boundaries of the insns | |
2322 | being scheduled. When the insns have been ordered, | |
2323 | these insns delimit where the new insns are to be | |
2324 | spliced back into the insn chain. */ | |
2325 | rtx next_tail; | |
2326 | rtx prev_head; | |
2327 | ||
2328 | /* Keep life information accurate. */ | |
2329 | register struct sometimes *regs_sometimes_live; | |
2330 | int sometimes_max; | |
2331 | ||
2332 | if (file) | |
2333 | fprintf (file, ";;\t -- basic block number %d from %d to %d --\n", | |
2334 | b, INSN_UID (basic_block_head[b]), INSN_UID (basic_block_end[b])); | |
2335 | ||
2336 | i = max_reg_num (); | |
2337 | reg_last_uses = (rtx *) alloca (i * sizeof (rtx)); | |
2338 | bzero (reg_last_uses, i * sizeof (rtx)); | |
2339 | reg_last_sets = (rtx *) alloca (i * sizeof (rtx)); | |
2340 | bzero (reg_last_sets, i * sizeof (rtx)); | |
2341 | ||
2342 | /* Remove certain insns at the beginning from scheduling, | |
2343 | by advancing HEAD. */ | |
2344 | ||
2345 | /* At the start of a function, before reload has run, don't delay getting | |
2346 | parameters from hard registers into pseudo registers. */ | |
2347 | if (reload_completed == 0 && b == 0) | |
2348 | { | |
2349 | while (head != tail | |
2350 | && GET_CODE (head) == NOTE | |
2351 | && NOTE_LINE_NUMBER (head) != NOTE_INSN_FUNCTION_BEG) | |
2352 | head = NEXT_INSN (head); | |
2353 | while (head != tail | |
2354 | && GET_CODE (head) == INSN | |
2355 | && GET_CODE (PATTERN (head)) == SET) | |
2356 | { | |
2357 | rtx src = SET_SRC (PATTERN (head)); | |
2358 | while (GET_CODE (src) == SUBREG | |
2359 | || GET_CODE (src) == SIGN_EXTEND | |
2360 | || GET_CODE (src) == ZERO_EXTEND | |
2361 | || GET_CODE (src) == SIGN_EXTRACT | |
2362 | || GET_CODE (src) == ZERO_EXTRACT) | |
2363 | src = XEXP (src, 0); | |
2364 | if (GET_CODE (src) != REG | |
2365 | || REGNO (src) >= FIRST_PSEUDO_REGISTER) | |
2366 | break; | |
2367 | /* Keep this insn from ever being scheduled. */ | |
2368 | INSN_REF_COUNT (head) = 1; | |
2369 | head = NEXT_INSN (head); | |
2370 | } | |
2371 | } | |
2372 | ||
2373 | /* Don't include any notes or labels at the beginning of the | |
2374 | basic block, or notes at the ends of basic blocks. */ | |
2375 | while (head != tail) | |
2376 | { | |
2377 | if (GET_CODE (head) == NOTE) | |
2378 | head = NEXT_INSN (head); | |
2379 | else if (GET_CODE (tail) == NOTE) | |
2380 | tail = PREV_INSN (tail); | |
2381 | else if (GET_CODE (head) == CODE_LABEL) | |
2382 | head = NEXT_INSN (head); | |
2383 | else break; | |
2384 | } | |
2385 | /* If the only insn left is a NOTE or a CODE_LABEL, then there is no need | |
2386 | to schedule this block. */ | |
2387 | if (head == tail | |
2388 | && (GET_CODE (head) == NOTE || GET_CODE (head) == CODE_LABEL)) | |
2389 | return; | |
2390 | ||
2391 | #if 0 | |
2392 | /* This short-cut doesn't work. It does not count call insns crossed by | |
2393 | registers in reg_sometimes_live. It does not mark these registers as | |
2394 | dead if they die in this block. It does not mark these registers live | |
2395 | (or create new reg_sometimes_live entries if necessary) if they are born | |
2396 | in this block. | |
2397 | ||
2398 | The easy solution is to just always schedule a block. This block only | |
2399 | has one insn, so this won't slow down this pass by much. */ | |
2400 | ||
2401 | if (head == tail) | |
2402 | return; | |
2403 | #endif | |
2404 | ||
bd58420c RK |
2405 | /* Now HEAD through TAIL are the insns actually to be rearranged; |
2406 | Let PREV_HEAD and NEXT_TAIL enclose them. */ | |
2407 | prev_head = PREV_INSN (head); | |
2408 | next_tail = NEXT_INSN (tail); | |
2409 | ||
2410 | /* Initialize basic block data structures. */ | |
2411 | dead_notes = 0; | |
2412 | pending_read_insns = 0; | |
2413 | pending_read_mems = 0; | |
2414 | pending_write_insns = 0; | |
2415 | pending_write_mems = 0; | |
2416 | pending_lists_length = 0; | |
2417 | last_pending_memory_flush = 0; | |
2418 | last_function_call = 0; | |
2419 | last_scheduled_insn = 0; | |
2420 | ||
2421 | LOG_LINKS (sched_before_next_call) = 0; | |
2422 | ||
2423 | n_insns += sched_analyze (head, tail); | |
2424 | if (n_insns == 0) | |
2425 | { | |
2426 | free_pending_lists (); | |
2427 | return; | |
2428 | } | |
2429 | ||
2430 | /* Allocate vector to hold insns to be rearranged (except those | |
2431 | insns which are controlled by an insn with SCHED_GROUP_P set). | |
2432 | All these insns are included between ORIG_HEAD and ORIG_TAIL, | |
2433 | as those variables ultimately are set up. */ | |
2434 | ready = (rtx *) alloca ((n_insns+1) * sizeof (rtx)); | |
2435 | ||
2436 | /* TAIL is now the last of the insns to be rearranged. | |
2437 | Put those insns into the READY vector. */ | |
2438 | insn = tail; | |
2439 | ||
aa265568 JW |
2440 | /* For all branches, calls, uses, and cc0 setters, force them to remain |
2441 | in order at the end of the block by giving them high priorities. | |
2442 | There may be notes present, and prev_head may also be a note. | |
2443 | ||
2444 | Branches must obviously remain at the end. Calls should remain at the | |
2445 | end since moving them results in worse register allocation. Uses remain | |
2446 | at the end to ensure proper register allocation. cc0 setters remaim | |
2447 | at the end because they can't be moved away from their cc0 user. */ | |
2448 | i = 0; | |
2449 | while (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == JUMP_INSN | |
2450 | || (GET_CODE (insn) == INSN && GET_CODE (PATTERN (insn)) == USE) | |
2451 | #ifdef HAVE_cc0 | |
2452 | || sets_cc0_p (PATTERN (insn)) | |
2453 | #endif | |
2454 | || GET_CODE (insn) == NOTE) | |
bd58420c | 2455 | { |
aa265568 JW |
2456 | if (GET_CODE (insn) != NOTE) |
2457 | { | |
2458 | priority (insn); | |
2459 | ready[n_ready++] = insn; | |
2460 | INSN_PRIORITY (insn) = TAIL_PRIORITY - i; | |
2461 | i++; | |
2462 | INSN_REF_COUNT (insn) = 0; | |
2463 | ||
2464 | /* Skip over insns that are part of a group. */ | |
2465 | while (SCHED_GROUP_P (insn)) | |
2466 | { | |
2467 | insn = prev_nonnote_insn (insn); | |
2468 | priority (insn); | |
2469 | } | |
2470 | } | |
2471 | ||
2472 | insn = PREV_INSN (insn); | |
2473 | /* Don't overrun the bounds of the basic block. */ | |
2474 | if (insn == prev_head) | |
2475 | break; | |
bd58420c RK |
2476 | } |
2477 | ||
2478 | /* Assign priorities to instructions. Also check whether they | |
2479 | are in priority order already. If so then I will be nonnegative. | |
2480 | We use this shortcut only before reloading. */ | |
2481 | #if 0 | |
2482 | i = reload_completed ? DONE_PRIORITY : MAX_PRIORITY; | |
2483 | #endif | |
2484 | ||
2485 | for (; insn != prev_head; insn = PREV_INSN (insn)) | |
2486 | { | |
2487 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
2488 | { | |
2489 | priority (insn); | |
2490 | if (INSN_REF_COUNT (insn) == 0) | |
2491 | ready[n_ready++] = insn; | |
2492 | if (SCHED_GROUP_P (insn)) | |
2493 | { | |
2494 | while (SCHED_GROUP_P (insn)) | |
2495 | { | |
2496 | insn = PREV_INSN (insn); | |
2497 | while (GET_CODE (insn) == NOTE) | |
2498 | insn = PREV_INSN (insn); | |
2499 | priority (insn); | |
2500 | } | |
2501 | continue; | |
2502 | } | |
2503 | #if 0 | |
2504 | if (i < 0) | |
2505 | continue; | |
2506 | if (INSN_PRIORITY (insn) < i) | |
2507 | i = INSN_PRIORITY (insn); | |
2508 | else if (INSN_PRIORITY (insn) > i) | |
2509 | i = DONE_PRIORITY; | |
2510 | #endif | |
2511 | } | |
2512 | } | |
2513 | ||
2514 | #if 0 | |
2515 | /* This short-cut doesn't work. It does not count call insns crossed by | |
2516 | registers in reg_sometimes_live. It does not mark these registers as | |
2517 | dead if they die in this block. It does not mark these registers live | |
2518 | (or create new reg_sometimes_live entries if necessary) if they are born | |
2519 | in this block. | |
2520 | ||
2521 | The easy solution is to just always schedule a block. These blocks tend | |
2522 | to be very short, so this doesn't slow down this pass by much. */ | |
2523 | ||
2524 | /* If existing order is good, don't bother to reorder. */ | |
2525 | if (i != DONE_PRIORITY) | |
2526 | { | |
2527 | if (file) | |
2528 | fprintf (file, ";; already scheduled\n"); | |
2529 | ||
2530 | if (reload_completed == 0) | |
2531 | { | |
2532 | for (i = 0; i < sometimes_max; i++) | |
2533 | regs_sometimes_live[i].live_length += n_insns; | |
2534 | ||
2535 | finish_sometimes_live (regs_sometimes_live, sometimes_max); | |
2536 | } | |
2537 | free_pending_lists (); | |
2538 | return; | |
2539 | } | |
2540 | #endif | |
2541 | ||
2542 | /* Scan all the insns to be scheduled, removing NOTE insns | |
2543 | and register death notes. | |
2544 | Line number NOTE insns end up in NOTE_LIST. | |
2545 | Register death notes end up in DEAD_NOTES. | |
2546 | ||
2547 | Recreate the register life information for the end of this basic | |
2548 | block. */ | |
2549 | ||
2550 | if (reload_completed == 0) | |
2551 | { | |
2552 | bcopy (basic_block_live_at_start[b], bb_live_regs, regset_bytes); | |
2553 | bzero (bb_dead_regs, regset_bytes); | |
2554 | ||
2555 | if (b == 0) | |
2556 | { | |
2557 | /* This is the first block in the function. There may be insns | |
2558 | before head that we can't schedule. We still need to examine | |
2559 | them though for accurate register lifetime analysis. */ | |
2560 | ||
2561 | /* We don't want to remove any REG_DEAD notes as the code below | |
2562 | does. */ | |
2563 | ||
2564 | for (insn = basic_block_head[b]; insn != head; | |
2565 | insn = NEXT_INSN (insn)) | |
2566 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
2567 | { | |
2568 | /* See if the register gets born here. */ | |
2569 | /* We must check for registers being born before we check for | |
2570 | registers dying. It is possible for a register to be born | |
2571 | and die in the same insn, e.g. reading from a volatile | |
2572 | memory location into an otherwise unused register. Such | |
2573 | a register must be marked as dead after this insn. */ | |
2574 | if (GET_CODE (PATTERN (insn)) == SET | |
2575 | || GET_CODE (PATTERN (insn)) == CLOBBER) | |
2576 | sched_note_set (b, PATTERN (insn), 0); | |
2577 | else if (GET_CODE (PATTERN (insn)) == PARALLEL) | |
2578 | { | |
2579 | int j; | |
2580 | for (j = XVECLEN (PATTERN (insn), 0) - 1; j >= 0; j--) | |
2581 | if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET | |
2582 | || GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == CLOBBER) | |
2583 | sched_note_set (b, XVECEXP (PATTERN (insn), 0, j), 0); | |
2584 | ||
53dd0e6e JW |
2585 | /* ??? This code is obsolete and should be deleted. It |
2586 | is harmless though, so we will leave it in for now. */ | |
bd58420c RK |
2587 | for (j = XVECLEN (PATTERN (insn), 0) - 1; j >= 0; j--) |
2588 | if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == USE) | |
2589 | sched_note_set (b, XVECEXP (PATTERN (insn), 0, j), 0); | |
2590 | } | |
2591 | ||
2592 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) | |
2593 | { | |
2594 | if ((REG_NOTE_KIND (link) == REG_DEAD | |
2595 | || REG_NOTE_KIND (link) == REG_UNUSED) | |
2596 | /* Verify that the REG_NOTE has a legal value. */ | |
2597 | && GET_CODE (XEXP (link, 0)) == REG) | |
2598 | { | |
2599 | register int regno = REGNO (XEXP (link, 0)); | |
2600 | register int offset = regno / REGSET_ELT_BITS; | |
fb3821f7 CH |
2601 | register REGSET_ELT_TYPE bit |
2602 | = (REGSET_ELT_TYPE) 1 << (regno % REGSET_ELT_BITS); | |
bd58420c RK |
2603 | |
2604 | if (regno < FIRST_PSEUDO_REGISTER) | |
2605 | { | |
2606 | int j = HARD_REGNO_NREGS (regno, | |
2607 | GET_MODE (XEXP (link, 0))); | |
2608 | while (--j >= 0) | |
2609 | { | |
2610 | offset = (regno + j) / REGSET_ELT_BITS; | |
fb3821f7 CH |
2611 | bit = ((REGSET_ELT_TYPE) 1 |
2612 | << ((regno + j) % REGSET_ELT_BITS)); | |
bd58420c RK |
2613 | |
2614 | bb_live_regs[offset] &= ~bit; | |
2615 | bb_dead_regs[offset] |= bit; | |
2616 | } | |
2617 | } | |
2618 | else | |
2619 | { | |
2620 | bb_live_regs[offset] &= ~bit; | |
2621 | bb_dead_regs[offset] |= bit; | |
2622 | } | |
2623 | } | |
2624 | } | |
2625 | } | |
2626 | } | |
2627 | } | |
2628 | ||
2629 | /* If debugging information is being produced, keep track of the line | |
2630 | number notes for each insn. */ | |
2631 | if (write_symbols != NO_DEBUG) | |
2632 | { | |
2633 | /* We must use the true line number for the first insn in the block | |
2634 | that was computed and saved at the start of this pass. We can't | |
2635 | use the current line number, because scheduling of the previous | |
2636 | block may have changed the current line number. */ | |
2637 | rtx line = line_note_head[b]; | |
2638 | ||
2639 | for (insn = basic_block_head[b]; | |
2640 | insn != next_tail; | |
2641 | insn = NEXT_INSN (insn)) | |
2642 | if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0) | |
2643 | line = insn; | |
2644 | else | |
2645 | LINE_NOTE (insn) = line; | |
2646 | } | |
2647 | ||
2648 | for (insn = head; insn != next_tail; insn = NEXT_INSN (insn)) | |
2649 | { | |
2650 | rtx prev, next, link; | |
2651 | ||
2652 | /* Farm out notes. This is needed to keep the debugger from | |
2653 | getting completely deranged. */ | |
2654 | if (GET_CODE (insn) == NOTE) | |
2655 | { | |
2656 | prev = insn; | |
2657 | insn = unlink_notes (insn, next_tail); | |
2658 | if (prev == tail) | |
2659 | abort (); | |
2660 | if (prev == head) | |
2661 | abort (); | |
2662 | if (insn == next_tail) | |
2663 | abort (); | |
2664 | } | |
2665 | ||
2666 | if (reload_completed == 0 | |
2667 | && GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
2668 | { | |
2669 | /* See if the register gets born here. */ | |
2670 | /* We must check for registers being born before we check for | |
2671 | registers dying. It is possible for a register to be born and | |
2672 | die in the same insn, e.g. reading from a volatile memory | |
2673 | location into an otherwise unused register. Such a register | |
2674 | must be marked as dead after this insn. */ | |
2675 | if (GET_CODE (PATTERN (insn)) == SET | |
2676 | || GET_CODE (PATTERN (insn)) == CLOBBER) | |
2677 | sched_note_set (b, PATTERN (insn), 0); | |
2678 | else if (GET_CODE (PATTERN (insn)) == PARALLEL) | |
2679 | { | |
2680 | int j; | |
2681 | for (j = XVECLEN (PATTERN (insn), 0) - 1; j >= 0; j--) | |
2682 | if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET | |
2683 | || GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == CLOBBER) | |
2684 | sched_note_set (b, XVECEXP (PATTERN (insn), 0, j), 0); | |
2685 | ||
53dd0e6e JW |
2686 | /* ??? This code is obsolete and should be deleted. It |
2687 | is harmless though, so we will leave it in for now. */ | |
bd58420c RK |
2688 | for (j = XVECLEN (PATTERN (insn), 0) - 1; j >= 0; j--) |
2689 | if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == USE) | |
2690 | sched_note_set (b, XVECEXP (PATTERN (insn), 0, j), 0); | |
2691 | } | |
2692 | ||
2693 | /* Need to know what registers this insn kills. */ | |
2694 | for (prev = 0, link = REG_NOTES (insn); link; link = next) | |
2695 | { | |
2696 | int regno; | |
2697 | ||
2698 | next = XEXP (link, 1); | |
2699 | if ((REG_NOTE_KIND (link) == REG_DEAD | |
2700 | || REG_NOTE_KIND (link) == REG_UNUSED) | |
2701 | /* Verify that the REG_NOTE has a legal value. */ | |
2702 | && GET_CODE (XEXP (link, 0)) == REG) | |
2703 | { | |
2704 | register int regno = REGNO (XEXP (link, 0)); | |
2705 | register int offset = regno / REGSET_ELT_BITS; | |
fb3821f7 CH |
2706 | register REGSET_ELT_TYPE bit |
2707 | = (REGSET_ELT_TYPE) 1 << (regno % REGSET_ELT_BITS); | |
bd58420c RK |
2708 | |
2709 | /* Only unlink REG_DEAD notes; leave REG_UNUSED notes | |
2710 | alone. */ | |
2711 | if (REG_NOTE_KIND (link) == REG_DEAD) | |
2712 | { | |
2713 | if (prev) | |
2714 | XEXP (prev, 1) = next; | |
2715 | else | |
2716 | REG_NOTES (insn) = next; | |
2717 | XEXP (link, 1) = dead_notes; | |
2718 | dead_notes = link; | |
2719 | } | |
2720 | else | |
2721 | prev = link; | |
2722 | ||
2723 | if (regno < FIRST_PSEUDO_REGISTER) | |
2724 | { | |
2725 | int j = HARD_REGNO_NREGS (regno, | |
2726 | GET_MODE (XEXP (link, 0))); | |
2727 | while (--j >= 0) | |
2728 | { | |
2729 | offset = (regno + j) / REGSET_ELT_BITS; | |
fb3821f7 CH |
2730 | bit = ((REGSET_ELT_TYPE) 1 |
2731 | << ((regno + j) % REGSET_ELT_BITS)); | |
bd58420c RK |
2732 | |
2733 | bb_live_regs[offset] &= ~bit; | |
2734 | bb_dead_regs[offset] |= bit; | |
2735 | } | |
2736 | } | |
2737 | else | |
2738 | { | |
2739 | bb_live_regs[offset] &= ~bit; | |
2740 | bb_dead_regs[offset] |= bit; | |
2741 | } | |
2742 | } | |
2743 | else | |
2744 | prev = link; | |
2745 | } | |
2746 | } | |
2747 | } | |
2748 | ||
2749 | if (reload_completed == 0) | |
2750 | { | |
2751 | /* Keep track of register lives. */ | |
2752 | old_live_regs = (regset) alloca (regset_bytes); | |
2753 | regs_sometimes_live | |
2754 | = (struct sometimes *) alloca (max_regno * sizeof (struct sometimes)); | |
2755 | sometimes_max = 0; | |
2756 | ||
2757 | /* Start with registers live at end. */ | |
2758 | for (j = 0; j < regset_size; j++) | |
2759 | { | |
fb3821f7 | 2760 | REGSET_ELT_TYPE live = bb_live_regs[j]; |
bd58420c RK |
2761 | old_live_regs[j] = live; |
2762 | if (live) | |
2763 | { | |
fb3821f7 | 2764 | register REGSET_ELT_TYPE bit; |
bd58420c | 2765 | for (bit = 0; bit < REGSET_ELT_BITS; bit++) |
fb3821f7 | 2766 | if (live & ((REGSET_ELT_TYPE) 1 << bit)) |
bd58420c RK |
2767 | sometimes_max = new_sometimes_live (regs_sometimes_live, j, |
2768 | bit, sometimes_max); | |
2769 | } | |
2770 | } | |
2771 | } | |
2772 | ||
2773 | SCHED_SORT (ready, n_ready, 1); | |
2774 | ||
2775 | if (file) | |
2776 | { | |
2777 | fprintf (file, ";; ready list initially:\n;; "); | |
2778 | for (i = 0; i < n_ready; i++) | |
2779 | fprintf (file, "%d ", INSN_UID (ready[i])); | |
2780 | fprintf (file, "\n\n"); | |
2781 | ||
2782 | for (insn = head; insn != next_tail; insn = NEXT_INSN (insn)) | |
2783 | if (INSN_PRIORITY (insn) > 0) | |
2784 | fprintf (file, ";; insn[%4d]: priority = %4d, ref_count = %4d\n", | |
2785 | INSN_UID (insn), INSN_PRIORITY (insn), | |
2786 | INSN_REF_COUNT (insn)); | |
2787 | } | |
2788 | ||
2789 | /* Now HEAD and TAIL are going to become disconnected | |
2790 | entirely from the insn chain. */ | |
2791 | tail = ready[0]; | |
2792 | ||
2793 | /* Q_SIZE will always be zero here. */ | |
2794 | q_ptr = 0; | |
2795 | bzero (insn_queue, sizeof (insn_queue)); | |
2796 | ||
2797 | /* Now, perform list scheduling. */ | |
2798 | ||
2799 | /* Where we start inserting insns is after TAIL. */ | |
2800 | last = next_tail; | |
2801 | ||
2802 | new_needs = (NEXT_INSN (prev_head) == basic_block_head[b] | |
2803 | ? NEED_HEAD : NEED_NOTHING); | |
2804 | if (PREV_INSN (next_tail) == basic_block_end[b]) | |
2805 | new_needs |= NEED_TAIL; | |
2806 | ||
2807 | new_ready = n_ready; | |
2808 | while (sched_n_insns < n_insns) | |
2809 | { | |
2810 | q_ptr = NEXT_Q (q_ptr); | |
2811 | ||
2812 | /* Add all pending insns that can be scheduled without stalls to the | |
2813 | ready list. */ | |
2814 | for (insn = insn_queue[q_ptr]; insn; insn = NEXT_INSN (insn)) | |
2815 | { | |
2816 | if (file) | |
2817 | fprintf (file, ";; launching %d before %d with no stalls\n", | |
2818 | INSN_UID (insn), INSN_UID (last)); | |
2819 | ready[new_ready++] = insn; | |
2820 | q_size -= 1; | |
2821 | } | |
2822 | insn_queue[q_ptr] = 0; | |
2823 | ||
2824 | /* If there are no ready insns, stall until one is ready and add all | |
2825 | of the pending insns at that point to the ready list. */ | |
2826 | if (new_ready == 0) | |
2827 | { | |
2828 | register int stalls; | |
2829 | ||
2830 | for (stalls = 1; stalls < Q_SIZE; stalls++) | |
2831 | if (insn = insn_queue[NEXT_Q_AFTER (q_ptr, stalls)]) | |
2832 | { | |
2833 | for (; insn; insn = NEXT_INSN (insn)) | |
2834 | { | |
2835 | if (file) | |
2836 | fprintf (file, ";; issue insn %d before %d with %d stalls\n", | |
2837 | INSN_UID (insn), INSN_UID (last), stalls); | |
2838 | ready[new_ready++] = insn; | |
2839 | q_size -= 1; | |
2840 | } | |
2841 | insn_queue[NEXT_Q_AFTER (q_ptr, stalls)] = 0; | |
2842 | break; | |
2843 | } | |
2844 | ||
2845 | #if 0 | |
2846 | /* This looks logically correct, but on the SPEC benchmark set on | |
2847 | the SPARC, I get better code without it. */ | |
2848 | q_ptr = NEXT_Q_AFTER (q_ptr, stalls); | |
2849 | #endif | |
2850 | } | |
2851 | ||
2852 | /* There should be some instructions waiting to fire. */ | |
2853 | if (new_ready == 0) | |
2854 | abort (); | |
2855 | ||
2856 | /* Sort the ready list and choose the best insn to schedule. | |
2857 | N_READY holds the number of items that were scheduled the last time, | |
2858 | minus the one instruction scheduled on the last loop iteration; it | |
2859 | is not modified for any other reason in this loop. */ | |
2860 | SCHED_SORT (ready, new_ready, n_ready); | |
2861 | n_ready = new_ready; | |
2862 | last_scheduled_insn = insn = ready[0]; | |
2863 | ||
2864 | if (DONE_PRIORITY_P (insn)) | |
2865 | abort (); | |
2866 | ||
2867 | if (reload_completed == 0) | |
2868 | { | |
2869 | /* Process this insn, and each insn linked to this one which must | |
2870 | be immediately output after this insn. */ | |
2871 | do | |
2872 | { | |
2873 | /* First we kill registers set by this insn, and then we | |
2874 | make registers used by this insn live. This is the opposite | |
2875 | order used above because we are traversing the instructions | |
2876 | backwards. */ | |
2877 | ||
2878 | /* Strictly speaking, we should scan REG_UNUSED notes and make | |
2879 | every register mentioned there live, however, we will just | |
2880 | kill them again immediately below, so there doesn't seem to | |
2881 | be any reason why we bother to do this. */ | |
2882 | ||
2883 | /* See if this is the last notice we must take of a register. */ | |
2884 | if (GET_CODE (PATTERN (insn)) == SET | |
2885 | || GET_CODE (PATTERN (insn)) == CLOBBER) | |
2886 | sched_note_set (b, PATTERN (insn), 1); | |
2887 | else if (GET_CODE (PATTERN (insn)) == PARALLEL) | |
2888 | { | |
2889 | int j; | |
2890 | for (j = XVECLEN (PATTERN (insn), 0) - 1; j >= 0; j--) | |
2891 | if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET | |
2892 | || GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == CLOBBER) | |
2893 | sched_note_set (b, XVECEXP (PATTERN (insn), 0, j), 1); | |
2894 | } | |
2895 | ||
2896 | /* This code keeps life analysis information up to date. */ | |
2897 | if (GET_CODE (insn) == CALL_INSN) | |
2898 | { | |
2899 | register struct sometimes *p; | |
2900 | ||
2901 | /* A call kills all call used and global registers, except | |
2902 | for those mentioned in the call pattern which will be | |
2903 | made live again later. */ | |
2904 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
2905 | if (call_used_regs[i] || global_regs[i]) | |
2906 | { | |
2907 | register int offset = i / REGSET_ELT_BITS; | |
fb3821f7 CH |
2908 | register REGSET_ELT_TYPE bit |
2909 | = (REGSET_ELT_TYPE) 1 << (i % REGSET_ELT_BITS); | |
bd58420c RK |
2910 | |
2911 | bb_live_regs[offset] &= ~bit; | |
2912 | bb_dead_regs[offset] |= bit; | |
2913 | } | |
2914 | ||
2915 | /* Regs live at the time of a call instruction must not | |
2916 | go in a register clobbered by calls. Record this for | |
2917 | all regs now live. Note that insns which are born or | |
2918 | die in a call do not cross a call, so this must be done | |
2919 | after the killings (above) and before the births | |
2920 | (below). */ | |
2921 | p = regs_sometimes_live; | |
2922 | for (i = 0; i < sometimes_max; i++, p++) | |
fb3821f7 CH |
2923 | if (bb_live_regs[p->offset] |
2924 | & ((REGSET_ELT_TYPE) 1 << p->bit)) | |
bd58420c RK |
2925 | p->calls_crossed += 1; |
2926 | } | |
2927 | ||
2928 | /* Make every register used live, and add REG_DEAD notes for | |
2929 | registers which were not live before we started. */ | |
2930 | attach_deaths_insn (insn); | |
2931 | ||
2932 | /* Find registers now made live by that instruction. */ | |
2933 | for (i = 0; i < regset_size; i++) | |
2934 | { | |
fb3821f7 | 2935 | REGSET_ELT_TYPE diff = bb_live_regs[i] & ~old_live_regs[i]; |
bd58420c RK |
2936 | if (diff) |
2937 | { | |
2938 | register int bit; | |
2939 | old_live_regs[i] |= diff; | |
2940 | for (bit = 0; bit < REGSET_ELT_BITS; bit++) | |
fb3821f7 | 2941 | if (diff & ((REGSET_ELT_TYPE) 1 << bit)) |
bd58420c RK |
2942 | sometimes_max |
2943 | = new_sometimes_live (regs_sometimes_live, i, bit, | |
2944 | sometimes_max); | |
2945 | } | |
2946 | } | |
2947 | ||
2948 | /* Count lengths of all regs we are worrying about now, | |
2949 | and handle registers no longer live. */ | |
2950 | ||
2951 | for (i = 0; i < sometimes_max; i++) | |
2952 | { | |
2953 | register struct sometimes *p = ®s_sometimes_live[i]; | |
2954 | int regno = p->offset*REGSET_ELT_BITS + p->bit; | |
2955 | ||
2956 | p->live_length += 1; | |
2957 | ||
fb3821f7 CH |
2958 | if ((bb_live_regs[p->offset] |
2959 | & ((REGSET_ELT_TYPE) 1 << p->bit)) == 0) | |
bd58420c RK |
2960 | { |
2961 | /* This is the end of one of this register's lifetime | |
2962 | segments. Save the lifetime info collected so far, | |
2963 | and clear its bit in the old_live_regs entry. */ | |
2964 | sched_reg_live_length[regno] += p->live_length; | |
2965 | sched_reg_n_calls_crossed[regno] += p->calls_crossed; | |
fb3821f7 CH |
2966 | old_live_regs[p->offset] |
2967 | &= ~((REGSET_ELT_TYPE) 1 << p->bit); | |
bd58420c RK |
2968 | |
2969 | /* Delete the reg_sometimes_live entry for this reg by | |
2970 | copying the last entry over top of it. */ | |
2971 | *p = regs_sometimes_live[--sometimes_max]; | |
2972 | /* ...and decrement i so that this newly copied entry | |
2973 | will be processed. */ | |
2974 | i--; | |
2975 | } | |
2976 | } | |
2977 | ||
2978 | link = insn; | |
2979 | insn = PREV_INSN (insn); | |
2980 | } | |
2981 | while (SCHED_GROUP_P (link)); | |
2982 | ||
2983 | /* Set INSN back to the insn we are scheduling now. */ | |
2984 | insn = ready[0]; | |
2985 | } | |
2986 | ||
2987 | /* Schedule INSN. Remove it from the ready list. */ | |
2988 | ready += 1; | |
2989 | n_ready -= 1; | |
2990 | ||
2991 | sched_n_insns += 1; | |
2992 | NEXT_INSN (insn) = last; | |
2993 | PREV_INSN (last) = insn; | |
2994 | last = insn; | |
2995 | ||
2996 | /* Everything that precedes INSN now either becomes "ready", if | |
2997 | it can execute immediately before INSN, or "pending", if | |
2998 | there must be a delay. Give INSN high enough priority that | |
2999 | at least one (maybe more) reg-killing insns can be launched | |
3000 | ahead of all others. Mark INSN as scheduled by changing its | |
3001 | priority to -1. */ | |
3002 | INSN_PRIORITY (insn) = LAUNCH_PRIORITY; | |
3003 | new_ready = launch_links (insn, ready, n_ready); | |
3004 | INSN_PRIORITY (insn) = DONE_PRIORITY; | |
3005 | ||
3006 | /* Schedule all prior insns that must not be moved. */ | |
3007 | if (SCHED_GROUP_P (insn)) | |
3008 | { | |
3009 | /* Disable these insns from being launched. */ | |
3010 | link = insn; | |
3011 | while (SCHED_GROUP_P (link)) | |
3012 | { | |
3013 | /* Disable these insns from being launched by anybody. */ | |
3014 | link = PREV_INSN (link); | |
3015 | INSN_REF_COUNT (link) = 0; | |
3016 | } | |
3017 | ||
3018 | /* None of these insns can move forward into delay slots. */ | |
3019 | while (SCHED_GROUP_P (insn)) | |
3020 | { | |
3021 | insn = PREV_INSN (insn); | |
3022 | new_ready = launch_links (insn, ready, new_ready); | |
3023 | INSN_PRIORITY (insn) = DONE_PRIORITY; | |
3024 | ||
3025 | sched_n_insns += 1; | |
3026 | NEXT_INSN (insn) = last; | |
3027 | PREV_INSN (last) = insn; | |
3028 | last = insn; | |
3029 | } | |
3030 | } | |
3031 | } | |
3032 | if (q_size != 0) | |
3033 | abort (); | |
3034 | ||
3035 | if (reload_completed == 0) | |
3036 | finish_sometimes_live (regs_sometimes_live, sometimes_max); | |
3037 | ||
3038 | /* HEAD is now the first insn in the chain of insns that | |
3039 | been scheduled by the loop above. | |
3040 | TAIL is the last of those insns. */ | |
3041 | head = insn; | |
3042 | ||
3043 | /* NOTE_LIST is the end of a chain of notes previously found | |
3044 | among the insns. Insert them at the beginning of the insns. */ | |
3045 | if (note_list != 0) | |
3046 | { | |
3047 | rtx note_head = note_list; | |
3048 | while (PREV_INSN (note_head)) | |
3049 | note_head = PREV_INSN (note_head); | |
3050 | ||
3051 | PREV_INSN (head) = note_list; | |
3052 | NEXT_INSN (note_list) = head; | |
3053 | head = note_head; | |
3054 | } | |
3055 | ||
3056 | /* In theory, there should be no REG_DEAD notes leftover at the end. | |
3057 | In practice, this can occur as the result of bugs in flow, combine.c, | |
3058 | and/or sched.c. The values of the REG_DEAD notes remaining are | |
3059 | meaningless, because dead_notes is just used as a free list. */ | |
3060 | #if 1 | |
3061 | if (dead_notes != 0) | |
3062 | abort (); | |
3063 | #endif | |
3064 | ||
3065 | if (new_needs & NEED_HEAD) | |
3066 | basic_block_head[b] = head; | |
3067 | PREV_INSN (head) = prev_head; | |
3068 | NEXT_INSN (prev_head) = head; | |
3069 | ||
3070 | if (new_needs & NEED_TAIL) | |
3071 | basic_block_end[b] = tail; | |
3072 | NEXT_INSN (tail) = next_tail; | |
3073 | PREV_INSN (next_tail) = tail; | |
3074 | ||
3075 | /* Restore the line-number notes of each insn. */ | |
3076 | if (write_symbols != NO_DEBUG) | |
3077 | { | |
3078 | rtx line, note, prev, new; | |
3079 | int notes = 0; | |
3080 | ||
3081 | head = basic_block_head[b]; | |
3082 | next_tail = NEXT_INSN (basic_block_end[b]); | |
3083 | ||
3084 | /* Determine the current line-number. We want to know the current | |
3085 | line number of the first insn of the block here, in case it is | |
3086 | different from the true line number that was saved earlier. If | |
3087 | different, then we need a line number note before the first insn | |
3088 | of this block. If it happens to be the same, then we don't want to | |
3089 | emit another line number note here. */ | |
3090 | for (line = head; line; line = PREV_INSN (line)) | |
3091 | if (GET_CODE (line) == NOTE && NOTE_LINE_NUMBER (line) > 0) | |
3092 | break; | |
3093 | ||
3094 | /* Walk the insns keeping track of the current line-number and inserting | |
3095 | the line-number notes as needed. */ | |
3096 | for (insn = head; insn != next_tail; insn = NEXT_INSN (insn)) | |
3097 | if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0) | |
3098 | line = insn; | |
3099 | else if (! (GET_CODE (insn) == NOTE | |
3100 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_DELETED) | |
3101 | && (note = LINE_NOTE (insn)) != 0 | |
3102 | && note != line | |
3103 | && (line == 0 | |
3104 | || NOTE_LINE_NUMBER (note) != NOTE_LINE_NUMBER (line) | |
3105 | || NOTE_SOURCE_FILE (note) != NOTE_SOURCE_FILE (line))) | |
3106 | { | |
3107 | line = note; | |
3108 | prev = PREV_INSN (insn); | |
3109 | if (LINE_NOTE (note)) | |
3110 | { | |
6dc42e49 | 3111 | /* Re-use the original line-number note. */ |
bd58420c RK |
3112 | LINE_NOTE (note) = 0; |
3113 | PREV_INSN (note) = prev; | |
3114 | NEXT_INSN (prev) = note; | |
3115 | PREV_INSN (insn) = note; | |
3116 | NEXT_INSN (note) = insn; | |
3117 | } | |
3118 | else | |
3119 | { | |
3120 | notes++; | |
3121 | new = emit_note_after (NOTE_LINE_NUMBER (note), prev); | |
3122 | NOTE_SOURCE_FILE (new) = NOTE_SOURCE_FILE (note); | |
3123 | } | |
3124 | } | |
3125 | if (file && notes) | |
3126 | fprintf (file, ";; added %d line-number notes\n", notes); | |
3127 | } | |
3128 | ||
3129 | if (file) | |
3130 | { | |
3131 | fprintf (file, ";; new basic block head = %d\n;; new basic block end = %d\n\n", | |
3132 | INSN_UID (basic_block_head[b]), INSN_UID (basic_block_end[b])); | |
3133 | } | |
3134 | ||
3135 | /* Yow! We're done! */ | |
3136 | free_pending_lists (); | |
3137 | ||
3138 | return; | |
3139 | } | |
3140 | \f | |
3141 | /* Subroutine of split_hard_reg_notes. Searches X for any reference to | |
3142 | REGNO, returning the rtx of the reference found if any. Otherwise, | |
3143 | returns 0. */ | |
3144 | ||
3145 | rtx | |
3146 | regno_use_in (regno, x) | |
3147 | int regno; | |
3148 | rtx x; | |
3149 | { | |
3150 | register char *fmt; | |
3151 | int i, j; | |
3152 | rtx tem; | |
3153 | ||
3154 | if (GET_CODE (x) == REG && REGNO (x) == regno) | |
3155 | return x; | |
3156 | ||
3157 | fmt = GET_RTX_FORMAT (GET_CODE (x)); | |
3158 | for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--) | |
3159 | { | |
3160 | if (fmt[i] == 'e') | |
3161 | { | |
3162 | if (tem = regno_use_in (regno, XEXP (x, i))) | |
3163 | return tem; | |
3164 | } | |
3165 | else if (fmt[i] == 'E') | |
3166 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
3167 | if (tem = regno_use_in (regno , XVECEXP (x, i, j))) | |
3168 | return tem; | |
3169 | } | |
3170 | ||
3171 | return 0; | |
3172 | } | |
3173 | ||
3174 | /* Subroutine of update_flow_info. Determines whether any new REG_NOTEs are | |
3175 | needed for the hard register mentioned in the note. This can happen | |
3176 | if the reference to the hard register in the original insn was split into | |
3177 | several smaller hard register references in the split insns. */ | |
3178 | ||
3179 | static void | |
3180 | split_hard_reg_notes (note, first, last, orig_insn) | |
3181 | rtx note, first, last, orig_insn; | |
3182 | { | |
3183 | rtx reg, temp, link; | |
3184 | int n_regs, i, new_reg; | |
3185 | rtx insn; | |
3186 | ||
3187 | /* Assume that this is a REG_DEAD note. */ | |
3188 | if (REG_NOTE_KIND (note) != REG_DEAD) | |
3189 | abort (); | |
3190 | ||
3191 | reg = XEXP (note, 0); | |
3192 | ||
3193 | n_regs = HARD_REGNO_NREGS (REGNO (reg), GET_MODE (reg)); | |
3194 | ||
3195 | /* ??? Could add check here to see whether, the hard register is referenced | |
3196 | in the same mode as in the original insn. If so, then it has not been | |
3197 | split, and the rest of the code below is unnecessary. */ | |
3198 | ||
3199 | for (i = 1; i < n_regs; i++) | |
3200 | { | |
3201 | new_reg = REGNO (reg) + i; | |
3202 | ||
3203 | /* Check for references to new_reg in the split insns. */ | |
3204 | for (insn = last; ; insn = PREV_INSN (insn)) | |
3205 | { | |
3206 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
3207 | && (temp = regno_use_in (new_reg, PATTERN (insn)))) | |
3208 | { | |
3209 | /* Create a new reg dead note here. */ | |
3210 | link = rtx_alloc (EXPR_LIST); | |
3211 | PUT_REG_NOTE_KIND (link, REG_DEAD); | |
3212 | XEXP (link, 0) = temp; | |
3213 | XEXP (link, 1) = REG_NOTES (insn); | |
3214 | REG_NOTES (insn) = link; | |
3215 | break; | |
3216 | } | |
3217 | /* It isn't mentioned anywhere, so no new reg note is needed for | |
3218 | this register. */ | |
3219 | if (insn == first) | |
3220 | break; | |
3221 | } | |
3222 | } | |
3223 | } | |
3224 | ||
3225 | /* Subroutine of update_flow_info. Determines whether a SET or CLOBBER in an | |
3226 | insn created by splitting needs a REG_DEAD or REG_UNUSED note added. */ | |
3227 | ||
3228 | static void | |
3229 | new_insn_dead_notes (pat, insn, last, orig_insn) | |
3230 | rtx pat, insn, last, orig_insn; | |
3231 | { | |
3232 | rtx dest, tem, set; | |
3233 | ||
3234 | /* PAT is either a CLOBBER or a SET here. */ | |
3235 | dest = XEXP (pat, 0); | |
3236 | ||
3237 | while (GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SUBREG | |
3238 | || GET_CODE (dest) == STRICT_LOW_PART | |
3239 | || GET_CODE (dest) == SIGN_EXTRACT) | |
3240 | dest = XEXP (dest, 0); | |
3241 | ||
3242 | if (GET_CODE (dest) == REG) | |
3243 | { | |
3244 | for (tem = last; tem != insn; tem = PREV_INSN (tem)) | |
3245 | { | |
3246 | if (GET_RTX_CLASS (GET_CODE (tem)) == 'i' | |
3247 | && reg_overlap_mentioned_p (dest, PATTERN (tem)) | |
3248 | && (set = single_set (tem))) | |
3249 | { | |
3250 | rtx tem_dest = SET_DEST (set); | |
3251 | ||
3252 | while (GET_CODE (tem_dest) == ZERO_EXTRACT | |
3253 | || GET_CODE (tem_dest) == SUBREG | |
3254 | || GET_CODE (tem_dest) == STRICT_LOW_PART | |
3255 | || GET_CODE (tem_dest) == SIGN_EXTRACT) | |
3256 | tem_dest = XEXP (tem_dest, 0); | |
3257 | ||
3258 | if (tem_dest != dest) | |
3259 | { | |
3260 | /* Use the same scheme as combine.c, don't put both REG_DEAD | |
3261 | and REG_UNUSED notes on the same insn. */ | |
3262 | if (! find_regno_note (tem, REG_UNUSED, REGNO (dest)) | |
3263 | && ! find_regno_note (tem, REG_DEAD, REGNO (dest))) | |
3264 | { | |
3265 | rtx note = rtx_alloc (EXPR_LIST); | |
3266 | PUT_REG_NOTE_KIND (note, REG_DEAD); | |
3267 | XEXP (note, 0) = dest; | |
3268 | XEXP (note, 1) = REG_NOTES (tem); | |
3269 | REG_NOTES (tem) = note; | |
3270 | } | |
3271 | /* The reg only dies in one insn, the last one that uses | |
3272 | it. */ | |
3273 | break; | |
3274 | } | |
3275 | else if (reg_overlap_mentioned_p (dest, SET_SRC (set))) | |
3276 | /* We found an instruction that both uses the register, | |
3277 | and sets it, so no new REG_NOTE is needed for this set. */ | |
3278 | break; | |
3279 | } | |
3280 | } | |
3281 | /* If this is a set, it must die somewhere, unless it is the dest of | |
3282 | the original insn, and hence is live after the original insn. Abort | |
3283 | if it isn't supposed to be live after the original insn. | |
3284 | ||
3285 | If this is a clobber, then just add a REG_UNUSED note. */ | |
3286 | if (tem == insn) | |
3287 | { | |
3288 | int live_after_orig_insn = 0; | |
3289 | rtx pattern = PATTERN (orig_insn); | |
3290 | int i; | |
3291 | ||
3292 | if (GET_CODE (pat) == CLOBBER) | |
3293 | { | |
3294 | rtx note = rtx_alloc (EXPR_LIST); | |
3295 | PUT_REG_NOTE_KIND (note, REG_UNUSED); | |
3296 | XEXP (note, 0) = dest; | |
3297 | XEXP (note, 1) = REG_NOTES (insn); | |
3298 | REG_NOTES (insn) = note; | |
3299 | return; | |
3300 | } | |
3301 | ||
3302 | /* The original insn could have multiple sets, so search the | |
3303 | insn for all sets. */ | |
3304 | if (GET_CODE (pattern) == SET) | |
3305 | { | |
3306 | if (reg_overlap_mentioned_p (dest, SET_DEST (pattern))) | |
3307 | live_after_orig_insn = 1; | |
3308 | } | |
3309 | else if (GET_CODE (pattern) == PARALLEL) | |
3310 | { | |
3311 | for (i = 0; i < XVECLEN (pattern, 0); i++) | |
3312 | if (GET_CODE (XVECEXP (pattern, 0, i)) == SET | |
3313 | && reg_overlap_mentioned_p (dest, | |
3314 | SET_DEST (XVECEXP (pattern, | |
3315 | 0, i)))) | |
3316 | live_after_orig_insn = 1; | |
3317 | } | |
3318 | ||
3319 | if (! live_after_orig_insn) | |
3320 | abort (); | |
3321 | } | |
3322 | } | |
3323 | } | |
3324 | ||
3325 | /* Subroutine of update_flow_info. Update the value of reg_n_sets for all | |
3326 | registers modified by X. INC is -1 if the containing insn is being deleted, | |
3327 | and is 1 if the containing insn is a newly generated insn. */ | |
3328 | ||
3329 | static void | |
3330 | update_n_sets (x, inc) | |
3331 | rtx x; | |
3332 | int inc; | |
3333 | { | |
3334 | rtx dest = SET_DEST (x); | |
3335 | ||
3336 | while (GET_CODE (dest) == STRICT_LOW_PART || GET_CODE (dest) == SUBREG | |
3337 | || GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SIGN_EXTRACT) | |
3338 | dest = SUBREG_REG (dest); | |
3339 | ||
3340 | if (GET_CODE (dest) == REG) | |
3341 | { | |
3342 | int regno = REGNO (dest); | |
3343 | ||
3344 | if (regno < FIRST_PSEUDO_REGISTER) | |
3345 | { | |
3346 | register int i; | |
3347 | int endregno = regno + HARD_REGNO_NREGS (regno, GET_MODE (dest)); | |
3348 | ||
3349 | for (i = regno; i < endregno; i++) | |
3350 | reg_n_sets[i] += inc; | |
3351 | } | |
3352 | else | |
3353 | reg_n_sets[regno] += inc; | |
3354 | } | |
3355 | } | |
3356 | ||
3357 | /* Updates all flow-analysis related quantities (including REG_NOTES) for | |
3358 | the insns from FIRST to LAST inclusive that were created by splitting | |
3359 | ORIG_INSN. NOTES are the original REG_NOTES. */ | |
3360 | ||
3361 | static void | |
3362 | update_flow_info (notes, first, last, orig_insn) | |
3363 | rtx notes; | |
3364 | rtx first, last; | |
3365 | rtx orig_insn; | |
3366 | { | |
3367 | rtx insn, note; | |
3368 | rtx next; | |
3369 | rtx orig_dest, temp; | |
3370 | rtx set; | |
3371 | ||
3372 | /* Get and save the destination set by the original insn. */ | |
3373 | ||
3374 | orig_dest = single_set (orig_insn); | |
3375 | if (orig_dest) | |
3376 | orig_dest = SET_DEST (orig_dest); | |
3377 | ||
3378 | /* Move REG_NOTES from the original insn to where they now belong. */ | |
3379 | ||
3380 | for (note = notes; note; note = next) | |
3381 | { | |
3382 | next = XEXP (note, 1); | |
3383 | switch (REG_NOTE_KIND (note)) | |
3384 | { | |
3385 | case REG_DEAD: | |
3386 | case REG_UNUSED: | |
3387 | /* Move these notes from the original insn to the last new insn where | |
3388 | the register is now set. */ | |
3389 | ||
3390 | for (insn = last; ; insn = PREV_INSN (insn)) | |
3391 | { | |
3392 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
3393 | && reg_mentioned_p (XEXP (note, 0), PATTERN (insn))) | |
3394 | { | |
3395 | XEXP (note, 1) = REG_NOTES (insn); | |
3396 | REG_NOTES (insn) = note; | |
3397 | ||
3398 | /* Sometimes need to convert REG_UNUSED notes to REG_DEAD | |
3399 | notes. */ | |
6dc42e49 | 3400 | /* ??? This won't handle multiple word registers correctly, |
bd58420c RK |
3401 | but should be good enough for now. */ |
3402 | if (REG_NOTE_KIND (note) == REG_UNUSED | |
3403 | && ! dead_or_set_p (insn, XEXP (note, 0))) | |
3404 | PUT_REG_NOTE_KIND (note, REG_DEAD); | |
3405 | ||
3406 | /* The reg only dies in one insn, the last one that uses | |
3407 | it. */ | |
3408 | break; | |
3409 | } | |
3410 | /* It must die somewhere, fail it we couldn't find where it died. | |
3411 | ||
3412 | If this is a REG_UNUSED note, then it must be a temporary | |
3413 | register that was not needed by this instantiation of the | |
3414 | pattern, so we can safely ignore it. */ | |
3415 | if (insn == first) | |
3416 | { | |
3417 | if (REG_NOTE_KIND (note) != REG_UNUSED) | |
3418 | abort (); | |
3419 | ||
3420 | break; | |
3421 | } | |
3422 | } | |
3423 | ||
3424 | /* If this note refers to a multiple word hard register, it may | |
3425 | have been split into several smaller hard register references. | |
3426 | Check to see if there are any new register references that | |
3427 | need REG_NOTES added for them. */ | |
3428 | temp = XEXP (note, 0); | |
3429 | if (REG_NOTE_KIND (note) == REG_DEAD | |
3430 | && GET_CODE (temp) == REG | |
3431 | && REGNO (temp) < FIRST_PSEUDO_REGISTER | |
3432 | && HARD_REGNO_NREGS (REGNO (temp), GET_MODE (temp))) | |
3433 | split_hard_reg_notes (note, first, last, orig_insn); | |
3434 | break; | |
3435 | ||
3436 | case REG_WAS_0: | |
3437 | /* This note applies to the dest of the original insn. Find the | |
3438 | first new insn that now has the same dest, and move the note | |
3439 | there. */ | |
3440 | ||
3441 | if (! orig_dest) | |
3442 | abort (); | |
3443 | ||
3444 | for (insn = first; ; insn = NEXT_INSN (insn)) | |
3445 | { | |
3446 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
3447 | && (temp = single_set (insn)) | |
3448 | && rtx_equal_p (SET_DEST (temp), orig_dest)) | |
3449 | { | |
3450 | XEXP (note, 1) = REG_NOTES (insn); | |
3451 | REG_NOTES (insn) = note; | |
3452 | /* The reg is only zero before one insn, the first that | |
3453 | uses it. */ | |
3454 | break; | |
3455 | } | |
3456 | /* It must be set somewhere, fail if we couldn't find where it | |
3457 | was set. */ | |
3458 | if (insn == last) | |
3459 | abort (); | |
3460 | } | |
3461 | break; | |
3462 | ||
3463 | case REG_EQUAL: | |
3464 | case REG_EQUIV: | |
3465 | /* A REG_EQUIV or REG_EQUAL note on an insn with more than one | |
3466 | set is meaningless. Just drop the note. */ | |
3467 | if (! orig_dest) | |
3468 | break; | |
3469 | ||
3470 | case REG_NO_CONFLICT: | |
3471 | /* These notes apply to the dest of the original insn. Find the last | |
3472 | new insn that now has the same dest, and move the note there. */ | |
3473 | ||
3474 | if (! orig_dest) | |
3475 | abort (); | |
3476 | ||
3477 | for (insn = last; ; insn = PREV_INSN (insn)) | |
3478 | { | |
3479 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
3480 | && (temp = single_set (insn)) | |
3481 | && rtx_equal_p (SET_DEST (temp), orig_dest)) | |
3482 | { | |
3483 | XEXP (note, 1) = REG_NOTES (insn); | |
3484 | REG_NOTES (insn) = note; | |
3485 | /* Only put this note on one of the new insns. */ | |
3486 | break; | |
3487 | } | |
3488 | ||
3489 | /* The original dest must still be set someplace. Abort if we | |
3490 | couldn't find it. */ | |
3491 | if (insn == first) | |
3492 | abort (); | |
3493 | } | |
3494 | break; | |
3495 | ||
3496 | case REG_LIBCALL: | |
3497 | /* Move a REG_LIBCALL note to the first insn created, and update | |
3498 | the corresponding REG_RETVAL note. */ | |
3499 | XEXP (note, 1) = REG_NOTES (first); | |
3500 | REG_NOTES (first) = note; | |
3501 | ||
3502 | insn = XEXP (note, 0); | |
fb3821f7 | 3503 | note = find_reg_note (insn, REG_RETVAL, NULL_RTX); |
bd58420c RK |
3504 | if (note) |
3505 | XEXP (note, 0) = first; | |
3506 | break; | |
3507 | ||
3508 | case REG_RETVAL: | |
3509 | /* Move a REG_RETVAL note to the last insn created, and update | |
3510 | the corresponding REG_LIBCALL note. */ | |
3511 | XEXP (note, 1) = REG_NOTES (last); | |
3512 | REG_NOTES (last) = note; | |
3513 | ||
3514 | insn = XEXP (note, 0); | |
fb3821f7 | 3515 | note = find_reg_note (insn, REG_LIBCALL, NULL_RTX); |
bd58420c RK |
3516 | if (note) |
3517 | XEXP (note, 0) = last; | |
3518 | break; | |
3519 | ||
3520 | case REG_NONNEG: | |
3521 | /* This should be moved to whichever instruction is a JUMP_INSN. */ | |
3522 | ||
3523 | for (insn = last; ; insn = PREV_INSN (insn)) | |
3524 | { | |
3525 | if (GET_CODE (insn) == JUMP_INSN) | |
3526 | { | |
3527 | XEXP (note, 1) = REG_NOTES (insn); | |
3528 | REG_NOTES (insn) = note; | |
3529 | /* Only put this note on one of the new insns. */ | |
3530 | break; | |
3531 | } | |
3532 | /* Fail if we couldn't find a JUMP_INSN. */ | |
3533 | if (insn == first) | |
3534 | abort (); | |
3535 | } | |
3536 | break; | |
3537 | ||
3538 | case REG_INC: | |
3539 | /* This should be moved to whichever instruction now has the | |
3540 | increment operation. */ | |
3541 | abort (); | |
3542 | ||
3543 | case REG_LABEL: | |
3544 | /* Should be moved to the new insn(s) which use the label. */ | |
9ae57db8 RS |
3545 | for (insn = first; insn != NEXT_INSN (last); insn = NEXT_INSN (insn)) |
3546 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
3547 | && reg_mentioned_p (XEXP (note, 0), PATTERN (insn))) | |
3548 | REG_NOTES (insn) = gen_rtx (EXPR_LIST, REG_LABEL, | |
3549 | XEXP (note, 0), REG_NOTES (insn)); | |
3550 | break; | |
bd58420c RK |
3551 | |
3552 | case REG_CC_SETTER: | |
3553 | case REG_CC_USER: | |
3554 | /* These two notes will never appear until after reorg, so we don't | |
3555 | have to handle them here. */ | |
3556 | default: | |
3557 | abort (); | |
3558 | } | |
3559 | } | |
3560 | ||
3561 | /* Each new insn created, except the last, has a new set. If the destination | |
3562 | is a register, then this reg is now live across several insns, whereas | |
3563 | previously the dest reg was born and died within the same insn. To | |
3564 | reflect this, we now need a REG_DEAD note on the insn where this | |
3565 | dest reg dies. | |
3566 | ||
3567 | Similarly, the new insns may have clobbers that need REG_UNUSED notes. */ | |
3568 | ||
3569 | for (insn = first; insn != last; insn = NEXT_INSN (insn)) | |
3570 | { | |
3571 | rtx pat; | |
3572 | int i; | |
3573 | ||
3574 | pat = PATTERN (insn); | |
3575 | if (GET_CODE (pat) == SET || GET_CODE (pat) == CLOBBER) | |
3576 | new_insn_dead_notes (pat, insn, last, orig_insn); | |
3577 | else if (GET_CODE (pat) == PARALLEL) | |
3578 | { | |
3579 | for (i = 0; i < XVECLEN (pat, 0); i++) | |
3580 | if (GET_CODE (XVECEXP (pat, 0, i)) == SET | |
3581 | || GET_CODE (XVECEXP (pat, 0, i)) == CLOBBER) | |
3582 | new_insn_dead_notes (XVECEXP (pat, 0, i), insn, last, orig_insn); | |
3583 | } | |
3584 | } | |
3585 | ||
3586 | /* If any insn, except the last, uses the register set by the last insn, | |
3587 | then we need a new REG_DEAD note on that insn. In this case, there | |
3588 | would not have been a REG_DEAD note for this register in the original | |
3589 | insn because it was used and set within one insn. | |
3590 | ||
3591 | There is no new REG_DEAD note needed if the last insn uses the register | |
3592 | that it is setting. */ | |
3593 | ||
3594 | set = single_set (last); | |
3595 | if (set) | |
3596 | { | |
3597 | rtx dest = SET_DEST (set); | |
3598 | ||
3599 | while (GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SUBREG | |
3600 | || GET_CODE (dest) == STRICT_LOW_PART | |
3601 | || GET_CODE (dest) == SIGN_EXTRACT) | |
3602 | dest = XEXP (dest, 0); | |
3603 | ||
3604 | if (GET_CODE (dest) == REG | |
3605 | && ! reg_overlap_mentioned_p (dest, SET_SRC (set))) | |
3606 | { | |
3607 | for (insn = PREV_INSN (last); ; insn = PREV_INSN (insn)) | |
3608 | { | |
3609 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
3610 | && reg_mentioned_p (dest, PATTERN (insn)) | |
3611 | && (set = single_set (insn))) | |
3612 | { | |
3613 | rtx insn_dest = SET_DEST (set); | |
3614 | ||
3615 | while (GET_CODE (insn_dest) == ZERO_EXTRACT | |
3616 | || GET_CODE (insn_dest) == SUBREG | |
3617 | || GET_CODE (insn_dest) == STRICT_LOW_PART | |
3618 | || GET_CODE (insn_dest) == SIGN_EXTRACT) | |
3619 | insn_dest = XEXP (insn_dest, 0); | |
3620 | ||
3621 | if (insn_dest != dest) | |
3622 | { | |
3623 | note = rtx_alloc (EXPR_LIST); | |
3624 | PUT_REG_NOTE_KIND (note, REG_DEAD); | |
3625 | XEXP (note, 0) = dest; | |
3626 | XEXP (note, 1) = REG_NOTES (insn); | |
3627 | REG_NOTES (insn) = note; | |
3628 | /* The reg only dies in one insn, the last one | |
3629 | that uses it. */ | |
3630 | break; | |
3631 | } | |
3632 | } | |
3633 | if (insn == first) | |
3634 | break; | |
3635 | } | |
3636 | } | |
3637 | } | |
3638 | ||
3639 | /* If the original dest is modifying a multiple register target, and the | |
3640 | original instruction was split such that the original dest is now set | |
3641 | by two or more SUBREG sets, then the split insns no longer kill the | |
3642 | destination of the original insn. | |
3643 | ||
3644 | In this case, if there exists an instruction in the same basic block, | |
3645 | before the split insn, which uses the original dest, and this use is | |
3646 | killed by the original insn, then we must remove the REG_DEAD note on | |
3647 | this insn, because it is now superfluous. | |
3648 | ||
3649 | This does not apply when a hard register gets split, because the code | |
3650 | knows how to handle overlapping hard registers properly. */ | |
3651 | if (orig_dest && GET_CODE (orig_dest) == REG) | |
3652 | { | |
3653 | int found_orig_dest = 0; | |
3654 | int found_split_dest = 0; | |
3655 | ||
3656 | for (insn = first; ; insn = NEXT_INSN (insn)) | |
3657 | { | |
3658 | set = single_set (insn); | |
3659 | if (set) | |
3660 | { | |
3661 | if (GET_CODE (SET_DEST (set)) == REG | |
3662 | && REGNO (SET_DEST (set)) == REGNO (orig_dest)) | |
3663 | { | |
3664 | found_orig_dest = 1; | |
3665 | break; | |
3666 | } | |
3667 | else if (GET_CODE (SET_DEST (set)) == SUBREG | |
3668 | && SUBREG_REG (SET_DEST (set)) == orig_dest) | |
3669 | { | |
3670 | found_split_dest = 1; | |
3671 | break; | |
3672 | } | |
3673 | } | |
3674 | ||
3675 | if (insn == last) | |
3676 | break; | |
3677 | } | |
3678 | ||
3679 | if (found_split_dest) | |
3680 | { | |
3681 | /* Search backwards from FIRST, looking for the first insn that uses | |
3682 | the original dest. Stop if we pass a CODE_LABEL or a JUMP_INSN. | |
3683 | If we find an insn, and it has a REG_DEAD note, then delete the | |
3684 | note. */ | |
3685 | ||
3686 | for (insn = first; insn; insn = PREV_INSN (insn)) | |
3687 | { | |
3688 | if (GET_CODE (insn) == CODE_LABEL | |
3689 | || GET_CODE (insn) == JUMP_INSN) | |
3690 | break; | |
3691 | else if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
3692 | && reg_mentioned_p (orig_dest, insn)) | |
3693 | { | |
3694 | note = find_regno_note (insn, REG_DEAD, REGNO (orig_dest)); | |
3695 | if (note) | |
3696 | remove_note (insn, note); | |
3697 | } | |
3698 | } | |
3699 | } | |
3700 | else if (! found_orig_dest) | |
3701 | { | |
3702 | /* This should never happen. */ | |
3703 | abort (); | |
3704 | } | |
3705 | } | |
3706 | ||
3707 | /* Update reg_n_sets. This is necessary to prevent local alloc from | |
3708 | converting REG_EQUAL notes to REG_EQUIV when splitting has modified | |
3709 | a reg from set once to set multiple times. */ | |
3710 | ||
3711 | { | |
3712 | rtx x = PATTERN (orig_insn); | |
3713 | RTX_CODE code = GET_CODE (x); | |
3714 | ||
3715 | if (code == SET || code == CLOBBER) | |
3716 | update_n_sets (x, -1); | |
3717 | else if (code == PARALLEL) | |
3718 | { | |
3719 | int i; | |
3720 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
3721 | { | |
3722 | code = GET_CODE (XVECEXP (x, 0, i)); | |
3723 | if (code == SET || code == CLOBBER) | |
3724 | update_n_sets (XVECEXP (x, 0, i), -1); | |
3725 | } | |
3726 | } | |
3727 | ||
3728 | for (insn = first; ; insn = NEXT_INSN (insn)) | |
3729 | { | |
3730 | x = PATTERN (insn); | |
3731 | code = GET_CODE (x); | |
3732 | ||
3733 | if (code == SET || code == CLOBBER) | |
3734 | update_n_sets (x, 1); | |
3735 | else if (code == PARALLEL) | |
3736 | { | |
3737 | int i; | |
3738 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
3739 | { | |
3740 | code = GET_CODE (XVECEXP (x, 0, i)); | |
3741 | if (code == SET || code == CLOBBER) | |
3742 | update_n_sets (XVECEXP (x, 0, i), 1); | |
3743 | } | |
3744 | } | |
3745 | ||
3746 | if (insn == last) | |
3747 | break; | |
3748 | } | |
3749 | } | |
3750 | } | |
3751 | ||
3752 | /* The one entry point in this file. DUMP_FILE is the dump file for | |
3753 | this pass. */ | |
3754 | ||
3755 | void | |
3756 | schedule_insns (dump_file) | |
3757 | FILE *dump_file; | |
3758 | { | |
3759 | int max_uid = MAX_INSNS_PER_SPLIT * (get_max_uid () + 1); | |
3760 | int i, b; | |
3761 | rtx insn; | |
3762 | ||
3763 | /* Taking care of this degenerate case makes the rest of | |
3764 | this code simpler. */ | |
3765 | if (n_basic_blocks == 0) | |
3766 | return; | |
3767 | ||
3768 | /* Create an insn here so that we can hang dependencies off of it later. */ | |
fb3821f7 CH |
3769 | sched_before_next_call |
3770 | = gen_rtx (INSN, VOIDmode, 0, NULL_RTX, NULL_RTX, | |
3771 | NULL_RTX, 0, NULL_RTX, 0); | |
bd58420c RK |
3772 | |
3773 | /* Initialize the unused_*_lists. We can't use the ones left over from | |
3774 | the previous function, because gcc has freed that memory. We can use | |
3775 | the ones left over from the first sched pass in the second pass however, | |
3776 | so only clear them on the first sched pass. The first pass is before | |
3777 | reload if flag_schedule_insns is set, otherwise it is afterwards. */ | |
3778 | ||
3779 | if (reload_completed == 0 || ! flag_schedule_insns) | |
3780 | { | |
3781 | unused_insn_list = 0; | |
3782 | unused_expr_list = 0; | |
3783 | } | |
3784 | ||
3785 | /* We create no insns here, only reorder them, so we | |
3786 | remember how far we can cut back the stack on exit. */ | |
3787 | ||
3788 | /* Allocate data for this pass. See comments, above, | |
3789 | for what these vectors do. */ | |
bd58420c RK |
3790 | insn_luid = (int *) alloca (max_uid * sizeof (int)); |
3791 | insn_priority = (int *) alloca (max_uid * sizeof (int)); | |
c3de4fe6 | 3792 | insn_costs = (short *) alloca (max_uid * sizeof (short)); |
bd58420c RK |
3793 | insn_ref_count = (int *) alloca (max_uid * sizeof (int)); |
3794 | ||
3795 | if (reload_completed == 0) | |
3796 | { | |
3797 | sched_reg_n_deaths = (short *) alloca (max_regno * sizeof (short)); | |
3798 | sched_reg_n_calls_crossed = (int *) alloca (max_regno * sizeof (int)); | |
3799 | sched_reg_live_length = (int *) alloca (max_regno * sizeof (int)); | |
3800 | bb_dead_regs = (regset) alloca (regset_bytes); | |
3801 | bb_live_regs = (regset) alloca (regset_bytes); | |
3802 | bzero (sched_reg_n_calls_crossed, max_regno * sizeof (int)); | |
3803 | bzero (sched_reg_live_length, max_regno * sizeof (int)); | |
3804 | bcopy (reg_n_deaths, sched_reg_n_deaths, max_regno * sizeof (short)); | |
3805 | init_alias_analysis (); | |
3806 | } | |
3807 | else | |
3808 | { | |
3809 | sched_reg_n_deaths = 0; | |
3810 | sched_reg_n_calls_crossed = 0; | |
3811 | sched_reg_live_length = 0; | |
3812 | bb_dead_regs = 0; | |
3813 | bb_live_regs = 0; | |
3814 | if (! flag_schedule_insns) | |
3815 | init_alias_analysis (); | |
3816 | } | |
3817 | ||
3818 | if (write_symbols != NO_DEBUG) | |
3819 | { | |
3820 | rtx line; | |
3821 | ||
3822 | line_note = (rtx *) alloca (max_uid * sizeof (rtx)); | |
3823 | bzero (line_note, max_uid * sizeof (rtx)); | |
3824 | line_note_head = (rtx *) alloca (n_basic_blocks * sizeof (rtx)); | |
3825 | bzero (line_note_head, n_basic_blocks * sizeof (rtx)); | |
3826 | ||
3827 | /* Determine the line-number at the start of each basic block. | |
3828 | This must be computed and saved now, because after a basic block's | |
3829 | predecessor has been scheduled, it is impossible to accurately | |
3830 | determine the correct line number for the first insn of the block. */ | |
3831 | ||
3832 | for (b = 0; b < n_basic_blocks; b++) | |
3833 | for (line = basic_block_head[b]; line; line = PREV_INSN (line)) | |
3834 | if (GET_CODE (line) == NOTE && NOTE_LINE_NUMBER (line) > 0) | |
3835 | { | |
3836 | line_note_head[b] = line; | |
3837 | break; | |
3838 | } | |
3839 | } | |
3840 | ||
3841 | bzero (insn_luid, max_uid * sizeof (int)); | |
3842 | bzero (insn_priority, max_uid * sizeof (int)); | |
c3de4fe6 | 3843 | bzero (insn_costs, max_uid * sizeof (short)); |
bd58420c RK |
3844 | bzero (insn_ref_count, max_uid * sizeof (int)); |
3845 | ||
3846 | /* Schedule each basic block, block by block. */ | |
3847 | ||
3848 | if (NEXT_INSN (basic_block_end[n_basic_blocks-1]) == 0 | |
3849 | || (GET_CODE (basic_block_end[n_basic_blocks-1]) != NOTE | |
3850 | && GET_CODE (basic_block_end[n_basic_blocks-1]) != CODE_LABEL)) | |
3851 | emit_note_after (NOTE_INSN_DELETED, basic_block_end[n_basic_blocks-1]); | |
3852 | ||
3853 | for (b = 0; b < n_basic_blocks; b++) | |
3854 | { | |
3855 | rtx insn, next; | |
3856 | rtx insns; | |
3857 | ||
3858 | note_list = 0; | |
3859 | ||
3860 | for (insn = basic_block_head[b]; ; insn = next) | |
3861 | { | |
3862 | rtx prev; | |
3863 | rtx set; | |
3864 | ||
3865 | /* Can't use `next_real_insn' because that | |
3866 | might go across CODE_LABELS and short-out basic blocks. */ | |
3867 | next = NEXT_INSN (insn); | |
3868 | if (GET_CODE (insn) != INSN) | |
3869 | { | |
3870 | if (insn == basic_block_end[b]) | |
3871 | break; | |
3872 | ||
3873 | continue; | |
3874 | } | |
3875 | ||
3876 | /* Don't split no-op move insns. These should silently disappear | |
3877 | later in final. Splitting such insns would break the code | |
3878 | that handles REG_NO_CONFLICT blocks. */ | |
3879 | set = single_set (insn); | |
3880 | if (set && rtx_equal_p (SET_SRC (set), SET_DEST (set))) | |
3881 | { | |
3882 | if (insn == basic_block_end[b]) | |
3883 | break; | |
3884 | ||
3885 | /* Nops get in the way while scheduling, so delete them now if | |
3886 | register allocation has already been done. It is too risky | |
3887 | to try to do this before register allocation, and there are | |
3888 | unlikely to be very many nops then anyways. */ | |
3889 | if (reload_completed) | |
3890 | { | |
3891 | PUT_CODE (insn, NOTE); | |
3892 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
3893 | NOTE_SOURCE_FILE (insn) = 0; | |
3894 | } | |
3895 | ||
3896 | continue; | |
3897 | } | |
3898 | ||
3899 | /* Split insns here to get max fine-grain parallelism. */ | |
3900 | prev = PREV_INSN (insn); | |
3901 | if (reload_completed == 0) | |
3902 | { | |
3903 | rtx last, first = PREV_INSN (insn); | |
3904 | rtx notes = REG_NOTES (insn); | |
3905 | ||
3906 | last = try_split (PATTERN (insn), insn, 1); | |
3907 | if (last != insn) | |
3908 | { | |
3909 | /* try_split returns the NOTE that INSN became. */ | |
3910 | first = NEXT_INSN (first); | |
3911 | update_flow_info (notes, first, last, insn); | |
3912 | ||
3913 | PUT_CODE (insn, NOTE); | |
3914 | NOTE_SOURCE_FILE (insn) = 0; | |
3915 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
3916 | if (insn == basic_block_head[b]) | |
3917 | basic_block_head[b] = first; | |
3918 | if (insn == basic_block_end[b]) | |
3919 | { | |
3920 | basic_block_end[b] = last; | |
3921 | break; | |
3922 | } | |
3923 | } | |
3924 | } | |
3925 | ||
3926 | if (insn == basic_block_end[b]) | |
3927 | break; | |
3928 | } | |
3929 | ||
3930 | schedule_block (b, dump_file); | |
3931 | ||
3932 | #ifdef USE_C_ALLOCA | |
3933 | alloca (0); | |
3934 | #endif | |
3935 | } | |
3936 | ||
bdac5f58 TW |
3937 | /* Reposition the prologue and epilogue notes in case we moved the |
3938 | prologue/epilogue insns. */ | |
3939 | if (reload_completed) | |
3940 | reposition_prologue_and_epilogue_notes (get_insns ()); | |
3941 | ||
bd58420c RK |
3942 | if (write_symbols != NO_DEBUG) |
3943 | { | |
3944 | rtx line = 0; | |
3945 | rtx insn = get_insns (); | |
3946 | int active_insn = 0; | |
3947 | int notes = 0; | |
3948 | ||
3949 | /* Walk the insns deleting redundant line-number notes. Many of these | |
3950 | are already present. The remainder tend to occur at basic | |
3951 | block boundaries. */ | |
3952 | for (insn = get_last_insn (); insn; insn = PREV_INSN (insn)) | |
3953 | if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0) | |
3954 | { | |
3955 | /* If there are no active insns following, INSN is redundant. */ | |
3956 | if (active_insn == 0) | |
3957 | { | |
3958 | notes++; | |
3959 | NOTE_SOURCE_FILE (insn) = 0; | |
3960 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
3961 | } | |
3962 | /* If the line number is unchanged, LINE is redundant. */ | |
3963 | else if (line | |
3964 | && NOTE_LINE_NUMBER (line) == NOTE_LINE_NUMBER (insn) | |
3965 | && NOTE_SOURCE_FILE (line) == NOTE_SOURCE_FILE (insn)) | |
3966 | { | |
3967 | notes++; | |
3968 | NOTE_SOURCE_FILE (line) = 0; | |
3969 | NOTE_LINE_NUMBER (line) = NOTE_INSN_DELETED; | |
3970 | line = insn; | |
3971 | } | |
3972 | else | |
3973 | line = insn; | |
3974 | active_insn = 0; | |
3975 | } | |
3976 | else if (! ((GET_CODE (insn) == NOTE | |
3977 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_DELETED) | |
3978 | || (GET_CODE (insn) == INSN | |
3979 | && (GET_CODE (PATTERN (insn)) == USE | |
3980 | || GET_CODE (PATTERN (insn)) == CLOBBER)))) | |
3981 | active_insn++; | |
3982 | ||
3983 | if (dump_file && notes) | |
3984 | fprintf (dump_file, ";; deleted %d line-number notes\n", notes); | |
3985 | } | |
3986 | ||
3987 | if (reload_completed == 0) | |
3988 | { | |
3989 | int regno; | |
3990 | for (regno = 0; regno < max_regno; regno++) | |
3991 | if (sched_reg_live_length[regno]) | |
3992 | { | |
3993 | if (dump_file) | |
3994 | { | |
3995 | if (reg_live_length[regno] > sched_reg_live_length[regno]) | |
3996 | fprintf (dump_file, | |
3997 | ";; register %d life shortened from %d to %d\n", | |
3998 | regno, reg_live_length[regno], | |
3999 | sched_reg_live_length[regno]); | |
4000 | /* Negative values are special; don't overwrite the current | |
4001 | reg_live_length value if it is negative. */ | |
4002 | else if (reg_live_length[regno] < sched_reg_live_length[regno] | |
4003 | && reg_live_length[regno] >= 0) | |
4004 | fprintf (dump_file, | |
4005 | ";; register %d life extended from %d to %d\n", | |
4006 | regno, reg_live_length[regno], | |
4007 | sched_reg_live_length[regno]); | |
4008 | ||
4009 | if (reg_n_calls_crossed[regno] | |
4010 | && ! sched_reg_n_calls_crossed[regno]) | |
4011 | fprintf (dump_file, | |
4012 | ";; register %d no longer crosses calls\n", regno); | |
4013 | else if (! reg_n_calls_crossed[regno] | |
4014 | && sched_reg_n_calls_crossed[regno]) | |
4015 | fprintf (dump_file, | |
4016 | ";; register %d now crosses calls\n", regno); | |
4017 | } | |
b4ac57ab RS |
4018 | /* Negative values are special; don't overwrite the current |
4019 | reg_live_length value if it is negative. */ | |
4020 | if (reg_live_length[regno] >= 0) | |
4021 | reg_live_length[regno] = sched_reg_live_length[regno]; | |
bd58420c RK |
4022 | reg_n_calls_crossed[regno] = sched_reg_n_calls_crossed[regno]; |
4023 | } | |
4024 | } | |
4025 | } | |
4026 | #endif /* INSN_SCHEDULING */ |