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9bf86ebb PR |
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 either queue it until sufficient time has elapsed | |
50 | or add it to the ready list. As the instructions are scheduled or | |
51 | when stalls are introduced, the queue advances and dumps insns into | |
52 | the ready list. When all insns down to the lowest priority have | |
53 | been scheduled, the critical path of the basic block has been made | |
54 | as short as possible. The remaining insns are then scheduled in | |
55 | remaining slots. | |
56 | ||
57 | Function unit conflicts are resolved during reverse list scheduling | |
58 | by tracking the time when each insn is committed to the schedule | |
59 | and from that, the time the function units it uses must be free. | |
60 | As insns on the ready list are considered for scheduling, those | |
61 | that would result in a blockage of the already committed insns are | |
62 | queued until no blockage will result. Among the remaining insns on | |
63 | the ready list to be considered, the first one with the largest | |
64 | potential for causing a subsequent blockage is chosen. | |
65 | ||
66 | The following list shows the order in which we want to break ties | |
67 | among insns in the ready list: | |
68 | ||
69 | 1. choose insn with lowest conflict cost, ties broken by | |
70 | 2. choose insn with the longest path to end of bb, ties broken by | |
71 | 3. choose insn that kills the most registers, ties broken by | |
72 | 4. choose insn that conflicts with the most ready insns, or finally | |
73 | 5. choose insn with lowest UID. | |
74 | ||
75 | Memory references complicate matters. Only if we can be certain | |
76 | that memory references are not part of the data dependency graph | |
77 | (via true, anti, or output dependence), can we move operations past | |
78 | memory references. To first approximation, reads can be done | |
79 | independently, while writes introduce dependencies. Better | |
80 | approximations will yield fewer dependencies. | |
81 | ||
82 | Dependencies set up by memory references are treated in exactly the | |
83 | same way as other dependencies, by using LOG_LINKS. | |
84 | ||
85 | Having optimized the critical path, we may have also unduly | |
86 | extended the lifetimes of some registers. If an operation requires | |
87 | that constants be loaded into registers, it is certainly desirable | |
88 | to load those constants as early as necessary, but no earlier. | |
89 | I.e., it will not do to load up a bunch of registers at the | |
90 | beginning of a basic block only to use them at the end, if they | |
91 | could be loaded later, since this may result in excessive register | |
92 | utilization. | |
93 | ||
94 | Note that since branches are never in basic blocks, but only end | |
95 | basic blocks, this pass will not do any branch scheduling. But | |
96 | that is ok, since we can use GNU's delayed branch scheduling | |
97 | pass to take care of this case. | |
98 | ||
99 | Also note that no further optimizations based on algebraic identities | |
100 | are performed, so this pass would be a good one to perform instruction | |
101 | splitting, such as breaking up a multiply instruction into shifts | |
102 | and adds where that is profitable. | |
103 | ||
104 | Given the memory aliasing analysis that this pass should perform, | |
105 | it should be possible to remove redundant stores to memory, and to | |
106 | load values from registers instead of hitting memory. | |
107 | ||
108 | This pass must update information that subsequent passes expect to be | |
109 | correct. Namely: reg_n_refs, reg_n_sets, reg_n_deaths, | |
110 | reg_n_calls_crossed, and reg_live_length. Also, basic_block_head, | |
111 | basic_block_end. | |
112 | ||
113 | The information in the line number notes is carefully retained by this | |
114 | pass. All other NOTE insns are grouped in their same relative order at | |
115 | the beginning of basic blocks that have been scheduled. */ | |
116 | \f | |
117 | #include <stdio.h> | |
118 | #include "config.h" | |
119 | #include "rtl.h" | |
120 | #include "basic-block.h" | |
121 | #include "regs.h" | |
122 | #include "hard-reg-set.h" | |
123 | #include "flags.h" | |
124 | #include "insn-config.h" | |
125 | #include "insn-attr.h" | |
126 | ||
127 | #ifdef INSN_SCHEDULING | |
128 | /* Arrays set up by scheduling for the same respective purposes as | |
129 | similar-named arrays set up by flow analysis. We work with these | |
130 | arrays during the scheduling pass so we can compare values against | |
131 | unscheduled code. | |
132 | ||
133 | Values of these arrays are copied at the end of this pass into the | |
134 | arrays set up by flow analysis. */ | |
135 | static short *sched_reg_n_deaths; | |
136 | static int *sched_reg_n_calls_crossed; | |
137 | static int *sched_reg_live_length; | |
138 | ||
139 | /* Element N is the next insn that sets (hard or pseudo) register | |
140 | N within the current basic block; or zero, if there is no | |
141 | such insn. Needed for new registers which may be introduced | |
142 | by splitting insns. */ | |
143 | static rtx *reg_last_uses; | |
144 | static rtx *reg_last_sets; | |
145 | ||
146 | /* Vector indexed by INSN_UID giving the original ordering of the insns. */ | |
147 | static int *insn_luid; | |
148 | #define INSN_LUID(INSN) (insn_luid[INSN_UID (INSN)]) | |
149 | ||
150 | /* Vector indexed by INSN_UID giving each instruction a priority. */ | |
151 | static int *insn_priority; | |
152 | #define INSN_PRIORITY(INSN) (insn_priority[INSN_UID (INSN)]) | |
153 | ||
154 | static short *insn_costs; | |
155 | #define INSN_COST(INSN) insn_costs[INSN_UID (INSN)] | |
156 | ||
157 | /* Vector indexed by INSN_UID giving an encoding of the function units | |
158 | used. */ | |
159 | static short *insn_units; | |
160 | #define INSN_UNIT(INSN) insn_units[INSN_UID (INSN)] | |
161 | ||
162 | /* Vector indexed by INSN_UID giving an encoding of the blockage range | |
163 | function. The unit and the range are encoded. */ | |
164 | static unsigned int *insn_blockage; | |
165 | #define INSN_BLOCKAGE(INSN) insn_blockage[INSN_UID (INSN)] | |
166 | #define UNIT_BITS 5 | |
167 | #define BLOCKAGE_MASK ((1 << BLOCKAGE_BITS) - 1) | |
168 | #define ENCODE_BLOCKAGE(U,R) \ | |
169 | ((((U) << UNIT_BITS) << BLOCKAGE_BITS \ | |
170 | | MIN_BLOCKAGE_COST (R)) << BLOCKAGE_BITS \ | |
171 | | MAX_BLOCKAGE_COST (R)) | |
172 | #define UNIT_BLOCKED(B) ((B) >> (2 * BLOCKAGE_BITS)) | |
173 | #define BLOCKAGE_RANGE(B) \ | |
174 | (((((B) >> BLOCKAGE_BITS) & BLOCKAGE_MASK) << (HOST_BITS_PER_INT / 2)) \ | |
175 | | (B) & BLOCKAGE_MASK) | |
176 | ||
177 | /* Encodings of the `<name>_unit_blockage_range' function. */ | |
178 | #define MIN_BLOCKAGE_COST(R) ((R) >> (HOST_BITS_PER_INT / 2)) | |
179 | #define MAX_BLOCKAGE_COST(R) ((R) & ((1 << (HOST_BITS_PER_INT / 2)) - 1)) | |
180 | ||
181 | #define DONE_PRIORITY -1 | |
182 | #define MAX_PRIORITY 0x7fffffff | |
183 | #define TAIL_PRIORITY 0x7ffffffe | |
184 | #define LAUNCH_PRIORITY 0x7f000001 | |
185 | #define DONE_PRIORITY_P(INSN) (INSN_PRIORITY (INSN) < 0) | |
186 | #define LOW_PRIORITY_P(INSN) ((INSN_PRIORITY (INSN) & 0x7f000000) == 0) | |
187 | ||
188 | /* Vector indexed by INSN_UID giving number of insns referring to this insn. */ | |
189 | static int *insn_ref_count; | |
190 | #define INSN_REF_COUNT(INSN) (insn_ref_count[INSN_UID (INSN)]) | |
191 | ||
192 | /* Vector indexed by INSN_UID giving line-number note in effect for each | |
193 | insn. For line-number notes, this indicates whether the note may be | |
194 | reused. */ | |
195 | static rtx *line_note; | |
196 | #define LINE_NOTE(INSN) (line_note[INSN_UID (INSN)]) | |
197 | ||
198 | /* Vector indexed by basic block number giving the starting line-number | |
199 | for each basic block. */ | |
200 | static rtx *line_note_head; | |
201 | ||
202 | /* List of important notes we must keep around. This is a pointer to the | |
203 | last element in the list. */ | |
204 | static rtx note_list; | |
205 | ||
206 | /* Regsets telling whether a given register is live or dead before the last | |
207 | scheduled insn. Must scan the instructions once before scheduling to | |
208 | determine what registers are live or dead at the end of the block. */ | |
209 | static regset bb_dead_regs; | |
210 | static regset bb_live_regs; | |
211 | ||
212 | /* Regset telling whether a given register is live after the insn currently | |
213 | being scheduled. Before processing an insn, this is equal to bb_live_regs | |
214 | above. This is used so that we can find registers that are newly born/dead | |
215 | after processing an insn. */ | |
216 | static regset old_live_regs; | |
217 | ||
218 | /* The chain of REG_DEAD notes. REG_DEAD notes are removed from all insns | |
219 | during the initial scan and reused later. If there are not exactly as | |
220 | many REG_DEAD notes in the post scheduled code as there were in the | |
221 | prescheduled code then we trigger an abort because this indicates a bug. */ | |
222 | static rtx dead_notes; | |
223 | ||
224 | /* Queues, etc. */ | |
225 | ||
226 | /* An instruction is ready to be scheduled when all insns following it | |
227 | have already been scheduled. It is important to ensure that all | |
228 | insns which use its result will not be executed until its result | |
229 | has been computed. An insn is maintained in one of four structures: | |
230 | ||
231 | (P) the "Pending" set of insns which cannot be scheduled until | |
232 | their dependencies have been satisfied. | |
233 | (Q) the "Queued" set of insns that can be scheduled when sufficient | |
234 | time has passed. | |
235 | (R) the "Ready" list of unscheduled, uncommitted insns. | |
236 | (S) the "Scheduled" list of insns. | |
237 | ||
238 | Initially, all insns are either "Pending" or "Ready" depending on | |
239 | whether their dependencies are satisfied. | |
240 | ||
241 | Insns move from the "Ready" list to the "Scheduled" list as they | |
242 | are committed to the schedule. As this occurs, the insns in the | |
243 | "Pending" list have their dependencies satisfied and move to either | |
244 | the "Ready" list or the "Queued" set depending on whether | |
245 | sufficient time has passed to make them ready. As time passes, | |
246 | insns move from the "Queued" set to the "Ready" list. Insns may | |
247 | move from the "Ready" list to the "Queued" set if they are blocked | |
248 | due to a function unit conflict. | |
249 | ||
250 | The "Pending" list (P) are the insns in the LOG_LINKS of the unscheduled | |
251 | insns, i.e., those that are ready, queued, and pending. | |
252 | The "Queued" set (Q) is implemented by the variable `insn_queue'. | |
253 | The "Ready" list (R) is implemented by the variables `ready' and | |
254 | `n_ready'. | |
255 | The "Scheduled" list (S) is the new insn chain built by this pass. | |
256 | ||
257 | The transition (R->S) is implemented in the scheduling loop in | |
258 | `schedule_block' when the best insn to schedule is chosen. | |
259 | The transition (R->Q) is implemented in `schedule_select' when an | |
260 | insn is found to to have a function unit conflict with the already | |
261 | committed insns. | |
262 | The transitions (P->R and P->Q) are implemented in `schedule_insn' as | |
263 | insns move from the ready list to the scheduled list. | |
264 | The transition (Q->R) is implemented at the top of the scheduling | |
265 | loop in `schedule_block' as time passes or stalls are introduced. */ | |
266 | ||
267 | /* Implement a circular buffer to delay instructions until sufficient | |
268 | time has passed. INSN_QUEUE_SIZE is a power of two larger than | |
269 | MAX_BLOCKAGE and MAX_READY_COST computed by genattr.c. This is the | |
270 | longest time an isnsn may be queued. */ | |
271 | static rtx insn_queue[INSN_QUEUE_SIZE]; | |
272 | static int q_ptr = 0; | |
273 | static int q_size = 0; | |
274 | #define NEXT_Q(X) (((X)+1) & (INSN_QUEUE_SIZE-1)) | |
275 | #define NEXT_Q_AFTER(X,C) (((X)+C) & (INSN_QUEUE_SIZE-1)) | |
276 | ||
277 | /* Vector indexed by INSN_UID giving the minimum clock tick at which | |
278 | the insn becomes ready. This is used to note timing constraints for | |
279 | insns in the pending list. */ | |
280 | static int *insn_tick; | |
281 | #define INSN_TICK(INSN) (insn_tick[INSN_UID (INSN)]) | |
282 | ||
283 | /* Forward declarations. */ | |
284 | static void sched_analyze_2 (); | |
285 | static void schedule_block (); | |
286 | ||
287 | /* Main entry point of this file. */ | |
288 | void schedule_insns (); | |
289 | #endif /* INSN_SCHEDULING */ | |
290 | \f | |
291 | #define SIZE_FOR_MODE(X) (GET_MODE_SIZE (GET_MODE (X))) | |
292 | ||
293 | /* Vector indexed by N giving the initial (unchanging) value known | |
294 | for pseudo-register N. */ | |
295 | static rtx *reg_known_value; | |
296 | ||
297 | /* Vector recording for each reg_known_value whether it is due to a | |
298 | REG_EQUIV note. Future passes (viz., reload) may replace the | |
299 | pseudo with the equivalent expression and so we account for the | |
300 | dependences that would be introduced if that happens. */ | |
301 | /* ??? This is a problem only on the Convex. The REG_EQUIV notes created in | |
302 | assign_parms mention the arg pointer, and there are explicit insns in the | |
303 | RTL that modify the arg pointer. Thus we must ensure that such insns don't | |
304 | get scheduled across each other because that would invalidate the REG_EQUIV | |
305 | notes. One could argue that the REG_EQUIV notes are wrong, but solving | |
306 | the problem in the scheduler will likely give better code, so we do it | |
307 | here. */ | |
308 | static char *reg_known_equiv_p; | |
309 | ||
310 | /* Indicates number of valid entries in reg_known_value. */ | |
311 | static int reg_known_value_size; | |
312 | ||
313 | static rtx | |
314 | canon_rtx (x) | |
315 | rtx x; | |
316 | { | |
317 | if (GET_CODE (x) == REG && REGNO (x) >= FIRST_PSEUDO_REGISTER | |
318 | && REGNO (x) <= reg_known_value_size) | |
319 | return reg_known_value[REGNO (x)]; | |
320 | else if (GET_CODE (x) == PLUS) | |
321 | { | |
322 | rtx x0 = canon_rtx (XEXP (x, 0)); | |
323 | rtx x1 = canon_rtx (XEXP (x, 1)); | |
324 | ||
325 | if (x0 != XEXP (x, 0) || x1 != XEXP (x, 1)) | |
326 | { | |
327 | /* We can tolerate LO_SUMs being offset here; these | |
328 | rtl are used for nothing other than comparisons. */ | |
329 | if (GET_CODE (x0) == CONST_INT) | |
330 | return plus_constant_for_output (x1, INTVAL (x0)); | |
331 | else if (GET_CODE (x1) == CONST_INT) | |
332 | return plus_constant_for_output (x0, INTVAL (x1)); | |
333 | return gen_rtx (PLUS, GET_MODE (x), x0, x1); | |
334 | } | |
335 | } | |
336 | return x; | |
337 | } | |
338 | ||
339 | /* Set up all info needed to perform alias analysis on memory references. */ | |
340 | ||
341 | void | |
342 | init_alias_analysis () | |
343 | { | |
344 | int maxreg = max_reg_num (); | |
345 | rtx insn; | |
346 | rtx note; | |
347 | rtx set; | |
348 | ||
349 | reg_known_value_size = maxreg; | |
350 | ||
351 | reg_known_value | |
352 | = (rtx *) oballoc ((maxreg-FIRST_PSEUDO_REGISTER) * sizeof (rtx)) | |
353 | - FIRST_PSEUDO_REGISTER; | |
354 | bzero (reg_known_value+FIRST_PSEUDO_REGISTER, | |
355 | (maxreg-FIRST_PSEUDO_REGISTER) * sizeof (rtx)); | |
356 | ||
357 | reg_known_equiv_p | |
358 | = (char *) oballoc ((maxreg-FIRST_PSEUDO_REGISTER) * sizeof (char)) | |
359 | - FIRST_PSEUDO_REGISTER; | |
360 | bzero (reg_known_equiv_p+FIRST_PSEUDO_REGISTER, | |
361 | (maxreg-FIRST_PSEUDO_REGISTER) * sizeof (char)); | |
362 | ||
363 | /* Fill in the entries with known constant values. */ | |
364 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) | |
365 | if ((set = single_set (insn)) != 0 | |
366 | && GET_CODE (SET_DEST (set)) == REG | |
367 | && REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER | |
368 | && (((note = find_reg_note (insn, REG_EQUAL, 0)) != 0 | |
369 | && reg_n_sets[REGNO (SET_DEST (set))] == 1) | |
370 | || (note = find_reg_note (insn, REG_EQUIV, NULL_RTX)) != 0) | |
371 | && GET_CODE (XEXP (note, 0)) != EXPR_LIST) | |
372 | { | |
373 | int regno = REGNO (SET_DEST (set)); | |
374 | reg_known_value[regno] = XEXP (note, 0); | |
375 | reg_known_equiv_p[regno] = REG_NOTE_KIND (note) == REG_EQUIV; | |
376 | } | |
377 | ||
378 | /* Fill in the remaining entries. */ | |
379 | while (--maxreg >= FIRST_PSEUDO_REGISTER) | |
380 | if (reg_known_value[maxreg] == 0) | |
381 | reg_known_value[maxreg] = regno_reg_rtx[maxreg]; | |
382 | } | |
383 | ||
384 | /* Return 1 if X and Y are identical-looking rtx's. | |
385 | ||
386 | We use the data in reg_known_value above to see if two registers with | |
387 | different numbers are, in fact, equivalent. */ | |
388 | ||
389 | static int | |
390 | rtx_equal_for_memref_p (x, y) | |
391 | rtx x, y; | |
392 | { | |
393 | register int i; | |
394 | register int j; | |
395 | register enum rtx_code code; | |
396 | register char *fmt; | |
397 | ||
398 | if (x == 0 && y == 0) | |
399 | return 1; | |
400 | if (x == 0 || y == 0) | |
401 | return 0; | |
402 | x = canon_rtx (x); | |
403 | y = canon_rtx (y); | |
404 | ||
405 | if (x == y) | |
406 | return 1; | |
407 | ||
408 | code = GET_CODE (x); | |
409 | /* Rtx's of different codes cannot be equal. */ | |
410 | if (code != GET_CODE (y)) | |
411 | return 0; | |
412 | ||
413 | /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. | |
414 | (REG:SI x) and (REG:HI x) are NOT equivalent. */ | |
415 | ||
416 | if (GET_MODE (x) != GET_MODE (y)) | |
417 | return 0; | |
418 | ||
419 | /* REG, LABEL_REF, and SYMBOL_REF can be compared nonrecursively. */ | |
420 | ||
421 | if (code == REG) | |
422 | return REGNO (x) == REGNO (y); | |
423 | if (code == LABEL_REF) | |
424 | return XEXP (x, 0) == XEXP (y, 0); | |
425 | if (code == SYMBOL_REF) | |
426 | return XSTR (x, 0) == XSTR (y, 0); | |
427 | ||
428 | /* Compare the elements. If any pair of corresponding elements | |
429 | fail to match, return 0 for the whole things. */ | |
430 | ||
431 | fmt = GET_RTX_FORMAT (code); | |
432 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
433 | { | |
434 | switch (fmt[i]) | |
435 | { | |
436 | case 'w': | |
437 | if (XWINT (x, i) != XWINT (y, i)) | |
438 | return 0; | |
439 | break; | |
440 | ||
441 | case 'n': | |
442 | case 'i': | |
443 | if (XINT (x, i) != XINT (y, i)) | |
444 | return 0; | |
445 | break; | |
446 | ||
447 | case 'V': | |
448 | case 'E': | |
449 | /* Two vectors must have the same length. */ | |
450 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
451 | return 0; | |
452 | ||
453 | /* And the corresponding elements must match. */ | |
454 | for (j = 0; j < XVECLEN (x, i); j++) | |
455 | if (rtx_equal_for_memref_p (XVECEXP (x, i, j), XVECEXP (y, i, j)) == 0) | |
456 | return 0; | |
457 | break; | |
458 | ||
459 | case 'e': | |
460 | if (rtx_equal_for_memref_p (XEXP (x, i), XEXP (y, i)) == 0) | |
461 | return 0; | |
462 | break; | |
463 | ||
464 | case 'S': | |
465 | case 's': | |
466 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
467 | return 0; | |
468 | break; | |
469 | ||
470 | case 'u': | |
471 | /* These are just backpointers, so they don't matter. */ | |
472 | break; | |
473 | ||
474 | case '0': | |
475 | break; | |
476 | ||
477 | /* It is believed that rtx's at this level will never | |
478 | contain anything but integers and other rtx's, | |
479 | except for within LABEL_REFs and SYMBOL_REFs. */ | |
480 | default: | |
481 | abort (); | |
482 | } | |
483 | } | |
484 | return 1; | |
485 | } | |
486 | ||
487 | /* Given an rtx X, find a SYMBOL_REF or LABEL_REF within | |
488 | X and return it, or return 0 if none found. */ | |
489 | ||
490 | static rtx | |
491 | find_symbolic_term (x) | |
492 | rtx x; | |
493 | { | |
494 | register int i; | |
495 | register enum rtx_code code; | |
496 | register char *fmt; | |
497 | ||
498 | code = GET_CODE (x); | |
499 | if (code == SYMBOL_REF || code == LABEL_REF) | |
500 | return x; | |
501 | if (GET_RTX_CLASS (code) == 'o') | |
502 | return 0; | |
503 | ||
504 | fmt = GET_RTX_FORMAT (code); | |
505 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
506 | { | |
507 | rtx t; | |
508 | ||
509 | if (fmt[i] == 'e') | |
510 | { | |
511 | t = find_symbolic_term (XEXP (x, i)); | |
512 | if (t != 0) | |
513 | return t; | |
514 | } | |
515 | else if (fmt[i] == 'E') | |
516 | break; | |
517 | } | |
518 | return 0; | |
519 | } | |
520 | ||
521 | /* Return nonzero if X and Y (memory addresses) could reference the | |
522 | same location in memory. C is an offset accumulator. When | |
523 | C is nonzero, we are testing aliases between X and Y + C. | |
524 | XSIZE is the size in bytes of the X reference, | |
525 | similarly YSIZE is the size in bytes for Y. | |
526 | ||
527 | If XSIZE or YSIZE is zero, we do not know the amount of memory being | |
528 | referenced (the reference was BLKmode), so make the most pessimistic | |
529 | assumptions. | |
530 | ||
531 | We recognize the following cases of non-conflicting memory: | |
532 | ||
533 | (1) addresses involving the frame pointer cannot conflict | |
534 | with addresses involving static variables. | |
535 | (2) static variables with different addresses cannot conflict. | |
536 | ||
537 | Nice to notice that varying addresses cannot conflict with fp if no | |
538 | local variables had their addresses taken, but that's too hard now. */ | |
539 | ||
540 | /* ??? In Fortran, references to a array parameter can never conflict with | |
541 | another array parameter. */ | |
542 | ||
543 | static int | |
544 | memrefs_conflict_p (xsize, x, ysize, y, c) | |
545 | rtx x, y; | |
546 | int xsize, ysize; | |
547 | HOST_WIDE_INT c; | |
548 | { | |
549 | if (GET_CODE (x) == HIGH) | |
550 | x = XEXP (x, 0); | |
551 | else if (GET_CODE (x) == LO_SUM) | |
552 | x = XEXP (x, 1); | |
553 | else | |
554 | x = canon_rtx (x); | |
555 | if (GET_CODE (y) == HIGH) | |
556 | y = XEXP (y, 0); | |
557 | else if (GET_CODE (y) == LO_SUM) | |
558 | y = XEXP (y, 1); | |
559 | else | |
560 | y = canon_rtx (y); | |
561 | ||
562 | if (rtx_equal_for_memref_p (x, y)) | |
563 | return (xsize == 0 || ysize == 0 || | |
564 | (c >= 0 && xsize > c) || (c < 0 && ysize+c > 0)); | |
565 | ||
566 | if (y == frame_pointer_rtx || y == stack_pointer_rtx) | |
567 | { | |
568 | rtx t = y; | |
569 | int tsize = ysize; | |
570 | y = x; ysize = xsize; | |
571 | x = t; xsize = tsize; | |
572 | } | |
573 | ||
574 | if (x == frame_pointer_rtx || x == stack_pointer_rtx) | |
575 | { | |
576 | rtx y1; | |
577 | ||
578 | if (CONSTANT_P (y)) | |
579 | return 0; | |
580 | ||
581 | if (GET_CODE (y) == PLUS | |
582 | && canon_rtx (XEXP (y, 0)) == x | |
583 | && (y1 = canon_rtx (XEXP (y, 1))) | |
584 | && GET_CODE (y1) == CONST_INT) | |
585 | { | |
586 | c += INTVAL (y1); | |
587 | return (xsize == 0 || ysize == 0 | |
588 | || (c >= 0 && xsize > c) || (c < 0 && ysize+c > 0)); | |
589 | } | |
590 | ||
591 | if (GET_CODE (y) == PLUS | |
592 | && (y1 = canon_rtx (XEXP (y, 0))) | |
593 | && CONSTANT_P (y1)) | |
594 | return 0; | |
595 | ||
596 | return 1; | |
597 | } | |
598 | ||
599 | if (GET_CODE (x) == PLUS) | |
600 | { | |
601 | /* The fact that X is canonicalized means that this | |
602 | PLUS rtx is canonicalized. */ | |
603 | rtx x0 = XEXP (x, 0); | |
604 | rtx x1 = XEXP (x, 1); | |
605 | ||
606 | if (GET_CODE (y) == PLUS) | |
607 | { | |
608 | /* The fact that Y is canonicalized means that this | |
609 | PLUS rtx is canonicalized. */ | |
610 | rtx y0 = XEXP (y, 0); | |
611 | rtx y1 = XEXP (y, 1); | |
612 | ||
613 | if (rtx_equal_for_memref_p (x1, y1)) | |
614 | return memrefs_conflict_p (xsize, x0, ysize, y0, c); | |
615 | if (rtx_equal_for_memref_p (x0, y0)) | |
616 | return memrefs_conflict_p (xsize, x1, ysize, y1, c); | |
617 | if (GET_CODE (x1) == CONST_INT) | |
618 | if (GET_CODE (y1) == CONST_INT) | |
619 | return memrefs_conflict_p (xsize, x0, ysize, y0, | |
620 | c - INTVAL (x1) + INTVAL (y1)); | |
621 | else | |
622 | return memrefs_conflict_p (xsize, x0, ysize, y, c - INTVAL (x1)); | |
623 | else if (GET_CODE (y1) == CONST_INT) | |
624 | return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1)); | |
625 | ||
626 | /* Handle case where we cannot understand iteration operators, | |
627 | but we notice that the base addresses are distinct objects. */ | |
628 | x = find_symbolic_term (x); | |
629 | if (x == 0) | |
630 | return 1; | |
631 | y = find_symbolic_term (y); | |
632 | if (y == 0) | |
633 | return 1; | |
634 | return rtx_equal_for_memref_p (x, y); | |
635 | } | |
636 | else if (GET_CODE (x1) == CONST_INT) | |
637 | return memrefs_conflict_p (xsize, x0, ysize, y, c - INTVAL (x1)); | |
638 | } | |
639 | else if (GET_CODE (y) == PLUS) | |
640 | { | |
641 | /* The fact that Y is canonicalized means that this | |
642 | PLUS rtx is canonicalized. */ | |
643 | rtx y0 = XEXP (y, 0); | |
644 | rtx y1 = XEXP (y, 1); | |
645 | ||
646 | if (GET_CODE (y1) == CONST_INT) | |
647 | return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1)); | |
648 | else | |
649 | return 1; | |
650 | } | |
651 | ||
652 | if (GET_CODE (x) == GET_CODE (y)) | |
653 | switch (GET_CODE (x)) | |
654 | { | |
655 | case MULT: | |
656 | { | |
657 | /* Handle cases where we expect the second operands to be the | |
658 | same, and check only whether the first operand would conflict | |
659 | or not. */ | |
660 | rtx x0, y0; | |
661 | rtx x1 = canon_rtx (XEXP (x, 1)); | |
662 | rtx y1 = canon_rtx (XEXP (y, 1)); | |
663 | if (! rtx_equal_for_memref_p (x1, y1)) | |
664 | return 1; | |
665 | x0 = canon_rtx (XEXP (x, 0)); | |
666 | y0 = canon_rtx (XEXP (y, 0)); | |
667 | if (rtx_equal_for_memref_p (x0, y0)) | |
668 | return (xsize == 0 || ysize == 0 | |
669 | || (c >= 0 && xsize > c) || (c < 0 && ysize+c > 0)); | |
670 | ||
671 | /* Can't properly adjust our sizes. */ | |
672 | if (GET_CODE (x1) != CONST_INT) | |
673 | return 1; | |
674 | xsize /= INTVAL (x1); | |
675 | ysize /= INTVAL (x1); | |
676 | c /= INTVAL (x1); | |
677 | return memrefs_conflict_p (xsize, x0, ysize, y0, c); | |
678 | } | |
679 | } | |
680 | ||
681 | if (CONSTANT_P (x)) | |
682 | { | |
683 | if (GET_CODE (x) == CONST_INT && GET_CODE (y) == CONST_INT) | |
684 | { | |
685 | c += (INTVAL (y) - INTVAL (x)); | |
686 | return (xsize == 0 || ysize == 0 | |
687 | || (c >= 0 && xsize > c) || (c < 0 && ysize+c > 0)); | |
688 | } | |
689 | ||
690 | if (GET_CODE (x) == CONST) | |
691 | { | |
692 | if (GET_CODE (y) == CONST) | |
693 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), | |
694 | ysize, canon_rtx (XEXP (y, 0)), c); | |
695 | else | |
696 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), | |
697 | ysize, y, c); | |
698 | } | |
699 | if (GET_CODE (y) == CONST) | |
700 | return memrefs_conflict_p (xsize, x, ysize, | |
701 | canon_rtx (XEXP (y, 0)), c); | |
702 | ||
703 | if (CONSTANT_P (y)) | |
704 | return (rtx_equal_for_memref_p (x, y) | |
705 | && (xsize == 0 || ysize == 0 | |
706 | || (c >= 0 && xsize > c) || (c < 0 && ysize+c > 0))); | |
707 | ||
708 | return 1; | |
709 | } | |
710 | return 1; | |
711 | } | |
712 | ||
713 | /* Functions to compute memory dependencies. | |
714 | ||
715 | Since we process the insns in execution order, we can build tables | |
716 | to keep track of what registers are fixed (and not aliased), what registers | |
717 | are varying in known ways, and what registers are varying in unknown | |
718 | ways. | |
719 | ||
720 | If both memory references are volatile, then there must always be a | |
721 | dependence between the two references, since their order can not be | |
722 | changed. A volatile and non-volatile reference can be interchanged | |
723 | though. | |
724 | ||
725 | A MEM_IN_STRUCT reference at a non-QImode varying address can never | |
726 | conflict with a non-MEM_IN_STRUCT reference at a fixed address. We must | |
727 | allow QImode aliasing because the ANSI C standard allows character | |
728 | pointers to alias anything. We are assuming that characters are | |
729 | always QImode here. */ | |
730 | ||
731 | /* Read dependence: X is read after read in MEM takes place. There can | |
732 | only be a dependence here if both reads are volatile. */ | |
733 | ||
734 | int | |
735 | read_dependence (mem, x) | |
736 | rtx mem; | |
737 | rtx x; | |
738 | { | |
739 | return MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem); | |
740 | } | |
741 | ||
742 | /* True dependence: X is read after store in MEM takes place. */ | |
743 | ||
744 | int | |
745 | true_dependence (mem, x) | |
746 | rtx mem; | |
747 | rtx x; | |
748 | { | |
749 | /* If X is an unchanging read, then it can't possibly conflict with any | |
750 | non-unchanging store. It may conflict with an unchanging write though, | |
751 | because there may be a single store to this address to initialize it. | |
752 | Just fall through to the code below to resolve the case where we have | |
753 | both an unchanging read and an unchanging write. This won't handle all | |
754 | cases optimally, but the possible performance loss should be | |
755 | negligible. */ | |
756 | if (RTX_UNCHANGING_P (x) && ! RTX_UNCHANGING_P (mem)) | |
757 | return 0; | |
758 | ||
759 | return ((MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) | |
760 | || (memrefs_conflict_p (SIZE_FOR_MODE (mem), XEXP (mem, 0), | |
761 | SIZE_FOR_MODE (x), XEXP (x, 0), 0) | |
762 | && ! (MEM_IN_STRUCT_P (mem) && rtx_addr_varies_p (mem) | |
763 | && GET_MODE (mem) != QImode | |
764 | && ! MEM_IN_STRUCT_P (x) && ! rtx_addr_varies_p (x)) | |
765 | && ! (MEM_IN_STRUCT_P (x) && rtx_addr_varies_p (x) | |
766 | && GET_MODE (x) != QImode | |
767 | && ! MEM_IN_STRUCT_P (mem) && ! rtx_addr_varies_p (mem)))); | |
768 | } | |
769 | ||
770 | /* Anti dependence: X is written after read in MEM takes place. */ | |
771 | ||
772 | int | |
773 | anti_dependence (mem, x) | |
774 | rtx mem; | |
775 | rtx x; | |
776 | { | |
777 | /* If MEM is an unchanging read, then it can't possibly conflict with | |
778 | the store to X, because there is at most one store to MEM, and it must | |
779 | have occured somewhere before MEM. */ | |
780 | if (RTX_UNCHANGING_P (mem)) | |
781 | return 0; | |
782 | ||
783 | return ((MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) | |
784 | || (memrefs_conflict_p (SIZE_FOR_MODE (mem), XEXP (mem, 0), | |
785 | SIZE_FOR_MODE (x), XEXP (x, 0), 0) | |
786 | && ! (MEM_IN_STRUCT_P (mem) && rtx_addr_varies_p (mem) | |
787 | && GET_MODE (mem) != QImode | |
788 | && ! MEM_IN_STRUCT_P (x) && ! rtx_addr_varies_p (x)) | |
789 | && ! (MEM_IN_STRUCT_P (x) && rtx_addr_varies_p (x) | |
790 | && GET_MODE (x) != QImode | |
791 | && ! MEM_IN_STRUCT_P (mem) && ! rtx_addr_varies_p (mem)))); | |
792 | } | |
793 | ||
794 | /* Output dependence: X is written after store in MEM takes place. */ | |
795 | ||
796 | int | |
797 | output_dependence (mem, x) | |
798 | rtx mem; | |
799 | rtx x; | |
800 | { | |
801 | return ((MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) | |
802 | || (memrefs_conflict_p (SIZE_FOR_MODE (mem), XEXP (mem, 0), | |
803 | SIZE_FOR_MODE (x), XEXP (x, 0), 0) | |
804 | && ! (MEM_IN_STRUCT_P (mem) && rtx_addr_varies_p (mem) | |
805 | && GET_MODE (mem) != QImode | |
806 | && ! MEM_IN_STRUCT_P (x) && ! rtx_addr_varies_p (x)) | |
807 | && ! (MEM_IN_STRUCT_P (x) && rtx_addr_varies_p (x) | |
808 | && GET_MODE (x) != QImode | |
809 | && ! MEM_IN_STRUCT_P (mem) && ! rtx_addr_varies_p (mem)))); | |
810 | } | |
811 | \f | |
812 | /* Helper functions for instruction scheduling. */ | |
813 | ||
814 | /* Add ELEM wrapped in an INSN_LIST with reg note kind DEP_TYPE to the | |
815 | LOG_LINKS of INSN, if not already there. DEP_TYPE indicates the type | |
816 | of dependence that this link represents. */ | |
817 | ||
818 | void | |
819 | add_dependence (insn, elem, dep_type) | |
820 | rtx insn; | |
821 | rtx elem; | |
822 | enum reg_note dep_type; | |
823 | { | |
824 | rtx link, next; | |
825 | ||
826 | /* Don't depend an insn on itself. */ | |
827 | if (insn == elem) | |
828 | return; | |
829 | ||
830 | /* If elem is part of a sequence that must be scheduled together, then | |
831 | make the dependence point to the last insn of the sequence. | |
832 | When HAVE_cc0, it is possible for NOTEs to exist between users and | |
833 | setters of the condition codes, so we must skip past notes here. | |
834 | Otherwise, NOTEs are impossible here. */ | |
835 | ||
836 | next = NEXT_INSN (elem); | |
837 | ||
838 | #ifdef HAVE_cc0 | |
839 | while (next && GET_CODE (next) == NOTE) | |
840 | next = NEXT_INSN (next); | |
841 | #endif | |
842 | ||
843 | if (next && SCHED_GROUP_P (next)) | |
844 | { | |
845 | /* Notes will never intervene here though, so don't bother checking | |
846 | for them. */ | |
2a5f595d PR |
847 | /* We must reject CODE_LABELs, so that we don't get confused by one |
848 | that has LABEL_PRESERVE_P set, which is represented by the same | |
849 | bit in the rtl as SCHED_GROUP_P. A CODE_LABEL can never be | |
850 | SCHED_GROUP_P. */ | |
851 | while (NEXT_INSN (next) && SCHED_GROUP_P (NEXT_INSN (next)) | |
852 | && GET_CODE (NEXT_INSN (next)) != CODE_LABEL) | |
9bf86ebb PR |
853 | next = NEXT_INSN (next); |
854 | ||
855 | /* Again, don't depend an insn on itself. */ | |
856 | if (insn == next) | |
857 | return; | |
858 | ||
859 | /* Make the dependence to NEXT, the last insn of the group, instead | |
860 | of the original ELEM. */ | |
861 | elem = next; | |
862 | } | |
863 | ||
864 | /* Check that we don't already have this dependence. */ | |
865 | for (link = LOG_LINKS (insn); link; link = XEXP (link, 1)) | |
866 | if (XEXP (link, 0) == elem) | |
867 | { | |
868 | /* If this is a more restrictive type of dependence than the existing | |
869 | one, then change the existing dependence to this type. */ | |
870 | if ((int) dep_type < (int) REG_NOTE_KIND (link)) | |
871 | PUT_REG_NOTE_KIND (link, dep_type); | |
872 | return; | |
873 | } | |
874 | /* Might want to check one level of transitivity to save conses. */ | |
875 | ||
876 | link = rtx_alloc (INSN_LIST); | |
877 | /* Insn dependency, not data dependency. */ | |
878 | PUT_REG_NOTE_KIND (link, dep_type); | |
879 | XEXP (link, 0) = elem; | |
880 | XEXP (link, 1) = LOG_LINKS (insn); | |
881 | LOG_LINKS (insn) = link; | |
882 | } | |
883 | ||
884 | /* Remove ELEM wrapped in an INSN_LIST from the LOG_LINKS | |
885 | of INSN. Abort if not found. */ | |
886 | void | |
887 | remove_dependence (insn, elem) | |
888 | rtx insn; | |
889 | rtx elem; | |
890 | { | |
891 | rtx prev, link; | |
892 | int found = 0; | |
893 | ||
894 | for (prev = 0, link = LOG_LINKS (insn); link; | |
895 | prev = link, link = XEXP (link, 1)) | |
896 | { | |
897 | if (XEXP (link, 0) == elem) | |
898 | { | |
899 | if (prev) | |
900 | XEXP (prev, 1) = XEXP (link, 1); | |
901 | else | |
902 | LOG_LINKS (insn) = XEXP (link, 1); | |
903 | found = 1; | |
904 | } | |
905 | } | |
906 | ||
907 | if (! found) | |
908 | abort (); | |
909 | return; | |
910 | } | |
911 | \f | |
912 | #ifndef INSN_SCHEDULING | |
913 | void schedule_insns () {} | |
914 | #else | |
915 | #ifndef __GNUC__ | |
916 | #define __inline | |
917 | #endif | |
918 | ||
919 | /* Computation of memory dependencies. */ | |
920 | ||
921 | /* The *_insns and *_mems are paired lists. Each pending memory operation | |
922 | will have a pointer to the MEM rtx on one list and a pointer to the | |
923 | containing insn on the other list in the same place in the list. */ | |
924 | ||
925 | /* We can't use add_dependence like the old code did, because a single insn | |
926 | may have multiple memory accesses, and hence needs to be on the list | |
927 | once for each memory access. Add_dependence won't let you add an insn | |
928 | to a list more than once. */ | |
929 | ||
930 | /* An INSN_LIST containing all insns with pending read operations. */ | |
931 | static rtx pending_read_insns; | |
932 | ||
933 | /* An EXPR_LIST containing all MEM rtx's which are pending reads. */ | |
934 | static rtx pending_read_mems; | |
935 | ||
936 | /* An INSN_LIST containing all insns with pending write operations. */ | |
937 | static rtx pending_write_insns; | |
938 | ||
939 | /* An EXPR_LIST containing all MEM rtx's which are pending writes. */ | |
940 | static rtx pending_write_mems; | |
941 | ||
942 | /* Indicates the combined length of the two pending lists. We must prevent | |
943 | these lists from ever growing too large since the number of dependencies | |
944 | produced is at least O(N*N), and execution time is at least O(4*N*N), as | |
945 | a function of the length of these pending lists. */ | |
946 | ||
947 | static int pending_lists_length; | |
948 | ||
949 | /* An INSN_LIST containing all INSN_LISTs allocated but currently unused. */ | |
950 | ||
951 | static rtx unused_insn_list; | |
952 | ||
953 | /* An EXPR_LIST containing all EXPR_LISTs allocated but currently unused. */ | |
954 | ||
955 | static rtx unused_expr_list; | |
956 | ||
957 | /* The last insn upon which all memory references must depend. | |
958 | This is an insn which flushed the pending lists, creating a dependency | |
959 | between it and all previously pending memory references. This creates | |
960 | a barrier (or a checkpoint) which no memory reference is allowed to cross. | |
961 | ||
962 | This includes all non constant CALL_INSNs. When we do interprocedural | |
963 | alias analysis, this restriction can be relaxed. | |
964 | This may also be an INSN that writes memory if the pending lists grow | |
965 | too large. */ | |
966 | ||
967 | static rtx last_pending_memory_flush; | |
968 | ||
969 | /* The last function call we have seen. All hard regs, and, of course, | |
970 | the last function call, must depend on this. */ | |
971 | ||
972 | static rtx last_function_call; | |
973 | ||
974 | /* The LOG_LINKS field of this is a list of insns which use a pseudo register | |
975 | that does not already cross a call. We create dependencies between each | |
976 | of those insn and the next call insn, to ensure that they won't cross a call | |
977 | after scheduling is done. */ | |
978 | ||
979 | static rtx sched_before_next_call; | |
980 | ||
981 | /* Pointer to the last instruction scheduled. Used by rank_for_schedule, | |
982 | so that insns independent of the last scheduled insn will be preferred | |
983 | over dependent instructions. */ | |
984 | ||
985 | static rtx last_scheduled_insn; | |
986 | ||
987 | /* Process an insn's memory dependencies. There are four kinds of | |
988 | dependencies: | |
989 | ||
990 | (0) read dependence: read follows read | |
991 | (1) true dependence: read follows write | |
992 | (2) anti dependence: write follows read | |
993 | (3) output dependence: write follows write | |
994 | ||
995 | We are careful to build only dependencies which actually exist, and | |
996 | use transitivity to avoid building too many links. */ | |
997 | \f | |
998 | /* Return the INSN_LIST containing INSN in LIST, or NULL | |
999 | if LIST does not contain INSN. */ | |
1000 | ||
1001 | __inline static rtx | |
1002 | find_insn_list (insn, list) | |
1003 | rtx insn; | |
1004 | rtx list; | |
1005 | { | |
1006 | while (list) | |
1007 | { | |
1008 | if (XEXP (list, 0) == insn) | |
1009 | return list; | |
1010 | list = XEXP (list, 1); | |
1011 | } | |
1012 | return 0; | |
1013 | } | |
1014 | ||
1015 | /* Compute the function units used by INSN. This caches the value | |
1016 | returned by function_units_used. A function unit is encoded as the | |
1017 | unit number if the value is non-negative and the compliment of a | |
1018 | mask if the value is negative. A function unit index is the | |
1019 | non-negative encoding. */ | |
1020 | ||
1021 | __inline static int | |
1022 | insn_unit (insn) | |
1023 | rtx insn; | |
1024 | { | |
1025 | register int unit = INSN_UNIT (insn); | |
1026 | ||
1027 | if (unit == 0) | |
1028 | { | |
1029 | recog_memoized (insn); | |
1030 | ||
1031 | /* A USE insn, or something else we don't need to understand. | |
1032 | We can't pass these directly to function_units_used because it will | |
1033 | trigger a fatal error for unrecognizable insns. */ | |
1034 | if (INSN_CODE (insn) < 0) | |
1035 | unit = -1; | |
1036 | else | |
1037 | { | |
1038 | unit = function_units_used (insn); | |
1039 | /* Increment non-negative values so we can cache zero. */ | |
1040 | if (unit >= 0) unit++; | |
1041 | } | |
1042 | /* We only cache 16 bits of the result, so if the value is out of | |
1043 | range, don't cache it. */ | |
1044 | if (FUNCTION_UNITS_SIZE < HOST_BITS_PER_SHORT | |
1045 | || unit >= 0 | |
1046 | || (~unit & ((1 << (HOST_BITS_PER_SHORT - 1)) - 1)) == 0) | |
1047 | INSN_UNIT (insn) = unit; | |
1048 | } | |
1049 | return (unit > 0 ? unit - 1 : unit); | |
1050 | } | |
1051 | ||
1052 | /* Compute the blockage range for executing INSN on UNIT. This caches | |
1053 | the value returned by the blockage_range_function for the unit. | |
1054 | These values are encoded in an int where the upper half gives the | |
1055 | minimum value and the lower half gives the maximum value. */ | |
1056 | ||
1057 | __inline static unsigned int | |
1058 | blockage_range (unit, insn) | |
1059 | int unit; | |
1060 | rtx insn; | |
1061 | { | |
1062 | unsigned int blockage = INSN_BLOCKAGE (insn); | |
1063 | unsigned int range; | |
1064 | ||
1065 | if (UNIT_BLOCKED (blockage) != unit + 1) | |
1066 | { | |
1067 | range = function_units[unit].blockage_range_function (insn); | |
1068 | /* We only cache the blockage range for one unit and then only if | |
1069 | the values fit. */ | |
1070 | if (HOST_BITS_PER_INT >= UNIT_BITS + 2 * BLOCKAGE_BITS) | |
1071 | INSN_BLOCKAGE (insn) = ENCODE_BLOCKAGE (unit + 1, range); | |
1072 | } | |
1073 | else | |
1074 | range = BLOCKAGE_RANGE (blockage); | |
1075 | ||
1076 | return range; | |
1077 | } | |
1078 | ||
1079 | /* A vector indexed by function unit instance giving the last insn to use | |
1080 | the unit. The value of the function unit instance index for unit U | |
1081 | instance I is (U + I * FUNCTION_UNITS_SIZE). */ | |
1082 | static rtx unit_last_insn[FUNCTION_UNITS_SIZE * MAX_MULTIPLICITY]; | |
1083 | ||
1084 | /* A vector indexed by function unit instance giving the minimum time when | |
1085 | the unit will unblock based on the maximum blockage cost. */ | |
1086 | static int unit_tick[FUNCTION_UNITS_SIZE * MAX_MULTIPLICITY]; | |
1087 | ||
1088 | /* A vector indexed by function unit number giving the number of insns | |
1089 | that remain to use the unit. */ | |
1090 | static int unit_n_insns[FUNCTION_UNITS_SIZE]; | |
1091 | ||
1092 | /* Reset the function unit state to the null state. */ | |
1093 | ||
1094 | static void | |
1095 | clear_units () | |
1096 | { | |
1097 | int unit; | |
1098 | ||
1099 | bzero (unit_last_insn, sizeof (unit_last_insn)); | |
1100 | bzero (unit_tick, sizeof (unit_tick)); | |
1101 | bzero (unit_n_insns, sizeof (unit_n_insns)); | |
1102 | } | |
1103 | ||
1104 | /* Record an insn as one that will use the units encoded by UNIT. */ | |
1105 | ||
1106 | __inline static void | |
1107 | prepare_unit (unit) | |
1108 | int unit; | |
1109 | { | |
1110 | int i; | |
1111 | ||
1112 | if (unit >= 0) | |
1113 | unit_n_insns[unit]++; | |
1114 | else | |
1115 | for (i = 0, unit = ~unit; unit; i++, unit >>= 1) | |
1116 | if ((unit & 1) != 0) | |
1117 | prepare_unit (i); | |
1118 | } | |
1119 | ||
1120 | /* Return the actual hazard cost of executing INSN on the unit UNIT, | |
1121 | instance INSTANCE at time CLOCK if the previous actual hazard cost | |
1122 | was COST. */ | |
1123 | ||
1124 | __inline static int | |
1125 | actual_hazard_this_instance (unit, instance, insn, clock, cost) | |
1126 | int unit, instance, clock, cost; | |
1127 | rtx insn; | |
1128 | { | |
1129 | int i; | |
1130 | int tick = unit_tick[instance]; | |
1131 | ||
1132 | if (tick - clock > cost) | |
1133 | { | |
1134 | /* The scheduler is operating in reverse, so INSN is the executing | |
1135 | insn and the unit's last insn is the candidate insn. We want a | |
1136 | more exact measure of the blockage if we execute INSN at CLOCK | |
1137 | given when we committed the execution of the unit's last insn. | |
1138 | ||
1139 | The blockage value is given by either the unit's max blockage | |
1140 | constant, blockage range function, or blockage function. Use | |
1141 | the most exact form for the given unit. */ | |
1142 | ||
1143 | if (function_units[unit].blockage_range_function) | |
1144 | { | |
1145 | if (function_units[unit].blockage_function) | |
1146 | tick += (function_units[unit].blockage_function | |
1147 | (insn, unit_last_insn[instance]) | |
1148 | - function_units[unit].max_blockage); | |
1149 | else | |
1150 | tick += ((int) MAX_BLOCKAGE_COST (blockage_range (unit, insn)) | |
1151 | - function_units[unit].max_blockage); | |
1152 | } | |
1153 | if (tick - clock > cost) | |
1154 | cost = tick - clock; | |
1155 | } | |
1156 | return cost; | |
1157 | } | |
1158 | ||
1159 | /* Record INSN as having begun execution on the units encoded by UNIT at | |
1160 | time CLOCK. */ | |
1161 | ||
1162 | __inline static void | |
1163 | schedule_unit (unit, insn, clock) | |
1164 | int unit, clock; | |
1165 | rtx insn; | |
1166 | { | |
1167 | int i; | |
1168 | ||
1169 | if (unit >= 0) | |
1170 | { | |
1171 | int instance = unit; | |
1172 | #if MAX_MULTIPLICITY > 1 | |
1173 | /* Find the first free instance of the function unit and use that | |
1174 | one. We assume that one is free. */ | |
1175 | for (i = function_units[unit].multiplicity - 1; i > 0; i--) | |
1176 | { | |
1177 | if (! actual_hazard_this_instance (unit, instance, insn, clock, 0)) | |
1178 | break; | |
1179 | instance += FUNCTION_UNITS_SIZE; | |
1180 | } | |
1181 | #endif | |
1182 | unit_last_insn[instance] = insn; | |
1183 | unit_tick[instance] = (clock + function_units[unit].max_blockage); | |
1184 | } | |
1185 | else | |
1186 | for (i = 0, unit = ~unit; unit; i++, unit >>= 1) | |
1187 | if ((unit & 1) != 0) | |
1188 | schedule_unit (i, insn, clock); | |
1189 | } | |
1190 | ||
1191 | /* Return the actual hazard cost of executing INSN on the units encoded by | |
1192 | UNIT at time CLOCK if the previous actual hazard cost was COST. */ | |
1193 | ||
1194 | __inline static int | |
1195 | actual_hazard (unit, insn, clock, cost) | |
1196 | int unit, clock, cost; | |
1197 | rtx insn; | |
1198 | { | |
1199 | int i; | |
1200 | ||
1201 | if (unit >= 0) | |
1202 | { | |
1203 | /* Find the instance of the function unit with the minimum hazard. */ | |
1204 | int instance = unit; | |
1205 | int best = instance; | |
1206 | int best_cost = actual_hazard_this_instance (unit, instance, insn, | |
1207 | clock, cost); | |
1208 | int this_cost; | |
1209 | ||
1210 | #if MAX_MULTIPLICITY > 1 | |
1211 | if (best_cost > cost) | |
1212 | { | |
1213 | for (i = function_units[unit].multiplicity - 1; i > 0; i--) | |
1214 | { | |
1215 | instance += FUNCTION_UNITS_SIZE; | |
1216 | this_cost = actual_hazard_this_instance (unit, instance, insn, | |
1217 | clock, cost); | |
1218 | if (this_cost < best_cost) | |
1219 | { | |
1220 | best = instance; | |
1221 | best_cost = this_cost; | |
1222 | if (this_cost <= cost) | |
1223 | break; | |
1224 | } | |
1225 | } | |
1226 | } | |
1227 | #endif | |
1228 | cost = MAX (cost, best_cost); | |
1229 | } | |
1230 | else | |
1231 | for (i = 0, unit = ~unit; unit; i++, unit >>= 1) | |
1232 | if ((unit & 1) != 0) | |
1233 | cost = actual_hazard (i, insn, clock, cost); | |
1234 | ||
1235 | return cost; | |
1236 | } | |
1237 | ||
1238 | /* Return the potential hazard cost of executing an instruction on the | |
1239 | units encoded by UNIT if the previous potential hazard cost was COST. | |
1240 | An insn with a large blockage time is chosen in preference to one | |
1241 | with a smaller time; an insn that uses a unit that is more likely | |
1242 | to be used is chosen in preference to one with a unit that is less | |
1243 | used. We are trying to minimize a subsequent actual hazard. */ | |
1244 | ||
1245 | __inline static int | |
1246 | potential_hazard (unit, insn, cost) | |
1247 | int unit, cost; | |
1248 | rtx insn; | |
1249 | { | |
1250 | int i, ncost; | |
1251 | unsigned int minb, maxb; | |
1252 | ||
1253 | if (unit >= 0) | |
1254 | { | |
1255 | minb = maxb = function_units[unit].max_blockage; | |
1256 | if (maxb > 1) | |
1257 | { | |
1258 | if (function_units[unit].blockage_range_function) | |
1259 | { | |
1260 | maxb = minb = blockage_range (unit, insn); | |
1261 | maxb = MAX_BLOCKAGE_COST (maxb); | |
1262 | minb = MIN_BLOCKAGE_COST (minb); | |
1263 | } | |
1264 | ||
1265 | if (maxb > 1) | |
1266 | { | |
1267 | /* Make the number of instructions left dominate. Make the | |
1268 | minimum delay dominate the maximum delay. If all these | |
1269 | are the same, use the unit number to add an arbitrary | |
1270 | ordering. Other terms can be added. */ | |
1271 | ncost = minb * 0x40 + maxb; | |
1272 | ncost *= (unit_n_insns[unit] - 1) * 0x1000 + unit; | |
1273 | if (ncost > cost) | |
1274 | cost = ncost; | |
1275 | } | |
1276 | } | |
1277 | } | |
1278 | else | |
1279 | for (i = 0, unit = ~unit; unit; i++, unit >>= 1) | |
1280 | if ((unit & 1) != 0) | |
1281 | cost = potential_hazard (i, insn, cost); | |
1282 | ||
1283 | return cost; | |
1284 | } | |
1285 | ||
1286 | /* Compute cost of executing INSN given the dependence LINK on the insn USED. | |
1287 | This is the number of virtual cycles taken between instruction issue and | |
1288 | instruction results. */ | |
1289 | ||
1290 | __inline static int | |
1291 | insn_cost (insn, link, used) | |
1292 | rtx insn, link, used; | |
1293 | { | |
1294 | register int cost = INSN_COST (insn); | |
1295 | ||
1296 | if (cost == 0) | |
1297 | { | |
1298 | recog_memoized (insn); | |
1299 | ||
1300 | /* A USE insn, or something else we don't need to understand. | |
1301 | We can't pass these directly to result_ready_cost because it will | |
1302 | trigger a fatal error for unrecognizable insns. */ | |
1303 | if (INSN_CODE (insn) < 0) | |
1304 | { | |
1305 | INSN_COST (insn) = 1; | |
1306 | return 1; | |
1307 | } | |
1308 | else | |
1309 | { | |
1310 | cost = result_ready_cost (insn); | |
1311 | ||
1312 | if (cost < 1) | |
1313 | cost = 1; | |
1314 | ||
1315 | INSN_COST (insn) = cost; | |
1316 | } | |
1317 | } | |
1318 | ||
1319 | /* A USE insn should never require the value used to be computed. This | |
1320 | allows the computation of a function's result and parameter values to | |
1321 | overlap the return and call. */ | |
1322 | recog_memoized (used); | |
1323 | if (INSN_CODE (used) < 0) | |
1324 | LINK_COST_FREE (link) = 1; | |
1325 | ||
1326 | /* If some dependencies vary the cost, compute the adjustment. Most | |
1327 | commonly, the adjustment is complete: either the cost is ignored | |
1328 | (in the case of an output- or anti-dependence), or the cost is | |
1329 | unchanged. These values are cached in the link as LINK_COST_FREE | |
1330 | and LINK_COST_ZERO. */ | |
1331 | ||
1332 | if (LINK_COST_FREE (link)) | |
1333 | cost = 1; | |
1334 | #ifdef ADJUST_COST | |
1335 | else if (! LINK_COST_ZERO (link)) | |
1336 | { | |
1337 | int ncost = cost; | |
1338 | ||
1339 | ADJUST_COST (used, link, insn, ncost); | |
1340 | if (ncost <= 1) | |
1341 | LINK_COST_FREE (link) = ncost = 1; | |
1342 | if (cost == ncost) | |
1343 | LINK_COST_ZERO (link) = 1; | |
1344 | cost = ncost; | |
1345 | } | |
1346 | #endif | |
1347 | return cost; | |
1348 | } | |
1349 | ||
1350 | /* Compute the priority number for INSN. */ | |
1351 | ||
1352 | static int | |
1353 | priority (insn) | |
1354 | rtx insn; | |
1355 | { | |
1356 | if (insn && GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
1357 | { | |
1358 | int prev_priority; | |
1359 | int max_priority; | |
1360 | int this_priority = INSN_PRIORITY (insn); | |
1361 | rtx prev; | |
1362 | ||
1363 | if (this_priority > 0) | |
1364 | return this_priority; | |
1365 | ||
1366 | max_priority = 1; | |
1367 | ||
1368 | /* Nonzero if these insns must be scheduled together. */ | |
1369 | if (SCHED_GROUP_P (insn)) | |
1370 | { | |
1371 | prev = insn; | |
1372 | while (SCHED_GROUP_P (prev)) | |
1373 | { | |
1374 | prev = PREV_INSN (prev); | |
1375 | INSN_REF_COUNT (prev) += 1; | |
1376 | } | |
1377 | } | |
1378 | ||
1379 | for (prev = LOG_LINKS (insn); prev; prev = XEXP (prev, 1)) | |
1380 | { | |
1381 | rtx x = XEXP (prev, 0); | |
1382 | ||
1383 | /* A dependence pointing to a note is always obsolete, because | |
1384 | sched_analyze_insn will have created any necessary new dependences | |
1385 | which replace it. Notes can be created when instructions are | |
1386 | deleted by insn splitting, or by register allocation. */ | |
1387 | if (GET_CODE (x) == NOTE) | |
1388 | { | |
1389 | remove_dependence (insn, x); | |
1390 | continue; | |
1391 | } | |
1392 | ||
1393 | /* Clear the link cost adjustment bits. */ | |
1394 | LINK_COST_FREE (prev) = 0; | |
1395 | #ifdef ADJUST_COST | |
1396 | LINK_COST_ZERO (prev) = 0; | |
1397 | #endif | |
1398 | ||
1399 | /* This priority calculation was chosen because it results in the | |
1400 | least instruction movement, and does not hurt the performance | |
1401 | of the resulting code compared to the old algorithm. | |
1402 | This makes the sched algorithm more stable, which results | |
1403 | in better code, because there is less register pressure, | |
1404 | cross jumping is more likely to work, and debugging is easier. | |
1405 | ||
1406 | When all instructions have a latency of 1, there is no need to | |
1407 | move any instructions. Subtracting one here ensures that in such | |
1408 | cases all instructions will end up with a priority of one, and | |
1409 | hence no scheduling will be done. | |
1410 | ||
1411 | The original code did not subtract the one, and added the | |
1412 | insn_cost of the current instruction to its priority (e.g. | |
1413 | move the insn_cost call down to the end). */ | |
1414 | ||
1415 | if (REG_NOTE_KIND (prev) == 0) | |
1416 | /* Data dependence. */ | |
1417 | prev_priority = priority (x) + insn_cost (x, prev, insn) - 1; | |
1418 | else | |
1419 | /* Anti or output dependence. Don't add the latency of this | |
1420 | insn's result, because it isn't being used. */ | |
1421 | prev_priority = priority (x); | |
1422 | ||
1423 | if (prev_priority > max_priority) | |
1424 | max_priority = prev_priority; | |
1425 | INSN_REF_COUNT (x) += 1; | |
1426 | } | |
1427 | ||
1428 | prepare_unit (insn_unit (insn)); | |
1429 | INSN_PRIORITY (insn) = max_priority; | |
1430 | return INSN_PRIORITY (insn); | |
1431 | } | |
1432 | return 0; | |
1433 | } | |
1434 | \f | |
1435 | /* Remove all INSN_LISTs and EXPR_LISTs from the pending lists and add | |
1436 | them to the unused_*_list variables, so that they can be reused. */ | |
1437 | ||
1438 | static void | |
1439 | free_pending_lists () | |
1440 | { | |
1441 | register rtx link, prev_link; | |
1442 | ||
1443 | if (pending_read_insns) | |
1444 | { | |
1445 | prev_link = pending_read_insns; | |
1446 | link = XEXP (prev_link, 1); | |
1447 | ||
1448 | while (link) | |
1449 | { | |
1450 | prev_link = link; | |
1451 | link = XEXP (link, 1); | |
1452 | } | |
1453 | ||
1454 | XEXP (prev_link, 1) = unused_insn_list; | |
1455 | unused_insn_list = pending_read_insns; | |
1456 | pending_read_insns = 0; | |
1457 | } | |
1458 | ||
1459 | if (pending_write_insns) | |
1460 | { | |
1461 | prev_link = pending_write_insns; | |
1462 | link = XEXP (prev_link, 1); | |
1463 | ||
1464 | while (link) | |
1465 | { | |
1466 | prev_link = link; | |
1467 | link = XEXP (link, 1); | |
1468 | } | |
1469 | ||
1470 | XEXP (prev_link, 1) = unused_insn_list; | |
1471 | unused_insn_list = pending_write_insns; | |
1472 | pending_write_insns = 0; | |
1473 | } | |
1474 | ||
1475 | if (pending_read_mems) | |
1476 | { | |
1477 | prev_link = pending_read_mems; | |
1478 | link = XEXP (prev_link, 1); | |
1479 | ||
1480 | while (link) | |
1481 | { | |
1482 | prev_link = link; | |
1483 | link = XEXP (link, 1); | |
1484 | } | |
1485 | ||
1486 | XEXP (prev_link, 1) = unused_expr_list; | |
1487 | unused_expr_list = pending_read_mems; | |
1488 | pending_read_mems = 0; | |
1489 | } | |
1490 | ||
1491 | if (pending_write_mems) | |
1492 | { | |
1493 | prev_link = pending_write_mems; | |
1494 | link = XEXP (prev_link, 1); | |
1495 | ||
1496 | while (link) | |
1497 | { | |
1498 | prev_link = link; | |
1499 | link = XEXP (link, 1); | |
1500 | } | |
1501 | ||
1502 | XEXP (prev_link, 1) = unused_expr_list; | |
1503 | unused_expr_list = pending_write_mems; | |
1504 | pending_write_mems = 0; | |
1505 | } | |
1506 | } | |
1507 | ||
1508 | /* Add an INSN and MEM reference pair to a pending INSN_LIST and MEM_LIST. | |
1509 | The MEM is a memory reference contained within INSN, which we are saving | |
1510 | so that we can do memory aliasing on it. */ | |
1511 | ||
1512 | static void | |
1513 | add_insn_mem_dependence (insn_list, mem_list, insn, mem) | |
1514 | rtx *insn_list, *mem_list, insn, mem; | |
1515 | { | |
1516 | register rtx link; | |
1517 | ||
1518 | if (unused_insn_list) | |
1519 | { | |
1520 | link = unused_insn_list; | |
1521 | unused_insn_list = XEXP (link, 1); | |
1522 | } | |
1523 | else | |
1524 | link = rtx_alloc (INSN_LIST); | |
1525 | XEXP (link, 0) = insn; | |
1526 | XEXP (link, 1) = *insn_list; | |
1527 | *insn_list = link; | |
1528 | ||
1529 | if (unused_expr_list) | |
1530 | { | |
1531 | link = unused_expr_list; | |
1532 | unused_expr_list = XEXP (link, 1); | |
1533 | } | |
1534 | else | |
1535 | link = rtx_alloc (EXPR_LIST); | |
1536 | XEXP (link, 0) = mem; | |
1537 | XEXP (link, 1) = *mem_list; | |
1538 | *mem_list = link; | |
1539 | ||
1540 | pending_lists_length++; | |
1541 | } | |
1542 | \f | |
1543 | /* Make a dependency between every memory reference on the pending lists | |
1544 | and INSN, thus flushing the pending lists. */ | |
1545 | ||
1546 | static void | |
1547 | flush_pending_lists (insn) | |
1548 | rtx insn; | |
1549 | { | |
1550 | rtx link; | |
1551 | ||
1552 | while (pending_read_insns) | |
1553 | { | |
1554 | add_dependence (insn, XEXP (pending_read_insns, 0), REG_DEP_ANTI); | |
1555 | ||
1556 | link = pending_read_insns; | |
1557 | pending_read_insns = XEXP (pending_read_insns, 1); | |
1558 | XEXP (link, 1) = unused_insn_list; | |
1559 | unused_insn_list = link; | |
1560 | ||
1561 | link = pending_read_mems; | |
1562 | pending_read_mems = XEXP (pending_read_mems, 1); | |
1563 | XEXP (link, 1) = unused_expr_list; | |
1564 | unused_expr_list = link; | |
1565 | } | |
1566 | while (pending_write_insns) | |
1567 | { | |
1568 | add_dependence (insn, XEXP (pending_write_insns, 0), REG_DEP_ANTI); | |
1569 | ||
1570 | link = pending_write_insns; | |
1571 | pending_write_insns = XEXP (pending_write_insns, 1); | |
1572 | XEXP (link, 1) = unused_insn_list; | |
1573 | unused_insn_list = link; | |
1574 | ||
1575 | link = pending_write_mems; | |
1576 | pending_write_mems = XEXP (pending_write_mems, 1); | |
1577 | XEXP (link, 1) = unused_expr_list; | |
1578 | unused_expr_list = link; | |
1579 | } | |
1580 | pending_lists_length = 0; | |
1581 | ||
1582 | if (last_pending_memory_flush) | |
1583 | add_dependence (insn, last_pending_memory_flush, REG_DEP_ANTI); | |
1584 | ||
1585 | last_pending_memory_flush = insn; | |
1586 | } | |
1587 | ||
1588 | /* Analyze a single SET or CLOBBER rtx, X, creating all dependencies generated | |
1589 | by the write to the destination of X, and reads of everything mentioned. */ | |
1590 | ||
1591 | static void | |
1592 | sched_analyze_1 (x, insn) | |
1593 | rtx x; | |
1594 | rtx insn; | |
1595 | { | |
1596 | register int regno; | |
1597 | register rtx dest = SET_DEST (x); | |
1598 | ||
1599 | if (dest == 0) | |
1600 | return; | |
1601 | ||
1602 | while (GET_CODE (dest) == STRICT_LOW_PART || GET_CODE (dest) == SUBREG | |
1603 | || GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SIGN_EXTRACT) | |
1604 | { | |
1605 | if (GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SIGN_EXTRACT) | |
1606 | { | |
1607 | /* The second and third arguments are values read by this insn. */ | |
1608 | sched_analyze_2 (XEXP (dest, 1), insn); | |
1609 | sched_analyze_2 (XEXP (dest, 2), insn); | |
1610 | } | |
1611 | dest = SUBREG_REG (dest); | |
1612 | } | |
1613 | ||
1614 | if (GET_CODE (dest) == REG) | |
1615 | { | |
1616 | register int offset, bit, i; | |
1617 | ||
1618 | regno = REGNO (dest); | |
1619 | ||
1620 | /* A hard reg in a wide mode may really be multiple registers. | |
1621 | If so, mark all of them just like the first. */ | |
1622 | if (regno < FIRST_PSEUDO_REGISTER) | |
1623 | { | |
1624 | i = HARD_REGNO_NREGS (regno, GET_MODE (dest)); | |
1625 | while (--i >= 0) | |
1626 | { | |
1627 | rtx u; | |
1628 | ||
1629 | for (u = reg_last_uses[regno+i]; u; u = XEXP (u, 1)) | |
1630 | add_dependence (insn, XEXP (u, 0), REG_DEP_ANTI); | |
1631 | reg_last_uses[regno + i] = 0; | |
1632 | if (reg_last_sets[regno + i]) | |
1633 | add_dependence (insn, reg_last_sets[regno + i], | |
1634 | REG_DEP_OUTPUT); | |
1635 | reg_last_sets[regno + i] = insn; | |
1636 | if ((call_used_regs[i] || global_regs[i]) | |
1637 | && last_function_call) | |
1638 | /* Function calls clobber all call_used regs. */ | |
1639 | add_dependence (insn, last_function_call, REG_DEP_ANTI); | |
1640 | } | |
1641 | } | |
1642 | else | |
1643 | { | |
1644 | rtx u; | |
1645 | ||
1646 | for (u = reg_last_uses[regno]; u; u = XEXP (u, 1)) | |
1647 | add_dependence (insn, XEXP (u, 0), REG_DEP_ANTI); | |
1648 | reg_last_uses[regno] = 0; | |
1649 | if (reg_last_sets[regno]) | |
1650 | add_dependence (insn, reg_last_sets[regno], REG_DEP_OUTPUT); | |
1651 | reg_last_sets[regno] = insn; | |
1652 | ||
1653 | /* Pseudos that are REG_EQUIV to something may be replaced | |
1654 | by that during reloading. We need only add dependencies for | |
1655 | the address in the REG_EQUIV note. */ | |
1656 | if (! reload_completed | |
1657 | && reg_known_equiv_p[regno] | |
1658 | && GET_CODE (reg_known_value[regno]) == MEM) | |
1659 | sched_analyze_2 (XEXP (reg_known_value[regno], 0), insn); | |
1660 | ||
1661 | /* Don't let it cross a call after scheduling if it doesn't | |
1662 | already cross one. */ | |
1663 | if (reg_n_calls_crossed[regno] == 0 && last_function_call) | |
1664 | add_dependence (insn, last_function_call, REG_DEP_ANTI); | |
1665 | } | |
1666 | } | |
1667 | else if (GET_CODE (dest) == MEM) | |
1668 | { | |
1669 | /* Writing memory. */ | |
1670 | ||
1671 | if (pending_lists_length > 32) | |
1672 | { | |
1673 | /* Flush all pending reads and writes to prevent the pending lists | |
1674 | from getting any larger. Insn scheduling runs too slowly when | |
1675 | these lists get long. The number 32 was chosen because it | |
1676 | seems like a reasonable number. When compiling GCC with itself, | |
1677 | this flush occurs 8 times for sparc, and 10 times for m88k using | |
1678 | the number 32. */ | |
1679 | flush_pending_lists (insn); | |
1680 | } | |
1681 | else | |
1682 | { | |
1683 | rtx pending, pending_mem; | |
1684 | ||
1685 | pending = pending_read_insns; | |
1686 | pending_mem = pending_read_mems; | |
1687 | while (pending) | |
1688 | { | |
1689 | /* If a dependency already exists, don't create a new one. */ | |
1690 | if (! find_insn_list (XEXP (pending, 0), LOG_LINKS (insn))) | |
1691 | if (anti_dependence (XEXP (pending_mem, 0), dest)) | |
1692 | add_dependence (insn, XEXP (pending, 0), REG_DEP_ANTI); | |
1693 | ||
1694 | pending = XEXP (pending, 1); | |
1695 | pending_mem = XEXP (pending_mem, 1); | |
1696 | } | |
1697 | ||
1698 | pending = pending_write_insns; | |
1699 | pending_mem = pending_write_mems; | |
1700 | while (pending) | |
1701 | { | |
1702 | /* If a dependency already exists, don't create a new one. */ | |
1703 | if (! find_insn_list (XEXP (pending, 0), LOG_LINKS (insn))) | |
1704 | if (output_dependence (XEXP (pending_mem, 0), dest)) | |
1705 | add_dependence (insn, XEXP (pending, 0), REG_DEP_OUTPUT); | |
1706 | ||
1707 | pending = XEXP (pending, 1); | |
1708 | pending_mem = XEXP (pending_mem, 1); | |
1709 | } | |
1710 | ||
1711 | if (last_pending_memory_flush) | |
1712 | add_dependence (insn, last_pending_memory_flush, REG_DEP_ANTI); | |
1713 | ||
1714 | add_insn_mem_dependence (&pending_write_insns, &pending_write_mems, | |
1715 | insn, dest); | |
1716 | } | |
1717 | sched_analyze_2 (XEXP (dest, 0), insn); | |
1718 | } | |
1719 | ||
1720 | /* Analyze reads. */ | |
1721 | if (GET_CODE (x) == SET) | |
1722 | sched_analyze_2 (SET_SRC (x), insn); | |
1723 | } | |
1724 | ||
1725 | /* Analyze the uses of memory and registers in rtx X in INSN. */ | |
1726 | ||
1727 | static void | |
1728 | sched_analyze_2 (x, insn) | |
1729 | rtx x; | |
1730 | rtx insn; | |
1731 | { | |
1732 | register int i; | |
1733 | register int j; | |
1734 | register enum rtx_code code; | |
1735 | register char *fmt; | |
1736 | ||
1737 | if (x == 0) | |
1738 | return; | |
1739 | ||
1740 | code = GET_CODE (x); | |
1741 | ||
1742 | switch (code) | |
1743 | { | |
1744 | case CONST_INT: | |
1745 | case CONST_DOUBLE: | |
1746 | case SYMBOL_REF: | |
1747 | case CONST: | |
1748 | case LABEL_REF: | |
1749 | /* Ignore constants. Note that we must handle CONST_DOUBLE here | |
1750 | because it may have a cc0_rtx in its CONST_DOUBLE_CHAIN field, but | |
1751 | this does not mean that this insn is using cc0. */ | |
1752 | return; | |
1753 | ||
1754 | #ifdef HAVE_cc0 | |
1755 | case CC0: | |
1756 | { | |
1757 | rtx link, prev; | |
1758 | ||
1759 | /* There may be a note before this insn now, but all notes will | |
1760 | be removed before we actually try to schedule the insns, so | |
1761 | it won't cause a problem later. We must avoid it here though. */ | |
1762 | ||
1763 | /* User of CC0 depends on immediately preceding insn. */ | |
1764 | SCHED_GROUP_P (insn) = 1; | |
1765 | ||
1766 | /* Make a copy of all dependencies on the immediately previous insn, | |
1767 | and add to this insn. This is so that all the dependencies will | |
1768 | apply to the group. Remove an explicit dependence on this insn | |
1769 | as SCHED_GROUP_P now represents it. */ | |
1770 | ||
1771 | prev = PREV_INSN (insn); | |
1772 | while (GET_CODE (prev) == NOTE) | |
1773 | prev = PREV_INSN (prev); | |
1774 | ||
1775 | if (find_insn_list (prev, LOG_LINKS (insn))) | |
1776 | remove_dependence (insn, prev); | |
1777 | ||
1778 | for (link = LOG_LINKS (prev); link; link = XEXP (link, 1)) | |
1779 | add_dependence (insn, XEXP (link, 0), REG_NOTE_KIND (link)); | |
1780 | ||
1781 | return; | |
1782 | } | |
1783 | #endif | |
1784 | ||
1785 | case REG: | |
1786 | { | |
1787 | int regno = REGNO (x); | |
1788 | if (regno < FIRST_PSEUDO_REGISTER) | |
1789 | { | |
1790 | int i; | |
1791 | ||
1792 | i = HARD_REGNO_NREGS (regno, GET_MODE (x)); | |
1793 | while (--i >= 0) | |
1794 | { | |
1795 | reg_last_uses[regno + i] | |
1796 | = gen_rtx (INSN_LIST, VOIDmode, | |
1797 | insn, reg_last_uses[regno + i]); | |
1798 | if (reg_last_sets[regno + i]) | |
1799 | add_dependence (insn, reg_last_sets[regno + i], 0); | |
1800 | if ((call_used_regs[regno + i] || global_regs[regno + i]) | |
1801 | && last_function_call) | |
1802 | /* Function calls clobber all call_used regs. */ | |
1803 | add_dependence (insn, last_function_call, REG_DEP_ANTI); | |
1804 | } | |
1805 | } | |
1806 | else | |
1807 | { | |
1808 | reg_last_uses[regno] | |
1809 | = gen_rtx (INSN_LIST, VOIDmode, insn, reg_last_uses[regno]); | |
1810 | if (reg_last_sets[regno]) | |
1811 | add_dependence (insn, reg_last_sets[regno], 0); | |
1812 | ||
1813 | /* Pseudos that are REG_EQUIV to something may be replaced | |
1814 | by that during reloading. We need only add dependencies for | |
1815 | the address in the REG_EQUIV note. */ | |
1816 | if (! reload_completed | |
1817 | && reg_known_equiv_p[regno] | |
1818 | && GET_CODE (reg_known_value[regno]) == MEM) | |
1819 | sched_analyze_2 (XEXP (reg_known_value[regno], 0), insn); | |
1820 | ||
1821 | /* If the register does not already cross any calls, then add this | |
1822 | insn to the sched_before_next_call list so that it will still | |
1823 | not cross calls after scheduling. */ | |
1824 | if (reg_n_calls_crossed[regno] == 0) | |
1825 | add_dependence (sched_before_next_call, insn, REG_DEP_ANTI); | |
1826 | } | |
1827 | return; | |
1828 | } | |
1829 | ||
1830 | case MEM: | |
1831 | { | |
1832 | /* Reading memory. */ | |
1833 | ||
1834 | rtx pending, pending_mem; | |
1835 | ||
1836 | pending = pending_read_insns; | |
1837 | pending_mem = pending_read_mems; | |
1838 | while (pending) | |
1839 | { | |
1840 | /* If a dependency already exists, don't create a new one. */ | |
1841 | if (! find_insn_list (XEXP (pending, 0), LOG_LINKS (insn))) | |
1842 | if (read_dependence (XEXP (pending_mem, 0), x)) | |
1843 | add_dependence (insn, XEXP (pending, 0), REG_DEP_ANTI); | |
1844 | ||
1845 | pending = XEXP (pending, 1); | |
1846 | pending_mem = XEXP (pending_mem, 1); | |
1847 | } | |
1848 | ||
1849 | pending = pending_write_insns; | |
1850 | pending_mem = pending_write_mems; | |
1851 | while (pending) | |
1852 | { | |
1853 | /* If a dependency already exists, don't create a new one. */ | |
1854 | if (! find_insn_list (XEXP (pending, 0), LOG_LINKS (insn))) | |
1855 | if (true_dependence (XEXP (pending_mem, 0), x)) | |
1856 | add_dependence (insn, XEXP (pending, 0), 0); | |
1857 | ||
1858 | pending = XEXP (pending, 1); | |
1859 | pending_mem = XEXP (pending_mem, 1); | |
1860 | } | |
1861 | if (last_pending_memory_flush) | |
1862 | add_dependence (insn, last_pending_memory_flush, REG_DEP_ANTI); | |
1863 | ||
1864 | /* Always add these dependencies to pending_reads, since | |
1865 | this insn may be followed by a write. */ | |
1866 | add_insn_mem_dependence (&pending_read_insns, &pending_read_mems, | |
1867 | insn, x); | |
1868 | ||
1869 | /* Take advantage of tail recursion here. */ | |
1870 | sched_analyze_2 (XEXP (x, 0), insn); | |
1871 | return; | |
1872 | } | |
1873 | ||
1874 | case ASM_OPERANDS: | |
1875 | case ASM_INPUT: | |
1876 | case UNSPEC_VOLATILE: | |
1877 | case TRAP_IF: | |
1878 | { | |
1879 | rtx u; | |
1880 | ||
1881 | /* Traditional and volatile asm instructions must be considered to use | |
1882 | and clobber all hard registers and all of memory. So must | |
1883 | TRAP_IF and UNSPEC_VOLATILE operations. */ | |
1884 | if (code != ASM_OPERANDS || MEM_VOLATILE_P (x)) | |
1885 | { | |
1886 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
1887 | { | |
1888 | for (u = reg_last_uses[i]; u; u = XEXP (u, 1)) | |
2a5f595d | 1889 | add_dependence (insn, XEXP (u, 0), REG_DEP_ANTI); |
9bf86ebb | 1890 | reg_last_uses[i] = 0; |
2a5f595d | 1891 | if (reg_last_sets[i]) |
9bf86ebb PR |
1892 | add_dependence (insn, reg_last_sets[i], 0); |
1893 | reg_last_sets[i] = insn; | |
1894 | } | |
1895 | ||
1896 | flush_pending_lists (insn); | |
1897 | } | |
1898 | ||
1899 | /* For all ASM_OPERANDS, we must traverse the vector of input operands. | |
1900 | We can not just fall through here since then we would be confused | |
1901 | by the ASM_INPUT rtx inside ASM_OPERANDS, which do not indicate | |
1902 | traditional asms unlike their normal usage. */ | |
1903 | ||
1904 | if (code == ASM_OPERANDS) | |
1905 | { | |
1906 | for (j = 0; j < ASM_OPERANDS_INPUT_LENGTH (x); j++) | |
1907 | sched_analyze_2 (ASM_OPERANDS_INPUT (x, j), insn); | |
1908 | return; | |
1909 | } | |
1910 | break; | |
1911 | } | |
1912 | ||
1913 | case PRE_DEC: | |
1914 | case POST_DEC: | |
1915 | case PRE_INC: | |
1916 | case POST_INC: | |
1917 | /* These both read and modify the result. We must handle them as writes | |
1918 | to get proper dependencies for following instructions. We must handle | |
1919 | them as reads to get proper dependencies from this to previous | |
1920 | instructions. Thus we need to pass them to both sched_analyze_1 | |
1921 | and sched_analyze_2. We must call sched_analyze_2 first in order | |
1922 | to get the proper antecedent for the read. */ | |
1923 | sched_analyze_2 (XEXP (x, 0), insn); | |
1924 | sched_analyze_1 (x, insn); | |
1925 | return; | |
1926 | } | |
1927 | ||
1928 | /* Other cases: walk the insn. */ | |
1929 | fmt = GET_RTX_FORMAT (code); | |
1930 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1931 | { | |
1932 | if (fmt[i] == 'e') | |
1933 | sched_analyze_2 (XEXP (x, i), insn); | |
1934 | else if (fmt[i] == 'E') | |
1935 | for (j = 0; j < XVECLEN (x, i); j++) | |
1936 | sched_analyze_2 (XVECEXP (x, i, j), insn); | |
1937 | } | |
1938 | } | |
1939 | ||
1940 | /* Analyze an INSN with pattern X to find all dependencies. */ | |
1941 | ||
1942 | static void | |
1943 | sched_analyze_insn (x, insn) | |
1944 | rtx x, insn; | |
1945 | { | |
1946 | register RTX_CODE code = GET_CODE (x); | |
1947 | rtx link; | |
1948 | ||
1949 | if (code == SET || code == CLOBBER) | |
1950 | sched_analyze_1 (x, insn); | |
1951 | else if (code == PARALLEL) | |
1952 | { | |
1953 | register int i; | |
1954 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
1955 | { | |
1956 | code = GET_CODE (XVECEXP (x, 0, i)); | |
1957 | if (code == SET || code == CLOBBER) | |
1958 | sched_analyze_1 (XVECEXP (x, 0, i), insn); | |
1959 | else | |
1960 | sched_analyze_2 (XVECEXP (x, 0, i), insn); | |
1961 | } | |
1962 | } | |
1963 | else | |
1964 | sched_analyze_2 (x, insn); | |
1965 | ||
1966 | /* Handle function calls. */ | |
1967 | if (GET_CODE (insn) == CALL_INSN) | |
1968 | { | |
1969 | rtx dep_insn; | |
1970 | rtx prev_dep_insn; | |
1971 | ||
1972 | /* When scheduling instructions, we make sure calls don't lose their | |
1973 | accompanying USE insns by depending them one on another in order. */ | |
1974 | ||
1975 | prev_dep_insn = insn; | |
1976 | dep_insn = PREV_INSN (insn); | |
1977 | while (GET_CODE (dep_insn) == INSN | |
1978 | && GET_CODE (PATTERN (dep_insn)) == USE) | |
1979 | { | |
1980 | SCHED_GROUP_P (prev_dep_insn) = 1; | |
1981 | ||
1982 | /* Make a copy of all dependencies on dep_insn, and add to insn. | |
1983 | This is so that all of the dependencies will apply to the | |
1984 | group. */ | |
1985 | ||
1986 | for (link = LOG_LINKS (dep_insn); link; link = XEXP (link, 1)) | |
1987 | add_dependence (insn, XEXP (link, 0), REG_NOTE_KIND (link)); | |
1988 | ||
1989 | prev_dep_insn = dep_insn; | |
1990 | dep_insn = PREV_INSN (dep_insn); | |
1991 | } | |
1992 | } | |
1993 | } | |
1994 | ||
1995 | /* Analyze every insn between HEAD and TAIL inclusive, creating LOG_LINKS | |
1996 | for every dependency. */ | |
1997 | ||
1998 | static int | |
1999 | sched_analyze (head, tail) | |
2000 | rtx head, tail; | |
2001 | { | |
2002 | register rtx insn; | |
2003 | register int n_insns = 0; | |
2004 | register rtx u; | |
2005 | register int luid = 0; | |
2006 | ||
2007 | for (insn = head; ; insn = NEXT_INSN (insn)) | |
2008 | { | |
2009 | INSN_LUID (insn) = luid++; | |
2010 | ||
2011 | if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN) | |
2012 | { | |
2013 | sched_analyze_insn (PATTERN (insn), insn); | |
2014 | n_insns += 1; | |
2015 | } | |
2016 | else if (GET_CODE (insn) == CALL_INSN) | |
2017 | { | |
2018 | rtx dest = 0; | |
2019 | rtx x; | |
2020 | register int i; | |
2021 | ||
2022 | /* Any instruction using a hard register which may get clobbered | |
2023 | by a call needs to be marked as dependent on this call. | |
2024 | This prevents a use of a hard return reg from being moved | |
2025 | past a void call (i.e. it does not explicitly set the hard | |
2026 | return reg). */ | |
2027 | ||
2028 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
2029 | if (call_used_regs[i] || global_regs[i]) | |
2030 | { | |
2031 | for (u = reg_last_uses[i]; u; u = XEXP (u, 1)) | |
2a5f595d | 2032 | add_dependence (insn, XEXP (u, 0), REG_DEP_ANTI); |
9bf86ebb | 2033 | reg_last_uses[i] = 0; |
2a5f595d | 2034 | if (reg_last_sets[i]) |
9bf86ebb PR |
2035 | add_dependence (insn, reg_last_sets[i], REG_DEP_ANTI); |
2036 | reg_last_sets[i] = insn; | |
2037 | /* Insn, being a CALL_INSN, magically depends on | |
2038 | `last_function_call' already. */ | |
2039 | } | |
2040 | ||
2041 | /* For each insn which shouldn't cross a call, add a dependence | |
2042 | between that insn and this call insn. */ | |
2043 | x = LOG_LINKS (sched_before_next_call); | |
2044 | while (x) | |
2045 | { | |
2046 | add_dependence (insn, XEXP (x, 0), REG_DEP_ANTI); | |
2047 | x = XEXP (x, 1); | |
2048 | } | |
2049 | LOG_LINKS (sched_before_next_call) = 0; | |
2050 | ||
2051 | sched_analyze_insn (PATTERN (insn), insn); | |
2052 | ||
2053 | /* We don't need to flush memory for a function call which does | |
2054 | not involve memory. */ | |
2055 | if (! CONST_CALL_P (insn)) | |
2056 | { | |
2057 | /* In the absence of interprocedural alias analysis, | |
2058 | we must flush all pending reads and writes, and | |
2059 | start new dependencies starting from here. */ | |
2060 | flush_pending_lists (insn); | |
2061 | } | |
2062 | ||
2063 | /* Depend this function call (actually, the user of this | |
2064 | function call) on all hard register clobberage. */ | |
2065 | last_function_call = insn; | |
2066 | n_insns += 1; | |
2067 | } | |
2068 | ||
2069 | if (insn == tail) | |
2070 | return n_insns; | |
2071 | } | |
2072 | } | |
2073 | \f | |
2074 | /* Called when we see a set of a register. If death is true, then we are | |
2075 | scanning backwards. Mark that register as unborn. If nobody says | |
2076 | otherwise, that is how things will remain. If death is false, then we | |
2077 | are scanning forwards. Mark that register as being born. */ | |
2078 | ||
2079 | static void | |
2080 | sched_note_set (b, x, death) | |
2081 | int b; | |
2082 | rtx x; | |
2083 | int death; | |
2084 | { | |
2085 | register int regno, j; | |
2086 | register rtx reg = SET_DEST (x); | |
2087 | int subreg_p = 0; | |
2088 | ||
2089 | if (reg == 0) | |
2090 | return; | |
2091 | ||
2092 | while (GET_CODE (reg) == SUBREG || GET_CODE (reg) == STRICT_LOW_PART | |
2093 | || GET_CODE (reg) == SIGN_EXTRACT || GET_CODE (reg) == ZERO_EXTRACT) | |
2094 | { | |
2095 | /* Must treat modification of just one hardware register of a multi-reg | |
2096 | value or just a byte field of a register exactly the same way that | |
2097 | mark_set_1 in flow.c does, i.e. anything except a paradoxical subreg | |
2098 | does not kill the entire register. */ | |
2099 | if (GET_CODE (reg) != SUBREG | |
2100 | || REG_SIZE (SUBREG_REG (reg)) > REG_SIZE (reg)) | |
2101 | subreg_p = 1; | |
2102 | ||
2103 | reg = SUBREG_REG (reg); | |
2104 | } | |
2105 | ||
2106 | if (GET_CODE (reg) != REG) | |
2107 | return; | |
2108 | ||
2109 | /* Global registers are always live, so the code below does not apply | |
2110 | to them. */ | |
2111 | ||
2112 | regno = REGNO (reg); | |
2113 | if (regno >= FIRST_PSEUDO_REGISTER || ! global_regs[regno]) | |
2114 | { | |
2115 | register int offset = regno / REGSET_ELT_BITS; | |
2116 | register REGSET_ELT_TYPE bit | |
2117 | = (REGSET_ELT_TYPE) 1 << (regno % REGSET_ELT_BITS); | |
2118 | ||
2119 | if (death) | |
2120 | { | |
2121 | /* If we only set part of the register, then this set does not | |
2122 | kill it. */ | |
2123 | if (subreg_p) | |
2124 | return; | |
2125 | ||
2126 | /* Try killing this register. */ | |
2127 | if (regno < FIRST_PSEUDO_REGISTER) | |
2128 | { | |
2129 | int j = HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
2130 | while (--j >= 0) | |
2131 | { | |
2132 | offset = (regno + j) / REGSET_ELT_BITS; | |
2133 | bit = (REGSET_ELT_TYPE) 1 << ((regno + j) % REGSET_ELT_BITS); | |
2134 | ||
2135 | bb_live_regs[offset] &= ~bit; | |
2136 | bb_dead_regs[offset] |= bit; | |
2137 | } | |
2138 | } | |
2139 | else | |
2140 | { | |
2141 | bb_live_regs[offset] &= ~bit; | |
2142 | bb_dead_regs[offset] |= bit; | |
2143 | } | |
2144 | } | |
2145 | else | |
2146 | { | |
2147 | /* Make the register live again. */ | |
2148 | if (regno < FIRST_PSEUDO_REGISTER) | |
2149 | { | |
2150 | int j = HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
2151 | while (--j >= 0) | |
2152 | { | |
2153 | offset = (regno + j) / REGSET_ELT_BITS; | |
2154 | bit = (REGSET_ELT_TYPE) 1 << ((regno + j) % REGSET_ELT_BITS); | |
2155 | ||
2156 | bb_live_regs[offset] |= bit; | |
2157 | bb_dead_regs[offset] &= ~bit; | |
2158 | } | |
2159 | } | |
2160 | else | |
2161 | { | |
2162 | bb_live_regs[offset] |= bit; | |
2163 | bb_dead_regs[offset] &= ~bit; | |
2164 | } | |
2165 | } | |
2166 | } | |
2167 | } | |
2168 | \f | |
2169 | /* Macros and functions for keeping the priority queue sorted, and | |
2170 | dealing with queueing and unqueueing of instructions. */ | |
2171 | ||
2172 | #define SCHED_SORT(READY, NEW_READY, OLD_READY) \ | |
2173 | do { if ((NEW_READY) - (OLD_READY) == 1) \ | |
2174 | swap_sort (READY, NEW_READY); \ | |
2175 | else if ((NEW_READY) - (OLD_READY) > 1) \ | |
2176 | qsort (READY, NEW_READY, sizeof (rtx), rank_for_schedule); } \ | |
2177 | while (0) | |
2178 | ||
2179 | /* Returns a positive value if y is preferred; returns a negative value if | |
2180 | x is preferred. Should never return 0, since that will make the sort | |
2181 | unstable. */ | |
2182 | ||
2183 | static int | |
2184 | rank_for_schedule (x, y) | |
2185 | rtx *x, *y; | |
2186 | { | |
2187 | rtx tmp = *y; | |
2188 | rtx tmp2 = *x; | |
2189 | rtx link; | |
2190 | int tmp_class, tmp2_class; | |
2191 | int value; | |
2192 | ||
2193 | /* Choose the instruction with the highest priority, if different. */ | |
2194 | if (value = INSN_PRIORITY (tmp) - INSN_PRIORITY (tmp2)) | |
2195 | return value; | |
2196 | ||
2197 | if (last_scheduled_insn) | |
2198 | { | |
2199 | /* Classify the instructions into three classes: | |
2200 | 1) Data dependent on last schedule insn. | |
2201 | 2) Anti/Output dependent on last scheduled insn. | |
2202 | 3) Independent of last scheduled insn, or has latency of one. | |
2203 | Choose the insn from the highest numbered class if different. */ | |
2204 | link = find_insn_list (tmp, LOG_LINKS (last_scheduled_insn)); | |
2205 | if (link == 0 || insn_cost (tmp, link, last_scheduled_insn) == 1) | |
2206 | tmp_class = 3; | |
2207 | else if (REG_NOTE_KIND (link) == 0) /* Data dependence. */ | |
2208 | tmp_class = 1; | |
2209 | else | |
2210 | tmp_class = 2; | |
2211 | ||
2212 | link = find_insn_list (tmp2, LOG_LINKS (last_scheduled_insn)); | |
2213 | if (link == 0 || insn_cost (tmp2, link, last_scheduled_insn) == 1) | |
2214 | tmp2_class = 3; | |
2215 | else if (REG_NOTE_KIND (link) == 0) /* Data dependence. */ | |
2216 | tmp2_class = 1; | |
2217 | else | |
2218 | tmp2_class = 2; | |
2219 | ||
2220 | if (value = tmp_class - tmp2_class) | |
2221 | return value; | |
2222 | } | |
2223 | ||
2224 | /* If insns are equally good, sort by INSN_LUID (original insn order), | |
2225 | so that we make the sort stable. This minimizes instruction movement, | |
2226 | thus minimizing sched's effect on debugging and cross-jumping. */ | |
2227 | return INSN_LUID (tmp) - INSN_LUID (tmp2); | |
2228 | } | |
2229 | ||
2230 | /* Resort the array A in which only element at index N may be out of order. */ | |
2231 | ||
2232 | __inline static void | |
2233 | swap_sort (a, n) | |
2234 | rtx *a; | |
2235 | int n; | |
2236 | { | |
2237 | rtx insn = a[n-1]; | |
2238 | int i = n-2; | |
2239 | ||
2240 | while (i >= 0 && rank_for_schedule (a+i, &insn) >= 0) | |
2241 | { | |
2242 | a[i+1] = a[i]; | |
2243 | i -= 1; | |
2244 | } | |
2245 | a[i+1] = insn; | |
2246 | } | |
2247 | ||
2248 | static int max_priority; | |
2249 | ||
2250 | /* Add INSN to the insn queue so that it fires at least N_CYCLES | |
2251 | before the currently executing insn. */ | |
2252 | ||
2253 | __inline static void | |
2254 | queue_insn (insn, n_cycles) | |
2255 | rtx insn; | |
2256 | int n_cycles; | |
2257 | { | |
2258 | int next_q = NEXT_Q_AFTER (q_ptr, n_cycles); | |
2259 | NEXT_INSN (insn) = insn_queue[next_q]; | |
2260 | insn_queue[next_q] = insn; | |
2261 | q_size += 1; | |
2262 | } | |
2263 | ||
2264 | /* Return nonzero if PAT is the pattern of an insn which makes a | |
2265 | register live. */ | |
2266 | ||
2267 | __inline static int | |
2268 | birthing_insn_p (pat) | |
2269 | rtx pat; | |
2270 | { | |
2271 | int j; | |
2272 | ||
2273 | if (reload_completed == 1) | |
2274 | return 0; | |
2275 | ||
2276 | if (GET_CODE (pat) == SET | |
2277 | && GET_CODE (SET_DEST (pat)) == REG) | |
2278 | { | |
2279 | rtx dest = SET_DEST (pat); | |
2280 | int i = REGNO (dest); | |
2281 | int offset = i / REGSET_ELT_BITS; | |
2282 | REGSET_ELT_TYPE bit = (REGSET_ELT_TYPE) 1 << (i % REGSET_ELT_BITS); | |
2283 | ||
2284 | /* It would be more accurate to use refers_to_regno_p or | |
2285 | reg_mentioned_p to determine when the dest is not live before this | |
2286 | insn. */ | |
2287 | ||
2288 | if (bb_live_regs[offset] & bit) | |
2289 | return (reg_n_sets[i] == 1); | |
2290 | ||
2291 | return 0; | |
2292 | } | |
2293 | if (GET_CODE (pat) == PARALLEL) | |
2294 | { | |
2295 | for (j = 0; j < XVECLEN (pat, 0); j++) | |
2296 | if (birthing_insn_p (XVECEXP (pat, 0, j))) | |
2297 | return 1; | |
2298 | } | |
2299 | return 0; | |
2300 | } | |
2301 | ||
2302 | /* PREV is an insn that is ready to execute. Adjust its priority if that | |
2303 | will help shorten register lifetimes. */ | |
2304 | ||
2305 | __inline static void | |
2306 | adjust_priority (prev) | |
2307 | rtx prev; | |
2308 | { | |
2309 | /* Trying to shorten register lives after reload has completed | |
2310 | is useless and wrong. It gives inaccurate schedules. */ | |
2311 | if (reload_completed == 0) | |
2312 | { | |
2313 | rtx note; | |
2314 | int n_deaths = 0; | |
2315 | ||
2316 | /* ??? This code has no effect, because REG_DEAD notes are removed | |
2317 | before we ever get here. */ | |
2318 | for (note = REG_NOTES (prev); note; note = XEXP (note, 1)) | |
2319 | if (REG_NOTE_KIND (note) == REG_DEAD) | |
2320 | n_deaths += 1; | |
2321 | ||
2322 | /* Defer scheduling insns which kill registers, since that | |
2323 | shortens register lives. Prefer scheduling insns which | |
2324 | make registers live for the same reason. */ | |
2325 | switch (n_deaths) | |
2326 | { | |
2327 | default: | |
2328 | INSN_PRIORITY (prev) >>= 3; | |
2329 | break; | |
2330 | case 3: | |
2331 | INSN_PRIORITY (prev) >>= 2; | |
2332 | break; | |
2333 | case 2: | |
2334 | case 1: | |
2335 | INSN_PRIORITY (prev) >>= 1; | |
2336 | break; | |
2337 | case 0: | |
2338 | if (birthing_insn_p (PATTERN (prev))) | |
2339 | { | |
2340 | int max = max_priority; | |
2341 | ||
2342 | if (max > INSN_PRIORITY (prev)) | |
2343 | INSN_PRIORITY (prev) = max; | |
2344 | } | |
2345 | break; | |
2346 | } | |
2347 | } | |
2348 | } | |
2349 | ||
2350 | /* INSN is the "currently executing insn". Launch each insn which was | |
2351 | waiting on INSN (in the backwards dataflow sense). READY is a | |
2352 | vector of insns which are ready to fire. N_READY is the number of | |
2353 | elements in READY. CLOCK is the current virtual cycle. */ | |
2354 | ||
2355 | static int | |
2356 | schedule_insn (insn, ready, n_ready, clock) | |
2357 | rtx insn; | |
2358 | rtx *ready; | |
2359 | int n_ready; | |
2360 | int clock; | |
2361 | { | |
2362 | rtx link; | |
2363 | int new_ready = n_ready; | |
2364 | ||
2365 | if (MAX_BLOCKAGE > 1) | |
2366 | schedule_unit (insn_unit (insn), insn, clock); | |
2367 | ||
2368 | if (LOG_LINKS (insn) == 0) | |
2369 | return n_ready; | |
2370 | ||
2371 | /* This is used by the function adjust_priority above. */ | |
2372 | if (n_ready > 0) | |
2373 | max_priority = MAX (INSN_PRIORITY (ready[0]), INSN_PRIORITY (insn)); | |
2374 | else | |
2375 | max_priority = INSN_PRIORITY (insn); | |
2376 | ||
2377 | for (link = LOG_LINKS (insn); link != 0; link = XEXP (link, 1)) | |
2378 | { | |
2379 | rtx prev = XEXP (link, 0); | |
2380 | int cost = insn_cost (prev, link, insn); | |
2381 | ||
2382 | if ((INSN_REF_COUNT (prev) -= 1) != 0) | |
2383 | { | |
2384 | /* We satisfied one requirement to fire PREV. Record the earliest | |
2385 | time when PREV can fire. No need to do this if the cost is 1, | |
2386 | because PREV can fire no sooner than the next cycle. */ | |
2387 | if (cost > 1) | |
2388 | INSN_TICK (prev) = MAX (INSN_TICK (prev), clock + cost); | |
2389 | } | |
2390 | else | |
2391 | { | |
2392 | /* We satisfied the last requirement to fire PREV. Ensure that all | |
2393 | timing requirements are satisfied. */ | |
2394 | if (INSN_TICK (prev) - clock > cost) | |
2395 | cost = INSN_TICK (prev) - clock; | |
2396 | ||
2397 | /* Adjust the priority of PREV and either put it on the ready | |
2398 | list or queue it. */ | |
2399 | adjust_priority (prev); | |
2400 | if (cost <= 1) | |
2401 | ready[new_ready++] = prev; | |
2402 | else | |
2403 | queue_insn (prev, cost); | |
2404 | } | |
2405 | } | |
2406 | ||
2407 | return new_ready; | |
2408 | } | |
2409 | ||
2410 | /* Given N_READY insns in the ready list READY at time CLOCK, queue | |
2411 | those that are blocked due to function unit hazards and rearrange | |
2412 | the remaining ones to minimize subsequent function unit hazards. */ | |
2413 | ||
2414 | static int | |
2415 | schedule_select (ready, n_ready, clock, file) | |
2416 | rtx *ready; | |
2417 | int n_ready, clock; | |
2418 | FILE *file; | |
2419 | { | |
2420 | int pri = INSN_PRIORITY (ready[0]); | |
2421 | int i, j, k, q, cost, best_cost, best_insn = 0, new_ready = n_ready; | |
2422 | rtx insn; | |
2423 | ||
2424 | /* Work down the ready list in groups of instructions with the same | |
2425 | priority value. Queue insns in the group that are blocked and | |
2426 | select among those that remain for the one with the largest | |
2427 | potential hazard. */ | |
2428 | for (i = 0; i < n_ready; i = j) | |
2429 | { | |
2430 | int opri = pri; | |
2431 | for (j = i + 1; j < n_ready; j++) | |
2432 | if ((pri = INSN_PRIORITY (ready[j])) != opri) | |
2433 | break; | |
2434 | ||
2435 | /* Queue insns in the group that are blocked. */ | |
2436 | for (k = i, q = 0; k < j; k++) | |
2437 | { | |
2438 | insn = ready[k]; | |
2439 | if ((cost = actual_hazard (insn_unit (insn), insn, clock, 0)) != 0) | |
2440 | { | |
2441 | q++; | |
2442 | ready[k] = 0; | |
2443 | queue_insn (insn, cost); | |
2444 | if (file) | |
2445 | fprintf (file, "\n;; blocking insn %d for %d cycles", | |
2446 | INSN_UID (insn), cost); | |
2447 | } | |
2448 | } | |
2449 | new_ready -= q; | |
2450 | ||
2451 | /* Check the next group if all insns were queued. */ | |
2452 | if (j - i - q == 0) | |
2453 | continue; | |
2454 | ||
2455 | /* If more than one remains, select the first one with the largest | |
2456 | potential hazard. */ | |
2457 | else if (j - i - q > 1) | |
2458 | { | |
2459 | best_cost = -1; | |
2460 | for (k = i; k < j; k++) | |
2461 | { | |
2462 | if ((insn = ready[k]) == 0) | |
2463 | continue; | |
2464 | if ((cost = potential_hazard (insn_unit (insn), insn, 0)) | |
2465 | > best_cost) | |
2466 | { | |
2467 | best_cost = cost; | |
2468 | best_insn = k; | |
2469 | } | |
2470 | } | |
2471 | } | |
2472 | /* We have found a suitable insn to schedule. */ | |
2473 | break; | |
2474 | } | |
2475 | ||
2476 | /* Move the best insn to be front of the ready list. */ | |
2477 | if (best_insn != 0) | |
2478 | { | |
2479 | if (file) | |
2480 | { | |
2481 | fprintf (file, ", now"); | |
2482 | for (i = 0; i < n_ready; i++) | |
2483 | if (ready[i]) | |
2484 | fprintf (file, " %d", INSN_UID (ready[i])); | |
2485 | fprintf (file, "\n;; insn %d has a greater potential hazard", | |
2486 | INSN_UID (ready[best_insn])); | |
2487 | } | |
2488 | for (i = best_insn; i > 0; i--) | |
2489 | { | |
2490 | insn = ready[i-1]; | |
2491 | ready[i-1] = ready[i]; | |
2492 | ready[i] = insn; | |
2493 | } | |
2494 | } | |
2495 | ||
2496 | /* Compact the ready list. */ | |
2497 | if (new_ready < n_ready) | |
2498 | for (i = j = 0; i < n_ready; i++) | |
2499 | if (ready[i]) | |
2500 | ready[j++] = ready[i]; | |
2501 | ||
2502 | return new_ready; | |
2503 | } | |
2504 | ||
2505 | /* Add a REG_DEAD note for REG to INSN, reusing a REG_DEAD note from the | |
2506 | dead_notes list. */ | |
2507 | ||
2508 | static void | |
2509 | create_reg_dead_note (reg, insn) | |
2510 | rtx reg, insn; | |
2511 | { | |
2512 | rtx link, backlink; | |
2513 | ||
2514 | /* The number of registers killed after scheduling must be the same as the | |
2515 | number of registers killed before scheduling. The number of REG_DEAD | |
2516 | notes may not be conserved, i.e. two SImode hard register REG_DEAD notes | |
2517 | might become one DImode hard register REG_DEAD note, but the number of | |
2518 | registers killed will be conserved. | |
2519 | ||
2520 | We carefully remove REG_DEAD notes from the dead_notes list, so that | |
2521 | there will be none left at the end. If we run out early, then there | |
2522 | is a bug somewhere in flow, combine and/or sched. */ | |
2523 | ||
2524 | if (dead_notes == 0) | |
2525 | { | |
2526 | #if 1 | |
2527 | abort (); | |
2528 | #else | |
2529 | link = rtx_alloc (EXPR_LIST); | |
2530 | PUT_REG_NOTE_KIND (link, REG_DEAD); | |
2531 | #endif | |
2532 | } | |
2533 | else | |
2534 | { | |
2535 | /* Number of regs killed by REG. */ | |
2536 | int regs_killed = (REGNO (reg) >= FIRST_PSEUDO_REGISTER ? 1 | |
2537 | : HARD_REGNO_NREGS (REGNO (reg), GET_MODE (reg))); | |
2538 | /* Number of regs killed by REG_DEAD notes taken off the list. */ | |
2539 | int reg_note_regs; | |
2540 | ||
2541 | link = dead_notes; | |
2542 | reg_note_regs = (REGNO (XEXP (link, 0)) >= FIRST_PSEUDO_REGISTER ? 1 | |
2543 | : HARD_REGNO_NREGS (REGNO (XEXP (link, 0)), | |
2544 | GET_MODE (XEXP (link, 0)))); | |
2545 | while (reg_note_regs < regs_killed) | |
2546 | { | |
2547 | link = XEXP (link, 1); | |
2548 | reg_note_regs += (REGNO (XEXP (link, 0)) >= FIRST_PSEUDO_REGISTER ? 1 | |
2549 | : HARD_REGNO_NREGS (REGNO (XEXP (link, 0)), | |
2550 | GET_MODE (XEXP (link, 0)))); | |
2551 | } | |
2552 | dead_notes = XEXP (link, 1); | |
2553 | ||
2554 | /* If we took too many regs kills off, put the extra ones back. */ | |
2555 | while (reg_note_regs > regs_killed) | |
2556 | { | |
2557 | rtx temp_reg, temp_link; | |
2558 | ||
2559 | temp_reg = gen_rtx (REG, word_mode, 0); | |
2560 | temp_link = rtx_alloc (EXPR_LIST); | |
2561 | PUT_REG_NOTE_KIND (temp_link, REG_DEAD); | |
2562 | XEXP (temp_link, 0) = temp_reg; | |
2563 | XEXP (temp_link, 1) = dead_notes; | |
2564 | dead_notes = temp_link; | |
2565 | reg_note_regs--; | |
2566 | } | |
2567 | } | |
2568 | ||
2569 | XEXP (link, 0) = reg; | |
2570 | XEXP (link, 1) = REG_NOTES (insn); | |
2571 | REG_NOTES (insn) = link; | |
2572 | } | |
2573 | ||
2574 | /* Subroutine on attach_deaths_insn--handles the recursive search | |
2575 | through INSN. If SET_P is true, then x is being modified by the insn. */ | |
2576 | ||
2577 | static void | |
2578 | attach_deaths (x, insn, set_p) | |
2579 | rtx x; | |
2580 | rtx insn; | |
2581 | int set_p; | |
2582 | { | |
2583 | register int i; | |
2584 | register int j; | |
2585 | register enum rtx_code code; | |
2586 | register char *fmt; | |
2587 | ||
2588 | if (x == 0) | |
2589 | return; | |
2590 | ||
2591 | code = GET_CODE (x); | |
2592 | ||
2593 | switch (code) | |
2594 | { | |
2595 | case CONST_INT: | |
2596 | case CONST_DOUBLE: | |
2597 | case LABEL_REF: | |
2598 | case SYMBOL_REF: | |
2599 | case CONST: | |
2600 | case CODE_LABEL: | |
2601 | case PC: | |
2602 | case CC0: | |
2603 | /* Get rid of the easy cases first. */ | |
2604 | return; | |
2605 | ||
2606 | case REG: | |
2607 | { | |
2608 | /* If the register dies in this insn, queue that note, and mark | |
2609 | this register as needing to die. */ | |
2610 | /* This code is very similar to mark_used_1 (if set_p is false) | |
2611 | and mark_set_1 (if set_p is true) in flow.c. */ | |
2612 | ||
2613 | register int regno = REGNO (x); | |
2614 | register int offset = regno / REGSET_ELT_BITS; | |
2615 | register REGSET_ELT_TYPE bit | |
2616 | = (REGSET_ELT_TYPE) 1 << (regno % REGSET_ELT_BITS); | |
2617 | REGSET_ELT_TYPE all_needed = (old_live_regs[offset] & bit); | |
2618 | REGSET_ELT_TYPE some_needed = (old_live_regs[offset] & bit); | |
2619 | ||
2620 | if (set_p) | |
2621 | return; | |
2622 | ||
2623 | if (regno < FIRST_PSEUDO_REGISTER) | |
2624 | { | |
2625 | int n; | |
2626 | ||
2627 | n = HARD_REGNO_NREGS (regno, GET_MODE (x)); | |
2628 | while (--n > 0) | |
2629 | { | |
2630 | some_needed |= (old_live_regs[(regno + n) / REGSET_ELT_BITS] | |
2631 | & ((REGSET_ELT_TYPE) 1 | |
2632 | << ((regno + n) % REGSET_ELT_BITS))); | |
2633 | all_needed &= (old_live_regs[(regno + n) / REGSET_ELT_BITS] | |
2634 | & ((REGSET_ELT_TYPE) 1 | |
2635 | << ((regno + n) % REGSET_ELT_BITS))); | |
2636 | } | |
2637 | } | |
2638 | ||
2639 | /* If it wasn't live before we started, then add a REG_DEAD note. | |
2640 | We must check the previous lifetime info not the current info, | |
2641 | because we may have to execute this code several times, e.g. | |
2642 | once for a clobber (which doesn't add a note) and later | |
2643 | for a use (which does add a note). | |
2644 | ||
2645 | Always make the register live. We must do this even if it was | |
2646 | live before, because this may be an insn which sets and uses | |
2647 | the same register, in which case the register has already been | |
2648 | killed, so we must make it live again. | |
2649 | ||
2650 | Global registers are always live, and should never have a REG_DEAD | |
2651 | note added for them, so none of the code below applies to them. */ | |
2652 | ||
2653 | if (regno >= FIRST_PSEUDO_REGISTER || ! global_regs[regno]) | |
2654 | { | |
2655 | /* Never add REG_DEAD notes for the FRAME_POINTER_REGNUM or the | |
2656 | STACK_POINTER_REGNUM, since these are always considered to be | |
2657 | live. Similarly for ARG_POINTER_REGNUM if it is fixed. */ | |
2658 | if (regno != FRAME_POINTER_REGNUM | |
2659 | #if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM | |
2660 | && ! (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) | |
2661 | #endif | |
2662 | && regno != STACK_POINTER_REGNUM) | |
2663 | { | |
2664 | if (! all_needed && ! dead_or_set_p (insn, x)) | |
2665 | { | |
2666 | /* If none of the words in X is needed, make a REG_DEAD | |
2667 | note. Otherwise, we must make partial REG_DEAD | |
2668 | notes. */ | |
2669 | if (! some_needed) | |
2670 | create_reg_dead_note (x, insn); | |
2671 | else | |
2672 | { | |
2673 | int i; | |
2674 | ||
2675 | /* Don't make a REG_DEAD note for a part of a | |
2676 | register that is set in the insn. */ | |
2677 | for (i = HARD_REGNO_NREGS (regno, GET_MODE (x)) - 1; | |
2678 | i >= 0; i--) | |
2679 | if ((old_live_regs[(regno + i) / REGSET_ELT_BITS] | |
2680 | & ((REGSET_ELT_TYPE) 1 | |
2681 | << ((regno +i) % REGSET_ELT_BITS))) == 0 | |
2682 | && ! dead_or_set_regno_p (insn, regno + i)) | |
2683 | create_reg_dead_note (gen_rtx (REG, word_mode, | |
2684 | regno + i), | |
2685 | insn); | |
2686 | } | |
2687 | } | |
2688 | } | |
2689 | ||
2690 | if (regno < FIRST_PSEUDO_REGISTER) | |
2691 | { | |
2692 | int j = HARD_REGNO_NREGS (regno, GET_MODE (x)); | |
2693 | while (--j >= 0) | |
2694 | { | |
2695 | offset = (regno + j) / REGSET_ELT_BITS; | |
2696 | bit | |
2697 | = (REGSET_ELT_TYPE) 1 << ((regno + j) % REGSET_ELT_BITS); | |
2698 | ||
2699 | bb_dead_regs[offset] &= ~bit; | |
2700 | bb_live_regs[offset] |= bit; | |
2701 | } | |
2702 | } | |
2703 | else | |
2704 | { | |
2705 | bb_dead_regs[offset] &= ~bit; | |
2706 | bb_live_regs[offset] |= bit; | |
2707 | } | |
2708 | } | |
2709 | return; | |
2710 | } | |
2711 | ||
2712 | case MEM: | |
2713 | /* Handle tail-recursive case. */ | |
2714 | attach_deaths (XEXP (x, 0), insn, 0); | |
2715 | return; | |
2716 | ||
2717 | case SUBREG: | |
2718 | case STRICT_LOW_PART: | |
2719 | /* These two cases preserve the value of SET_P, so handle them | |
2720 | separately. */ | |
2721 | attach_deaths (XEXP (x, 0), insn, set_p); | |
2722 | return; | |
2723 | ||
2724 | case ZERO_EXTRACT: | |
2725 | case SIGN_EXTRACT: | |
2726 | /* This case preserves the value of SET_P for the first operand, but | |
2727 | clears it for the other two. */ | |
2728 | attach_deaths (XEXP (x, 0), insn, set_p); | |
2729 | attach_deaths (XEXP (x, 1), insn, 0); | |
2730 | attach_deaths (XEXP (x, 2), insn, 0); | |
2731 | return; | |
2732 | ||
2733 | default: | |
2734 | /* Other cases: walk the insn. */ | |
2735 | fmt = GET_RTX_FORMAT (code); | |
2736 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
2737 | { | |
2738 | if (fmt[i] == 'e') | |
2739 | attach_deaths (XEXP (x, i), insn, 0); | |
2740 | else if (fmt[i] == 'E') | |
2741 | for (j = 0; j < XVECLEN (x, i); j++) | |
2742 | attach_deaths (XVECEXP (x, i, j), insn, 0); | |
2743 | } | |
2744 | } | |
2745 | } | |
2746 | ||
2747 | /* After INSN has executed, add register death notes for each register | |
2748 | that is dead after INSN. */ | |
2749 | ||
2750 | static void | |
2751 | attach_deaths_insn (insn) | |
2752 | rtx insn; | |
2753 | { | |
2754 | rtx x = PATTERN (insn); | |
2755 | register RTX_CODE code = GET_CODE (x); | |
2756 | ||
2757 | if (code == SET) | |
2758 | { | |
2759 | attach_deaths (SET_SRC (x), insn, 0); | |
2760 | ||
2761 | /* A register might die here even if it is the destination, e.g. | |
2762 | it is the target of a volatile read and is otherwise unused. | |
2763 | Hence we must always call attach_deaths for the SET_DEST. */ | |
2764 | attach_deaths (SET_DEST (x), insn, 1); | |
2765 | } | |
2766 | else if (code == PARALLEL) | |
2767 | { | |
2768 | register int i; | |
2769 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
2770 | { | |
2771 | code = GET_CODE (XVECEXP (x, 0, i)); | |
2772 | if (code == SET) | |
2773 | { | |
2774 | attach_deaths (SET_SRC (XVECEXP (x, 0, i)), insn, 0); | |
2775 | ||
2776 | attach_deaths (SET_DEST (XVECEXP (x, 0, i)), insn, 1); | |
2777 | } | |
2778 | /* Flow does not add REG_DEAD notes to registers that die in | |
2779 | clobbers, so we can't either. */ | |
2780 | else if (code != CLOBBER) | |
2781 | attach_deaths (XVECEXP (x, 0, i), insn, 0); | |
2782 | } | |
2783 | } | |
2784 | /* Flow does not add REG_DEAD notes to registers that die in | |
2785 | clobbers, so we can't either. */ | |
2786 | else if (code != CLOBBER) | |
2787 | attach_deaths (x, insn, 0); | |
2788 | } | |
2789 | ||
2790 | /* Delete notes beginning with INSN and maybe put them in the chain | |
2791 | of notes ended by NOTE_LIST. | |
2792 | Returns the insn following the notes. */ | |
2793 | ||
2794 | static rtx | |
2795 | unlink_notes (insn, tail) | |
2796 | rtx insn, tail; | |
2797 | { | |
2798 | rtx prev = PREV_INSN (insn); | |
2799 | ||
2800 | while (insn != tail && GET_CODE (insn) == NOTE) | |
2801 | { | |
2802 | rtx next = NEXT_INSN (insn); | |
2803 | /* Delete the note from its current position. */ | |
2804 | if (prev) | |
2805 | NEXT_INSN (prev) = next; | |
2806 | if (next) | |
2807 | PREV_INSN (next) = prev; | |
2808 | ||
2809 | if (write_symbols != NO_DEBUG && NOTE_LINE_NUMBER (insn) > 0) | |
2810 | /* Record line-number notes so they can be reused. */ | |
2811 | LINE_NOTE (insn) = insn; | |
2812 | else | |
2813 | { | |
2814 | /* Insert the note at the end of the notes list. */ | |
2815 | PREV_INSN (insn) = note_list; | |
2816 | if (note_list) | |
2817 | NEXT_INSN (note_list) = insn; | |
2818 | note_list = insn; | |
2819 | } | |
2820 | ||
2821 | insn = next; | |
2822 | } | |
2823 | return insn; | |
2824 | } | |
2825 | ||
2826 | /* Data structure for keeping track of register information | |
2827 | during that register's life. */ | |
2828 | ||
2829 | struct sometimes | |
2830 | { | |
2831 | short offset; short bit; | |
2832 | short live_length; short calls_crossed; | |
2833 | }; | |
2834 | ||
2835 | /* Constructor for `sometimes' data structure. */ | |
2836 | ||
2837 | static int | |
2838 | new_sometimes_live (regs_sometimes_live, offset, bit, sometimes_max) | |
2839 | struct sometimes *regs_sometimes_live; | |
2840 | int offset, bit; | |
2841 | int sometimes_max; | |
2842 | { | |
2843 | register struct sometimes *p; | |
2844 | register int regno = offset * REGSET_ELT_BITS + bit; | |
2845 | int i; | |
2846 | ||
2847 | /* There should never be a register greater than max_regno here. If there | |
2848 | is, it means that a define_split has created a new pseudo reg. This | |
2849 | is not allowed, since there will not be flow info available for any | |
2850 | new register, so catch the error here. */ | |
2851 | if (regno >= max_regno) | |
2852 | abort (); | |
2853 | ||
2854 | p = ®s_sometimes_live[sometimes_max]; | |
2855 | p->offset = offset; | |
2856 | p->bit = bit; | |
2857 | p->live_length = 0; | |
2858 | p->calls_crossed = 0; | |
2859 | sometimes_max++; | |
2860 | return sometimes_max; | |
2861 | } | |
2862 | ||
2863 | /* Count lengths of all regs we are currently tracking, | |
2864 | and find new registers no longer live. */ | |
2865 | ||
2866 | static void | |
2867 | finish_sometimes_live (regs_sometimes_live, sometimes_max) | |
2868 | struct sometimes *regs_sometimes_live; | |
2869 | int sometimes_max; | |
2870 | { | |
2871 | int i; | |
2872 | ||
2873 | for (i = 0; i < sometimes_max; i++) | |
2874 | { | |
2875 | register struct sometimes *p = ®s_sometimes_live[i]; | |
2876 | int regno; | |
2877 | ||
2878 | regno = p->offset * REGSET_ELT_BITS + p->bit; | |
2879 | ||
2880 | sched_reg_live_length[regno] += p->live_length; | |
2881 | sched_reg_n_calls_crossed[regno] += p->calls_crossed; | |
2882 | } | |
2883 | } | |
2884 | ||
2885 | /* Use modified list scheduling to rearrange insns in basic block | |
2886 | B. FILE, if nonzero, is where we dump interesting output about | |
2887 | this pass. */ | |
2888 | ||
2889 | static void | |
2890 | schedule_block (b, file) | |
2891 | int b; | |
2892 | FILE *file; | |
2893 | { | |
2894 | rtx insn, last; | |
2895 | rtx last_note = 0; | |
2896 | rtx *ready, link; | |
2897 | int i, j, n_ready = 0, new_ready, n_insns = 0; | |
2898 | int sched_n_insns = 0; | |
2899 | int clock; | |
2900 | #define NEED_NOTHING 0 | |
2901 | #define NEED_HEAD 1 | |
2902 | #define NEED_TAIL 2 | |
2903 | int new_needs; | |
2904 | ||
2905 | /* HEAD and TAIL delimit the region being scheduled. */ | |
2906 | rtx head = basic_block_head[b]; | |
2907 | rtx tail = basic_block_end[b]; | |
2908 | /* PREV_HEAD and NEXT_TAIL are the boundaries of the insns | |
2909 | being scheduled. When the insns have been ordered, | |
2910 | these insns delimit where the new insns are to be | |
2911 | spliced back into the insn chain. */ | |
2912 | rtx next_tail; | |
2913 | rtx prev_head; | |
2914 | ||
2915 | /* Keep life information accurate. */ | |
2916 | register struct sometimes *regs_sometimes_live; | |
2917 | int sometimes_max; | |
2918 | ||
2919 | if (file) | |
2920 | fprintf (file, ";;\t -- basic block number %d from %d to %d --\n", | |
2921 | b, INSN_UID (basic_block_head[b]), INSN_UID (basic_block_end[b])); | |
2922 | ||
2923 | i = max_reg_num (); | |
2924 | reg_last_uses = (rtx *) alloca (i * sizeof (rtx)); | |
2925 | bzero (reg_last_uses, i * sizeof (rtx)); | |
2926 | reg_last_sets = (rtx *) alloca (i * sizeof (rtx)); | |
2927 | bzero (reg_last_sets, i * sizeof (rtx)); | |
2928 | clear_units (); | |
2929 | ||
2930 | /* Remove certain insns at the beginning from scheduling, | |
2931 | by advancing HEAD. */ | |
2932 | ||
2933 | /* At the start of a function, before reload has run, don't delay getting | |
2934 | parameters from hard registers into pseudo registers. */ | |
2935 | if (reload_completed == 0 && b == 0) | |
2936 | { | |
2937 | while (head != tail | |
2938 | && GET_CODE (head) == NOTE | |
2939 | && NOTE_LINE_NUMBER (head) != NOTE_INSN_FUNCTION_BEG) | |
2940 | head = NEXT_INSN (head); | |
2941 | while (head != tail | |
2942 | && GET_CODE (head) == INSN | |
2943 | && GET_CODE (PATTERN (head)) == SET) | |
2944 | { | |
2945 | rtx src = SET_SRC (PATTERN (head)); | |
2946 | while (GET_CODE (src) == SUBREG | |
2947 | || GET_CODE (src) == SIGN_EXTEND | |
2948 | || GET_CODE (src) == ZERO_EXTEND | |
2949 | || GET_CODE (src) == SIGN_EXTRACT | |
2950 | || GET_CODE (src) == ZERO_EXTRACT) | |
2951 | src = XEXP (src, 0); | |
2952 | if (GET_CODE (src) != REG | |
2953 | || REGNO (src) >= FIRST_PSEUDO_REGISTER) | |
2954 | break; | |
2955 | /* Keep this insn from ever being scheduled. */ | |
2956 | INSN_REF_COUNT (head) = 1; | |
2957 | head = NEXT_INSN (head); | |
2958 | } | |
2959 | } | |
2960 | ||
2961 | /* Don't include any notes or labels at the beginning of the | |
2962 | basic block, or notes at the ends of basic blocks. */ | |
2963 | while (head != tail) | |
2964 | { | |
2965 | if (GET_CODE (head) == NOTE) | |
2966 | head = NEXT_INSN (head); | |
2967 | else if (GET_CODE (tail) == NOTE) | |
2968 | tail = PREV_INSN (tail); | |
2969 | else if (GET_CODE (head) == CODE_LABEL) | |
2970 | head = NEXT_INSN (head); | |
2971 | else break; | |
2972 | } | |
2973 | /* If the only insn left is a NOTE or a CODE_LABEL, then there is no need | |
2974 | to schedule this block. */ | |
2975 | if (head == tail | |
2976 | && (GET_CODE (head) == NOTE || GET_CODE (head) == CODE_LABEL)) | |
2977 | return; | |
2978 | ||
2979 | #if 0 | |
2980 | /* This short-cut doesn't work. It does not count call insns crossed by | |
2981 | registers in reg_sometimes_live. It does not mark these registers as | |
2982 | dead if they die in this block. It does not mark these registers live | |
2983 | (or create new reg_sometimes_live entries if necessary) if they are born | |
2984 | in this block. | |
2985 | ||
2986 | The easy solution is to just always schedule a block. This block only | |
2987 | has one insn, so this won't slow down this pass by much. */ | |
2988 | ||
2989 | if (head == tail) | |
2990 | return; | |
2991 | #endif | |
2992 | ||
2993 | /* Now HEAD through TAIL are the insns actually to be rearranged; | |
2994 | Let PREV_HEAD and NEXT_TAIL enclose them. */ | |
2995 | prev_head = PREV_INSN (head); | |
2996 | next_tail = NEXT_INSN (tail); | |
2997 | ||
2998 | /* Initialize basic block data structures. */ | |
2999 | dead_notes = 0; | |
3000 | pending_read_insns = 0; | |
3001 | pending_read_mems = 0; | |
3002 | pending_write_insns = 0; | |
3003 | pending_write_mems = 0; | |
3004 | pending_lists_length = 0; | |
3005 | last_pending_memory_flush = 0; | |
3006 | last_function_call = 0; | |
3007 | last_scheduled_insn = 0; | |
3008 | ||
3009 | LOG_LINKS (sched_before_next_call) = 0; | |
3010 | ||
3011 | n_insns += sched_analyze (head, tail); | |
3012 | if (n_insns == 0) | |
3013 | { | |
3014 | free_pending_lists (); | |
3015 | return; | |
3016 | } | |
3017 | ||
3018 | /* Allocate vector to hold insns to be rearranged (except those | |
3019 | insns which are controlled by an insn with SCHED_GROUP_P set). | |
3020 | All these insns are included between ORIG_HEAD and ORIG_TAIL, | |
3021 | as those variables ultimately are set up. */ | |
3022 | ready = (rtx *) alloca ((n_insns+1) * sizeof (rtx)); | |
3023 | ||
3024 | /* TAIL is now the last of the insns to be rearranged. | |
3025 | Put those insns into the READY vector. */ | |
3026 | insn = tail; | |
3027 | ||
3028 | /* For all branches, calls, uses, and cc0 setters, force them to remain | |
3029 | in order at the end of the block by adding dependencies and giving | |
3030 | the last a high priority. There may be notes present, and prev_head | |
3031 | may also be a note. | |
3032 | ||
3033 | Branches must obviously remain at the end. Calls should remain at the | |
3034 | end since moving them results in worse register allocation. Uses remain | |
3035 | at the end to ensure proper register allocation. cc0 setters remaim | |
3036 | at the end because they can't be moved away from their cc0 user. */ | |
3037 | last = 0; | |
3038 | while (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == JUMP_INSN | |
3039 | || (GET_CODE (insn) == INSN | |
3040 | && (GET_CODE (PATTERN (insn)) == USE | |
3041 | #ifdef HAVE_cc0 | |
3042 | || sets_cc0_p (PATTERN (insn)) | |
3043 | #endif | |
3044 | )) | |
3045 | || GET_CODE (insn) == NOTE) | |
3046 | { | |
3047 | if (GET_CODE (insn) != NOTE) | |
3048 | { | |
3049 | priority (insn); | |
3050 | if (last == 0) | |
3051 | { | |
3052 | ready[n_ready++] = insn; | |
3053 | INSN_PRIORITY (insn) = TAIL_PRIORITY - i; | |
3054 | INSN_REF_COUNT (insn) = 0; | |
3055 | } | |
3056 | else if (! find_insn_list (insn, LOG_LINKS (last))) | |
3057 | { | |
3058 | add_dependence (last, insn, REG_DEP_ANTI); | |
3059 | INSN_REF_COUNT (insn)++; | |
3060 | } | |
3061 | last = insn; | |
3062 | ||
3063 | /* Skip over insns that are part of a group. */ | |
3064 | while (SCHED_GROUP_P (insn)) | |
3065 | { | |
3066 | insn = prev_nonnote_insn (insn); | |
3067 | priority (insn); | |
3068 | } | |
3069 | } | |
3070 | ||
3071 | insn = PREV_INSN (insn); | |
3072 | /* Don't overrun the bounds of the basic block. */ | |
3073 | if (insn == prev_head) | |
3074 | break; | |
3075 | } | |
3076 | ||
3077 | /* Assign priorities to instructions. Also check whether they | |
3078 | are in priority order already. If so then I will be nonnegative. | |
3079 | We use this shortcut only before reloading. */ | |
3080 | #if 0 | |
3081 | i = reload_completed ? DONE_PRIORITY : MAX_PRIORITY; | |
3082 | #endif | |
3083 | ||
3084 | for (; insn != prev_head; insn = PREV_INSN (insn)) | |
3085 | { | |
3086 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
3087 | { | |
3088 | priority (insn); | |
3089 | if (INSN_REF_COUNT (insn) == 0) | |
3090 | { | |
3091 | if (last == 0) | |
3092 | ready[n_ready++] = insn; | |
3093 | else | |
3094 | { | |
3095 | /* Make this dependent on the last of the instructions | |
3096 | that must remain in order at the end of the block. */ | |
3097 | add_dependence (last, insn, REG_DEP_ANTI); | |
3098 | INSN_REF_COUNT (insn) = 1; | |
3099 | } | |
3100 | } | |
3101 | if (SCHED_GROUP_P (insn)) | |
3102 | { | |
3103 | while (SCHED_GROUP_P (insn)) | |
3104 | { | |
3105 | insn = PREV_INSN (insn); | |
3106 | while (GET_CODE (insn) == NOTE) | |
3107 | insn = PREV_INSN (insn); | |
3108 | priority (insn); | |
3109 | } | |
3110 | continue; | |
3111 | } | |
3112 | #if 0 | |
3113 | if (i < 0) | |
3114 | continue; | |
3115 | if (INSN_PRIORITY (insn) < i) | |
3116 | i = INSN_PRIORITY (insn); | |
3117 | else if (INSN_PRIORITY (insn) > i) | |
3118 | i = DONE_PRIORITY; | |
3119 | #endif | |
3120 | } | |
3121 | } | |
3122 | ||
3123 | #if 0 | |
3124 | /* This short-cut doesn't work. It does not count call insns crossed by | |
3125 | registers in reg_sometimes_live. It does not mark these registers as | |
3126 | dead if they die in this block. It does not mark these registers live | |
3127 | (or create new reg_sometimes_live entries if necessary) if they are born | |
3128 | in this block. | |
3129 | ||
3130 | The easy solution is to just always schedule a block. These blocks tend | |
3131 | to be very short, so this doesn't slow down this pass by much. */ | |
3132 | ||
3133 | /* If existing order is good, don't bother to reorder. */ | |
3134 | if (i != DONE_PRIORITY) | |
3135 | { | |
3136 | if (file) | |
3137 | fprintf (file, ";; already scheduled\n"); | |
3138 | ||
3139 | if (reload_completed == 0) | |
3140 | { | |
3141 | for (i = 0; i < sometimes_max; i++) | |
3142 | regs_sometimes_live[i].live_length += n_insns; | |
3143 | ||
3144 | finish_sometimes_live (regs_sometimes_live, sometimes_max); | |
3145 | } | |
3146 | free_pending_lists (); | |
3147 | return; | |
3148 | } | |
3149 | #endif | |
3150 | ||
3151 | /* Scan all the insns to be scheduled, removing NOTE insns | |
3152 | and register death notes. | |
3153 | Line number NOTE insns end up in NOTE_LIST. | |
3154 | Register death notes end up in DEAD_NOTES. | |
3155 | ||
3156 | Recreate the register life information for the end of this basic | |
3157 | block. */ | |
3158 | ||
3159 | if (reload_completed == 0) | |
3160 | { | |
3161 | bcopy (basic_block_live_at_start[b], bb_live_regs, regset_bytes); | |
3162 | bzero (bb_dead_regs, regset_bytes); | |
3163 | ||
3164 | if (b == 0) | |
3165 | { | |
3166 | /* This is the first block in the function. There may be insns | |
3167 | before head that we can't schedule. We still need to examine | |
3168 | them though for accurate register lifetime analysis. */ | |
3169 | ||
3170 | /* We don't want to remove any REG_DEAD notes as the code below | |
3171 | does. */ | |
3172 | ||
3173 | for (insn = basic_block_head[b]; insn != head; | |
3174 | insn = NEXT_INSN (insn)) | |
3175 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
3176 | { | |
3177 | /* See if the register gets born here. */ | |
3178 | /* We must check for registers being born before we check for | |
3179 | registers dying. It is possible for a register to be born | |
3180 | and die in the same insn, e.g. reading from a volatile | |
3181 | memory location into an otherwise unused register. Such | |
3182 | a register must be marked as dead after this insn. */ | |
3183 | if (GET_CODE (PATTERN (insn)) == SET | |
3184 | || GET_CODE (PATTERN (insn)) == CLOBBER) | |
3185 | sched_note_set (b, PATTERN (insn), 0); | |
3186 | else if (GET_CODE (PATTERN (insn)) == PARALLEL) | |
3187 | { | |
3188 | int j; | |
3189 | for (j = XVECLEN (PATTERN (insn), 0) - 1; j >= 0; j--) | |
3190 | if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET | |
3191 | || GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == CLOBBER) | |
3192 | sched_note_set (b, XVECEXP (PATTERN (insn), 0, j), 0); | |
3193 | ||
3194 | /* ??? This code is obsolete and should be deleted. It | |
3195 | is harmless though, so we will leave it in for now. */ | |
3196 | for (j = XVECLEN (PATTERN (insn), 0) - 1; j >= 0; j--) | |
3197 | if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == USE) | |
3198 | sched_note_set (b, XVECEXP (PATTERN (insn), 0, j), 0); | |
3199 | } | |
3200 | ||
3201 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) | |
3202 | { | |
3203 | if ((REG_NOTE_KIND (link) == REG_DEAD | |
3204 | || REG_NOTE_KIND (link) == REG_UNUSED) | |
3205 | /* Verify that the REG_NOTE has a legal value. */ | |
3206 | && GET_CODE (XEXP (link, 0)) == REG) | |
3207 | { | |
3208 | register int regno = REGNO (XEXP (link, 0)); | |
3209 | register int offset = regno / REGSET_ELT_BITS; | |
3210 | register REGSET_ELT_TYPE bit | |
3211 | = (REGSET_ELT_TYPE) 1 << (regno % REGSET_ELT_BITS); | |
3212 | ||
3213 | if (regno < FIRST_PSEUDO_REGISTER) | |
3214 | { | |
3215 | int j = HARD_REGNO_NREGS (regno, | |
3216 | GET_MODE (XEXP (link, 0))); | |
3217 | while (--j >= 0) | |
3218 | { | |
3219 | offset = (regno + j) / REGSET_ELT_BITS; | |
3220 | bit = ((REGSET_ELT_TYPE) 1 | |
3221 | << ((regno + j) % REGSET_ELT_BITS)); | |
3222 | ||
3223 | bb_live_regs[offset] &= ~bit; | |
3224 | bb_dead_regs[offset] |= bit; | |
3225 | } | |
3226 | } | |
3227 | else | |
3228 | { | |
3229 | bb_live_regs[offset] &= ~bit; | |
3230 | bb_dead_regs[offset] |= bit; | |
3231 | } | |
3232 | } | |
3233 | } | |
3234 | } | |
3235 | } | |
3236 | } | |
3237 | ||
3238 | /* If debugging information is being produced, keep track of the line | |
3239 | number notes for each insn. */ | |
3240 | if (write_symbols != NO_DEBUG) | |
3241 | { | |
3242 | /* We must use the true line number for the first insn in the block | |
3243 | that was computed and saved at the start of this pass. We can't | |
3244 | use the current line number, because scheduling of the previous | |
3245 | block may have changed the current line number. */ | |
3246 | rtx line = line_note_head[b]; | |
3247 | ||
3248 | for (insn = basic_block_head[b]; | |
3249 | insn != next_tail; | |
3250 | insn = NEXT_INSN (insn)) | |
3251 | if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0) | |
3252 | line = insn; | |
3253 | else | |
3254 | LINE_NOTE (insn) = line; | |
3255 | } | |
3256 | ||
3257 | for (insn = head; insn != next_tail; insn = NEXT_INSN (insn)) | |
3258 | { | |
3259 | rtx prev, next, link; | |
3260 | ||
3261 | /* Farm out notes. This is needed to keep the debugger from | |
3262 | getting completely deranged. */ | |
3263 | if (GET_CODE (insn) == NOTE) | |
3264 | { | |
3265 | prev = insn; | |
3266 | insn = unlink_notes (insn, next_tail); | |
3267 | if (prev == tail) | |
3268 | abort (); | |
3269 | if (prev == head) | |
3270 | abort (); | |
3271 | if (insn == next_tail) | |
3272 | abort (); | |
3273 | } | |
3274 | ||
3275 | if (reload_completed == 0 | |
3276 | && GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
3277 | { | |
3278 | /* See if the register gets born here. */ | |
3279 | /* We must check for registers being born before we check for | |
3280 | registers dying. It is possible for a register to be born and | |
3281 | die in the same insn, e.g. reading from a volatile memory | |
3282 | location into an otherwise unused register. Such a register | |
3283 | must be marked as dead after this insn. */ | |
3284 | if (GET_CODE (PATTERN (insn)) == SET | |
3285 | || GET_CODE (PATTERN (insn)) == CLOBBER) | |
3286 | sched_note_set (b, PATTERN (insn), 0); | |
3287 | else if (GET_CODE (PATTERN (insn)) == PARALLEL) | |
3288 | { | |
3289 | int j; | |
3290 | for (j = XVECLEN (PATTERN (insn), 0) - 1; j >= 0; j--) | |
3291 | if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET | |
3292 | || GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == CLOBBER) | |
3293 | sched_note_set (b, XVECEXP (PATTERN (insn), 0, j), 0); | |
3294 | ||
3295 | /* ??? This code is obsolete and should be deleted. It | |
3296 | is harmless though, so we will leave it in for now. */ | |
3297 | for (j = XVECLEN (PATTERN (insn), 0) - 1; j >= 0; j--) | |
3298 | if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == USE) | |
3299 | sched_note_set (b, XVECEXP (PATTERN (insn), 0, j), 0); | |
3300 | } | |
3301 | ||
3302 | /* Need to know what registers this insn kills. */ | |
3303 | for (prev = 0, link = REG_NOTES (insn); link; link = next) | |
3304 | { | |
3305 | int regno; | |
3306 | ||
3307 | next = XEXP (link, 1); | |
3308 | if ((REG_NOTE_KIND (link) == REG_DEAD | |
3309 | || REG_NOTE_KIND (link) == REG_UNUSED) | |
3310 | /* Verify that the REG_NOTE has a legal value. */ | |
3311 | && GET_CODE (XEXP (link, 0)) == REG) | |
3312 | { | |
3313 | register int regno = REGNO (XEXP (link, 0)); | |
3314 | register int offset = regno / REGSET_ELT_BITS; | |
3315 | register REGSET_ELT_TYPE bit | |
3316 | = (REGSET_ELT_TYPE) 1 << (regno % REGSET_ELT_BITS); | |
3317 | ||
3318 | /* Only unlink REG_DEAD notes; leave REG_UNUSED notes | |
3319 | alone. */ | |
3320 | if (REG_NOTE_KIND (link) == REG_DEAD) | |
3321 | { | |
3322 | if (prev) | |
3323 | XEXP (prev, 1) = next; | |
3324 | else | |
3325 | REG_NOTES (insn) = next; | |
3326 | XEXP (link, 1) = dead_notes; | |
3327 | dead_notes = link; | |
3328 | } | |
3329 | else | |
3330 | prev = link; | |
3331 | ||
3332 | if (regno < FIRST_PSEUDO_REGISTER) | |
3333 | { | |
3334 | int j = HARD_REGNO_NREGS (regno, | |
3335 | GET_MODE (XEXP (link, 0))); | |
3336 | while (--j >= 0) | |
3337 | { | |
3338 | offset = (regno + j) / REGSET_ELT_BITS; | |
3339 | bit = ((REGSET_ELT_TYPE) 1 | |
3340 | << ((regno + j) % REGSET_ELT_BITS)); | |
3341 | ||
3342 | bb_live_regs[offset] &= ~bit; | |
3343 | bb_dead_regs[offset] |= bit; | |
3344 | } | |
3345 | } | |
3346 | else | |
3347 | { | |
3348 | bb_live_regs[offset] &= ~bit; | |
3349 | bb_dead_regs[offset] |= bit; | |
3350 | } | |
3351 | } | |
3352 | else | |
3353 | prev = link; | |
3354 | } | |
3355 | } | |
3356 | } | |
3357 | ||
3358 | if (reload_completed == 0) | |
3359 | { | |
3360 | /* Keep track of register lives. */ | |
3361 | old_live_regs = (regset) alloca (regset_bytes); | |
3362 | regs_sometimes_live | |
3363 | = (struct sometimes *) alloca (max_regno * sizeof (struct sometimes)); | |
3364 | sometimes_max = 0; | |
3365 | ||
3366 | /* Start with registers live at end. */ | |
3367 | for (j = 0; j < regset_size; j++) | |
3368 | { | |
3369 | REGSET_ELT_TYPE live = bb_live_regs[j]; | |
3370 | old_live_regs[j] = live; | |
3371 | if (live) | |
3372 | { | |
3373 | register REGSET_ELT_TYPE bit; | |
3374 | for (bit = 0; bit < REGSET_ELT_BITS; bit++) | |
3375 | if (live & ((REGSET_ELT_TYPE) 1 << bit)) | |
3376 | sometimes_max = new_sometimes_live (regs_sometimes_live, j, | |
3377 | bit, sometimes_max); | |
3378 | } | |
3379 | } | |
3380 | } | |
3381 | ||
3382 | SCHED_SORT (ready, n_ready, 1); | |
3383 | ||
3384 | if (file) | |
3385 | { | |
3386 | fprintf (file, ";; ready list initially:\n;; "); | |
3387 | for (i = 0; i < n_ready; i++) | |
3388 | fprintf (file, "%d ", INSN_UID (ready[i])); | |
3389 | fprintf (file, "\n\n"); | |
3390 | ||
3391 | for (insn = head; insn != next_tail; insn = NEXT_INSN (insn)) | |
3392 | if (INSN_PRIORITY (insn) > 0) | |
3393 | fprintf (file, ";; insn[%4d]: priority = %4d, ref_count = %4d\n", | |
3394 | INSN_UID (insn), INSN_PRIORITY (insn), | |
3395 | INSN_REF_COUNT (insn)); | |
3396 | } | |
3397 | ||
3398 | /* Now HEAD and TAIL are going to become disconnected | |
3399 | entirely from the insn chain. */ | |
3400 | tail = 0; | |
3401 | ||
3402 | /* Q_SIZE will always be zero here. */ | |
3403 | q_ptr = 0; clock = 0; | |
3404 | bzero (insn_queue, sizeof (insn_queue)); | |
3405 | ||
3406 | /* Now, perform list scheduling. */ | |
3407 | ||
3408 | /* Where we start inserting insns is after TAIL. */ | |
3409 | last = next_tail; | |
3410 | ||
3411 | new_needs = (NEXT_INSN (prev_head) == basic_block_head[b] | |
3412 | ? NEED_HEAD : NEED_NOTHING); | |
3413 | if (PREV_INSN (next_tail) == basic_block_end[b]) | |
3414 | new_needs |= NEED_TAIL; | |
3415 | ||
3416 | new_ready = n_ready; | |
3417 | while (sched_n_insns < n_insns) | |
3418 | { | |
3419 | q_ptr = NEXT_Q (q_ptr); clock++; | |
3420 | ||
3421 | /* Add all pending insns that can be scheduled without stalls to the | |
3422 | ready list. */ | |
3423 | for (insn = insn_queue[q_ptr]; insn; insn = NEXT_INSN (insn)) | |
3424 | { | |
3425 | if (file) | |
3426 | fprintf (file, ";; launching %d before %d with no stalls at T-%d\n", | |
3427 | INSN_UID (insn), INSN_UID (last), clock); | |
3428 | ready[new_ready++] = insn; | |
3429 | q_size -= 1; | |
3430 | } | |
3431 | insn_queue[q_ptr] = 0; | |
3432 | ||
3433 | /* If there are no ready insns, stall until one is ready and add all | |
3434 | of the pending insns at that point to the ready list. */ | |
3435 | if (new_ready == 0) | |
3436 | { | |
3437 | register int stalls; | |
3438 | ||
3439 | for (stalls = 1; stalls < INSN_QUEUE_SIZE; stalls++) | |
3440 | if (insn = insn_queue[NEXT_Q_AFTER (q_ptr, stalls)]) | |
3441 | { | |
3442 | for (; insn; insn = NEXT_INSN (insn)) | |
3443 | { | |
3444 | if (file) | |
3445 | fprintf (file, ";; launching %d before %d with %d stalls at T-%d\n", | |
3446 | INSN_UID (insn), INSN_UID (last), stalls, clock); | |
3447 | ready[new_ready++] = insn; | |
3448 | q_size -= 1; | |
3449 | } | |
3450 | insn_queue[NEXT_Q_AFTER (q_ptr, stalls)] = 0; | |
3451 | break; | |
3452 | } | |
3453 | ||
3454 | q_ptr = NEXT_Q_AFTER (q_ptr, stalls); clock += stalls; | |
3455 | } | |
3456 | ||
3457 | /* There should be some instructions waiting to fire. */ | |
3458 | if (new_ready == 0) | |
3459 | abort (); | |
3460 | ||
3461 | if (file) | |
3462 | { | |
3463 | fprintf (file, ";; ready list at T-%d:", clock); | |
3464 | for (i = 0; i < new_ready; i++) | |
3465 | fprintf (file, " %d (%x)", | |
3466 | INSN_UID (ready[i]), INSN_PRIORITY (ready[i])); | |
3467 | } | |
3468 | ||
3469 | /* Sort the ready list and choose the best insn to schedule. Select | |
3470 | which insn should issue in this cycle and queue those that are | |
3471 | blocked by function unit hazards. | |
3472 | ||
3473 | N_READY holds the number of items that were scheduled the last time, | |
3474 | minus the one instruction scheduled on the last loop iteration; it | |
3475 | is not modified for any other reason in this loop. */ | |
3476 | ||
3477 | SCHED_SORT (ready, new_ready, n_ready); | |
3478 | if (MAX_BLOCKAGE > 1) | |
3479 | { | |
3480 | new_ready = schedule_select (ready, new_ready, clock, file); | |
3481 | if (new_ready == 0) | |
3482 | { | |
3483 | if (file) | |
3484 | fprintf (file, "\n"); | |
3485 | /* We must set n_ready here, to ensure that sorting always | |
3486 | occurs when we come back to the SCHED_SORT line above. */ | |
3487 | n_ready = 0; | |
3488 | continue; | |
3489 | } | |
3490 | } | |
3491 | n_ready = new_ready; | |
3492 | last_scheduled_insn = insn = ready[0]; | |
3493 | ||
3494 | /* The first insn scheduled becomes the new tail. */ | |
3495 | if (tail == 0) | |
3496 | tail = insn; | |
3497 | ||
3498 | if (file) | |
3499 | { | |
3500 | fprintf (file, ", now"); | |
3501 | for (i = 0; i < n_ready; i++) | |
3502 | fprintf (file, " %d", INSN_UID (ready[i])); | |
3503 | fprintf (file, "\n"); | |
3504 | } | |
3505 | ||
3506 | if (DONE_PRIORITY_P (insn)) | |
3507 | abort (); | |
3508 | ||
3509 | if (reload_completed == 0) | |
3510 | { | |
3511 | /* Process this insn, and each insn linked to this one which must | |
3512 | be immediately output after this insn. */ | |
3513 | do | |
3514 | { | |
3515 | /* First we kill registers set by this insn, and then we | |
3516 | make registers used by this insn live. This is the opposite | |
3517 | order used above because we are traversing the instructions | |
3518 | backwards. */ | |
3519 | ||
3520 | /* Strictly speaking, we should scan REG_UNUSED notes and make | |
3521 | every register mentioned there live, however, we will just | |
3522 | kill them again immediately below, so there doesn't seem to | |
3523 | be any reason why we bother to do this. */ | |
3524 | ||
3525 | /* See if this is the last notice we must take of a register. */ | |
3526 | if (GET_CODE (PATTERN (insn)) == SET | |
3527 | || GET_CODE (PATTERN (insn)) == CLOBBER) | |
3528 | sched_note_set (b, PATTERN (insn), 1); | |
3529 | else if (GET_CODE (PATTERN (insn)) == PARALLEL) | |
3530 | { | |
3531 | int j; | |
3532 | for (j = XVECLEN (PATTERN (insn), 0) - 1; j >= 0; j--) | |
3533 | if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET | |
3534 | || GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == CLOBBER) | |
3535 | sched_note_set (b, XVECEXP (PATTERN (insn), 0, j), 1); | |
3536 | } | |
3537 | ||
3538 | /* This code keeps life analysis information up to date. */ | |
3539 | if (GET_CODE (insn) == CALL_INSN) | |
3540 | { | |
3541 | register struct sometimes *p; | |
3542 | ||
3543 | /* A call kills all call used and global registers, except | |
3544 | for those mentioned in the call pattern which will be | |
3545 | made live again later. */ | |
3546 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
3547 | if (call_used_regs[i] || global_regs[i]) | |
3548 | { | |
3549 | register int offset = i / REGSET_ELT_BITS; | |
3550 | register REGSET_ELT_TYPE bit | |
3551 | = (REGSET_ELT_TYPE) 1 << (i % REGSET_ELT_BITS); | |
3552 | ||
3553 | bb_live_regs[offset] &= ~bit; | |
3554 | bb_dead_regs[offset] |= bit; | |
3555 | } | |
3556 | ||
3557 | /* Regs live at the time of a call instruction must not | |
3558 | go in a register clobbered by calls. Record this for | |
3559 | all regs now live. Note that insns which are born or | |
3560 | die in a call do not cross a call, so this must be done | |
3561 | after the killings (above) and before the births | |
3562 | (below). */ | |
3563 | p = regs_sometimes_live; | |
3564 | for (i = 0; i < sometimes_max; i++, p++) | |
3565 | if (bb_live_regs[p->offset] | |
3566 | & ((REGSET_ELT_TYPE) 1 << p->bit)) | |
3567 | p->calls_crossed += 1; | |
3568 | } | |
3569 | ||
3570 | /* Make every register used live, and add REG_DEAD notes for | |
3571 | registers which were not live before we started. */ | |
3572 | attach_deaths_insn (insn); | |
3573 | ||
3574 | /* Find registers now made live by that instruction. */ | |
3575 | for (i = 0; i < regset_size; i++) | |
3576 | { | |
3577 | REGSET_ELT_TYPE diff = bb_live_regs[i] & ~old_live_regs[i]; | |
3578 | if (diff) | |
3579 | { | |
3580 | register int bit; | |
3581 | old_live_regs[i] |= diff; | |
3582 | for (bit = 0; bit < REGSET_ELT_BITS; bit++) | |
3583 | if (diff & ((REGSET_ELT_TYPE) 1 << bit)) | |
3584 | sometimes_max | |
3585 | = new_sometimes_live (regs_sometimes_live, i, bit, | |
3586 | sometimes_max); | |
3587 | } | |
3588 | } | |
3589 | ||
3590 | /* Count lengths of all regs we are worrying about now, | |
3591 | and handle registers no longer live. */ | |
3592 | ||
3593 | for (i = 0; i < sometimes_max; i++) | |
3594 | { | |
3595 | register struct sometimes *p = ®s_sometimes_live[i]; | |
3596 | int regno = p->offset*REGSET_ELT_BITS + p->bit; | |
3597 | ||
3598 | p->live_length += 1; | |
3599 | ||
3600 | if ((bb_live_regs[p->offset] | |
3601 | & ((REGSET_ELT_TYPE) 1 << p->bit)) == 0) | |
3602 | { | |
3603 | /* This is the end of one of this register's lifetime | |
3604 | segments. Save the lifetime info collected so far, | |
3605 | and clear its bit in the old_live_regs entry. */ | |
3606 | sched_reg_live_length[regno] += p->live_length; | |
3607 | sched_reg_n_calls_crossed[regno] += p->calls_crossed; | |
3608 | old_live_regs[p->offset] | |
3609 | &= ~((REGSET_ELT_TYPE) 1 << p->bit); | |
3610 | ||
3611 | /* Delete the reg_sometimes_live entry for this reg by | |
3612 | copying the last entry over top of it. */ | |
3613 | *p = regs_sometimes_live[--sometimes_max]; | |
3614 | /* ...and decrement i so that this newly copied entry | |
3615 | will be processed. */ | |
3616 | i--; | |
3617 | } | |
3618 | } | |
3619 | ||
3620 | link = insn; | |
3621 | insn = PREV_INSN (insn); | |
3622 | } | |
3623 | while (SCHED_GROUP_P (link)); | |
3624 | ||
3625 | /* Set INSN back to the insn we are scheduling now. */ | |
3626 | insn = ready[0]; | |
3627 | } | |
3628 | ||
3629 | /* Schedule INSN. Remove it from the ready list. */ | |
3630 | ready += 1; | |
3631 | n_ready -= 1; | |
3632 | ||
3633 | sched_n_insns += 1; | |
3634 | NEXT_INSN (insn) = last; | |
3635 | PREV_INSN (last) = insn; | |
3636 | last = insn; | |
3637 | ||
3638 | /* Everything that precedes INSN now either becomes "ready", if | |
3639 | it can execute immediately before INSN, or "pending", if | |
3640 | there must be a delay. Give INSN high enough priority that | |
3641 | at least one (maybe more) reg-killing insns can be launched | |
3642 | ahead of all others. Mark INSN as scheduled by changing its | |
3643 | priority to -1. */ | |
3644 | INSN_PRIORITY (insn) = LAUNCH_PRIORITY; | |
3645 | new_ready = schedule_insn (insn, ready, n_ready, clock); | |
3646 | INSN_PRIORITY (insn) = DONE_PRIORITY; | |
3647 | ||
3648 | /* Schedule all prior insns that must not be moved. */ | |
3649 | if (SCHED_GROUP_P (insn)) | |
3650 | { | |
3651 | /* Disable these insns from being launched. */ | |
3652 | link = insn; | |
3653 | while (SCHED_GROUP_P (link)) | |
3654 | { | |
3655 | /* Disable these insns from being launched by anybody. */ | |
3656 | link = PREV_INSN (link); | |
3657 | INSN_REF_COUNT (link) = 0; | |
3658 | } | |
3659 | ||
3660 | /* None of these insns can move forward into delay slots. */ | |
3661 | while (SCHED_GROUP_P (insn)) | |
3662 | { | |
3663 | insn = PREV_INSN (insn); | |
3664 | new_ready = schedule_insn (insn, ready, new_ready, clock); | |
3665 | INSN_PRIORITY (insn) = DONE_PRIORITY; | |
3666 | ||
3667 | sched_n_insns += 1; | |
3668 | NEXT_INSN (insn) = last; | |
3669 | PREV_INSN (last) = insn; | |
3670 | last = insn; | |
3671 | } | |
3672 | } | |
3673 | } | |
3674 | if (q_size != 0) | |
3675 | abort (); | |
3676 | ||
3677 | if (reload_completed == 0) | |
3678 | finish_sometimes_live (regs_sometimes_live, sometimes_max); | |
3679 | ||
3680 | /* HEAD is now the first insn in the chain of insns that | |
3681 | been scheduled by the loop above. | |
3682 | TAIL is the last of those insns. */ | |
3683 | head = insn; | |
3684 | ||
3685 | /* NOTE_LIST is the end of a chain of notes previously found | |
3686 | among the insns. Insert them at the beginning of the insns. */ | |
3687 | if (note_list != 0) | |
3688 | { | |
3689 | rtx note_head = note_list; | |
3690 | while (PREV_INSN (note_head)) | |
3691 | note_head = PREV_INSN (note_head); | |
3692 | ||
3693 | PREV_INSN (head) = note_list; | |
3694 | NEXT_INSN (note_list) = head; | |
3695 | head = note_head; | |
3696 | } | |
3697 | ||
3698 | /* There should be no REG_DEAD notes leftover at the end. | |
3699 | In practice, this can occur as the result of bugs in flow, combine.c, | |
3700 | and/or sched.c. The values of the REG_DEAD notes remaining are | |
3701 | meaningless, because dead_notes is just used as a free list. */ | |
3702 | #if 1 | |
3703 | if (dead_notes != 0) | |
3704 | abort (); | |
3705 | #endif | |
3706 | ||
3707 | if (new_needs & NEED_HEAD) | |
3708 | basic_block_head[b] = head; | |
3709 | PREV_INSN (head) = prev_head; | |
3710 | NEXT_INSN (prev_head) = head; | |
3711 | ||
3712 | if (new_needs & NEED_TAIL) | |
3713 | basic_block_end[b] = tail; | |
3714 | NEXT_INSN (tail) = next_tail; | |
3715 | PREV_INSN (next_tail) = tail; | |
3716 | ||
3717 | /* Restore the line-number notes of each insn. */ | |
3718 | if (write_symbols != NO_DEBUG) | |
3719 | { | |
3720 | rtx line, note, prev, new; | |
3721 | int notes = 0; | |
3722 | ||
3723 | head = basic_block_head[b]; | |
3724 | next_tail = NEXT_INSN (basic_block_end[b]); | |
3725 | ||
3726 | /* Determine the current line-number. We want to know the current | |
3727 | line number of the first insn of the block here, in case it is | |
3728 | different from the true line number that was saved earlier. If | |
3729 | different, then we need a line number note before the first insn | |
3730 | of this block. If it happens to be the same, then we don't want to | |
3731 | emit another line number note here. */ | |
3732 | for (line = head; line; line = PREV_INSN (line)) | |
3733 | if (GET_CODE (line) == NOTE && NOTE_LINE_NUMBER (line) > 0) | |
3734 | break; | |
3735 | ||
3736 | /* Walk the insns keeping track of the current line-number and inserting | |
3737 | the line-number notes as needed. */ | |
3738 | for (insn = head; insn != next_tail; insn = NEXT_INSN (insn)) | |
3739 | if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0) | |
3740 | line = insn; | |
3741 | else if (! (GET_CODE (insn) == NOTE | |
3742 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_DELETED) | |
3743 | && (note = LINE_NOTE (insn)) != 0 | |
3744 | && note != line | |
3745 | && (line == 0 | |
3746 | || NOTE_LINE_NUMBER (note) != NOTE_LINE_NUMBER (line) | |
3747 | || NOTE_SOURCE_FILE (note) != NOTE_SOURCE_FILE (line))) | |
3748 | { | |
3749 | line = note; | |
3750 | prev = PREV_INSN (insn); | |
3751 | if (LINE_NOTE (note)) | |
3752 | { | |
3753 | /* Re-use the original line-number note. */ | |
3754 | LINE_NOTE (note) = 0; | |
3755 | PREV_INSN (note) = prev; | |
3756 | NEXT_INSN (prev) = note; | |
3757 | PREV_INSN (insn) = note; | |
3758 | NEXT_INSN (note) = insn; | |
3759 | } | |
3760 | else | |
3761 | { | |
3762 | notes++; | |
3763 | new = emit_note_after (NOTE_LINE_NUMBER (note), prev); | |
3764 | NOTE_SOURCE_FILE (new) = NOTE_SOURCE_FILE (note); | |
3765 | } | |
3766 | } | |
3767 | if (file && notes) | |
3768 | fprintf (file, ";; added %d line-number notes\n", notes); | |
3769 | } | |
3770 | ||
3771 | if (file) | |
3772 | { | |
3773 | fprintf (file, ";; total time = %d\n;; new basic block head = %d\n;; new basic block end = %d\n\n", | |
3774 | clock, INSN_UID (basic_block_head[b]), INSN_UID (basic_block_end[b])); | |
3775 | } | |
3776 | ||
3777 | /* Yow! We're done! */ | |
3778 | free_pending_lists (); | |
3779 | ||
3780 | return; | |
3781 | } | |
3782 | \f | |
3783 | /* Subroutine of split_hard_reg_notes. Searches X for any reference to | |
3784 | REGNO, returning the rtx of the reference found if any. Otherwise, | |
3785 | returns 0. */ | |
3786 | ||
3787 | rtx | |
3788 | regno_use_in (regno, x) | |
3789 | int regno; | |
3790 | rtx x; | |
3791 | { | |
3792 | register char *fmt; | |
3793 | int i, j; | |
3794 | rtx tem; | |
3795 | ||
3796 | if (GET_CODE (x) == REG && REGNO (x) == regno) | |
3797 | return x; | |
3798 | ||
3799 | fmt = GET_RTX_FORMAT (GET_CODE (x)); | |
3800 | for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--) | |
3801 | { | |
3802 | if (fmt[i] == 'e') | |
3803 | { | |
3804 | if (tem = regno_use_in (regno, XEXP (x, i))) | |
3805 | return tem; | |
3806 | } | |
3807 | else if (fmt[i] == 'E') | |
3808 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
3809 | if (tem = regno_use_in (regno , XVECEXP (x, i, j))) | |
3810 | return tem; | |
3811 | } | |
3812 | ||
3813 | return 0; | |
3814 | } | |
3815 | ||
3816 | /* Subroutine of update_flow_info. Determines whether any new REG_NOTEs are | |
3817 | needed for the hard register mentioned in the note. This can happen | |
3818 | if the reference to the hard register in the original insn was split into | |
3819 | several smaller hard register references in the split insns. */ | |
3820 | ||
3821 | static void | |
3822 | split_hard_reg_notes (note, first, last, orig_insn) | |
3823 | rtx note, first, last, orig_insn; | |
3824 | { | |
3825 | rtx reg, temp, link; | |
3826 | int n_regs, i, new_reg; | |
3827 | rtx insn; | |
3828 | ||
3829 | /* Assume that this is a REG_DEAD note. */ | |
3830 | if (REG_NOTE_KIND (note) != REG_DEAD) | |
3831 | abort (); | |
3832 | ||
3833 | reg = XEXP (note, 0); | |
3834 | ||
3835 | n_regs = HARD_REGNO_NREGS (REGNO (reg), GET_MODE (reg)); | |
3836 | ||
3837 | for (i = 0; i < n_regs; i++) | |
3838 | { | |
3839 | new_reg = REGNO (reg) + i; | |
3840 | ||
3841 | /* Check for references to new_reg in the split insns. */ | |
3842 | for (insn = last; ; insn = PREV_INSN (insn)) | |
3843 | { | |
3844 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
3845 | && (temp = regno_use_in (new_reg, PATTERN (insn)))) | |
3846 | { | |
3847 | /* Create a new reg dead note here. */ | |
3848 | link = rtx_alloc (EXPR_LIST); | |
3849 | PUT_REG_NOTE_KIND (link, REG_DEAD); | |
3850 | XEXP (link, 0) = temp; | |
3851 | XEXP (link, 1) = REG_NOTES (insn); | |
3852 | REG_NOTES (insn) = link; | |
3853 | ||
3854 | /* If killed multiple registers here, then add in the excess. */ | |
3855 | i += HARD_REGNO_NREGS (REGNO (temp), GET_MODE (temp)) - 1; | |
3856 | ||
3857 | break; | |
3858 | } | |
3859 | /* It isn't mentioned anywhere, so no new reg note is needed for | |
3860 | this register. */ | |
3861 | if (insn == first) | |
3862 | break; | |
3863 | } | |
3864 | } | |
3865 | } | |
3866 | ||
3867 | /* Subroutine of update_flow_info. Determines whether a SET or CLOBBER in an | |
3868 | insn created by splitting needs a REG_DEAD or REG_UNUSED note added. */ | |
3869 | ||
3870 | static void | |
3871 | new_insn_dead_notes (pat, insn, last, orig_insn) | |
3872 | rtx pat, insn, last, orig_insn; | |
3873 | { | |
3874 | rtx dest, tem, set; | |
3875 | ||
3876 | /* PAT is either a CLOBBER or a SET here. */ | |
3877 | dest = XEXP (pat, 0); | |
3878 | ||
3879 | while (GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SUBREG | |
3880 | || GET_CODE (dest) == STRICT_LOW_PART | |
3881 | || GET_CODE (dest) == SIGN_EXTRACT) | |
3882 | dest = XEXP (dest, 0); | |
3883 | ||
3884 | if (GET_CODE (dest) == REG) | |
3885 | { | |
3886 | for (tem = last; tem != insn; tem = PREV_INSN (tem)) | |
3887 | { | |
3888 | if (GET_RTX_CLASS (GET_CODE (tem)) == 'i' | |
3889 | && reg_overlap_mentioned_p (dest, PATTERN (tem)) | |
3890 | && (set = single_set (tem))) | |
3891 | { | |
3892 | rtx tem_dest = SET_DEST (set); | |
3893 | ||
3894 | while (GET_CODE (tem_dest) == ZERO_EXTRACT | |
3895 | || GET_CODE (tem_dest) == SUBREG | |
3896 | || GET_CODE (tem_dest) == STRICT_LOW_PART | |
3897 | || GET_CODE (tem_dest) == SIGN_EXTRACT) | |
3898 | tem_dest = XEXP (tem_dest, 0); | |
3899 | ||
3900 | if (tem_dest != dest) | |
3901 | { | |
3902 | /* Use the same scheme as combine.c, don't put both REG_DEAD | |
3903 | and REG_UNUSED notes on the same insn. */ | |
3904 | if (! find_regno_note (tem, REG_UNUSED, REGNO (dest)) | |
3905 | && ! find_regno_note (tem, REG_DEAD, REGNO (dest))) | |
3906 | { | |
3907 | rtx note = rtx_alloc (EXPR_LIST); | |
3908 | PUT_REG_NOTE_KIND (note, REG_DEAD); | |
3909 | XEXP (note, 0) = dest; | |
3910 | XEXP (note, 1) = REG_NOTES (tem); | |
3911 | REG_NOTES (tem) = note; | |
3912 | } | |
3913 | /* The reg only dies in one insn, the last one that uses | |
3914 | it. */ | |
3915 | break; | |
3916 | } | |
3917 | else if (reg_overlap_mentioned_p (dest, SET_SRC (set))) | |
3918 | /* We found an instruction that both uses the register, | |
3919 | and sets it, so no new REG_NOTE is needed for this set. */ | |
3920 | break; | |
3921 | } | |
3922 | } | |
3923 | /* If this is a set, it must die somewhere, unless it is the dest of | |
3924 | the original insn, and hence is live after the original insn. Abort | |
3925 | if it isn't supposed to be live after the original insn. | |
3926 | ||
3927 | If this is a clobber, then just add a REG_UNUSED note. */ | |
3928 | if (tem == insn) | |
3929 | { | |
3930 | int live_after_orig_insn = 0; | |
3931 | rtx pattern = PATTERN (orig_insn); | |
3932 | int i; | |
3933 | ||
3934 | if (GET_CODE (pat) == CLOBBER) | |
3935 | { | |
3936 | rtx note = rtx_alloc (EXPR_LIST); | |
3937 | PUT_REG_NOTE_KIND (note, REG_UNUSED); | |
3938 | XEXP (note, 0) = dest; | |
3939 | XEXP (note, 1) = REG_NOTES (insn); | |
3940 | REG_NOTES (insn) = note; | |
3941 | return; | |
3942 | } | |
3943 | ||
3944 | /* The original insn could have multiple sets, so search the | |
3945 | insn for all sets. */ | |
3946 | if (GET_CODE (pattern) == SET) | |
3947 | { | |
3948 | if (reg_overlap_mentioned_p (dest, SET_DEST (pattern))) | |
3949 | live_after_orig_insn = 1; | |
3950 | } | |
3951 | else if (GET_CODE (pattern) == PARALLEL) | |
3952 | { | |
3953 | for (i = 0; i < XVECLEN (pattern, 0); i++) | |
3954 | if (GET_CODE (XVECEXP (pattern, 0, i)) == SET | |
3955 | && reg_overlap_mentioned_p (dest, | |
3956 | SET_DEST (XVECEXP (pattern, | |
3957 | 0, i)))) | |
3958 | live_after_orig_insn = 1; | |
3959 | } | |
3960 | ||
3961 | if (! live_after_orig_insn) | |
3962 | abort (); | |
3963 | } | |
3964 | } | |
3965 | } | |
3966 | ||
3967 | /* Subroutine of update_flow_info. Update the value of reg_n_sets for all | |
3968 | registers modified by X. INC is -1 if the containing insn is being deleted, | |
3969 | and is 1 if the containing insn is a newly generated insn. */ | |
3970 | ||
3971 | static void | |
3972 | update_n_sets (x, inc) | |
3973 | rtx x; | |
3974 | int inc; | |
3975 | { | |
3976 | rtx dest = SET_DEST (x); | |
3977 | ||
3978 | while (GET_CODE (dest) == STRICT_LOW_PART || GET_CODE (dest) == SUBREG | |
3979 | || GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SIGN_EXTRACT) | |
3980 | dest = SUBREG_REG (dest); | |
3981 | ||
3982 | if (GET_CODE (dest) == REG) | |
3983 | { | |
3984 | int regno = REGNO (dest); | |
3985 | ||
3986 | if (regno < FIRST_PSEUDO_REGISTER) | |
3987 | { | |
3988 | register int i; | |
3989 | int endregno = regno + HARD_REGNO_NREGS (regno, GET_MODE (dest)); | |
3990 | ||
3991 | for (i = regno; i < endregno; i++) | |
3992 | reg_n_sets[i] += inc; | |
3993 | } | |
3994 | else | |
3995 | reg_n_sets[regno] += inc; | |
3996 | } | |
3997 | } | |
3998 | ||
3999 | /* Updates all flow-analysis related quantities (including REG_NOTES) for | |
4000 | the insns from FIRST to LAST inclusive that were created by splitting | |
4001 | ORIG_INSN. NOTES are the original REG_NOTES. */ | |
4002 | ||
4003 | static void | |
4004 | update_flow_info (notes, first, last, orig_insn) | |
4005 | rtx notes; | |
4006 | rtx first, last; | |
4007 | rtx orig_insn; | |
4008 | { | |
4009 | rtx insn, note; | |
4010 | rtx next; | |
4011 | rtx orig_dest, temp; | |
4012 | rtx set; | |
4013 | ||
4014 | /* Get and save the destination set by the original insn. */ | |
4015 | ||
4016 | orig_dest = single_set (orig_insn); | |
4017 | if (orig_dest) | |
4018 | orig_dest = SET_DEST (orig_dest); | |
4019 | ||
4020 | /* Move REG_NOTES from the original insn to where they now belong. */ | |
4021 | ||
4022 | for (note = notes; note; note = next) | |
4023 | { | |
4024 | next = XEXP (note, 1); | |
4025 | switch (REG_NOTE_KIND (note)) | |
4026 | { | |
4027 | case REG_DEAD: | |
4028 | case REG_UNUSED: | |
4029 | /* Move these notes from the original insn to the last new insn where | |
4030 | the register is now set. */ | |
4031 | ||
4032 | for (insn = last; ; insn = PREV_INSN (insn)) | |
4033 | { | |
4034 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
4035 | && reg_mentioned_p (XEXP (note, 0), PATTERN (insn))) | |
4036 | { | |
4037 | /* If this note refers to a multiple word hard register, it | |
4038 | may have been split into several smaller hard register | |
4039 | references, so handle it specially. */ | |
4040 | temp = XEXP (note, 0); | |
4041 | if (REG_NOTE_KIND (note) == REG_DEAD | |
4042 | && GET_CODE (temp) == REG | |
4043 | && REGNO (temp) < FIRST_PSEUDO_REGISTER | |
4044 | && HARD_REGNO_NREGS (REGNO (temp), GET_MODE (temp)) > 1) | |
4045 | split_hard_reg_notes (note, first, last, orig_insn); | |
4046 | else | |
4047 | { | |
4048 | XEXP (note, 1) = REG_NOTES (insn); | |
4049 | REG_NOTES (insn) = note; | |
4050 | } | |
4051 | ||
4052 | /* Sometimes need to convert REG_UNUSED notes to REG_DEAD | |
4053 | notes. */ | |
4054 | /* ??? This won't handle multiple word registers correctly, | |
4055 | but should be good enough for now. */ | |
4056 | if (REG_NOTE_KIND (note) == REG_UNUSED | |
4057 | && ! dead_or_set_p (insn, XEXP (note, 0))) | |
4058 | PUT_REG_NOTE_KIND (note, REG_DEAD); | |
4059 | ||
4060 | /* The reg only dies in one insn, the last one that uses | |
4061 | it. */ | |
4062 | break; | |
4063 | } | |
4064 | /* It must die somewhere, fail it we couldn't find where it died. | |
4065 | ||
4066 | If this is a REG_UNUSED note, then it must be a temporary | |
4067 | register that was not needed by this instantiation of the | |
4068 | pattern, so we can safely ignore it. */ | |
4069 | if (insn == first) | |
4070 | { | |
4071 | if (REG_NOTE_KIND (note) != REG_UNUSED) | |
4072 | abort (); | |
4073 | ||
4074 | break; | |
4075 | } | |
4076 | } | |
4077 | break; | |
4078 | ||
4079 | case REG_WAS_0: | |
4080 | /* This note applies to the dest of the original insn. Find the | |
4081 | first new insn that now has the same dest, and move the note | |
4082 | there. */ | |
4083 | ||
4084 | if (! orig_dest) | |
4085 | abort (); | |
4086 | ||
4087 | for (insn = first; ; insn = NEXT_INSN (insn)) | |
4088 | { | |
4089 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
4090 | && (temp = single_set (insn)) | |
4091 | && rtx_equal_p (SET_DEST (temp), orig_dest)) | |
4092 | { | |
4093 | XEXP (note, 1) = REG_NOTES (insn); | |
4094 | REG_NOTES (insn) = note; | |
4095 | /* The reg is only zero before one insn, the first that | |
4096 | uses it. */ | |
4097 | break; | |
4098 | } | |
4099 | /* It must be set somewhere, fail if we couldn't find where it | |
4100 | was set. */ | |
4101 | if (insn == last) | |
4102 | abort (); | |
4103 | } | |
4104 | break; | |
4105 | ||
4106 | case REG_EQUAL: | |
4107 | case REG_EQUIV: | |
4108 | /* A REG_EQUIV or REG_EQUAL note on an insn with more than one | |
4109 | set is meaningless. Just drop the note. */ | |
4110 | if (! orig_dest) | |
4111 | break; | |
4112 | ||
4113 | case REG_NO_CONFLICT: | |
4114 | /* These notes apply to the dest of the original insn. Find the last | |
4115 | new insn that now has the same dest, and move the note there. */ | |
4116 | ||
4117 | if (! orig_dest) | |
4118 | abort (); | |
4119 | ||
4120 | for (insn = last; ; insn = PREV_INSN (insn)) | |
4121 | { | |
4122 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
4123 | && (temp = single_set (insn)) | |
4124 | && rtx_equal_p (SET_DEST (temp), orig_dest)) | |
4125 | { | |
4126 | XEXP (note, 1) = REG_NOTES (insn); | |
4127 | REG_NOTES (insn) = note; | |
4128 | /* Only put this note on one of the new insns. */ | |
4129 | break; | |
4130 | } | |
4131 | ||
4132 | /* The original dest must still be set someplace. Abort if we | |
4133 | couldn't find it. */ | |
4134 | if (insn == first) | |
4135 | abort (); | |
4136 | } | |
4137 | break; | |
4138 | ||
4139 | case REG_LIBCALL: | |
4140 | /* Move a REG_LIBCALL note to the first insn created, and update | |
4141 | the corresponding REG_RETVAL note. */ | |
4142 | XEXP (note, 1) = REG_NOTES (first); | |
4143 | REG_NOTES (first) = note; | |
4144 | ||
4145 | insn = XEXP (note, 0); | |
4146 | note = find_reg_note (insn, REG_RETVAL, NULL_RTX); | |
4147 | if (note) | |
4148 | XEXP (note, 0) = first; | |
4149 | break; | |
4150 | ||
4151 | case REG_RETVAL: | |
4152 | /* Move a REG_RETVAL note to the last insn created, and update | |
4153 | the corresponding REG_LIBCALL note. */ | |
4154 | XEXP (note, 1) = REG_NOTES (last); | |
4155 | REG_NOTES (last) = note; | |
4156 | ||
4157 | insn = XEXP (note, 0); | |
4158 | note = find_reg_note (insn, REG_LIBCALL, NULL_RTX); | |
4159 | if (note) | |
4160 | XEXP (note, 0) = last; | |
4161 | break; | |
4162 | ||
4163 | case REG_NONNEG: | |
4164 | /* This should be moved to whichever instruction is a JUMP_INSN. */ | |
4165 | ||
4166 | for (insn = last; ; insn = PREV_INSN (insn)) | |
4167 | { | |
4168 | if (GET_CODE (insn) == JUMP_INSN) | |
4169 | { | |
4170 | XEXP (note, 1) = REG_NOTES (insn); | |
4171 | REG_NOTES (insn) = note; | |
4172 | /* Only put this note on one of the new insns. */ | |
4173 | break; | |
4174 | } | |
4175 | /* Fail if we couldn't find a JUMP_INSN. */ | |
4176 | if (insn == first) | |
4177 | abort (); | |
4178 | } | |
4179 | break; | |
4180 | ||
4181 | case REG_INC: | |
4182 | /* This should be moved to whichever instruction now has the | |
4183 | increment operation. */ | |
4184 | abort (); | |
4185 | ||
4186 | case REG_LABEL: | |
4187 | /* Should be moved to the new insn(s) which use the label. */ | |
4188 | for (insn = first; insn != NEXT_INSN (last); insn = NEXT_INSN (insn)) | |
4189 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
4190 | && reg_mentioned_p (XEXP (note, 0), PATTERN (insn))) | |
4191 | REG_NOTES (insn) = gen_rtx (EXPR_LIST, REG_LABEL, | |
4192 | XEXP (note, 0), REG_NOTES (insn)); | |
4193 | break; | |
4194 | ||
4195 | case REG_CC_SETTER: | |
4196 | case REG_CC_USER: | |
4197 | /* These two notes will never appear until after reorg, so we don't | |
4198 | have to handle them here. */ | |
4199 | default: | |
4200 | abort (); | |
4201 | } | |
4202 | } | |
4203 | ||
4204 | /* Each new insn created, except the last, has a new set. If the destination | |
4205 | is a register, then this reg is now live across several insns, whereas | |
4206 | previously the dest reg was born and died within the same insn. To | |
4207 | reflect this, we now need a REG_DEAD note on the insn where this | |
4208 | dest reg dies. | |
4209 | ||
4210 | Similarly, the new insns may have clobbers that need REG_UNUSED notes. */ | |
4211 | ||
4212 | for (insn = first; insn != last; insn = NEXT_INSN (insn)) | |
4213 | { | |
4214 | rtx pat; | |
4215 | int i; | |
4216 | ||
4217 | pat = PATTERN (insn); | |
4218 | if (GET_CODE (pat) == SET || GET_CODE (pat) == CLOBBER) | |
4219 | new_insn_dead_notes (pat, insn, last, orig_insn); | |
4220 | else if (GET_CODE (pat) == PARALLEL) | |
4221 | { | |
4222 | for (i = 0; i < XVECLEN (pat, 0); i++) | |
4223 | if (GET_CODE (XVECEXP (pat, 0, i)) == SET | |
4224 | || GET_CODE (XVECEXP (pat, 0, i)) == CLOBBER) | |
4225 | new_insn_dead_notes (XVECEXP (pat, 0, i), insn, last, orig_insn); | |
4226 | } | |
4227 | } | |
4228 | ||
4229 | /* If any insn, except the last, uses the register set by the last insn, | |
4230 | then we need a new REG_DEAD note on that insn. In this case, there | |
4231 | would not have been a REG_DEAD note for this register in the original | |
4232 | insn because it was used and set within one insn. | |
4233 | ||
4234 | There is no new REG_DEAD note needed if the last insn uses the register | |
4235 | that it is setting. */ | |
4236 | ||
4237 | set = single_set (last); | |
4238 | if (set) | |
4239 | { | |
4240 | rtx dest = SET_DEST (set); | |
4241 | ||
4242 | while (GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SUBREG | |
4243 | || GET_CODE (dest) == STRICT_LOW_PART | |
4244 | || GET_CODE (dest) == SIGN_EXTRACT) | |
4245 | dest = XEXP (dest, 0); | |
4246 | ||
4247 | if (GET_CODE (dest) == REG | |
4248 | && ! reg_overlap_mentioned_p (dest, SET_SRC (set))) | |
4249 | { | |
4250 | for (insn = PREV_INSN (last); ; insn = PREV_INSN (insn)) | |
4251 | { | |
4252 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
4253 | && reg_mentioned_p (dest, PATTERN (insn)) | |
4254 | && (set = single_set (insn))) | |
4255 | { | |
4256 | rtx insn_dest = SET_DEST (set); | |
4257 | ||
4258 | while (GET_CODE (insn_dest) == ZERO_EXTRACT | |
4259 | || GET_CODE (insn_dest) == SUBREG | |
4260 | || GET_CODE (insn_dest) == STRICT_LOW_PART | |
4261 | || GET_CODE (insn_dest) == SIGN_EXTRACT) | |
4262 | insn_dest = XEXP (insn_dest, 0); | |
4263 | ||
4264 | if (insn_dest != dest) | |
4265 | { | |
4266 | note = rtx_alloc (EXPR_LIST); | |
4267 | PUT_REG_NOTE_KIND (note, REG_DEAD); | |
4268 | XEXP (note, 0) = dest; | |
4269 | XEXP (note, 1) = REG_NOTES (insn); | |
4270 | REG_NOTES (insn) = note; | |
4271 | /* The reg only dies in one insn, the last one | |
4272 | that uses it. */ | |
4273 | break; | |
4274 | } | |
4275 | } | |
4276 | if (insn == first) | |
4277 | break; | |
4278 | } | |
4279 | } | |
4280 | } | |
4281 | ||
4282 | /* If the original dest is modifying a multiple register target, and the | |
4283 | original instruction was split such that the original dest is now set | |
4284 | by two or more SUBREG sets, then the split insns no longer kill the | |
4285 | destination of the original insn. | |
4286 | ||
4287 | In this case, if there exists an instruction in the same basic block, | |
4288 | before the split insn, which uses the original dest, and this use is | |
4289 | killed by the original insn, then we must remove the REG_DEAD note on | |
4290 | this insn, because it is now superfluous. | |
4291 | ||
4292 | This does not apply when a hard register gets split, because the code | |
4293 | knows how to handle overlapping hard registers properly. */ | |
4294 | if (orig_dest && GET_CODE (orig_dest) == REG) | |
4295 | { | |
4296 | int found_orig_dest = 0; | |
4297 | int found_split_dest = 0; | |
4298 | ||
4299 | for (insn = first; ; insn = NEXT_INSN (insn)) | |
4300 | { | |
4301 | set = single_set (insn); | |
4302 | if (set) | |
4303 | { | |
4304 | if (GET_CODE (SET_DEST (set)) == REG | |
4305 | && REGNO (SET_DEST (set)) == REGNO (orig_dest)) | |
4306 | { | |
4307 | found_orig_dest = 1; | |
4308 | break; | |
4309 | } | |
4310 | else if (GET_CODE (SET_DEST (set)) == SUBREG | |
4311 | && SUBREG_REG (SET_DEST (set)) == orig_dest) | |
4312 | { | |
4313 | found_split_dest = 1; | |
4314 | break; | |
4315 | } | |
4316 | } | |
4317 | ||
4318 | if (insn == last) | |
4319 | break; | |
4320 | } | |
4321 | ||
4322 | if (found_split_dest) | |
4323 | { | |
4324 | /* Search backwards from FIRST, looking for the first insn that uses | |
4325 | the original dest. Stop if we pass a CODE_LABEL or a JUMP_INSN. | |
4326 | If we find an insn, and it has a REG_DEAD note, then delete the | |
4327 | note. */ | |
4328 | ||
4329 | for (insn = first; insn; insn = PREV_INSN (insn)) | |
4330 | { | |
4331 | if (GET_CODE (insn) == CODE_LABEL | |
4332 | || GET_CODE (insn) == JUMP_INSN) | |
4333 | break; | |
4334 | else if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
4335 | && reg_mentioned_p (orig_dest, insn)) | |
4336 | { | |
4337 | note = find_regno_note (insn, REG_DEAD, REGNO (orig_dest)); | |
4338 | if (note) | |
4339 | remove_note (insn, note); | |
4340 | } | |
4341 | } | |
4342 | } | |
4343 | else if (! found_orig_dest) | |
4344 | { | |
4345 | /* This should never happen. */ | |
4346 | abort (); | |
4347 | } | |
4348 | } | |
4349 | ||
4350 | /* Update reg_n_sets. This is necessary to prevent local alloc from | |
4351 | converting REG_EQUAL notes to REG_EQUIV when splitting has modified | |
4352 | a reg from set once to set multiple times. */ | |
4353 | ||
4354 | { | |
4355 | rtx x = PATTERN (orig_insn); | |
4356 | RTX_CODE code = GET_CODE (x); | |
4357 | ||
4358 | if (code == SET || code == CLOBBER) | |
4359 | update_n_sets (x, -1); | |
4360 | else if (code == PARALLEL) | |
4361 | { | |
4362 | int i; | |
4363 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
4364 | { | |
4365 | code = GET_CODE (XVECEXP (x, 0, i)); | |
4366 | if (code == SET || code == CLOBBER) | |
4367 | update_n_sets (XVECEXP (x, 0, i), -1); | |
4368 | } | |
4369 | } | |
4370 | ||
4371 | for (insn = first; ; insn = NEXT_INSN (insn)) | |
4372 | { | |
4373 | x = PATTERN (insn); | |
4374 | code = GET_CODE (x); | |
4375 | ||
4376 | if (code == SET || code == CLOBBER) | |
4377 | update_n_sets (x, 1); | |
4378 | else if (code == PARALLEL) | |
4379 | { | |
4380 | int i; | |
4381 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
4382 | { | |
4383 | code = GET_CODE (XVECEXP (x, 0, i)); | |
4384 | if (code == SET || code == CLOBBER) | |
4385 | update_n_sets (XVECEXP (x, 0, i), 1); | |
4386 | } | |
4387 | } | |
4388 | ||
4389 | if (insn == last) | |
4390 | break; | |
4391 | } | |
4392 | } | |
4393 | } | |
4394 | ||
4395 | /* The one entry point in this file. DUMP_FILE is the dump file for | |
4396 | this pass. */ | |
4397 | ||
4398 | void | |
4399 | schedule_insns (dump_file) | |
4400 | FILE *dump_file; | |
4401 | { | |
4402 | int max_uid = MAX_INSNS_PER_SPLIT * (get_max_uid () + 1); | |
4403 | int i, b; | |
4404 | rtx insn; | |
4405 | ||
4406 | /* Taking care of this degenerate case makes the rest of | |
4407 | this code simpler. */ | |
4408 | if (n_basic_blocks == 0) | |
4409 | return; | |
4410 | ||
4411 | /* Create an insn here so that we can hang dependencies off of it later. */ | |
4412 | sched_before_next_call | |
4413 | = gen_rtx (INSN, VOIDmode, 0, NULL_RTX, NULL_RTX, | |
4414 | NULL_RTX, 0, NULL_RTX, 0); | |
4415 | ||
4416 | /* Initialize the unused_*_lists. We can't use the ones left over from | |
4417 | the previous function, because gcc has freed that memory. We can use | |
4418 | the ones left over from the first sched pass in the second pass however, | |
4419 | so only clear them on the first sched pass. The first pass is before | |
4420 | reload if flag_schedule_insns is set, otherwise it is afterwards. */ | |
4421 | ||
4422 | if (reload_completed == 0 || ! flag_schedule_insns) | |
4423 | { | |
4424 | unused_insn_list = 0; | |
4425 | unused_expr_list = 0; | |
4426 | } | |
4427 | ||
4428 | /* We create no insns here, only reorder them, so we | |
4429 | remember how far we can cut back the stack on exit. */ | |
4430 | ||
4431 | /* Allocate data for this pass. See comments, above, | |
4432 | for what these vectors do. */ | |
4433 | insn_luid = (int *) alloca (max_uid * sizeof (int)); | |
4434 | insn_priority = (int *) alloca (max_uid * sizeof (int)); | |
4435 | insn_tick = (int *) alloca (max_uid * sizeof (int)); | |
4436 | insn_costs = (short *) alloca (max_uid * sizeof (short)); | |
4437 | insn_units = (short *) alloca (max_uid * sizeof (short)); | |
4438 | insn_blockage = (unsigned int *) alloca (max_uid * sizeof (unsigned int)); | |
4439 | insn_ref_count = (int *) alloca (max_uid * sizeof (int)); | |
4440 | ||
4441 | if (reload_completed == 0) | |
4442 | { | |
4443 | sched_reg_n_deaths = (short *) alloca (max_regno * sizeof (short)); | |
4444 | sched_reg_n_calls_crossed = (int *) alloca (max_regno * sizeof (int)); | |
4445 | sched_reg_live_length = (int *) alloca (max_regno * sizeof (int)); | |
4446 | bb_dead_regs = (regset) alloca (regset_bytes); | |
4447 | bb_live_regs = (regset) alloca (regset_bytes); | |
4448 | bzero (sched_reg_n_calls_crossed, max_regno * sizeof (int)); | |
4449 | bzero (sched_reg_live_length, max_regno * sizeof (int)); | |
4450 | bcopy (reg_n_deaths, sched_reg_n_deaths, max_regno * sizeof (short)); | |
4451 | init_alias_analysis (); | |
4452 | } | |
4453 | else | |
4454 | { | |
4455 | sched_reg_n_deaths = 0; | |
4456 | sched_reg_n_calls_crossed = 0; | |
4457 | sched_reg_live_length = 0; | |
4458 | bb_dead_regs = 0; | |
4459 | bb_live_regs = 0; | |
4460 | if (! flag_schedule_insns) | |
4461 | init_alias_analysis (); | |
4462 | } | |
4463 | ||
4464 | if (write_symbols != NO_DEBUG) | |
4465 | { | |
4466 | rtx line; | |
4467 | ||
4468 | line_note = (rtx *) alloca (max_uid * sizeof (rtx)); | |
4469 | bzero (line_note, max_uid * sizeof (rtx)); | |
4470 | line_note_head = (rtx *) alloca (n_basic_blocks * sizeof (rtx)); | |
4471 | bzero (line_note_head, n_basic_blocks * sizeof (rtx)); | |
4472 | ||
4473 | /* Determine the line-number at the start of each basic block. | |
4474 | This must be computed and saved now, because after a basic block's | |
4475 | predecessor has been scheduled, it is impossible to accurately | |
4476 | determine the correct line number for the first insn of the block. */ | |
4477 | ||
4478 | for (b = 0; b < n_basic_blocks; b++) | |
4479 | for (line = basic_block_head[b]; line; line = PREV_INSN (line)) | |
4480 | if (GET_CODE (line) == NOTE && NOTE_LINE_NUMBER (line) > 0) | |
4481 | { | |
4482 | line_note_head[b] = line; | |
4483 | break; | |
4484 | } | |
4485 | } | |
4486 | ||
4487 | bzero (insn_luid, max_uid * sizeof (int)); | |
4488 | bzero (insn_priority, max_uid * sizeof (int)); | |
4489 | bzero (insn_tick, max_uid * sizeof (int)); | |
4490 | bzero (insn_costs, max_uid * sizeof (short)); | |
4491 | bzero (insn_units, max_uid * sizeof (short)); | |
4492 | bzero (insn_blockage, max_uid * sizeof (unsigned int)); | |
4493 | bzero (insn_ref_count, max_uid * sizeof (int)); | |
4494 | ||
4495 | /* Schedule each basic block, block by block. */ | |
4496 | ||
4497 | if (NEXT_INSN (basic_block_end[n_basic_blocks-1]) == 0 | |
4498 | || (GET_CODE (basic_block_end[n_basic_blocks-1]) != NOTE | |
4499 | && GET_CODE (basic_block_end[n_basic_blocks-1]) != CODE_LABEL)) | |
4500 | emit_note_after (NOTE_INSN_DELETED, basic_block_end[n_basic_blocks-1]); | |
4501 | ||
4502 | for (b = 0; b < n_basic_blocks; b++) | |
4503 | { | |
4504 | rtx insn, next; | |
4505 | rtx insns; | |
4506 | ||
4507 | note_list = 0; | |
4508 | ||
4509 | for (insn = basic_block_head[b]; ; insn = next) | |
4510 | { | |
4511 | rtx prev; | |
4512 | rtx set; | |
4513 | ||
4514 | /* Can't use `next_real_insn' because that | |
4515 | might go across CODE_LABELS and short-out basic blocks. */ | |
4516 | next = NEXT_INSN (insn); | |
4517 | if (GET_CODE (insn) != INSN) | |
4518 | { | |
4519 | if (insn == basic_block_end[b]) | |
4520 | break; | |
4521 | ||
4522 | continue; | |
4523 | } | |
4524 | ||
4525 | /* Don't split no-op move insns. These should silently disappear | |
4526 | later in final. Splitting such insns would break the code | |
4527 | that handles REG_NO_CONFLICT blocks. */ | |
4528 | set = single_set (insn); | |
4529 | if (set && rtx_equal_p (SET_SRC (set), SET_DEST (set))) | |
4530 | { | |
4531 | if (insn == basic_block_end[b]) | |
4532 | break; | |
4533 | ||
4534 | /* Nops get in the way while scheduling, so delete them now if | |
4535 | register allocation has already been done. It is too risky | |
4536 | to try to do this before register allocation, and there are | |
4537 | unlikely to be very many nops then anyways. */ | |
4538 | if (reload_completed) | |
4539 | { | |
4540 | PUT_CODE (insn, NOTE); | |
4541 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
4542 | NOTE_SOURCE_FILE (insn) = 0; | |
4543 | } | |
4544 | ||
4545 | continue; | |
4546 | } | |
4547 | ||
4548 | /* Split insns here to get max fine-grain parallelism. */ | |
4549 | prev = PREV_INSN (insn); | |
4550 | if (reload_completed == 0) | |
4551 | { | |
4552 | rtx last, first = PREV_INSN (insn); | |
4553 | rtx notes = REG_NOTES (insn); | |
4554 | ||
4555 | last = try_split (PATTERN (insn), insn, 1); | |
4556 | if (last != insn) | |
4557 | { | |
4558 | /* try_split returns the NOTE that INSN became. */ | |
4559 | first = NEXT_INSN (first); | |
4560 | update_flow_info (notes, first, last, insn); | |
4561 | ||
4562 | PUT_CODE (insn, NOTE); | |
4563 | NOTE_SOURCE_FILE (insn) = 0; | |
4564 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
4565 | if (insn == basic_block_head[b]) | |
4566 | basic_block_head[b] = first; | |
4567 | if (insn == basic_block_end[b]) | |
4568 | { | |
4569 | basic_block_end[b] = last; | |
4570 | break; | |
4571 | } | |
4572 | } | |
4573 | } | |
4574 | ||
4575 | if (insn == basic_block_end[b]) | |
4576 | break; | |
4577 | } | |
4578 | ||
4579 | schedule_block (b, dump_file); | |
4580 | ||
4581 | #ifdef USE_C_ALLOCA | |
4582 | alloca (0); | |
4583 | #endif | |
4584 | } | |
4585 | ||
4586 | /* Reposition the prologue and epilogue notes in case we moved the | |
4587 | prologue/epilogue insns. */ | |
4588 | if (reload_completed) | |
4589 | reposition_prologue_and_epilogue_notes (get_insns ()); | |
4590 | ||
4591 | if (write_symbols != NO_DEBUG) | |
4592 | { | |
4593 | rtx line = 0; | |
4594 | rtx insn = get_insns (); | |
4595 | int active_insn = 0; | |
4596 | int notes = 0; | |
4597 | ||
4598 | /* Walk the insns deleting redundant line-number notes. Many of these | |
4599 | are already present. The remainder tend to occur at basic | |
4600 | block boundaries. */ | |
4601 | for (insn = get_last_insn (); insn; insn = PREV_INSN (insn)) | |
4602 | if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0) | |
4603 | { | |
4604 | /* If there are no active insns following, INSN is redundant. */ | |
4605 | if (active_insn == 0) | |
4606 | { | |
4607 | notes++; | |
4608 | NOTE_SOURCE_FILE (insn) = 0; | |
4609 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
4610 | } | |
4611 | /* If the line number is unchanged, LINE is redundant. */ | |
4612 | else if (line | |
4613 | && NOTE_LINE_NUMBER (line) == NOTE_LINE_NUMBER (insn) | |
4614 | && NOTE_SOURCE_FILE (line) == NOTE_SOURCE_FILE (insn)) | |
4615 | { | |
4616 | notes++; | |
4617 | NOTE_SOURCE_FILE (line) = 0; | |
4618 | NOTE_LINE_NUMBER (line) = NOTE_INSN_DELETED; | |
4619 | line = insn; | |
4620 | } | |
4621 | else | |
4622 | line = insn; | |
4623 | active_insn = 0; | |
4624 | } | |
4625 | else if (! ((GET_CODE (insn) == NOTE | |
4626 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_DELETED) | |
4627 | || (GET_CODE (insn) == INSN | |
4628 | && (GET_CODE (PATTERN (insn)) == USE | |
4629 | || GET_CODE (PATTERN (insn)) == CLOBBER)))) | |
4630 | active_insn++; | |
4631 | ||
4632 | if (dump_file && notes) | |
4633 | fprintf (dump_file, ";; deleted %d line-number notes\n", notes); | |
4634 | } | |
4635 | ||
4636 | if (reload_completed == 0) | |
4637 | { | |
4638 | int regno; | |
4639 | for (regno = 0; regno < max_regno; regno++) | |
4640 | if (sched_reg_live_length[regno]) | |
4641 | { | |
4642 | if (dump_file) | |
4643 | { | |
4644 | if (reg_live_length[regno] > sched_reg_live_length[regno]) | |
4645 | fprintf (dump_file, | |
4646 | ";; register %d life shortened from %d to %d\n", | |
4647 | regno, reg_live_length[regno], | |
4648 | sched_reg_live_length[regno]); | |
4649 | /* Negative values are special; don't overwrite the current | |
4650 | reg_live_length value if it is negative. */ | |
4651 | else if (reg_live_length[regno] < sched_reg_live_length[regno] | |
4652 | && reg_live_length[regno] >= 0) | |
4653 | fprintf (dump_file, | |
4654 | ";; register %d life extended from %d to %d\n", | |
4655 | regno, reg_live_length[regno], | |
4656 | sched_reg_live_length[regno]); | |
4657 | ||
4658 | if (reg_n_calls_crossed[regno] | |
4659 | && ! sched_reg_n_calls_crossed[regno]) | |
4660 | fprintf (dump_file, | |
4661 | ";; register %d no longer crosses calls\n", regno); | |
4662 | else if (! reg_n_calls_crossed[regno] | |
4663 | && sched_reg_n_calls_crossed[regno]) | |
4664 | fprintf (dump_file, | |
4665 | ";; register %d now crosses calls\n", regno); | |
4666 | } | |
4667 | /* Negative values are special; don't overwrite the current | |
4668 | reg_live_length value if it is negative. */ | |
4669 | if (reg_live_length[regno] >= 0) | |
4670 | reg_live_length[regno] = sched_reg_live_length[regno]; | |
4671 | reg_n_calls_crossed[regno] = sched_reg_n_calls_crossed[regno]; | |
4672 | } | |
4673 | } | |
4674 | } | |
4675 | #endif /* INSN_SCHEDULING */ |