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8c660648 | 1 | /* Move registers around to reduce number of move instructions needed. |
a5cad800 | 2 | Copyright (C) 1987, 88, 89, 92-98, 1999 Free Software Foundation, Inc. |
8c660648 JL |
3 | |
4 | This file is part of GNU CC. | |
5 | ||
6 | GNU CC is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2, or (at your option) | |
9 | any later version. | |
10 | ||
11 | GNU CC is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GNU CC; see the file COPYING. If not, write to | |
5f38fdda JL |
18 | the Free Software Foundation, 59 Temple Place - Suite 330, |
19 | Boston, MA 02111-1307, USA. */ | |
8c660648 JL |
20 | |
21 | ||
22 | /* This module looks for cases where matching constraints would force | |
23 | an instruction to need a reload, and this reload would be a register | |
24 | to register move. It then attempts to change the registers used by the | |
25 | instruction to avoid the move instruction. */ | |
26 | ||
27 | #include "config.h" | |
670ee920 | 28 | #include "system.h" |
789f983a | 29 | #include "rtl.h" /* stdio.h must precede rtl.h for FFS. */ |
8c660648 JL |
30 | #include "insn-config.h" |
31 | #include "recog.h" | |
32 | #include "output.h" | |
33 | #include "reload.h" | |
34 | #include "regs.h" | |
184bb750 R |
35 | #include "hard-reg-set.h" |
36 | #include "flags.h" | |
49ad7cfa | 37 | #include "function.h" |
184bb750 R |
38 | #include "expr.h" |
39 | #include "insn-flags.h" | |
ddc8bed2 | 40 | #include "basic-block.h" |
2e107e9e | 41 | #include "toplev.h" |
184bb750 | 42 | |
1230327b R |
43 | static int optimize_reg_copy_1 PROTO((rtx, rtx, rtx)); |
44 | static void optimize_reg_copy_2 PROTO((rtx, rtx, rtx)); | |
184bb750 | 45 | static void optimize_reg_copy_3 PROTO((rtx, rtx, rtx)); |
1a29f703 | 46 | static rtx gen_add3_insn PROTO((rtx, rtx, rtx)); |
78dd9906 | 47 | static void copy_src_to_dest PROTO((rtx, rtx, rtx, int, int)); |
ddc8bed2 | 48 | static int *regmove_bb_head; |
8c660648 | 49 | |
184bb750 R |
50 | struct match { |
51 | int with[MAX_RECOG_OPERANDS]; | |
52 | enum { READ, WRITE, READWRITE } use[MAX_RECOG_OPERANDS]; | |
53 | int commutative[MAX_RECOG_OPERANDS]; | |
54 | int early_clobber[MAX_RECOG_OPERANDS]; | |
55 | }; | |
56 | ||
dc2cb191 RH |
57 | static rtx discover_flags_reg PROTO((void)); |
58 | static void mark_flags_life_zones PROTO((rtx)); | |
59 | static void flags_set_1 PROTO((rtx, rtx)); | |
60 | ||
0e05e8ea | 61 | static int try_auto_increment PROTO((rtx, rtx, rtx, rtx, HOST_WIDE_INT, int)); |
184bb750 R |
62 | static int find_matches PROTO((rtx, struct match *)); |
63 | static int fixup_match_1 PROTO((rtx, rtx, rtx, rtx, rtx, int, int, int, FILE *)) | |
64 | ; | |
65 | static int reg_is_remote_constant_p PROTO((rtx, rtx, rtx)); | |
8c660648 | 66 | static int stable_but_for_p PROTO((rtx, rtx, rtx)); |
3bb806ed | 67 | static int regclass_compatible_p PROTO((int, int)); |
184bb750 | 68 | static int loop_depth; |
8c660648 | 69 | |
3bb806ed R |
70 | /* Return non-zero if registers with CLASS1 and CLASS2 can be merged without |
71 | causing too much register allocation problems. */ | |
72 | static int | |
73 | regclass_compatible_p (class0, class1) | |
74 | int class0, class1; | |
75 | { | |
76 | return (class0 == class1 | |
77 | || (reg_class_subset_p (class0, class1) | |
78 | && ! CLASS_LIKELY_SPILLED_P (class0)) | |
79 | || (reg_class_subset_p (class1, class0) | |
80 | && ! CLASS_LIKELY_SPILLED_P (class1))); | |
81 | } | |
82 | ||
1a29f703 R |
83 | /* Generate and return an insn body to add r1 and c, |
84 | storing the result in r0. */ | |
85 | static rtx | |
86 | gen_add3_insn (r0, r1, c) | |
87 | rtx r0, r1, c; | |
88 | { | |
89 | int icode = (int) add_optab->handlers[(int) GET_MODE (r0)].insn_code; | |
90 | ||
91 | if (icode == CODE_FOR_nothing | |
92 | || ! (*insn_operand_predicate[icode][0]) (r0, insn_operand_mode[icode][0]) | |
93 | || ! (*insn_operand_predicate[icode][1]) (r1, insn_operand_mode[icode][1]) | |
94 | || ! (*insn_operand_predicate[icode][2]) (c, insn_operand_mode[icode][2])) | |
95 | return NULL_RTX; | |
96 | ||
97 | return (GEN_FCN (icode) (r0, r1, c)); | |
98 | } | |
99 | ||
8c660648 JL |
100 | |
101 | /* INC_INSN is an instruction that adds INCREMENT to REG. | |
102 | Try to fold INC_INSN as a post/pre in/decrement into INSN. | |
103 | Iff INC_INSN_SET is nonzero, inc_insn has a destination different from src. | |
104 | Return nonzero for success. */ | |
105 | static int | |
106 | try_auto_increment (insn, inc_insn, inc_insn_set, reg, increment, pre) | |
107 | rtx reg, insn, inc_insn ,inc_insn_set; | |
108 | HOST_WIDE_INT increment; | |
109 | int pre; | |
110 | { | |
111 | enum rtx_code inc_code; | |
112 | ||
113 | rtx pset = single_set (insn); | |
114 | if (pset) | |
115 | { | |
116 | /* Can't use the size of SET_SRC, we might have something like | |
117 | (sign_extend:SI (mem:QI ... */ | |
118 | rtx use = find_use_as_address (pset, reg, 0); | |
119 | if (use != 0 && use != (rtx) 1) | |
120 | { | |
121 | int size = GET_MODE_SIZE (GET_MODE (use)); | |
122 | if (0 | |
940da324 JL |
123 | || (HAVE_POST_INCREMENT |
124 | && pre == 0 && (inc_code = POST_INC, increment == size)) | |
125 | || (HAVE_PRE_INCREMENT | |
126 | && pre == 1 && (inc_code = PRE_INC, increment == size)) | |
127 | || (HAVE_POST_DECREMENT | |
128 | && pre == 0 && (inc_code = POST_DEC, increment == -size)) | |
129 | || (HAVE_PRE_DECREMENT | |
130 | && pre == 1 && (inc_code = PRE_DEC, increment == -size)) | |
184bb750 R |
131 | ) |
132 | { | |
133 | if (inc_insn_set) | |
134 | validate_change | |
135 | (inc_insn, | |
136 | &SET_SRC (inc_insn_set), | |
8c660648 | 137 | XEXP (SET_SRC (inc_insn_set), 0), 1); |
184bb750 | 138 | validate_change (insn, &XEXP (use, 0), |
38a448ca | 139 | gen_rtx_fmt_e (inc_code, Pmode, reg), 1); |
184bb750 R |
140 | if (apply_change_group ()) |
141 | { | |
142 | REG_NOTES (insn) | |
38a448ca RH |
143 | = gen_rtx_EXPR_LIST (REG_INC, |
144 | reg, REG_NOTES (insn)); | |
184bb750 R |
145 | if (! inc_insn_set) |
146 | { | |
147 | PUT_CODE (inc_insn, NOTE); | |
148 | NOTE_LINE_NUMBER (inc_insn) = NOTE_INSN_DELETED; | |
149 | NOTE_SOURCE_FILE (inc_insn) = 0; | |
150 | } | |
8c660648 | 151 | return 1; |
184bb750 R |
152 | } |
153 | } | |
154 | } | |
155 | } | |
156 | return 0; | |
157 | } | |
dc2cb191 RH |
158 | \f |
159 | /* Determine if the pattern generated by add_optab has a clobber, | |
160 | such as might be issued for a flags hard register. To make the | |
161 | code elsewhere simpler, we handle cc0 in this same framework. | |
162 | ||
163 | Return the register if one was discovered. Return NULL_RTX if | |
164 | if no flags were found. Return pc_rtx if we got confused. */ | |
165 | ||
166 | static rtx | |
167 | discover_flags_reg () | |
168 | { | |
169 | rtx tmp; | |
cd4b3546 | 170 | tmp = gen_rtx_REG (word_mode, 10000); |
dc2cb191 RH |
171 | tmp = gen_add3_insn (tmp, tmp, GEN_INT (2)); |
172 | ||
173 | /* If we get something that isn't a simple set, or a | |
174 | [(set ..) (clobber ..)], this whole function will go wrong. */ | |
175 | if (GET_CODE (tmp) == SET) | |
176 | return NULL_RTX; | |
177 | else if (GET_CODE (tmp) == PARALLEL) | |
178 | { | |
179 | int found; | |
180 | ||
181 | if (XVECLEN (tmp, 0) != 2) | |
182 | return pc_rtx; | |
183 | tmp = XVECEXP (tmp, 0, 1); | |
184 | if (GET_CODE (tmp) != CLOBBER) | |
185 | return pc_rtx; | |
186 | tmp = XEXP (tmp, 0); | |
187 | ||
188 | /* Don't do anything foolish if the md wanted to clobber a | |
189 | scratch or something. We only care about hard regs. | |
190 | Moreover we don't like the notion of subregs of hard regs. */ | |
191 | if (GET_CODE (tmp) == SUBREG | |
192 | && GET_CODE (SUBREG_REG (tmp)) == REG | |
193 | && REGNO (SUBREG_REG (tmp)) < FIRST_PSEUDO_REGISTER) | |
194 | return pc_rtx; | |
195 | found = (GET_CODE (tmp) == REG && REGNO (tmp) < FIRST_PSEUDO_REGISTER); | |
196 | ||
dc2cb191 | 197 | return (found ? tmp : NULL_RTX); |
dc2cb191 RH |
198 | } |
199 | ||
200 | return pc_rtx; | |
201 | } | |
202 | ||
203 | /* It is a tedious task identifying when the flags register is live and | |
204 | when it is safe to optimize. Since we process the instruction stream | |
205 | multiple times, locate and record these live zones by marking the | |
206 | mode of the instructions -- | |
207 | ||
208 | QImode is used on the instruction at which the flags becomes live. | |
209 | ||
210 | HImode is used within the range (exclusive) that the flags are | |
211 | live. Thus the user of the flags is not marked. | |
212 | ||
213 | All other instructions are cleared to VOIDmode. */ | |
214 | ||
215 | /* Used to communicate with flags_set_1. */ | |
216 | static rtx flags_set_1_rtx; | |
217 | static int flags_set_1_set; | |
218 | ||
219 | static void | |
220 | mark_flags_life_zones (flags) | |
221 | rtx flags; | |
222 | { | |
223 | int flags_regno; | |
224 | int flags_nregs; | |
225 | int block; | |
226 | ||
e7f5b971 RH |
227 | #ifdef HAVE_cc0 |
228 | /* If we found a flags register on a cc0 host, bail. */ | |
229 | if (flags == NULL_RTX) | |
230 | flags = cc0_rtx; | |
231 | else if (flags != cc0_rtx) | |
232 | flags = pc_rtx; | |
233 | #endif | |
234 | ||
dc2cb191 RH |
235 | /* Simple cases first: if no flags, clear all modes. If confusing, |
236 | mark the entire function as being in a flags shadow. */ | |
237 | if (flags == NULL_RTX || flags == pc_rtx) | |
238 | { | |
239 | enum machine_mode mode = (flags ? HImode : VOIDmode); | |
240 | rtx insn; | |
241 | for (insn = get_insns(); insn; insn = NEXT_INSN (insn)) | |
242 | PUT_MODE (insn, mode); | |
243 | return; | |
244 | } | |
245 | ||
246 | #ifdef HAVE_cc0 | |
247 | flags_regno = -1; | |
248 | flags_nregs = 1; | |
249 | #else | |
250 | flags_regno = REGNO (flags); | |
251 | flags_nregs = HARD_REGNO_NREGS (flags_regno, GET_MODE (flags)); | |
252 | #endif | |
253 | flags_set_1_rtx = flags; | |
184bb750 | 254 | |
dc2cb191 RH |
255 | /* Process each basic block. */ |
256 | for (block = n_basic_blocks - 1; block >= 0; block--) | |
257 | { | |
258 | rtx insn, end; | |
259 | int live; | |
260 | ||
261 | insn = BLOCK_HEAD (block); | |
262 | end = BLOCK_END (block); | |
263 | ||
264 | /* Look out for the (unlikely) case of flags being live across | |
265 | basic block boundaries. */ | |
266 | live = 0; | |
267 | #ifndef HAVE_cc0 | |
268 | { | |
269 | int i; | |
270 | for (i = 0; i < flags_nregs; ++i) | |
e881bb1b | 271 | live |= REGNO_REG_SET_P (BASIC_BLOCK (block)->global_live_at_start, |
dc2cb191 RH |
272 | flags_regno + i); |
273 | } | |
274 | #endif | |
275 | ||
276 | while (1) | |
277 | { | |
278 | /* Process liveness in reverse order of importance -- | |
279 | alive, death, birth. This lets more important info | |
280 | overwrite the mode of lesser info. */ | |
281 | ||
282 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
283 | { | |
284 | #ifdef HAVE_cc0 | |
285 | /* In the cc0 case, death is not marked in reg notes, | |
286 | but is instead the mere use of cc0 when it is alive. */ | |
287 | if (live && reg_mentioned_p (cc0_rtx, PATTERN (insn))) | |
288 | live = 0; | |
289 | #else | |
290 | /* In the hard reg case, we watch death notes. */ | |
291 | if (live && find_regno_note (insn, REG_DEAD, flags_regno)) | |
292 | live = 0; | |
293 | #endif | |
294 | PUT_MODE (insn, (live ? HImode : VOIDmode)); | |
295 | ||
296 | /* In either case, birth is denoted simply by it's presence | |
297 | as the destination of a set. */ | |
298 | flags_set_1_set = 0; | |
299 | note_stores (PATTERN (insn), flags_set_1); | |
300 | if (flags_set_1_set) | |
301 | { | |
302 | live = 1; | |
303 | PUT_MODE (insn, QImode); | |
304 | } | |
305 | } | |
306 | else | |
307 | PUT_MODE (insn, (live ? HImode : VOIDmode)); | |
308 | ||
309 | if (insn == end) | |
310 | break; | |
311 | insn = NEXT_INSN (insn); | |
312 | } | |
313 | } | |
314 | } | |
315 | ||
316 | /* A subroutine of mark_flags_life_zones, called through note_stores. */ | |
317 | ||
318 | static void | |
319 | flags_set_1 (x, pat) | |
320 | rtx x, pat; | |
321 | { | |
322 | if (GET_CODE (pat) == SET | |
323 | && reg_overlap_mentioned_p (x, flags_set_1_rtx)) | |
324 | flags_set_1_set = 1; | |
325 | } | |
326 | \f | |
184bb750 R |
327 | static int *regno_src_regno; |
328 | ||
329 | /* Indicate how good a choice REG (which appears as a source) is to replace | |
330 | a destination register with. The higher the returned value, the better | |
331 | the choice. The main objective is to avoid using a register that is | |
332 | a candidate for tying to a hard register, since the output might in | |
333 | turn be a candidate to be tied to a different hard register. */ | |
334 | int | |
335 | replacement_quality(reg) | |
336 | rtx reg; | |
337 | { | |
338 | int src_regno; | |
339 | ||
340 | /* Bad if this isn't a register at all. */ | |
341 | if (GET_CODE (reg) != REG) | |
342 | return 0; | |
343 | ||
344 | /* If this register is not meant to get a hard register, | |
345 | it is a poor choice. */ | |
346 | if (REG_LIVE_LENGTH (REGNO (reg)) < 0) | |
347 | return 0; | |
348 | ||
349 | src_regno = regno_src_regno[REGNO (reg)]; | |
350 | ||
351 | /* If it was not copied from another register, it is fine. */ | |
352 | if (src_regno < 0) | |
353 | return 3; | |
354 | ||
355 | /* Copied from a hard register? */ | |
356 | if (src_regno < FIRST_PSEUDO_REGISTER) | |
357 | return 1; | |
358 | ||
359 | /* Copied from a pseudo register - not as bad as from a hard register, | |
360 | yet still cumbersome, since the register live length will be lengthened | |
361 | when the registers get tied. */ | |
362 | return 2; | |
363 | } | |
364 | ||
1230327b R |
365 | /* INSN is a copy from SRC to DEST, both registers, and SRC does not die |
366 | in INSN. | |
367 | ||
368 | Search forward to see if SRC dies before either it or DEST is modified, | |
369 | but don't scan past the end of a basic block. If so, we can replace SRC | |
370 | with DEST and let SRC die in INSN. | |
371 | ||
372 | This will reduce the number of registers live in that range and may enable | |
373 | DEST to be tied to SRC, thus often saving one register in addition to a | |
374 | register-register copy. */ | |
375 | ||
376 | static int | |
377 | optimize_reg_copy_1 (insn, dest, src) | |
378 | rtx insn; | |
379 | rtx dest; | |
380 | rtx src; | |
381 | { | |
382 | rtx p, q; | |
383 | rtx note; | |
384 | rtx dest_death = 0; | |
385 | int sregno = REGNO (src); | |
386 | int dregno = REGNO (dest); | |
387 | ||
388 | /* We don't want to mess with hard regs if register classes are small. */ | |
389 | if (sregno == dregno | |
390 | || (SMALL_REGISTER_CLASSES | |
391 | && (sregno < FIRST_PSEUDO_REGISTER | |
392 | || dregno < FIRST_PSEUDO_REGISTER)) | |
393 | /* We don't see all updates to SP if they are in an auto-inc memory | |
394 | reference, so we must disallow this optimization on them. */ | |
395 | || sregno == STACK_POINTER_REGNUM || dregno == STACK_POINTER_REGNUM) | |
396 | return 0; | |
397 | ||
398 | for (p = NEXT_INSN (insn); p; p = NEXT_INSN (p)) | |
399 | { | |
400 | if (GET_CODE (p) == CODE_LABEL || GET_CODE (p) == JUMP_INSN | |
401 | || (GET_CODE (p) == NOTE | |
402 | && (NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_BEG | |
403 | || NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_END))) | |
404 | break; | |
405 | ||
7bf825d2 JW |
406 | /* ??? We can't scan past the end of a basic block without updating |
407 | the register lifetime info (REG_DEAD/basic_block_live_at_start). | |
408 | A CALL_INSN might be the last insn of a basic block, if it is inside | |
409 | an EH region. There is no easy way to tell, so we just always break | |
410 | when we see a CALL_INSN if flag_exceptions is nonzero. */ | |
411 | if (flag_exceptions && GET_CODE (p) == CALL_INSN) | |
412 | break; | |
413 | ||
1230327b R |
414 | if (GET_RTX_CLASS (GET_CODE (p)) != 'i') |
415 | continue; | |
416 | ||
417 | if (reg_set_p (src, p) || reg_set_p (dest, p) | |
418 | /* Don't change a USE of a register. */ | |
419 | || (GET_CODE (PATTERN (p)) == USE | |
420 | && reg_overlap_mentioned_p (src, XEXP (PATTERN (p), 0)))) | |
421 | break; | |
422 | ||
423 | /* See if all of SRC dies in P. This test is slightly more | |
424 | conservative than it needs to be. */ | |
425 | if ((note = find_regno_note (p, REG_DEAD, sregno)) != 0 | |
426 | && GET_MODE (XEXP (note, 0)) == GET_MODE (src)) | |
427 | { | |
428 | int failed = 0; | |
1230327b | 429 | int d_length = 0; |
89098dc1 | 430 | int s_length = 0; |
1230327b | 431 | int d_n_calls = 0; |
89098dc1 | 432 | int s_n_calls = 0; |
1230327b R |
433 | |
434 | /* We can do the optimization. Scan forward from INSN again, | |
435 | replacing regs as we go. Set FAILED if a replacement can't | |
436 | be done. In that case, we can't move the death note for SRC. | |
437 | This should be rare. */ | |
438 | ||
439 | /* Set to stop at next insn. */ | |
440 | for (q = next_real_insn (insn); | |
441 | q != next_real_insn (p); | |
442 | q = next_real_insn (q)) | |
443 | { | |
444 | if (reg_overlap_mentioned_p (src, PATTERN (q))) | |
445 | { | |
446 | /* If SRC is a hard register, we might miss some | |
447 | overlapping registers with validate_replace_rtx, | |
448 | so we would have to undo it. We can't if DEST is | |
449 | present in the insn, so fail in that combination | |
450 | of cases. */ | |
451 | if (sregno < FIRST_PSEUDO_REGISTER | |
452 | && reg_mentioned_p (dest, PATTERN (q))) | |
453 | failed = 1; | |
454 | ||
455 | /* Replace all uses and make sure that the register | |
456 | isn't still present. */ | |
457 | else if (validate_replace_rtx (src, dest, q) | |
458 | && (sregno >= FIRST_PSEUDO_REGISTER | |
459 | || ! reg_overlap_mentioned_p (src, | |
460 | PATTERN (q)))) | |
461 | { | |
462 | /* We assume that a register is used exactly once per | |
7b31b7d9 JL |
463 | insn in the REG_N_REFS updates below. If this is not |
464 | correct, no great harm is done. | |
465 | ||
89098dc1 JL |
466 | Since we do not know if we will change the lifetime of |
467 | SREGNO or DREGNO, we must not update REG_LIVE_LENGTH | |
468 | or REG_N_CALLS_CROSSED at this time. */ | |
1230327b | 469 | if (sregno >= FIRST_PSEUDO_REGISTER) |
89098dc1 | 470 | REG_N_REFS (sregno) -= loop_depth; |
7b31b7d9 | 471 | |
1230327b | 472 | if (dregno >= FIRST_PSEUDO_REGISTER) |
89098dc1 | 473 | REG_N_REFS (dregno) += loop_depth; |
1230327b R |
474 | } |
475 | else | |
476 | { | |
477 | validate_replace_rtx (dest, src, q); | |
478 | failed = 1; | |
479 | } | |
480 | } | |
481 | ||
89098dc1 JL |
482 | /* For SREGNO, count the total number of insns scanned. |
483 | For DREGNO, count the total number of insns scanned after | |
484 | passing the death note for DREGNO. */ | |
485 | s_length++; | |
1230327b R |
486 | if (dest_death) |
487 | d_length++; | |
488 | ||
489 | /* If the insn in which SRC dies is a CALL_INSN, don't count it | |
490 | as a call that has been crossed. Otherwise, count it. */ | |
491 | if (q != p && GET_CODE (q) == CALL_INSN) | |
492 | { | |
89098dc1 JL |
493 | /* Similarly, total calls for SREGNO, total calls beyond |
494 | the death note for DREGNO. */ | |
495 | s_n_calls++; | |
1230327b R |
496 | if (dest_death) |
497 | d_n_calls++; | |
498 | } | |
499 | ||
500 | /* If DEST dies here, remove the death note and save it for | |
501 | later. Make sure ALL of DEST dies here; again, this is | |
502 | overly conservative. */ | |
503 | if (dest_death == 0 | |
504 | && (dest_death = find_regno_note (q, REG_DEAD, dregno)) != 0) | |
505 | { | |
506 | if (GET_MODE (XEXP (dest_death, 0)) != GET_MODE (dest)) | |
507 | failed = 1, dest_death = 0; | |
508 | else | |
509 | remove_note (q, dest_death); | |
510 | } | |
511 | } | |
512 | ||
513 | if (! failed) | |
514 | { | |
89098dc1 JL |
515 | /* These counters need to be updated if and only if we are |
516 | going to move the REG_DEAD note. */ | |
1230327b R |
517 | if (sregno >= FIRST_PSEUDO_REGISTER) |
518 | { | |
519 | if (REG_LIVE_LENGTH (sregno) >= 0) | |
520 | { | |
89098dc1 | 521 | REG_LIVE_LENGTH (sregno) -= s_length; |
1230327b R |
522 | /* REG_LIVE_LENGTH is only an approximation after |
523 | combine if sched is not run, so make sure that we | |
524 | still have a reasonable value. */ | |
525 | if (REG_LIVE_LENGTH (sregno) < 2) | |
526 | REG_LIVE_LENGTH (sregno) = 2; | |
527 | } | |
528 | ||
89098dc1 | 529 | REG_N_CALLS_CROSSED (sregno) -= s_n_calls; |
1230327b R |
530 | } |
531 | ||
532 | /* Move death note of SRC from P to INSN. */ | |
533 | remove_note (p, note); | |
534 | XEXP (note, 1) = REG_NOTES (insn); | |
535 | REG_NOTES (insn) = note; | |
536 | } | |
537 | ||
538 | /* Put death note of DEST on P if we saw it die. */ | |
539 | if (dest_death) | |
540 | { | |
541 | XEXP (dest_death, 1) = REG_NOTES (p); | |
542 | REG_NOTES (p) = dest_death; | |
89098dc1 JL |
543 | |
544 | if (dregno >= FIRST_PSEUDO_REGISTER) | |
545 | { | |
546 | /* If and only if we are moving the death note for DREGNO, | |
547 | then we need to update its counters. */ | |
548 | if (REG_LIVE_LENGTH (dregno) >= 0) | |
549 | REG_LIVE_LENGTH (dregno) += d_length; | |
550 | REG_N_CALLS_CROSSED (dregno) += d_n_calls; | |
551 | } | |
1230327b R |
552 | } |
553 | ||
554 | return ! failed; | |
555 | } | |
556 | ||
557 | /* If SRC is a hard register which is set or killed in some other | |
558 | way, we can't do this optimization. */ | |
559 | else if (sregno < FIRST_PSEUDO_REGISTER | |
560 | && dead_or_set_p (p, src)) | |
561 | break; | |
562 | } | |
563 | return 0; | |
564 | } | |
565 | \f | |
566 | /* INSN is a copy of SRC to DEST, in which SRC dies. See if we now have | |
567 | a sequence of insns that modify DEST followed by an insn that sets | |
568 | SRC to DEST in which DEST dies, with no prior modification of DEST. | |
569 | (There is no need to check if the insns in between actually modify | |
570 | DEST. We should not have cases where DEST is not modified, but | |
571 | the optimization is safe if no such modification is detected.) | |
572 | In that case, we can replace all uses of DEST, starting with INSN and | |
573 | ending with the set of SRC to DEST, with SRC. We do not do this | |
574 | optimization if a CALL_INSN is crossed unless SRC already crosses a | |
575 | call or if DEST dies before the copy back to SRC. | |
576 | ||
577 | It is assumed that DEST and SRC are pseudos; it is too complicated to do | |
578 | this for hard registers since the substitutions we may make might fail. */ | |
579 | ||
580 | static void | |
581 | optimize_reg_copy_2 (insn, dest, src) | |
582 | rtx insn; | |
583 | rtx dest; | |
584 | rtx src; | |
585 | { | |
586 | rtx p, q; | |
587 | rtx set; | |
588 | int sregno = REGNO (src); | |
589 | int dregno = REGNO (dest); | |
590 | ||
591 | for (p = NEXT_INSN (insn); p; p = NEXT_INSN (p)) | |
592 | { | |
593 | if (GET_CODE (p) == CODE_LABEL || GET_CODE (p) == JUMP_INSN | |
594 | || (GET_CODE (p) == NOTE | |
595 | && (NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_BEG | |
596 | || NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_END))) | |
597 | break; | |
598 | ||
7bf825d2 JW |
599 | /* ??? We can't scan past the end of a basic block without updating |
600 | the register lifetime info (REG_DEAD/basic_block_live_at_start). | |
601 | A CALL_INSN might be the last insn of a basic block, if it is inside | |
602 | an EH region. There is no easy way to tell, so we just always break | |
603 | when we see a CALL_INSN if flag_exceptions is nonzero. */ | |
604 | if (flag_exceptions && GET_CODE (p) == CALL_INSN) | |
605 | break; | |
606 | ||
1230327b R |
607 | if (GET_RTX_CLASS (GET_CODE (p)) != 'i') |
608 | continue; | |
609 | ||
610 | set = single_set (p); | |
611 | if (set && SET_SRC (set) == dest && SET_DEST (set) == src | |
612 | && find_reg_note (p, REG_DEAD, dest)) | |
613 | { | |
614 | /* We can do the optimization. Scan forward from INSN again, | |
615 | replacing regs as we go. */ | |
616 | ||
617 | /* Set to stop at next insn. */ | |
618 | for (q = insn; q != NEXT_INSN (p); q = NEXT_INSN (q)) | |
619 | if (GET_RTX_CLASS (GET_CODE (q)) == 'i') | |
620 | { | |
621 | if (reg_mentioned_p (dest, PATTERN (q))) | |
622 | { | |
623 | PATTERN (q) = replace_rtx (PATTERN (q), dest, src); | |
624 | ||
625 | /* We assume that a register is used exactly once per | |
626 | insn in the updates below. If this is not correct, | |
627 | no great harm is done. */ | |
628 | REG_N_REFS (dregno) -= loop_depth; | |
629 | REG_N_REFS (sregno) += loop_depth; | |
630 | } | |
631 | ||
632 | ||
633 | if (GET_CODE (q) == CALL_INSN) | |
634 | { | |
635 | REG_N_CALLS_CROSSED (dregno)--; | |
636 | REG_N_CALLS_CROSSED (sregno)++; | |
637 | } | |
638 | } | |
639 | ||
640 | remove_note (p, find_reg_note (p, REG_DEAD, dest)); | |
641 | REG_N_DEATHS (dregno)--; | |
642 | remove_note (insn, find_reg_note (insn, REG_DEAD, src)); | |
643 | REG_N_DEATHS (sregno)--; | |
644 | return; | |
645 | } | |
646 | ||
647 | if (reg_set_p (src, p) | |
648 | || find_reg_note (p, REG_DEAD, dest) | |
649 | || (GET_CODE (p) == CALL_INSN && REG_N_CALLS_CROSSED (sregno) == 0)) | |
650 | break; | |
651 | } | |
652 | } | |
184bb750 R |
653 | /* INSN is a ZERO_EXTEND or SIGN_EXTEND of SRC to DEST. |
654 | Look if SRC dies there, and if it is only set once, by loading | |
655 | it from memory. If so, try to encorporate the zero/sign extension | |
656 | into the memory read, change SRC to the mode of DEST, and alter | |
657 | the remaining accesses to use the appropriate SUBREG. This allows | |
658 | SRC and DEST to be tied later. */ | |
659 | static void | |
660 | optimize_reg_copy_3 (insn, dest, src) | |
661 | rtx insn; | |
662 | rtx dest; | |
663 | rtx src; | |
664 | { | |
665 | rtx src_reg = XEXP (src, 0); | |
666 | int src_no = REGNO (src_reg); | |
667 | int dst_no = REGNO (dest); | |
668 | rtx p, set, subreg; | |
669 | enum machine_mode old_mode; | |
670 | ||
671 | if (src_no < FIRST_PSEUDO_REGISTER | |
672 | || dst_no < FIRST_PSEUDO_REGISTER | |
673 | || ! find_reg_note (insn, REG_DEAD, src_reg) | |
674 | || REG_N_SETS (src_no) != 1) | |
675 | return; | |
676 | for (p = PREV_INSN (insn); ! reg_set_p (src_reg, p); p = PREV_INSN (p)) | |
677 | { | |
7bf825d2 JW |
678 | if (GET_CODE (p) == CODE_LABEL || GET_CODE (p) == JUMP_INSN |
679 | || (GET_CODE (p) == NOTE | |
680 | && (NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_BEG | |
681 | || NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_END))) | |
682 | return; | |
683 | ||
684 | /* ??? We can't scan past the end of a basic block without updating | |
685 | the register lifetime info (REG_DEAD/basic_block_live_at_start). | |
686 | A CALL_INSN might be the last insn of a basic block, if it is inside | |
687 | an EH region. There is no easy way to tell, so we just always break | |
688 | when we see a CALL_INSN if flag_exceptions is nonzero. */ | |
689 | if (flag_exceptions && GET_CODE (p) == CALL_INSN) | |
690 | return; | |
691 | ||
184bb750 R |
692 | if (GET_RTX_CLASS (GET_CODE (p)) != 'i') |
693 | continue; | |
184bb750 R |
694 | } |
695 | if (! (set = single_set (p)) | |
696 | || GET_CODE (SET_SRC (set)) != MEM | |
697 | || SET_DEST (set) != src_reg) | |
698 | return; | |
937e37cc | 699 | |
972b320c R |
700 | /* Be conserative: although this optimization is also valid for |
701 | volatile memory references, that could cause trouble in later passes. */ | |
702 | if (MEM_VOLATILE_P (SET_SRC (set))) | |
703 | return; | |
704 | ||
937e37cc JL |
705 | /* Do not use a SUBREG to truncate from one mode to another if truncation |
706 | is not a nop. */ | |
707 | if (GET_MODE_BITSIZE (GET_MODE (src_reg)) <= GET_MODE_BITSIZE (GET_MODE (src)) | |
708 | && !TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (GET_MODE (src)), | |
709 | GET_MODE_BITSIZE (GET_MODE (src_reg)))) | |
710 | return; | |
711 | ||
184bb750 R |
712 | old_mode = GET_MODE (src_reg); |
713 | PUT_MODE (src_reg, GET_MODE (src)); | |
714 | XEXP (src, 0) = SET_SRC (set); | |
e757da5e JL |
715 | |
716 | /* Include this change in the group so that it's easily undone if | |
717 | one of the changes in the group is invalid. */ | |
718 | validate_change (p, &SET_SRC (set), src, 1); | |
719 | ||
720 | /* Now walk forward making additional replacements. We want to be able | |
721 | to undo all the changes if a later substitution fails. */ | |
38a448ca | 722 | subreg = gen_rtx_SUBREG (old_mode, src_reg, 0); |
184bb750 R |
723 | while (p = NEXT_INSN (p), p != insn) |
724 | { | |
725 | if (GET_RTX_CLASS (GET_CODE (p)) != 'i') | |
726 | continue; | |
e757da5e JL |
727 | |
728 | /* Make a tenative change. */ | |
729 | validate_replace_rtx_group (src_reg, subreg, p); | |
730 | } | |
731 | ||
732 | validate_replace_rtx_group (src, src_reg, insn); | |
733 | ||
734 | /* Now see if all the changes are valid. */ | |
735 | if (! apply_change_group ()) | |
736 | { | |
737 | /* One or more changes were no good. Back out everything. */ | |
738 | PUT_MODE (src_reg, old_mode); | |
739 | XEXP (src, 0) = src_reg; | |
184bb750 | 740 | } |
184bb750 R |
741 | } |
742 | ||
ddc8bed2 MM |
743 | \f |
744 | /* If we were not able to update the users of src to use dest directly, try | |
745 | instead moving the value to dest directly before the operation. */ | |
746 | ||
cab634f2 | 747 | static void |
78dd9906 | 748 | copy_src_to_dest (insn, src, dest, loop_depth, old_max_uid) |
ddc8bed2 MM |
749 | rtx insn; |
750 | rtx src; | |
751 | rtx dest; | |
29a4c5ed | 752 | int loop_depth; |
78dd9906 | 753 | int old_max_uid; |
ddc8bed2 MM |
754 | { |
755 | rtx seq; | |
756 | rtx link; | |
757 | rtx next; | |
758 | rtx set; | |
759 | rtx move_insn; | |
760 | rtx *p_insn_notes; | |
761 | rtx *p_move_notes; | |
ddc8bed2 MM |
762 | int src_regno; |
763 | int dest_regno; | |
764 | int bb; | |
765 | int insn_uid; | |
766 | int move_uid; | |
767 | ||
768 | /* A REG_LIVE_LENGTH of -1 indicates the register is equivalent to a constant | |
769 | or memory location and is used infrequently; a REG_LIVE_LENGTH of -2 is | |
770 | parameter when there is no frame pointer that is not allocated a register. | |
771 | For now, we just reject them, rather than incrementing the live length. */ | |
772 | ||
3ac3da71 MM |
773 | if (GET_CODE (src) == REG |
774 | && REG_LIVE_LENGTH (REGNO (src)) > 0 | |
775 | && GET_CODE (dest) == REG | |
776 | && REG_LIVE_LENGTH (REGNO (dest)) > 0 | |
ddc8bed2 | 777 | && (set = single_set (insn)) != NULL_RTX |
9d2106a4 R |
778 | && !reg_mentioned_p (dest, SET_SRC (set)) |
779 | && GET_MODE (src) == GET_MODE (dest)) | |
ddc8bed2 | 780 | { |
1a8fca8a R |
781 | int old_num_regs = reg_rtx_no; |
782 | ||
ddc8bed2 MM |
783 | /* Generate the src->dest move. */ |
784 | start_sequence (); | |
785 | emit_move_insn (dest, src); | |
786 | seq = gen_sequence (); | |
787 | end_sequence (); | |
1a8fca8a R |
788 | /* If this sequence uses new registers, we may not use it. */ |
789 | if (old_num_regs != reg_rtx_no | |
790 | || ! validate_replace_rtx (src, dest, insn)) | |
791 | { | |
792 | /* We have to restore reg_rtx_no to its old value, lest | |
793 | recompute_reg_usage will try to compute the usage of the | |
794 | new regs, yet reg_n_info is not valid for them. */ | |
795 | reg_rtx_no = old_num_regs; | |
796 | return; | |
797 | } | |
ddc8bed2 MM |
798 | emit_insn_before (seq, insn); |
799 | move_insn = PREV_INSN (insn); | |
800 | p_move_notes = ®_NOTES (move_insn); | |
801 | p_insn_notes = ®_NOTES (insn); | |
802 | ||
803 | /* Move any notes mentioning src to the move instruction */ | |
804 | for (link = REG_NOTES (insn); link != NULL_RTX; link = next) | |
805 | { | |
806 | next = XEXP (link, 1); | |
807 | if (XEXP (link, 0) == src) | |
808 | { | |
809 | *p_move_notes = link; | |
810 | p_move_notes = &XEXP (link, 1); | |
811 | } | |
812 | else | |
813 | { | |
814 | *p_insn_notes = link; | |
815 | p_insn_notes = &XEXP (link, 1); | |
816 | } | |
817 | } | |
818 | ||
819 | *p_move_notes = NULL_RTX; | |
820 | *p_insn_notes = NULL_RTX; | |
821 | ||
822 | /* Is the insn the head of a basic block? If so extend it */ | |
823 | insn_uid = INSN_UID (insn); | |
824 | move_uid = INSN_UID (move_insn); | |
78dd9906 | 825 | if (insn_uid < old_max_uid) |
ddc8bed2 | 826 | { |
78dd9906 R |
827 | bb = regmove_bb_head[insn_uid]; |
828 | if (bb >= 0) | |
829 | { | |
830 | BLOCK_HEAD (bb) = move_insn; | |
831 | regmove_bb_head[insn_uid] = -1; | |
832 | } | |
ddc8bed2 MM |
833 | } |
834 | ||
835 | /* Update the various register tables. */ | |
836 | dest_regno = REGNO (dest); | |
837 | REG_N_SETS (dest_regno) += loop_depth; | |
838 | REG_N_REFS (dest_regno) += loop_depth; | |
839 | REG_LIVE_LENGTH (dest_regno)++; | |
840 | if (REGNO_FIRST_UID (dest_regno) == insn_uid) | |
841 | REGNO_FIRST_UID (dest_regno) = move_uid; | |
842 | ||
843 | src_regno = REGNO (src); | |
844 | if (! find_reg_note (move_insn, REG_DEAD, src)) | |
845 | REG_LIVE_LENGTH (src_regno)++; | |
846 | ||
847 | if (REGNO_FIRST_UID (src_regno) == insn_uid) | |
848 | REGNO_FIRST_UID (src_regno) = move_uid; | |
849 | ||
850 | if (REGNO_LAST_UID (src_regno) == insn_uid) | |
851 | REGNO_LAST_UID (src_regno) = move_uid; | |
852 | ||
853 | if (REGNO_LAST_NOTE_UID (src_regno) == insn_uid) | |
854 | REGNO_LAST_NOTE_UID (src_regno) = move_uid; | |
855 | } | |
856 | } | |
857 | ||
858 | \f | |
184bb750 R |
859 | /* Return whether REG is set in only one location, and is set to a |
860 | constant, but is set in a different basic block from INSN (an | |
861 | instructions which uses REG). In this case REG is equivalent to a | |
862 | constant, and we don't want to break that equivalence, because that | |
863 | may increase register pressure and make reload harder. If REG is | |
864 | set in the same basic block as INSN, we don't worry about it, | |
865 | because we'll probably need a register anyhow (??? but what if REG | |
866 | is used in a different basic block as well as this one?). FIRST is | |
867 | the first insn in the function. */ | |
868 | ||
869 | static int | |
870 | reg_is_remote_constant_p (reg, insn, first) | |
871 | rtx reg; | |
872 | rtx insn; | |
873 | rtx first; | |
874 | { | |
875 | register rtx p; | |
876 | ||
877 | if (REG_N_SETS (REGNO (reg)) != 1) | |
878 | return 0; | |
879 | ||
880 | /* Look for the set. */ | |
881 | for (p = LOG_LINKS (insn); p; p = XEXP (p, 1)) | |
882 | { | |
883 | rtx s; | |
884 | ||
885 | if (REG_NOTE_KIND (p) != 0) | |
886 | continue; | |
887 | s = single_set (XEXP (p, 0)); | |
888 | if (s != 0 | |
889 | && GET_CODE (SET_DEST (s)) == REG | |
890 | && REGNO (SET_DEST (s)) == REGNO (reg)) | |
891 | { | |
892 | /* The register is set in the same basic block. */ | |
893 | return 0; | |
894 | } | |
895 | } | |
896 | ||
897 | for (p = first; p && p != insn; p = NEXT_INSN (p)) | |
898 | { | |
899 | rtx s; | |
900 | ||
901 | if (GET_RTX_CLASS (GET_CODE (p)) != 'i') | |
902 | continue; | |
903 | s = single_set (p); | |
904 | if (s != 0 | |
905 | && GET_CODE (SET_DEST (s)) == REG | |
906 | && REGNO (SET_DEST (s)) == REGNO (reg)) | |
907 | { | |
908 | /* This is the instruction which sets REG. If there is a | |
909 | REG_EQUAL note, then REG is equivalent to a constant. */ | |
910 | if (find_reg_note (p, REG_EQUAL, NULL_RTX)) | |
911 | return 1; | |
912 | return 0; | |
913 | } | |
914 | } | |
915 | ||
916 | return 0; | |
917 | } | |
918 | ||
b1a7d591 JW |
919 | /* INSN is adding a CONST_INT to a REG. We search backwards looking for |
920 | another add immediate instruction with the same source and dest registers, | |
921 | and if we find one, we change INSN to an increment, and return 1. If | |
922 | no changes are made, we return 0. | |
923 | ||
924 | This changes | |
925 | (set (reg100) (plus reg1 offset1)) | |
926 | ... | |
927 | (set (reg100) (plus reg1 offset2)) | |
928 | to | |
929 | (set (reg100) (plus reg1 offset1)) | |
930 | ... | |
931 | (set (reg100) (plus reg100 offset2-offset1)) */ | |
932 | ||
933 | /* ??? What does this comment mean? */ | |
184bb750 R |
934 | /* cse disrupts preincrement / postdecrement squences when it finds a |
935 | hard register as ultimate source, like the frame pointer. */ | |
b1a7d591 | 936 | |
7bf825d2 JW |
937 | int |
938 | fixup_match_2 (insn, dst, src, offset, regmove_dump_file) | |
184bb750 R |
939 | rtx insn, dst, src, offset; |
940 | FILE *regmove_dump_file; | |
941 | { | |
942 | rtx p, dst_death = 0; | |
943 | int length, num_calls = 0; | |
944 | ||
945 | /* If SRC dies in INSN, we'd have to move the death note. This is | |
946 | considered to be very unlikely, so we just skip the optimization | |
947 | in this case. */ | |
948 | if (find_regno_note (insn, REG_DEAD, REGNO (src))) | |
949 | return 0; | |
950 | ||
951 | /* Scan backward to find the first instruction that sets DST. */ | |
952 | ||
953 | for (length = 0, p = PREV_INSN (insn); p; p = PREV_INSN (p)) | |
954 | { | |
955 | rtx pset; | |
956 | ||
957 | if (GET_CODE (p) == CODE_LABEL | |
958 | || GET_CODE (p) == JUMP_INSN | |
959 | || (GET_CODE (p) == NOTE | |
960 | && (NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_BEG | |
961 | || NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_END))) | |
962 | break; | |
963 | ||
7bf825d2 JW |
964 | /* ??? We can't scan past the end of a basic block without updating |
965 | the register lifetime info (REG_DEAD/basic_block_live_at_start). | |
966 | A CALL_INSN might be the last insn of a basic block, if it is inside | |
967 | an EH region. There is no easy way to tell, so we just always break | |
968 | when we see a CALL_INSN if flag_exceptions is nonzero. */ | |
969 | if (flag_exceptions && GET_CODE (p) == CALL_INSN) | |
970 | break; | |
971 | ||
184bb750 R |
972 | if (GET_RTX_CLASS (GET_CODE (p)) != 'i') |
973 | continue; | |
974 | ||
7bf825d2 JW |
975 | if (find_regno_note (p, REG_DEAD, REGNO (dst))) |
976 | dst_death = p; | |
977 | if (! dst_death) | |
978 | length++; | |
184bb750 R |
979 | |
980 | pset = single_set (p); | |
981 | if (pset && SET_DEST (pset) == dst | |
982 | && GET_CODE (SET_SRC (pset)) == PLUS | |
983 | && XEXP (SET_SRC (pset), 0) == src | |
984 | && GET_CODE (XEXP (SET_SRC (pset), 1)) == CONST_INT) | |
985 | { | |
986 | HOST_WIDE_INT newconst | |
987 | = INTVAL (offset) - INTVAL (XEXP (SET_SRC (pset), 1)); | |
1a29f703 R |
988 | rtx add = gen_add3_insn (dst, dst, GEN_INT (newconst)); |
989 | ||
990 | if (add && validate_change (insn, &PATTERN (insn), add, 0)) | |
184bb750 R |
991 | { |
992 | /* Remove the death note for DST from DST_DEATH. */ | |
993 | if (dst_death) | |
994 | { | |
995 | remove_death (REGNO (dst), dst_death); | |
996 | REG_LIVE_LENGTH (REGNO (dst)) += length; | |
997 | REG_N_CALLS_CROSSED (REGNO (dst)) += num_calls; | |
998 | } | |
999 | ||
1000 | REG_N_REFS (REGNO (dst)) += loop_depth; | |
1001 | REG_N_REFS (REGNO (src)) -= loop_depth; | |
1002 | ||
1003 | if (regmove_dump_file) | |
1004 | fprintf (regmove_dump_file, | |
1005 | "Fixed operand of insn %d.\n", | |
1006 | INSN_UID (insn)); | |
1007 | ||
1008 | #ifdef AUTO_INC_DEC | |
1009 | for (p = PREV_INSN (insn); p; p = PREV_INSN (p)) | |
1010 | { | |
1011 | if (GET_CODE (p) == CODE_LABEL | |
1012 | || GET_CODE (p) == JUMP_INSN | |
1013 | || (GET_CODE (p) == NOTE | |
1014 | && (NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_BEG | |
1015 | || NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_END))) | |
1016 | break; | |
e27a5106 JL |
1017 | if (GET_RTX_CLASS (GET_CODE (p)) != 'i') |
1018 | continue; | |
184bb750 R |
1019 | if (reg_overlap_mentioned_p (dst, PATTERN (p))) |
1020 | { | |
1021 | if (try_auto_increment (p, insn, 0, dst, newconst, 0)) | |
1022 | return 1; | |
1023 | break; | |
1024 | } | |
1025 | } | |
1026 | for (p = NEXT_INSN (insn); p; p = NEXT_INSN (p)) | |
1027 | { | |
1028 | if (GET_CODE (p) == CODE_LABEL | |
1029 | || GET_CODE (p) == JUMP_INSN | |
1030 | || (GET_CODE (p) == NOTE | |
1031 | && (NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_BEG | |
1032 | || NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_END))) | |
1033 | break; | |
8543c01e R |
1034 | if (GET_RTX_CLASS (GET_CODE (p)) != 'i') |
1035 | continue; | |
184bb750 R |
1036 | if (reg_overlap_mentioned_p (dst, PATTERN (p))) |
1037 | { | |
1038 | try_auto_increment (p, insn, 0, dst, newconst, 1); | |
1039 | break; | |
1040 | } | |
1041 | } | |
1042 | #endif | |
1043 | return 1; | |
1044 | } | |
8c660648 | 1045 | } |
184bb750 R |
1046 | |
1047 | if (reg_set_p (dst, PATTERN (p))) | |
1048 | break; | |
1049 | ||
1050 | /* If we have passed a call instruction, and the | |
1051 | pseudo-reg SRC is not already live across a call, | |
1052 | then don't perform the optimization. */ | |
1053 | /* reg_set_p is overly conservative for CALL_INSNS, thinks that all | |
1054 | hard regs are clobbered. Thus, we only use it for src for | |
1055 | non-call insns. */ | |
1056 | if (GET_CODE (p) == CALL_INSN) | |
1057 | { | |
1058 | if (! dst_death) | |
1059 | num_calls++; | |
1060 | ||
1061 | if (REG_N_CALLS_CROSSED (REGNO (src)) == 0) | |
1062 | break; | |
1063 | ||
1064 | if (call_used_regs [REGNO (dst)] | |
1065 | || find_reg_fusage (p, CLOBBER, dst)) | |
1066 | break; | |
1067 | } | |
1068 | else if (reg_set_p (src, PATTERN (p))) | |
1069 | break; | |
8c660648 | 1070 | } |
184bb750 | 1071 | |
8c660648 JL |
1072 | return 0; |
1073 | } | |
8c660648 JL |
1074 | |
1075 | void | |
1076 | regmove_optimize (f, nregs, regmove_dump_file) | |
1077 | rtx f; | |
1078 | int nregs; | |
1079 | FILE *regmove_dump_file; | |
1080 | { | |
961d4119 | 1081 | int old_max_uid = get_max_uid (); |
8c660648 | 1082 | rtx insn; |
184bb750 | 1083 | struct match match; |
8c660648 | 1084 | int pass; |
3bb806ed | 1085 | int i; |
ddc8bed2 | 1086 | rtx copy_src, copy_dst; |
184bb750 | 1087 | |
dc2cb191 RH |
1088 | /* Find out where a potential flags register is live, and so that we |
1089 | can supress some optimizations in those zones. */ | |
1090 | mark_flags_life_zones (discover_flags_reg ()); | |
1091 | ||
3bb806ed R |
1092 | regno_src_regno = (int *)alloca (sizeof *regno_src_regno * nregs); |
1093 | for (i = nregs; --i >= 0; ) regno_src_regno[i] = -1; | |
8c660648 | 1094 | |
961d4119 BS |
1095 | regmove_bb_head = (int *)alloca (sizeof (int) * (old_max_uid + 1)); |
1096 | for (i = old_max_uid; i >= 0; i--) regmove_bb_head[i] = -1; | |
ddc8bed2 | 1097 | for (i = 0; i < n_basic_blocks; i++) |
3b413743 | 1098 | regmove_bb_head[INSN_UID (BLOCK_HEAD (i))] = i; |
ddc8bed2 | 1099 | |
8c660648 JL |
1100 | /* A forward/backward pass. Replace output operands with input operands. */ |
1101 | ||
184bb750 R |
1102 | loop_depth = 1; |
1103 | ||
1104 | for (pass = 0; pass <= 2; pass++) | |
8c660648 | 1105 | { |
184bb750 R |
1106 | if (! flag_regmove && pass >= flag_expensive_optimizations) |
1107 | return; | |
1108 | ||
8c660648 JL |
1109 | if (regmove_dump_file) |
1110 | fprintf (regmove_dump_file, "Starting %s pass...\n", | |
1111 | pass ? "backward" : "forward"); | |
1112 | ||
1113 | for (insn = pass ? get_last_insn () : f; insn; | |
1114 | insn = pass ? PREV_INSN (insn) : NEXT_INSN (insn)) | |
1115 | { | |
184bb750 | 1116 | rtx set; |
0eadeb15 | 1117 | int op_no, match_no; |
184bb750 R |
1118 | |
1119 | if (GET_CODE (insn) == NOTE) | |
8c660648 | 1120 | { |
184bb750 R |
1121 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) |
1122 | loop_depth++; | |
1123 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) | |
1124 | loop_depth--; | |
1125 | } | |
8c660648 | 1126 | |
184bb750 R |
1127 | set = single_set (insn); |
1128 | if (! set) | |
1129 | continue; | |
8c660648 | 1130 | |
184bb750 R |
1131 | if (flag_expensive_optimizations && ! pass |
1132 | && (GET_CODE (SET_SRC (set)) == SIGN_EXTEND | |
1133 | || GET_CODE (SET_SRC (set)) == ZERO_EXTEND) | |
1134 | && GET_CODE (XEXP (SET_SRC (set), 0)) == REG | |
1135 | && GET_CODE (SET_DEST(set)) == REG) | |
1136 | optimize_reg_copy_3 (insn, SET_DEST (set), SET_SRC (set)); | |
1137 | ||
1138 | if (flag_expensive_optimizations && ! pass | |
1139 | && GET_CODE (SET_SRC (set)) == REG | |
1140 | && GET_CODE (SET_DEST(set)) == REG) | |
1141 | { | |
1142 | /* If this is a register-register copy where SRC is not dead, | |
1143 | see if we can optimize it. If this optimization succeeds, | |
1144 | it will become a copy where SRC is dead. */ | |
1145 | if ((find_reg_note (insn, REG_DEAD, SET_SRC (set)) | |
1146 | || optimize_reg_copy_1 (insn, SET_DEST (set), SET_SRC (set))) | |
1147 | && REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER) | |
8c660648 | 1148 | { |
184bb750 R |
1149 | /* Similarly for a pseudo-pseudo copy when SRC is dead. */ |
1150 | if (REGNO (SET_SRC (set)) >= FIRST_PSEUDO_REGISTER) | |
1151 | optimize_reg_copy_2 (insn, SET_DEST (set), SET_SRC (set)); | |
1152 | if (regno_src_regno[REGNO (SET_DEST (set))] < 0 | |
1153 | && SET_SRC (set) != SET_DEST (set)) | |
8c660648 | 1154 | { |
184bb750 R |
1155 | int srcregno = REGNO (SET_SRC(set)); |
1156 | if (regno_src_regno[srcregno] >= 0) | |
1157 | srcregno = regno_src_regno[srcregno]; | |
1158 | regno_src_regno[REGNO (SET_DEST (set))] = srcregno; | |
8c660648 JL |
1159 | } |
1160 | } | |
184bb750 | 1161 | } |
8d1d76c1 R |
1162 | if (! flag_regmove) |
1163 | continue; | |
184bb750 | 1164 | |
0eadeb15 | 1165 | #ifdef REGISTER_CONSTRAINTS |
3363316f | 1166 | if (! find_matches (insn, &match)) |
184bb750 R |
1167 | continue; |
1168 | ||
1169 | /* Now scan through the operands looking for a source operand | |
1170 | which is supposed to match the destination operand. | |
1171 | Then scan forward for an instruction which uses the dest | |
1172 | operand. | |
1173 | If it dies there, then replace the dest in both operands with | |
1174 | the source operand. */ | |
1175 | ||
0eadeb15 | 1176 | for (op_no = 0; op_no < recog_n_operands; op_no++) |
184bb750 | 1177 | { |
5e9defae | 1178 | rtx src, dst, src_subreg; |
184bb750 R |
1179 | enum reg_class src_class, dst_class; |
1180 | ||
0eadeb15 | 1181 | match_no = match.with[op_no]; |
184bb750 R |
1182 | |
1183 | /* Nothing to do if the two operands aren't supposed to match. */ | |
0eadeb15 | 1184 | if (match_no < 0) |
184bb750 R |
1185 | continue; |
1186 | ||
0eadeb15 BS |
1187 | src = recog_operand[op_no]; |
1188 | dst = recog_operand[match_no]; | |
184bb750 R |
1189 | |
1190 | if (GET_CODE (src) != REG) | |
1191 | continue; | |
1192 | ||
1193 | src_subreg = src; | |
1194 | if (GET_CODE (dst) == SUBREG | |
1195 | && GET_MODE_SIZE (GET_MODE (dst)) | |
1196 | >= GET_MODE_SIZE (GET_MODE (SUBREG_REG (dst)))) | |
1197 | { | |
1198 | src_subreg | |
38a448ca RH |
1199 | = gen_rtx_SUBREG (GET_MODE (SUBREG_REG (dst)), |
1200 | src, SUBREG_WORD (dst)); | |
184bb750 R |
1201 | dst = SUBREG_REG (dst); |
1202 | } | |
1203 | if (GET_CODE (dst) != REG | |
1204 | || REGNO (dst) < FIRST_PSEUDO_REGISTER) | |
1205 | continue; | |
1206 | ||
1207 | if (REGNO (src) < FIRST_PSEUDO_REGISTER) | |
1208 | { | |
0eadeb15 | 1209 | if (match.commutative[op_no] < op_no) |
184bb750 R |
1210 | regno_src_regno[REGNO (dst)] = REGNO (src); |
1211 | continue; | |
1212 | } | |
1213 | ||
1214 | if (REG_LIVE_LENGTH (REGNO (src)) < 0) | |
1215 | continue; | |
1216 | ||
0eadeb15 | 1217 | /* op_no/src must be a read-only operand, and |
184bb750 | 1218 | match_operand/dst must be a write-only operand. */ |
0eadeb15 BS |
1219 | if (match.use[op_no] != READ |
1220 | || match.use[match_no] != WRITE) | |
184bb750 R |
1221 | continue; |
1222 | ||
0eadeb15 | 1223 | if (match.early_clobber[match_no] |
184bb750 R |
1224 | && count_occurrences (PATTERN (insn), src) > 1) |
1225 | continue; | |
1226 | ||
1227 | /* Make sure match_operand is the destination. */ | |
0eadeb15 | 1228 | if (recog_operand[match_no] != SET_DEST (set)) |
184bb750 R |
1229 | continue; |
1230 | ||
1231 | /* If the operands already match, then there is nothing to do. */ | |
1232 | /* But in the commutative case, we might find a better match. */ | |
1233 | if (operands_match_p (src, dst) | |
0eadeb15 | 1234 | || (match.commutative[op_no] >= 0 |
184bb750 | 1235 | && operands_match_p (recog_operand[match.commutative |
0eadeb15 | 1236 | [op_no]], dst) |
184bb750 | 1237 | && (replacement_quality (recog_operand[match.commutative |
0eadeb15 | 1238 | [op_no]]) |
184bb750 R |
1239 | >= replacement_quality (src)))) |
1240 | continue; | |
1241 | ||
1242 | src_class = reg_preferred_class (REGNO (src)); | |
1243 | dst_class = reg_preferred_class (REGNO (dst)); | |
3bb806ed | 1244 | if (! regclass_compatible_p (src_class, dst_class)) |
184bb750 R |
1245 | continue; |
1246 | ||
1247 | if (fixup_match_1 (insn, set, src, src_subreg, dst, pass, | |
0eadeb15 | 1248 | op_no, match_no, |
184bb750 R |
1249 | regmove_dump_file)) |
1250 | break; | |
8c660648 JL |
1251 | } |
1252 | } | |
1253 | } | |
1254 | ||
1255 | /* A backward pass. Replace input operands with output operands. */ | |
1256 | ||
1257 | if (regmove_dump_file) | |
1258 | fprintf (regmove_dump_file, "Starting backward pass...\n"); | |
1259 | ||
184bb750 R |
1260 | loop_depth = 1; |
1261 | ||
8c660648 JL |
1262 | for (insn = get_last_insn (); insn; insn = PREV_INSN (insn)) |
1263 | { | |
184bb750 R |
1264 | if (GET_CODE (insn) == NOTE) |
1265 | { | |
1266 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) | |
1267 | loop_depth++; | |
1268 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
1269 | loop_depth--; | |
1270 | } | |
8c660648 JL |
1271 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') |
1272 | { | |
0eadeb15 | 1273 | int op_no, match_no; |
ddc8bed2 | 1274 | int success = 0; |
0eadeb15 | 1275 | |
3363316f | 1276 | if (! find_matches (insn, &match)) |
8c660648 JL |
1277 | continue; |
1278 | ||
8c660648 JL |
1279 | /* Now scan through the operands looking for a destination operand |
1280 | which is supposed to match a source operand. | |
1281 | Then scan backward for an instruction which sets the source | |
1282 | operand. If safe, then replace the source operand with the | |
1283 | dest operand in both instructions. */ | |
1284 | ||
ddc8bed2 MM |
1285 | copy_src = NULL_RTX; |
1286 | copy_dst = NULL_RTX; | |
0eadeb15 | 1287 | for (op_no = 0; op_no < recog_n_operands; op_no++) |
8c660648 | 1288 | { |
184bb750 R |
1289 | rtx set, p, src, dst; |
1290 | rtx src_note, dst_note; | |
184bb750 R |
1291 | int num_calls = 0; |
1292 | enum reg_class src_class, dst_class; | |
1293 | int length; | |
8c660648 | 1294 | |
0eadeb15 | 1295 | match_no = match.with[op_no]; |
8c660648 | 1296 | |
184bb750 | 1297 | /* Nothing to do if the two operands aren't supposed to match. */ |
0eadeb15 | 1298 | if (match_no < 0) |
184bb750 | 1299 | continue; |
8c660648 | 1300 | |
0eadeb15 BS |
1301 | dst = recog_operand[match_no]; |
1302 | src = recog_operand[op_no]; | |
8c660648 | 1303 | |
184bb750 R |
1304 | if (GET_CODE (src) != REG) |
1305 | continue; | |
8c660648 | 1306 | |
184bb750 R |
1307 | if (GET_CODE (dst) != REG |
1308 | || REGNO (dst) < FIRST_PSEUDO_REGISTER | |
1309 | || REG_LIVE_LENGTH (REGNO (dst)) < 0) | |
1310 | continue; | |
8c660648 | 1311 | |
184bb750 R |
1312 | /* If the operands already match, then there is nothing to do. */ |
1313 | if (operands_match_p (src, dst) | |
0eadeb15 BS |
1314 | || (match.commutative[op_no] >= 0 |
1315 | && operands_match_p (recog_operand[match.commutative[op_no]], dst))) | |
184bb750 | 1316 | continue; |
8c660648 | 1317 | |
184bb750 R |
1318 | set = single_set (insn); |
1319 | if (! set) | |
1320 | continue; | |
8c660648 | 1321 | |
0eadeb15 | 1322 | /* match_no/dst must be a write-only operand, and |
184bb750 | 1323 | operand_operand/src must be a read-only operand. */ |
0eadeb15 BS |
1324 | if (match.use[op_no] != READ |
1325 | || match.use[match_no] != WRITE) | |
184bb750 | 1326 | continue; |
8c660648 | 1327 | |
0eadeb15 | 1328 | if (match.early_clobber[match_no] |
184bb750 R |
1329 | && count_occurrences (PATTERN (insn), src) > 1) |
1330 | continue; | |
8c660648 | 1331 | |
0eadeb15 BS |
1332 | /* Make sure match_no is the destination. */ |
1333 | if (recog_operand[match_no] != SET_DEST (set)) | |
184bb750 | 1334 | continue; |
8c660648 | 1335 | |
184bb750 R |
1336 | if (REGNO (src) < FIRST_PSEUDO_REGISTER) |
1337 | { | |
1338 | if (GET_CODE (SET_SRC (set)) == PLUS | |
1339 | && GET_CODE (XEXP (SET_SRC (set), 1)) == CONST_INT | |
1340 | && XEXP (SET_SRC (set), 0) == src | |
1341 | && fixup_match_2 (insn, dst, src, | |
1342 | XEXP (SET_SRC (set), 1), | |
1343 | regmove_dump_file)) | |
1344 | break; | |
1345 | continue; | |
1346 | } | |
1347 | src_class = reg_preferred_class (REGNO (src)); | |
1348 | dst_class = reg_preferred_class (REGNO (dst)); | |
3bb806ed | 1349 | if (! regclass_compatible_p (src_class, dst_class)) |
ddc8bed2 MM |
1350 | { |
1351 | if (!copy_src) | |
1352 | { | |
1353 | copy_src = src; | |
1354 | copy_dst = dst; | |
1355 | } | |
1356 | continue; | |
1357 | } | |
8c660648 | 1358 | |
184bb750 R |
1359 | /* Can not modify an earlier insn to set dst if this insn |
1360 | uses an old value in the source. */ | |
1361 | if (reg_overlap_mentioned_p (dst, SET_SRC (set))) | |
ddc8bed2 MM |
1362 | { |
1363 | if (!copy_src) | |
1364 | { | |
1365 | copy_src = src; | |
1366 | copy_dst = dst; | |
1367 | } | |
1368 | continue; | |
1369 | } | |
1370 | ||
1371 | if (! (src_note = find_reg_note (insn, REG_DEAD, src))) | |
1372 | { | |
1373 | if (!copy_src) | |
1374 | { | |
1375 | copy_src = src; | |
1376 | copy_dst = dst; | |
1377 | } | |
1378 | continue; | |
1379 | } | |
8c660648 | 1380 | |
8c660648 | 1381 | |
184bb750 R |
1382 | /* If src is set once in a different basic block, |
1383 | and is set equal to a constant, then do not use | |
1384 | it for this optimization, as this would make it | |
1385 | no longer equivalent to a constant. */ | |
ddc8bed2 MM |
1386 | |
1387 | if (reg_is_remote_constant_p (src, insn, f)) | |
1388 | { | |
1389 | if (!copy_src) | |
1390 | { | |
1391 | copy_src = src; | |
1392 | copy_dst = dst; | |
1393 | } | |
1394 | continue; | |
1395 | } | |
1396 | ||
1397 | ||
1398 | if (regmove_dump_file) | |
1399 | fprintf (regmove_dump_file, | |
1400 | "Could fix operand %d of insn %d matching operand %d.\n", | |
0eadeb15 | 1401 | op_no, INSN_UID (insn), match_no); |
8c660648 | 1402 | |
184bb750 R |
1403 | /* Scan backward to find the first instruction that uses |
1404 | the input operand. If the operand is set here, then | |
0eadeb15 | 1405 | replace it in both instructions with match_no. */ |
184bb750 R |
1406 | |
1407 | for (length = 0, p = PREV_INSN (insn); p; p = PREV_INSN (p)) | |
1408 | { | |
1409 | rtx pset; | |
1410 | ||
1411 | if (GET_CODE (p) == CODE_LABEL | |
1412 | || GET_CODE (p) == JUMP_INSN | |
1413 | || (GET_CODE (p) == NOTE | |
1414 | && (NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_BEG | |
1415 | || NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_END))) | |
1416 | break; | |
1417 | ||
7bf825d2 JW |
1418 | /* ??? We can't scan past the end of a basic block without |
1419 | updating the register lifetime info | |
1420 | (REG_DEAD/basic_block_live_at_start). | |
1421 | A CALL_INSN might be the last insn of a basic block, if | |
1422 | it is inside an EH region. There is no easy way to tell, | |
1423 | so we just always break when we see a CALL_INSN if | |
1424 | flag_exceptions is nonzero. */ | |
1425 | if (flag_exceptions && GET_CODE (p) == CALL_INSN) | |
1426 | break; | |
1427 | ||
184bb750 R |
1428 | if (GET_RTX_CLASS (GET_CODE (p)) != 'i') |
1429 | continue; | |
8c660648 | 1430 | |
184bb750 | 1431 | length++; |
8c660648 | 1432 | |
184bb750 R |
1433 | /* ??? See if all of SRC is set in P. This test is much |
1434 | more conservative than it needs to be. */ | |
1435 | pset = single_set (p); | |
1436 | if (pset && SET_DEST (pset) == src) | |
1437 | { | |
1438 | /* We use validate_replace_rtx, in case there | |
1439 | are multiple identical source operands. All of | |
1440 | them have to be changed at the same time. */ | |
1441 | if (validate_replace_rtx (src, dst, insn)) | |
8c660648 | 1442 | { |
184bb750 R |
1443 | if (validate_change (p, &SET_DEST (pset), |
1444 | dst, 0)) | |
1445 | success = 1; | |
1446 | else | |
8c660648 | 1447 | { |
184bb750 R |
1448 | /* Change all source operands back. |
1449 | This modifies the dst as a side-effect. */ | |
1450 | validate_replace_rtx (dst, src, insn); | |
1451 | /* Now make sure the dst is right. */ | |
1452 | validate_change (insn, | |
0eadeb15 | 1453 | recog_operand_loc[match_no], |
184bb750 | 1454 | dst, 0); |
8c660648 | 1455 | } |
8c660648 | 1456 | } |
184bb750 R |
1457 | break; |
1458 | } | |
1459 | ||
1460 | if (reg_overlap_mentioned_p (src, PATTERN (p)) | |
1461 | || reg_overlap_mentioned_p (dst, PATTERN (p))) | |
1462 | break; | |
8c660648 | 1463 | |
184bb750 R |
1464 | /* If we have passed a call instruction, and the |
1465 | pseudo-reg DST is not already live across a call, | |
1466 | then don't perform the optimization. */ | |
1467 | if (GET_CODE (p) == CALL_INSN) | |
1468 | { | |
1469 | num_calls++; | |
1470 | ||
1471 | if (REG_N_CALLS_CROSSED (REGNO (dst)) == 0) | |
8c660648 | 1472 | break; |
184bb750 R |
1473 | } |
1474 | } | |
8c660648 | 1475 | |
184bb750 R |
1476 | if (success) |
1477 | { | |
1478 | int dstno, srcno; | |
8c660648 | 1479 | |
184bb750 R |
1480 | /* Remove the death note for SRC from INSN. */ |
1481 | remove_note (insn, src_note); | |
1482 | /* Move the death note for SRC to P if it is used | |
1483 | there. */ | |
1484 | if (reg_overlap_mentioned_p (src, PATTERN (p))) | |
1485 | { | |
1486 | XEXP (src_note, 1) = REG_NOTES (p); | |
1487 | REG_NOTES (p) = src_note; | |
8c660648 | 1488 | } |
184bb750 R |
1489 | /* If there is a REG_DEAD note for DST on P, then remove |
1490 | it, because DST is now set there. */ | |
5e9defae | 1491 | if ((dst_note = find_reg_note (p, REG_DEAD, dst))) |
184bb750 R |
1492 | remove_note (p, dst_note); |
1493 | ||
1494 | dstno = REGNO (dst); | |
1495 | srcno = REGNO (src); | |
1496 | ||
1497 | REG_N_SETS (dstno)++; | |
1498 | REG_N_SETS (srcno)--; | |
8c660648 | 1499 | |
184bb750 R |
1500 | REG_N_CALLS_CROSSED (dstno) += num_calls; |
1501 | REG_N_CALLS_CROSSED (srcno) -= num_calls; | |
1502 | ||
1503 | REG_LIVE_LENGTH (dstno) += length; | |
1504 | if (REG_LIVE_LENGTH (srcno) >= 0) | |
8c660648 | 1505 | { |
184bb750 R |
1506 | REG_LIVE_LENGTH (srcno) -= length; |
1507 | /* REG_LIVE_LENGTH is only an approximation after | |
1508 | combine if sched is not run, so make sure that we | |
1509 | still have a reasonable value. */ | |
1510 | if (REG_LIVE_LENGTH (srcno) < 2) | |
1511 | REG_LIVE_LENGTH (srcno) = 2; | |
1512 | } | |
8c660648 | 1513 | |
184bb750 R |
1514 | /* We assume that a register is used exactly once per |
1515 | insn in the updates above. If this is not correct, | |
1516 | no great harm is done. */ | |
8c660648 | 1517 | |
184bb750 R |
1518 | REG_N_REFS (dstno) += 2 * loop_depth; |
1519 | REG_N_REFS (srcno) -= 2 * loop_depth; | |
8c660648 | 1520 | |
184bb750 R |
1521 | /* If that was the only time src was set, |
1522 | and src was not live at the start of the | |
1523 | function, we know that we have no more | |
1524 | references to src; clear REG_N_REFS so it | |
1525 | won't make reload do any work. */ | |
1526 | if (REG_N_SETS (REGNO (src)) == 0 | |
1527 | && ! regno_uninitialized (REGNO (src))) | |
1528 | REG_N_REFS (REGNO (src)) = 0; | |
8c660648 | 1529 | |
184bb750 R |
1530 | if (regmove_dump_file) |
1531 | fprintf (regmove_dump_file, | |
1532 | "Fixed operand %d of insn %d matching operand %d.\n", | |
0eadeb15 | 1533 | op_no, INSN_UID (insn), match_no); |
8c660648 | 1534 | |
184bb750 | 1535 | break; |
8c660648 JL |
1536 | } |
1537 | } | |
ddc8bed2 MM |
1538 | |
1539 | /* If we weren't able to replace any of the alternatives, try an | |
1540 | alternative appoach of copying the source to the destination. */ | |
1541 | if (!success && copy_src != NULL_RTX) | |
78dd9906 R |
1542 | copy_src_to_dest (insn, copy_src, copy_dst, loop_depth, |
1543 | old_max_uid); | |
ddc8bed2 | 1544 | |
8c660648 JL |
1545 | } |
1546 | } | |
1547 | #endif /* REGISTER_CONSTRAINTS */ | |
961d4119 BS |
1548 | |
1549 | /* In fixup_match_1, some insns may have been inserted after basic block | |
1550 | ends. Fix that here. */ | |
1551 | for (i = 0; i < n_basic_blocks; i++) | |
1552 | { | |
3b413743 | 1553 | rtx end = BLOCK_END (i); |
961d4119 BS |
1554 | rtx new = end; |
1555 | rtx next = NEXT_INSN (new); | |
1556 | while (next != 0 && INSN_UID (next) >= old_max_uid | |
3b413743 | 1557 | && (i == n_basic_blocks - 1 || BLOCK_HEAD (i + 1) != next)) |
961d4119 | 1558 | new = next, next = NEXT_INSN (new); |
3b413743 | 1559 | BLOCK_END (i) = new; |
961d4119 | 1560 | } |
8c660648 JL |
1561 | } |
1562 | ||
0eadeb15 BS |
1563 | /* Returns nonzero if INSN's pattern has matching constraints for any operand. |
1564 | Returns 0 if INSN can't be recognized, or if the alternative can't be | |
1565 | determined. | |
b1a7d591 JW |
1566 | |
1567 | Initialize the info in MATCHP based on the constraints. */ | |
184bb750 R |
1568 | |
1569 | static int | |
1570 | find_matches (insn, matchp) | |
1571 | rtx insn; | |
1572 | struct match *matchp; | |
1573 | { | |
1574 | int likely_spilled[MAX_RECOG_OPERANDS]; | |
0eadeb15 | 1575 | int op_no; |
184bb750 R |
1576 | int any_matches = 0; |
1577 | ||
0eadeb15 BS |
1578 | extract_insn (insn); |
1579 | if (! constrain_operands (0)) | |
1580 | return 0; | |
184bb750 R |
1581 | |
1582 | /* Must initialize this before main loop, because the code for | |
1583 | the commutative case may set matches for operands other than | |
1584 | the current one. */ | |
0eadeb15 BS |
1585 | for (op_no = recog_n_operands; --op_no >= 0; ) |
1586 | matchp->with[op_no] = matchp->commutative[op_no] = -1; | |
184bb750 | 1587 | |
0eadeb15 | 1588 | for (op_no = 0; op_no < recog_n_operands; op_no++) |
184bb750 | 1589 | { |
9b3142b3 KG |
1590 | const char *p; |
1591 | char c; | |
184bb750 R |
1592 | int i = 0; |
1593 | ||
0eadeb15 | 1594 | p = recog_constraints[op_no]; |
184bb750 | 1595 | |
0eadeb15 BS |
1596 | likely_spilled[op_no] = 0; |
1597 | matchp->use[op_no] = READ; | |
1598 | matchp->early_clobber[op_no] = 0; | |
184bb750 | 1599 | if (*p == '=') |
0eadeb15 | 1600 | matchp->use[op_no] = WRITE; |
184bb750 | 1601 | else if (*p == '+') |
0eadeb15 | 1602 | matchp->use[op_no] = READWRITE; |
184bb750 R |
1603 | |
1604 | for (;*p && i < which_alternative; p++) | |
1605 | if (*p == ',') | |
1606 | i++; | |
1607 | ||
1608 | while ((c = *p++) != '\0' && c != ',') | |
1609 | switch (c) | |
1610 | { | |
1611 | case '=': | |
1612 | break; | |
1613 | case '+': | |
1614 | break; | |
1615 | case '&': | |
0eadeb15 | 1616 | matchp->early_clobber[op_no] = 1; |
184bb750 R |
1617 | break; |
1618 | case '%': | |
0eadeb15 BS |
1619 | matchp->commutative[op_no] = op_no + 1; |
1620 | matchp->commutative[op_no + 1] = op_no; | |
184bb750 R |
1621 | break; |
1622 | case '0': case '1': case '2': case '3': case '4': | |
1623 | case '5': case '6': case '7': case '8': case '9': | |
1624 | c -= '0'; | |
0eadeb15 | 1625 | if (c < op_no && likely_spilled[(unsigned char) c]) |
184bb750 | 1626 | break; |
0eadeb15 | 1627 | matchp->with[op_no] = c; |
184bb750 | 1628 | any_matches = 1; |
0eadeb15 BS |
1629 | if (matchp->commutative[op_no] >= 0) |
1630 | matchp->with[matchp->commutative[op_no]] = c; | |
184bb750 R |
1631 | break; |
1632 | case 'a': case 'b': case 'c': case 'd': case 'e': case 'f': case 'h': | |
1633 | case 'j': case 'k': case 'l': case 'p': case 'q': case 't': case 'u': | |
1634 | case 'v': case 'w': case 'x': case 'y': case 'z': case 'A': case 'B': | |
1635 | case 'C': case 'D': case 'W': case 'Y': case 'Z': | |
973838fd | 1636 | if (CLASS_LIKELY_SPILLED_P (REG_CLASS_FROM_LETTER ((unsigned char)c))) |
0eadeb15 | 1637 | likely_spilled[op_no] = 1; |
184bb750 R |
1638 | break; |
1639 | } | |
1640 | } | |
0eadeb15 | 1641 | return any_matches; |
184bb750 R |
1642 | } |
1643 | ||
1644 | /* Try to replace output operand DST in SET, with input operand SRC. SET is | |
06671717 | 1645 | the only set in INSN. INSN has just been recognized and constrained. |
184bb750 R |
1646 | SRC is operand number OPERAND_NUMBER in INSN. |
1647 | DST is operand number MATCH_NUMBER in INSN. | |
1648 | If BACKWARD is nonzero, we have been called in a backward pass. | |
1649 | Return nonzero for success. */ | |
1650 | static int | |
1651 | fixup_match_1 (insn, set, src, src_subreg, dst, backward, operand_number, | |
1652 | match_number, regmove_dump_file) | |
1653 | rtx insn, set, src, src_subreg, dst; | |
1654 | int backward, operand_number, match_number; | |
1655 | FILE *regmove_dump_file; | |
1656 | { | |
1657 | rtx p; | |
1658 | rtx post_inc = 0, post_inc_set = 0, search_end = 0; | |
1659 | int success = 0; | |
1660 | int num_calls = 0, s_num_calls = 0; | |
1661 | enum rtx_code code = NOTE; | |
1662 | HOST_WIDE_INT insn_const, newconst; | |
1663 | rtx overlap = 0; /* need to move insn ? */ | |
1664 | rtx src_note = find_reg_note (insn, REG_DEAD, src), dst_note; | |
1665 | int length, s_length, true_loop_depth; | |
1666 | ||
1667 | if (! src_note) | |
1668 | { | |
1669 | /* Look for (set (regX) (op regA constX)) | |
1670 | (set (regY) (op regA constY)) | |
1671 | and change that to | |
1672 | (set (regA) (op regA constX)). | |
1673 | (set (regY) (op regA constY-constX)). | |
1674 | This works for add and shift operations, if | |
1675 | regA is dead after or set by the second insn. */ | |
1676 | ||
1677 | code = GET_CODE (SET_SRC (set)); | |
1678 | if ((code == PLUS || code == LSHIFTRT | |
1679 | || code == ASHIFT || code == ASHIFTRT) | |
1680 | && XEXP (SET_SRC (set), 0) == src | |
1681 | && GET_CODE (XEXP (SET_SRC (set), 1)) == CONST_INT) | |
1682 | insn_const = INTVAL (XEXP (SET_SRC (set), 1)); | |
1683 | else if (! stable_but_for_p (SET_SRC (set), src, dst)) | |
1684 | return 0; | |
1685 | else | |
1686 | /* We might find a src_note while scanning. */ | |
1687 | code = NOTE; | |
1688 | } | |
1689 | ||
1690 | if (regmove_dump_file) | |
1691 | fprintf (regmove_dump_file, | |
1692 | "Could fix operand %d of insn %d matching operand %d.\n", | |
1693 | operand_number, INSN_UID (insn), match_number); | |
1694 | ||
1695 | /* If SRC is equivalent to a constant set in a different basic block, | |
1696 | then do not use it for this optimization. We want the equivalence | |
1697 | so that if we have to reload this register, we can reload the | |
1698 | constant, rather than extending the lifespan of the register. */ | |
1699 | if (reg_is_remote_constant_p (src, insn, get_insns ())) | |
1700 | return 0; | |
1701 | ||
1702 | /* Scan forward to find the next instruction that | |
1703 | uses the output operand. If the operand dies here, | |
1704 | then replace it in both instructions with | |
1705 | operand_number. */ | |
1706 | ||
1707 | for (length = s_length = 0, p = NEXT_INSN (insn); p; p = NEXT_INSN (p)) | |
1708 | { | |
1709 | if (GET_CODE (p) == CODE_LABEL || GET_CODE (p) == JUMP_INSN | |
1710 | || (GET_CODE (p) == NOTE | |
1711 | && (NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_BEG | |
1712 | || NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_END))) | |
1713 | break; | |
1714 | ||
7bf825d2 JW |
1715 | /* ??? We can't scan past the end of a basic block without updating |
1716 | the register lifetime info (REG_DEAD/basic_block_live_at_start). | |
1717 | A CALL_INSN might be the last insn of a basic block, if it is | |
1718 | inside an EH region. There is no easy way to tell, so we just | |
1719 | always break when we see a CALL_INSN if flag_exceptions is nonzero. */ | |
1720 | if (flag_exceptions && GET_CODE (p) == CALL_INSN) | |
1721 | break; | |
1722 | ||
184bb750 R |
1723 | if (GET_RTX_CLASS (GET_CODE (p)) != 'i') |
1724 | continue; | |
1725 | ||
1726 | length++; | |
1727 | if (src_note) | |
1728 | s_length++; | |
1729 | ||
1730 | if (reg_set_p (src, p) || reg_set_p (dst, p) | |
1731 | || (GET_CODE (PATTERN (p)) == USE | |
1732 | && reg_overlap_mentioned_p (src, XEXP (PATTERN (p), 0)))) | |
1733 | break; | |
1734 | ||
1735 | /* See if all of DST dies in P. This test is | |
1736 | slightly more conservative than it needs to be. */ | |
1737 | if ((dst_note = find_regno_note (p, REG_DEAD, REGNO (dst))) | |
1738 | && (GET_MODE (XEXP (dst_note, 0)) == GET_MODE (dst))) | |
1739 | { | |
2219e921 R |
1740 | /* If we would be moving INSN, check that we won't move it |
1741 | into the shadow of a live a live flags register. */ | |
1742 | /* ??? We only try to move it in front of P, although | |
1743 | we could move it anywhere between OVERLAP and P. */ | |
1744 | if (overlap && GET_MODE (PREV_INSN (p)) != VOIDmode) | |
1745 | break; | |
1746 | ||
184bb750 R |
1747 | if (! src_note) |
1748 | { | |
1749 | rtx q; | |
1750 | rtx set2; | |
1751 | ||
1752 | /* If an optimization is done, the value of SRC while P | |
1753 | is executed will be changed. Check that this is OK. */ | |
1754 | if (reg_overlap_mentioned_p (src, PATTERN (p))) | |
1755 | break; | |
1756 | for (q = p; q; q = NEXT_INSN (q)) | |
1757 | { | |
1758 | if (GET_CODE (q) == CODE_LABEL || GET_CODE (q) == JUMP_INSN | |
1759 | || (GET_CODE (q) == NOTE | |
1760 | && (NOTE_LINE_NUMBER (q) == NOTE_INSN_LOOP_BEG | |
1761 | || NOTE_LINE_NUMBER (q) == NOTE_INSN_LOOP_END))) | |
1762 | { | |
1763 | q = 0; | |
1764 | break; | |
1765 | } | |
7bf825d2 JW |
1766 | |
1767 | /* ??? We can't scan past the end of a basic block without | |
1768 | updating the register lifetime info | |
1769 | (REG_DEAD/basic_block_live_at_start). | |
1770 | A CALL_INSN might be the last insn of a basic block, if | |
1771 | it is inside an EH region. There is no easy way to tell, | |
1772 | so we just always break when we see a CALL_INSN if | |
1773 | flag_exceptions is nonzero. */ | |
a1ecb5ca | 1774 | if (flag_exceptions && GET_CODE (q) == CALL_INSN) |
7bf825d2 JW |
1775 | { |
1776 | q = 0; | |
1777 | break; | |
1778 | } | |
1779 | ||
184bb750 R |
1780 | if (GET_RTX_CLASS (GET_CODE (q)) != 'i') |
1781 | continue; | |
1782 | if (reg_overlap_mentioned_p (src, PATTERN (q)) | |
1783 | || reg_set_p (src, q)) | |
1784 | break; | |
1785 | } | |
1786 | if (q) | |
1787 | set2 = single_set (q); | |
1788 | if (! q || ! set2 || GET_CODE (SET_SRC (set2)) != code | |
1789 | || XEXP (SET_SRC (set2), 0) != src | |
1790 | || GET_CODE (XEXP (SET_SRC (set2), 1)) != CONST_INT | |
1791 | || (SET_DEST (set2) != src | |
1792 | && ! find_reg_note (q, REG_DEAD, src))) | |
1793 | { | |
1794 | /* If this is a PLUS, we can still save a register by doing | |
1795 | src += insn_const; | |
1796 | P; | |
1797 | src -= insn_const; . | |
1798 | This also gives opportunities for subsequent | |
1799 | optimizations in the backward pass, so do it there. */ | |
1800 | if (code == PLUS && backward | |
3bb806ed R |
1801 | /* Don't do this if we can likely tie DST to SET_DEST |
1802 | of P later; we can't do this tying here if we got a | |
1803 | hard register. */ | |
1804 | && ! (dst_note && ! REG_N_CALLS_CROSSED (REGNO (dst)) | |
1805 | && single_set (p) | |
1806 | && GET_CODE (SET_DEST (single_set (p))) == REG | |
1807 | && (REGNO (SET_DEST (single_set (p))) | |
1808 | < FIRST_PSEUDO_REGISTER)) | |
dc2cb191 RH |
1809 | /* We may only emit an insn directly after P if we |
1810 | are not in the shadow of a live flags register. */ | |
1811 | && GET_MODE (p) == VOIDmode) | |
184bb750 R |
1812 | { |
1813 | search_end = q; | |
1814 | q = insn; | |
1815 | set2 = set; | |
1816 | newconst = -insn_const; | |
1817 | code = MINUS; | |
1818 | } | |
1819 | else | |
1820 | break; | |
1821 | } | |
1822 | else | |
1823 | { | |
1824 | newconst = INTVAL (XEXP (SET_SRC (set2), 1)) - insn_const; | |
1825 | /* Reject out of range shifts. */ | |
1826 | if (code != PLUS | |
1827 | && (newconst < 0 | |
1828 | || (newconst | |
1829 | >= GET_MODE_BITSIZE (GET_MODE (SET_SRC (set2)))))) | |
1830 | break; | |
1831 | if (code == PLUS) | |
1832 | { | |
1833 | post_inc = q; | |
1834 | if (SET_DEST (set2) != src) | |
1835 | post_inc_set = set2; | |
1836 | } | |
1837 | } | |
1838 | /* We use 1 as last argument to validate_change so that all | |
1839 | changes are accepted or rejected together by apply_change_group | |
1840 | when it is called by validate_replace_rtx . */ | |
1841 | validate_change (q, &XEXP (SET_SRC (set2), 1), | |
1842 | GEN_INT (newconst), 1); | |
1843 | } | |
1844 | validate_change (insn, recog_operand_loc[match_number], src, 1); | |
1845 | if (validate_replace_rtx (dst, src_subreg, p)) | |
1846 | success = 1; | |
1847 | break; | |
1848 | } | |
1849 | ||
1850 | if (reg_overlap_mentioned_p (dst, PATTERN (p))) | |
1851 | break; | |
1852 | if (! src_note && reg_overlap_mentioned_p (src, PATTERN (p))) | |
1853 | { | |
2219e921 R |
1854 | /* INSN was already checked to be movable wrt. the registers that it |
1855 | sets / uses when we found no REG_DEAD note for src on it, but it | |
1856 | still might clobber the flags register. We'll have to check that | |
1857 | we won't insert it into the shadow of a live flags register when | |
1858 | we finally know where we are to move it. */ | |
184bb750 R |
1859 | overlap = p; |
1860 | src_note = find_reg_note (p, REG_DEAD, src); | |
1861 | } | |
1862 | ||
1863 | /* If we have passed a call instruction, and the pseudo-reg SRC is not | |
1864 | already live across a call, then don't perform the optimization. */ | |
1865 | if (GET_CODE (p) == CALL_INSN) | |
1866 | { | |
1867 | if (REG_N_CALLS_CROSSED (REGNO (src)) == 0) | |
1868 | break; | |
1869 | ||
1870 | num_calls++; | |
1871 | ||
1872 | if (src_note) | |
1873 | s_num_calls++; | |
1874 | ||
1875 | } | |
1876 | } | |
1877 | ||
1878 | if (! success) | |
1879 | return 0; | |
1880 | ||
1881 | true_loop_depth = backward ? 2 - loop_depth : loop_depth; | |
1882 | ||
1883 | /* Remove the death note for DST from P. */ | |
1884 | remove_note (p, dst_note); | |
1885 | if (code == MINUS) | |
1886 | { | |
1887 | post_inc = emit_insn_after (copy_rtx (PATTERN (insn)), p); | |
940da324 JL |
1888 | if ((HAVE_PRE_INCREMENT || HAVE_PRE_DECREMENT) |
1889 | && search_end | |
184bb750 R |
1890 | && try_auto_increment (search_end, post_inc, 0, src, newconst, 1)) |
1891 | post_inc = 0; | |
184bb750 R |
1892 | validate_change (insn, &XEXP (SET_SRC (set), 1), GEN_INT (insn_const), 0); |
1893 | REG_N_SETS (REGNO (src))++; | |
1894 | REG_N_REFS (REGNO (src)) += true_loop_depth; | |
1895 | REG_LIVE_LENGTH (REGNO (src))++; | |
1896 | } | |
1897 | if (overlap) | |
1898 | { | |
1899 | /* The lifetime of src and dest overlap, | |
1900 | but we can change this by moving insn. */ | |
1901 | rtx pat = PATTERN (insn); | |
1902 | if (src_note) | |
1903 | remove_note (overlap, src_note); | |
1ed9faee TM |
1904 | if ((HAVE_POST_INCREMENT || HAVE_POST_DECREMENT) |
1905 | && code == PLUS | |
184bb750 R |
1906 | && try_auto_increment (overlap, insn, 0, src, insn_const, 0)) |
1907 | insn = overlap; | |
1908 | else | |
184bb750 R |
1909 | { |
1910 | rtx notes = REG_NOTES (insn); | |
1911 | ||
1912 | emit_insn_after_with_line_notes (pat, PREV_INSN (p), insn); | |
1913 | PUT_CODE (insn, NOTE); | |
1914 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
1915 | NOTE_SOURCE_FILE (insn) = 0; | |
1916 | /* emit_insn_after_with_line_notes has no | |
1917 | return value, so search for the new insn. */ | |
ef178af3 ZW |
1918 | insn = p; |
1919 | while (GET_RTX_CLASS (GET_CODE (insn)) != 'i' | |
1920 | || PATTERN (insn) != pat) | |
184bb750 R |
1921 | insn = PREV_INSN (insn); |
1922 | ||
1923 | REG_NOTES (insn) = notes; | |
1924 | } | |
1925 | } | |
1926 | /* Sometimes we'd generate src = const; src += n; | |
1927 | if so, replace the instruction that set src | |
1928 | in the first place. */ | |
1929 | ||
1930 | if (! overlap && (code == PLUS || code == MINUS)) | |
1931 | { | |
1932 | rtx note = find_reg_note (insn, REG_EQUAL, NULL_RTX); | |
1933 | rtx q, set2; | |
1934 | int num_calls2 = 0, s_length2 = 0; | |
1935 | ||
1936 | if (note && CONSTANT_P (XEXP (note, 0))) | |
1937 | { | |
1938 | for (q = PREV_INSN (insn); q; q = PREV_INSN(q)) | |
1939 | { | |
7bf825d2 JW |
1940 | if (GET_CODE (q) == CODE_LABEL || GET_CODE (q) == JUMP_INSN |
1941 | || (GET_CODE (q) == NOTE | |
1942 | && (NOTE_LINE_NUMBER (q) == NOTE_INSN_LOOP_BEG | |
1943 | || NOTE_LINE_NUMBER (q) == NOTE_INSN_LOOP_END))) | |
184bb750 R |
1944 | { |
1945 | q = 0; | |
1946 | break; | |
1947 | } | |
7bf825d2 JW |
1948 | |
1949 | /* ??? We can't scan past the end of a basic block without | |
1950 | updating the register lifetime info | |
1951 | (REG_DEAD/basic_block_live_at_start). | |
1952 | A CALL_INSN might be the last insn of a basic block, if | |
1953 | it is inside an EH region. There is no easy way to tell, | |
1954 | so we just always break when we see a CALL_INSN if | |
1955 | flag_exceptions is nonzero. */ | |
a1ecb5ca | 1956 | if (flag_exceptions && GET_CODE (q) == CALL_INSN) |
7bf825d2 JW |
1957 | { |
1958 | q = 0; | |
1959 | break; | |
1960 | } | |
1961 | ||
184bb750 R |
1962 | if (GET_RTX_CLASS (GET_CODE (q)) != 'i') |
1963 | continue; | |
1964 | s_length2++; | |
1965 | if (reg_set_p (src, q)) | |
1966 | { | |
1967 | set2 = single_set (q); | |
1968 | break; | |
1969 | } | |
1970 | if (reg_overlap_mentioned_p (src, PATTERN (q))) | |
1971 | { | |
1972 | q = 0; | |
1973 | break; | |
1974 | } | |
1975 | if (GET_CODE (p) == CALL_INSN) | |
1976 | num_calls2++; | |
1977 | } | |
1978 | if (q && set2 && SET_DEST (set2) == src && CONSTANT_P (SET_SRC (set2)) | |
1979 | && validate_change (insn, &SET_SRC (set), XEXP (note, 0), 0)) | |
1980 | { | |
1981 | PUT_CODE (q, NOTE); | |
1982 | NOTE_LINE_NUMBER (q) = NOTE_INSN_DELETED; | |
1983 | NOTE_SOURCE_FILE (q) = 0; | |
1984 | REG_N_SETS (REGNO (src))--; | |
1985 | REG_N_CALLS_CROSSED (REGNO (src)) -= num_calls2; | |
1986 | REG_N_REFS (REGNO (src)) -= true_loop_depth; | |
1987 | REG_LIVE_LENGTH (REGNO (src)) -= s_length2; | |
1988 | insn_const = 0; | |
1989 | } | |
1990 | } | |
1991 | } | |
1a56b81f | 1992 | |
cb084004 | 1993 | if ((HAVE_PRE_INCREMENT || HAVE_PRE_DECREMENT) |
940da324 | 1994 | && (code == PLUS || code == MINUS) && insn_const |
184bb750 R |
1995 | && try_auto_increment (p, insn, 0, src, insn_const, 1)) |
1996 | insn = p; | |
940da324 JL |
1997 | else if ((HAVE_POST_INCREMENT || HAVE_POST_DECREMENT) |
1998 | && post_inc | |
184bb750 R |
1999 | && try_auto_increment (p, post_inc, post_inc_set, src, newconst, 0)) |
2000 | post_inc = 0; | |
184bb750 R |
2001 | /* If post_inc still prevails, try to find an |
2002 | insn where it can be used as a pre-in/decrement. | |
2003 | If code is MINUS, this was already tried. */ | |
2004 | if (post_inc && code == PLUS | |
2005 | /* Check that newconst is likely to be usable | |
2006 | in a pre-in/decrement before starting the search. */ | |
940da324 JL |
2007 | && ((HAVE_PRE_INCREMENT && newconst > 0 && newconst <= MOVE_MAX) |
2008 | || (HAVE_PRE_DECREMENT && newconst < 0 && newconst >= -MOVE_MAX)) | |
2009 | && exact_log2 (newconst)) | |
184bb750 R |
2010 | { |
2011 | rtx q, inc_dest; | |
2012 | ||
2013 | inc_dest = post_inc_set ? SET_DEST (post_inc_set) : src; | |
51723711 | 2014 | for (q = post_inc; (q = NEXT_INSN (q)); ) |
184bb750 R |
2015 | { |
2016 | if (GET_CODE (q) == CODE_LABEL || GET_CODE (q) == JUMP_INSN | |
2017 | || (GET_CODE (q) == NOTE | |
2018 | && (NOTE_LINE_NUMBER (q) == NOTE_INSN_LOOP_BEG | |
2019 | || NOTE_LINE_NUMBER (q) == NOTE_INSN_LOOP_END))) | |
2020 | break; | |
7bf825d2 JW |
2021 | |
2022 | /* ??? We can't scan past the end of a basic block without updating | |
2023 | the register lifetime info (REG_DEAD/basic_block_live_at_start). | |
2024 | A CALL_INSN might be the last insn of a basic block, if it | |
2025 | is inside an EH region. There is no easy way to tell so we | |
2026 | just always break when we see a CALL_INSN if flag_exceptions | |
2027 | is nonzero. */ | |
a1ecb5ca | 2028 | if (flag_exceptions && GET_CODE (q) == CALL_INSN) |
7bf825d2 JW |
2029 | break; |
2030 | ||
184bb750 R |
2031 | if (GET_RTX_CLASS (GET_CODE (q)) != 'i') |
2032 | continue; | |
2033 | if (src != inc_dest && (reg_overlap_mentioned_p (src, PATTERN (q)) | |
2034 | || reg_set_p (src, q))) | |
2035 | break; | |
2036 | if (reg_set_p (inc_dest, q)) | |
2037 | break; | |
2038 | if (reg_overlap_mentioned_p (inc_dest, PATTERN (q))) | |
2039 | { | |
2040 | try_auto_increment (q, post_inc, | |
2041 | post_inc_set, inc_dest, newconst, 1); | |
2042 | break; | |
2043 | } | |
2044 | } | |
2045 | } | |
184bb750 R |
2046 | /* Move the death note for DST to INSN if it is used |
2047 | there. */ | |
2048 | if (reg_overlap_mentioned_p (dst, PATTERN (insn))) | |
2049 | { | |
2050 | XEXP (dst_note, 1) = REG_NOTES (insn); | |
2051 | REG_NOTES (insn) = dst_note; | |
2052 | } | |
2053 | ||
2054 | if (src_note) | |
2055 | { | |
2056 | /* Move the death note for SRC from INSN to P. */ | |
2057 | if (! overlap) | |
2058 | remove_note (insn, src_note); | |
2059 | XEXP (src_note, 1) = REG_NOTES (p); | |
2060 | REG_NOTES (p) = src_note; | |
2061 | ||
2062 | REG_N_CALLS_CROSSED (REGNO (src)) += s_num_calls; | |
2063 | } | |
2064 | ||
2065 | REG_N_SETS (REGNO (src))++; | |
2066 | REG_N_SETS (REGNO (dst))--; | |
2067 | ||
2068 | REG_N_CALLS_CROSSED (REGNO (dst)) -= num_calls; | |
2069 | ||
2070 | REG_LIVE_LENGTH (REGNO (src)) += s_length; | |
2071 | if (REG_LIVE_LENGTH (REGNO (dst)) >= 0) | |
2072 | { | |
2073 | REG_LIVE_LENGTH (REGNO (dst)) -= length; | |
2074 | /* REG_LIVE_LENGTH is only an approximation after | |
2075 | combine if sched is not run, so make sure that we | |
2076 | still have a reasonable value. */ | |
2077 | if (REG_LIVE_LENGTH (REGNO (dst)) < 2) | |
2078 | REG_LIVE_LENGTH (REGNO (dst)) = 2; | |
2079 | } | |
2080 | ||
2081 | /* We assume that a register is used exactly once per | |
2082 | insn in the updates above. If this is not correct, | |
2083 | no great harm is done. */ | |
2084 | ||
2085 | REG_N_REFS (REGNO (src)) += 2 * true_loop_depth; | |
2086 | REG_N_REFS (REGNO (dst)) -= 2 * true_loop_depth; | |
2087 | ||
2088 | /* If that was the only time dst was set, | |
2089 | and dst was not live at the start of the | |
2090 | function, we know that we have no more | |
2091 | references to dst; clear REG_N_REFS so it | |
2092 | won't make reload do any work. */ | |
2093 | if (REG_N_SETS (REGNO (dst)) == 0 | |
2094 | && ! regno_uninitialized (REGNO (dst))) | |
2095 | REG_N_REFS (REGNO (dst)) = 0; | |
2096 | ||
2097 | if (regmove_dump_file) | |
2098 | fprintf (regmove_dump_file, | |
2099 | "Fixed operand %d of insn %d matching operand %d.\n", | |
2100 | operand_number, INSN_UID (insn), match_number); | |
2101 | return 1; | |
2102 | } | |
2103 | ||
2104 | ||
8c660648 JL |
2105 | /* return nonzero if X is stable but for mentioning SRC or mentioning / |
2106 | changing DST . If in doubt, presume it is unstable. */ | |
2107 | static int | |
2108 | stable_but_for_p (x, src, dst) | |
2109 | rtx x, src, dst; | |
2110 | { | |
2111 | RTX_CODE code = GET_CODE (x); | |
2112 | switch (GET_RTX_CLASS (code)) | |
2113 | { | |
2114 | case '<': case '1': case 'c': case '2': case 'b': case '3': | |
2115 | { | |
2116 | int i; | |
6f7d635c | 2117 | const char *fmt = GET_RTX_FORMAT (code); |
8c660648 JL |
2118 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) |
2119 | if (fmt[i] == 'e' && ! stable_but_for_p (XEXP (x, i), src, dst)) | |
2120 | return 0; | |
2121 | return 1; | |
2122 | } | |
2123 | case 'o': | |
2124 | if (x == src || x == dst) | |
2125 | return 1; | |
2126 | /* fall through */ | |
2127 | default: | |
2128 | return ! rtx_unstable_p (x); | |
2129 | } | |
2130 | } |