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fac41238 PB |
1 | /* Copy propagation on hard registers for the GNU compiler. |
2 | Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 | |
3 | Free Software Foundation, Inc. | |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it | |
8 | under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 3, or (at your option) | |
10 | any later version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT | |
13 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY | |
14 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public | |
15 | License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING3. If not see | |
19 | <http://www.gnu.org/licenses/>. */ | |
20 | ||
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
24 | #include "tm.h" | |
25 | #include "rtl.h" | |
26 | #include "tm_p.h" | |
27 | #include "insn-config.h" | |
28 | #include "regs.h" | |
29 | #include "addresses.h" | |
30 | #include "hard-reg-set.h" | |
31 | #include "basic-block.h" | |
32 | #include "reload.h" | |
33 | #include "output.h" | |
34 | #include "function.h" | |
35 | #include "recog.h" | |
36 | #include "flags.h" | |
37 | #include "toplev.h" | |
38 | #include "obstack.h" | |
39 | #include "timevar.h" | |
40 | #include "tree-pass.h" | |
41 | #include "df.h" | |
42 | ||
43 | /* The following code does forward propagation of hard register copies. | |
44 | The object is to eliminate as many dependencies as possible, so that | |
45 | we have the most scheduling freedom. As a side effect, we also clean | |
46 | up some silly register allocation decisions made by reload. This | |
47 | code may be obsoleted by a new register allocator. */ | |
48 | ||
49 | /* For each register, we have a list of registers that contain the same | |
50 | value. The OLDEST_REGNO field points to the head of the list, and | |
51 | the NEXT_REGNO field runs through the list. The MODE field indicates | |
52 | what mode the data is known to be in; this field is VOIDmode when the | |
53 | register is not known to contain valid data. */ | |
54 | ||
55 | struct value_data_entry | |
56 | { | |
57 | enum machine_mode mode; | |
58 | unsigned int oldest_regno; | |
59 | unsigned int next_regno; | |
60 | }; | |
61 | ||
62 | struct value_data | |
63 | { | |
64 | struct value_data_entry e[FIRST_PSEUDO_REGISTER]; | |
65 | unsigned int max_value_regs; | |
66 | }; | |
67 | ||
68 | static void kill_value_one_regno (unsigned, struct value_data *); | |
69 | static void kill_value_regno (unsigned, unsigned, struct value_data *); | |
70 | static void kill_value (rtx, struct value_data *); | |
71 | static void set_value_regno (unsigned, enum machine_mode, struct value_data *); | |
72 | static void init_value_data (struct value_data *); | |
73 | static void kill_clobbered_value (rtx, const_rtx, void *); | |
74 | static void kill_set_value (rtx, const_rtx, void *); | |
75 | static int kill_autoinc_value (rtx *, void *); | |
76 | static void copy_value (rtx, rtx, struct value_data *); | |
77 | static bool mode_change_ok (enum machine_mode, enum machine_mode, | |
78 | unsigned int); | |
79 | static rtx maybe_mode_change (enum machine_mode, enum machine_mode, | |
80 | enum machine_mode, unsigned int, unsigned int); | |
81 | static rtx find_oldest_value_reg (enum reg_class, rtx, struct value_data *); | |
82 | static bool replace_oldest_value_reg (rtx *, enum reg_class, rtx, | |
83 | struct value_data *); | |
84 | static bool replace_oldest_value_addr (rtx *, enum reg_class, | |
85 | enum machine_mode, rtx, | |
86 | struct value_data *); | |
87 | static bool replace_oldest_value_mem (rtx, rtx, struct value_data *); | |
88 | static bool copyprop_hardreg_forward_1 (basic_block, struct value_data *); | |
89 | extern void debug_value_data (struct value_data *); | |
90 | #ifdef ENABLE_CHECKING | |
91 | static void validate_value_data (struct value_data *); | |
92 | #endif | |
93 | ||
94 | /* Kill register REGNO. This involves removing it from any value | |
95 | lists, and resetting the value mode to VOIDmode. This is only a | |
96 | helper function; it does not handle any hard registers overlapping | |
97 | with REGNO. */ | |
98 | ||
99 | static void | |
100 | kill_value_one_regno (unsigned int regno, struct value_data *vd) | |
101 | { | |
102 | unsigned int i, next; | |
103 | ||
104 | if (vd->e[regno].oldest_regno != regno) | |
105 | { | |
106 | for (i = vd->e[regno].oldest_regno; | |
107 | vd->e[i].next_regno != regno; | |
108 | i = vd->e[i].next_regno) | |
109 | continue; | |
110 | vd->e[i].next_regno = vd->e[regno].next_regno; | |
111 | } | |
112 | else if ((next = vd->e[regno].next_regno) != INVALID_REGNUM) | |
113 | { | |
114 | for (i = next; i != INVALID_REGNUM; i = vd->e[i].next_regno) | |
115 | vd->e[i].oldest_regno = next; | |
116 | } | |
117 | ||
118 | vd->e[regno].mode = VOIDmode; | |
119 | vd->e[regno].oldest_regno = regno; | |
120 | vd->e[regno].next_regno = INVALID_REGNUM; | |
121 | ||
122 | #ifdef ENABLE_CHECKING | |
123 | validate_value_data (vd); | |
124 | #endif | |
125 | } | |
126 | ||
127 | /* Kill the value in register REGNO for NREGS, and any other registers | |
128 | whose values overlap. */ | |
129 | ||
130 | static void | |
131 | kill_value_regno (unsigned int regno, unsigned int nregs, | |
132 | struct value_data *vd) | |
133 | { | |
134 | unsigned int j; | |
135 | ||
136 | /* Kill the value we're told to kill. */ | |
137 | for (j = 0; j < nregs; ++j) | |
138 | kill_value_one_regno (regno + j, vd); | |
139 | ||
140 | /* Kill everything that overlapped what we're told to kill. */ | |
141 | if (regno < vd->max_value_regs) | |
142 | j = 0; | |
143 | else | |
144 | j = regno - vd->max_value_regs; | |
145 | for (; j < regno; ++j) | |
146 | { | |
147 | unsigned int i, n; | |
148 | if (vd->e[j].mode == VOIDmode) | |
149 | continue; | |
150 | n = hard_regno_nregs[j][vd->e[j].mode]; | |
151 | if (j + n > regno) | |
152 | for (i = 0; i < n; ++i) | |
153 | kill_value_one_regno (j + i, vd); | |
154 | } | |
155 | } | |
156 | ||
157 | /* Kill X. This is a convenience function wrapping kill_value_regno | |
158 | so that we mind the mode the register is in. */ | |
159 | ||
160 | static void | |
161 | kill_value (rtx x, struct value_data *vd) | |
162 | { | |
163 | rtx orig_rtx = x; | |
164 | ||
165 | if (GET_CODE (x) == SUBREG) | |
166 | { | |
167 | x = simplify_subreg (GET_MODE (x), SUBREG_REG (x), | |
168 | GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x)); | |
169 | if (x == NULL_RTX) | |
170 | x = SUBREG_REG (orig_rtx); | |
171 | } | |
172 | if (REG_P (x)) | |
173 | { | |
174 | unsigned int regno = REGNO (x); | |
175 | unsigned int n = hard_regno_nregs[regno][GET_MODE (x)]; | |
176 | ||
177 | kill_value_regno (regno, n, vd); | |
178 | } | |
179 | } | |
180 | ||
181 | /* Remember that REGNO is valid in MODE. */ | |
182 | ||
183 | static void | |
184 | set_value_regno (unsigned int regno, enum machine_mode mode, | |
185 | struct value_data *vd) | |
186 | { | |
187 | unsigned int nregs; | |
188 | ||
189 | vd->e[regno].mode = mode; | |
190 | ||
191 | nregs = hard_regno_nregs[regno][mode]; | |
192 | if (nregs > vd->max_value_regs) | |
193 | vd->max_value_regs = nregs; | |
194 | } | |
195 | ||
196 | /* Initialize VD such that there are no known relationships between regs. */ | |
197 | ||
198 | static void | |
199 | init_value_data (struct value_data *vd) | |
200 | { | |
201 | int i; | |
202 | for (i = 0; i < FIRST_PSEUDO_REGISTER; ++i) | |
203 | { | |
204 | vd->e[i].mode = VOIDmode; | |
205 | vd->e[i].oldest_regno = i; | |
206 | vd->e[i].next_regno = INVALID_REGNUM; | |
207 | } | |
208 | vd->max_value_regs = 0; | |
209 | } | |
210 | ||
211 | /* Called through note_stores. If X is clobbered, kill its value. */ | |
212 | ||
213 | static void | |
214 | kill_clobbered_value (rtx x, const_rtx set, void *data) | |
215 | { | |
216 | struct value_data *const vd = (struct value_data *) data; | |
217 | if (GET_CODE (set) == CLOBBER) | |
218 | kill_value (x, vd); | |
219 | } | |
220 | ||
221 | /* Called through note_stores. If X is set, not clobbered, kill its | |
222 | current value and install it as the root of its own value list. */ | |
223 | ||
224 | static void | |
225 | kill_set_value (rtx x, const_rtx set, void *data) | |
226 | { | |
227 | struct value_data *const vd = (struct value_data *) data; | |
228 | if (GET_CODE (set) != CLOBBER) | |
229 | { | |
230 | kill_value (x, vd); | |
231 | if (REG_P (x)) | |
232 | set_value_regno (REGNO (x), GET_MODE (x), vd); | |
233 | } | |
234 | } | |
235 | ||
236 | /* Called through for_each_rtx. Kill any register used as the base of an | |
237 | auto-increment expression, and install that register as the root of its | |
238 | own value list. */ | |
239 | ||
240 | static int | |
241 | kill_autoinc_value (rtx *px, void *data) | |
242 | { | |
243 | rtx x = *px; | |
244 | struct value_data *const vd = (struct value_data *) data; | |
245 | ||
246 | if (GET_RTX_CLASS (GET_CODE (x)) == RTX_AUTOINC) | |
247 | { | |
248 | x = XEXP (x, 0); | |
249 | kill_value (x, vd); | |
d4ebfa65 | 250 | set_value_regno (REGNO (x), GET_MODE (x), vd); |
fac41238 PB |
251 | return -1; |
252 | } | |
253 | ||
254 | return 0; | |
255 | } | |
256 | ||
257 | /* Assert that SRC has been copied to DEST. Adjust the data structures | |
258 | to reflect that SRC contains an older copy of the shared value. */ | |
259 | ||
260 | static void | |
261 | copy_value (rtx dest, rtx src, struct value_data *vd) | |
262 | { | |
263 | unsigned int dr = REGNO (dest); | |
264 | unsigned int sr = REGNO (src); | |
265 | unsigned int dn, sn; | |
266 | unsigned int i; | |
267 | ||
268 | /* ??? At present, it's possible to see noop sets. It'd be nice if | |
269 | this were cleaned up beforehand... */ | |
270 | if (sr == dr) | |
271 | return; | |
272 | ||
273 | /* Do not propagate copies to the stack pointer, as that can leave | |
274 | memory accesses with no scheduling dependency on the stack update. */ | |
275 | if (dr == STACK_POINTER_REGNUM) | |
276 | return; | |
277 | ||
278 | /* Likewise with the frame pointer, if we're using one. */ | |
279 | if (frame_pointer_needed && dr == HARD_FRAME_POINTER_REGNUM) | |
280 | return; | |
281 | ||
282 | /* Do not propagate copies to fixed or global registers, patterns | |
283 | can be relying to see particular fixed register or users can | |
284 | expect the chosen global register in asm. */ | |
285 | if (fixed_regs[dr] || global_regs[dr]) | |
286 | return; | |
287 | ||
288 | /* If SRC and DEST overlap, don't record anything. */ | |
289 | dn = hard_regno_nregs[dr][GET_MODE (dest)]; | |
290 | sn = hard_regno_nregs[sr][GET_MODE (dest)]; | |
291 | if ((dr > sr && dr < sr + sn) | |
292 | || (sr > dr && sr < dr + dn)) | |
293 | return; | |
294 | ||
295 | /* If SRC had no assigned mode (i.e. we didn't know it was live) | |
296 | assign it now and assume the value came from an input argument | |
297 | or somesuch. */ | |
298 | if (vd->e[sr].mode == VOIDmode) | |
299 | set_value_regno (sr, vd->e[dr].mode, vd); | |
300 | ||
301 | /* If we are narrowing the input to a smaller number of hard regs, | |
302 | and it is in big endian, we are really extracting a high part. | |
303 | Since we generally associate a low part of a value with the value itself, | |
304 | we must not do the same for the high part. | |
305 | Note we can still get low parts for the same mode combination through | |
306 | a two-step copy involving differently sized hard regs. | |
307 | Assume hard regs fr* are 32 bits bits each, while r* are 64 bits each: | |
308 | (set (reg:DI r0) (reg:DI fr0)) | |
309 | (set (reg:SI fr2) (reg:SI r0)) | |
310 | loads the low part of (reg:DI fr0) - i.e. fr1 - into fr2, while: | |
311 | (set (reg:SI fr2) (reg:SI fr0)) | |
312 | loads the high part of (reg:DI fr0) into fr2. | |
313 | ||
314 | We can't properly represent the latter case in our tables, so don't | |
315 | record anything then. */ | |
316 | else if (sn < (unsigned int) hard_regno_nregs[sr][vd->e[sr].mode] | |
317 | && (GET_MODE_SIZE (vd->e[sr].mode) > UNITS_PER_WORD | |
318 | ? WORDS_BIG_ENDIAN : BYTES_BIG_ENDIAN)) | |
319 | return; | |
320 | ||
321 | /* If SRC had been assigned a mode narrower than the copy, we can't | |
322 | link DEST into the chain, because not all of the pieces of the | |
323 | copy came from oldest_regno. */ | |
324 | else if (sn > (unsigned int) hard_regno_nregs[sr][vd->e[sr].mode]) | |
325 | return; | |
326 | ||
327 | /* Link DR at the end of the value chain used by SR. */ | |
328 | ||
329 | vd->e[dr].oldest_regno = vd->e[sr].oldest_regno; | |
330 | ||
331 | for (i = sr; vd->e[i].next_regno != INVALID_REGNUM; i = vd->e[i].next_regno) | |
332 | continue; | |
333 | vd->e[i].next_regno = dr; | |
334 | ||
335 | #ifdef ENABLE_CHECKING | |
336 | validate_value_data (vd); | |
337 | #endif | |
338 | } | |
339 | ||
340 | /* Return true if a mode change from ORIG to NEW is allowed for REGNO. */ | |
341 | ||
342 | static bool | |
343 | mode_change_ok (enum machine_mode orig_mode, enum machine_mode new_mode, | |
344 | unsigned int regno ATTRIBUTE_UNUSED) | |
345 | { | |
346 | if (GET_MODE_SIZE (orig_mode) < GET_MODE_SIZE (new_mode)) | |
347 | return false; | |
348 | ||
349 | #ifdef CANNOT_CHANGE_MODE_CLASS | |
350 | return !REG_CANNOT_CHANGE_MODE_P (regno, orig_mode, new_mode); | |
351 | #endif | |
352 | ||
353 | return true; | |
354 | } | |
355 | ||
356 | /* Register REGNO was originally set in ORIG_MODE. It - or a copy of it - | |
357 | was copied in COPY_MODE to COPY_REGNO, and then COPY_REGNO was accessed | |
358 | in NEW_MODE. | |
359 | Return a NEW_MODE rtx for REGNO if that's OK, otherwise return NULL_RTX. */ | |
360 | ||
361 | static rtx | |
362 | maybe_mode_change (enum machine_mode orig_mode, enum machine_mode copy_mode, | |
363 | enum machine_mode new_mode, unsigned int regno, | |
364 | unsigned int copy_regno ATTRIBUTE_UNUSED) | |
365 | { | |
366 | if (GET_MODE_SIZE (copy_mode) < GET_MODE_SIZE (orig_mode) | |
367 | && GET_MODE_SIZE (copy_mode) < GET_MODE_SIZE (new_mode)) | |
368 | return NULL_RTX; | |
369 | ||
370 | if (orig_mode == new_mode) | |
371 | return gen_rtx_raw_REG (new_mode, regno); | |
372 | else if (mode_change_ok (orig_mode, new_mode, regno)) | |
373 | { | |
374 | int copy_nregs = hard_regno_nregs[copy_regno][copy_mode]; | |
375 | int use_nregs = hard_regno_nregs[copy_regno][new_mode]; | |
376 | int copy_offset | |
377 | = GET_MODE_SIZE (copy_mode) / copy_nregs * (copy_nregs - use_nregs); | |
378 | int offset | |
379 | = GET_MODE_SIZE (orig_mode) - GET_MODE_SIZE (new_mode) - copy_offset; | |
380 | int byteoffset = offset % UNITS_PER_WORD; | |
381 | int wordoffset = offset - byteoffset; | |
382 | ||
383 | offset = ((WORDS_BIG_ENDIAN ? wordoffset : 0) | |
384 | + (BYTES_BIG_ENDIAN ? byteoffset : 0)); | |
385 | return gen_rtx_raw_REG (new_mode, | |
386 | regno + subreg_regno_offset (regno, orig_mode, | |
387 | offset, | |
388 | new_mode)); | |
389 | } | |
390 | return NULL_RTX; | |
391 | } | |
392 | ||
393 | /* Find the oldest copy of the value contained in REGNO that is in | |
394 | register class CL and has mode MODE. If found, return an rtx | |
395 | of that oldest register, otherwise return NULL. */ | |
396 | ||
397 | static rtx | |
398 | find_oldest_value_reg (enum reg_class cl, rtx reg, struct value_data *vd) | |
399 | { | |
400 | unsigned int regno = REGNO (reg); | |
401 | enum machine_mode mode = GET_MODE (reg); | |
402 | unsigned int i; | |
403 | ||
404 | /* If we are accessing REG in some mode other that what we set it in, | |
405 | make sure that the replacement is valid. In particular, consider | |
406 | (set (reg:DI r11) (...)) | |
407 | (set (reg:SI r9) (reg:SI r11)) | |
408 | (set (reg:SI r10) (...)) | |
409 | (set (...) (reg:DI r9)) | |
410 | Replacing r9 with r11 is invalid. */ | |
411 | if (mode != vd->e[regno].mode) | |
412 | { | |
413 | if (hard_regno_nregs[regno][mode] | |
414 | > hard_regno_nregs[regno][vd->e[regno].mode]) | |
415 | return NULL_RTX; | |
416 | } | |
417 | ||
418 | for (i = vd->e[regno].oldest_regno; i != regno; i = vd->e[i].next_regno) | |
419 | { | |
420 | enum machine_mode oldmode = vd->e[i].mode; | |
421 | rtx new_rtx; | |
422 | ||
423 | if (!in_hard_reg_set_p (reg_class_contents[cl], mode, i)) | |
424 | return NULL_RTX; | |
425 | ||
426 | new_rtx = maybe_mode_change (oldmode, vd->e[regno].mode, mode, i, regno); | |
427 | if (new_rtx) | |
428 | { | |
429 | ORIGINAL_REGNO (new_rtx) = ORIGINAL_REGNO (reg); | |
430 | REG_ATTRS (new_rtx) = REG_ATTRS (reg); | |
431 | REG_POINTER (new_rtx) = REG_POINTER (reg); | |
432 | return new_rtx; | |
433 | } | |
434 | } | |
435 | ||
436 | return NULL_RTX; | |
437 | } | |
438 | ||
439 | /* If possible, replace the register at *LOC with the oldest register | |
440 | in register class CL. Return true if successfully replaced. */ | |
441 | ||
442 | static bool | |
443 | replace_oldest_value_reg (rtx *loc, enum reg_class cl, rtx insn, | |
444 | struct value_data *vd) | |
445 | { | |
446 | rtx new_rtx = find_oldest_value_reg (cl, *loc, vd); | |
447 | if (new_rtx) | |
448 | { | |
449 | if (dump_file) | |
450 | fprintf (dump_file, "insn %u: replaced reg %u with %u\n", | |
451 | INSN_UID (insn), REGNO (*loc), REGNO (new_rtx)); | |
452 | ||
453 | validate_change (insn, loc, new_rtx, 1); | |
454 | return true; | |
455 | } | |
456 | return false; | |
457 | } | |
458 | ||
459 | /* Similar to replace_oldest_value_reg, but *LOC contains an address. | |
460 | Adapted from find_reloads_address_1. CL is INDEX_REG_CLASS or | |
461 | BASE_REG_CLASS depending on how the register is being considered. */ | |
462 | ||
463 | static bool | |
464 | replace_oldest_value_addr (rtx *loc, enum reg_class cl, | |
465 | enum machine_mode mode, rtx insn, | |
466 | struct value_data *vd) | |
467 | { | |
468 | rtx x = *loc; | |
469 | RTX_CODE code = GET_CODE (x); | |
470 | const char *fmt; | |
471 | int i, j; | |
472 | bool changed = false; | |
473 | ||
474 | switch (code) | |
475 | { | |
476 | case PLUS: | |
b5b8b0ac AO |
477 | if (DEBUG_INSN_P (insn)) |
478 | break; | |
479 | ||
fac41238 PB |
480 | { |
481 | rtx orig_op0 = XEXP (x, 0); | |
482 | rtx orig_op1 = XEXP (x, 1); | |
483 | RTX_CODE code0 = GET_CODE (orig_op0); | |
484 | RTX_CODE code1 = GET_CODE (orig_op1); | |
485 | rtx op0 = orig_op0; | |
486 | rtx op1 = orig_op1; | |
487 | rtx *locI = NULL; | |
488 | rtx *locB = NULL; | |
489 | enum rtx_code index_code = SCRATCH; | |
490 | ||
491 | if (GET_CODE (op0) == SUBREG) | |
492 | { | |
493 | op0 = SUBREG_REG (op0); | |
494 | code0 = GET_CODE (op0); | |
495 | } | |
496 | ||
497 | if (GET_CODE (op1) == SUBREG) | |
498 | { | |
499 | op1 = SUBREG_REG (op1); | |
500 | code1 = GET_CODE (op1); | |
501 | } | |
502 | ||
503 | if (code0 == MULT || code0 == SIGN_EXTEND || code0 == TRUNCATE | |
504 | || code0 == ZERO_EXTEND || code1 == MEM) | |
505 | { | |
506 | locI = &XEXP (x, 0); | |
507 | locB = &XEXP (x, 1); | |
508 | index_code = GET_CODE (*locI); | |
509 | } | |
510 | else if (code1 == MULT || code1 == SIGN_EXTEND || code1 == TRUNCATE | |
511 | || code1 == ZERO_EXTEND || code0 == MEM) | |
512 | { | |
513 | locI = &XEXP (x, 1); | |
514 | locB = &XEXP (x, 0); | |
515 | index_code = GET_CODE (*locI); | |
516 | } | |
517 | else if (code0 == CONST_INT || code0 == CONST | |
518 | || code0 == SYMBOL_REF || code0 == LABEL_REF) | |
519 | { | |
520 | locB = &XEXP (x, 1); | |
521 | index_code = GET_CODE (XEXP (x, 0)); | |
522 | } | |
523 | else if (code1 == CONST_INT || code1 == CONST | |
524 | || code1 == SYMBOL_REF || code1 == LABEL_REF) | |
525 | { | |
526 | locB = &XEXP (x, 0); | |
527 | index_code = GET_CODE (XEXP (x, 1)); | |
528 | } | |
529 | else if (code0 == REG && code1 == REG) | |
530 | { | |
531 | int index_op; | |
532 | unsigned regno0 = REGNO (op0), regno1 = REGNO (op1); | |
533 | ||
534 | if (REGNO_OK_FOR_INDEX_P (regno1) | |
535 | && regno_ok_for_base_p (regno0, mode, PLUS, REG)) | |
536 | index_op = 1; | |
537 | else if (REGNO_OK_FOR_INDEX_P (regno0) | |
538 | && regno_ok_for_base_p (regno1, mode, PLUS, REG)) | |
539 | index_op = 0; | |
540 | else if (regno_ok_for_base_p (regno0, mode, PLUS, REG) | |
541 | || REGNO_OK_FOR_INDEX_P (regno1)) | |
542 | index_op = 1; | |
543 | else if (regno_ok_for_base_p (regno1, mode, PLUS, REG)) | |
544 | index_op = 0; | |
545 | else | |
546 | index_op = 1; | |
547 | ||
548 | locI = &XEXP (x, index_op); | |
549 | locB = &XEXP (x, !index_op); | |
550 | index_code = GET_CODE (*locI); | |
551 | } | |
552 | else if (code0 == REG) | |
553 | { | |
554 | locI = &XEXP (x, 0); | |
555 | locB = &XEXP (x, 1); | |
556 | index_code = GET_CODE (*locI); | |
557 | } | |
558 | else if (code1 == REG) | |
559 | { | |
560 | locI = &XEXP (x, 1); | |
561 | locB = &XEXP (x, 0); | |
562 | index_code = GET_CODE (*locI); | |
563 | } | |
564 | ||
565 | if (locI) | |
566 | changed |= replace_oldest_value_addr (locI, INDEX_REG_CLASS, mode, | |
567 | insn, vd); | |
568 | if (locB) | |
569 | changed |= replace_oldest_value_addr (locB, | |
570 | base_reg_class (mode, PLUS, | |
571 | index_code), | |
572 | mode, insn, vd); | |
573 | return changed; | |
574 | } | |
575 | ||
576 | case POST_INC: | |
577 | case POST_DEC: | |
578 | case POST_MODIFY: | |
579 | case PRE_INC: | |
580 | case PRE_DEC: | |
581 | case PRE_MODIFY: | |
582 | return false; | |
583 | ||
584 | case MEM: | |
585 | return replace_oldest_value_mem (x, insn, vd); | |
586 | ||
587 | case REG: | |
588 | return replace_oldest_value_reg (loc, cl, insn, vd); | |
589 | ||
590 | default: | |
591 | break; | |
592 | } | |
593 | ||
594 | fmt = GET_RTX_FORMAT (code); | |
595 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
596 | { | |
597 | if (fmt[i] == 'e') | |
598 | changed |= replace_oldest_value_addr (&XEXP (x, i), cl, mode, | |
599 | insn, vd); | |
600 | else if (fmt[i] == 'E') | |
601 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
602 | changed |= replace_oldest_value_addr (&XVECEXP (x, i, j), cl, | |
603 | mode, insn, vd); | |
604 | } | |
605 | ||
606 | return changed; | |
607 | } | |
608 | ||
609 | /* Similar to replace_oldest_value_reg, but X contains a memory. */ | |
610 | ||
611 | static bool | |
612 | replace_oldest_value_mem (rtx x, rtx insn, struct value_data *vd) | |
613 | { | |
b5b8b0ac AO |
614 | enum reg_class cl; |
615 | ||
616 | if (DEBUG_INSN_P (insn)) | |
617 | cl = ALL_REGS; | |
618 | else | |
619 | cl = base_reg_class (GET_MODE (x), MEM, SCRATCH); | |
620 | ||
621 | return replace_oldest_value_addr (&XEXP (x, 0), cl, | |
fac41238 PB |
622 | GET_MODE (x), insn, vd); |
623 | } | |
624 | ||
625 | /* Perform the forward copy propagation on basic block BB. */ | |
626 | ||
627 | static bool | |
628 | copyprop_hardreg_forward_1 (basic_block bb, struct value_data *vd) | |
629 | { | |
b5b8b0ac | 630 | bool anything_changed = false; |
fac41238 PB |
631 | rtx insn; |
632 | ||
633 | for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) | |
634 | { | |
635 | int n_ops, i, alt, predicated; | |
636 | bool is_asm, any_replacements; | |
637 | rtx set; | |
638 | bool replaced[MAX_RECOG_OPERANDS]; | |
b5b8b0ac | 639 | bool changed = false; |
fac41238 | 640 | |
b5b8b0ac | 641 | if (!NONDEBUG_INSN_P (insn)) |
fac41238 | 642 | { |
b5b8b0ac AO |
643 | if (DEBUG_INSN_P (insn)) |
644 | { | |
645 | rtx loc = INSN_VAR_LOCATION_LOC (insn); | |
646 | if (!VAR_LOC_UNKNOWN_P (loc) | |
647 | && replace_oldest_value_addr (&INSN_VAR_LOCATION_LOC (insn), | |
648 | ALL_REGS, GET_MODE (loc), | |
649 | insn, vd)) | |
650 | { | |
651 | changed = apply_change_group (); | |
652 | gcc_assert (changed); | |
653 | df_insn_rescan (insn); | |
654 | anything_changed = true; | |
655 | } | |
656 | } | |
657 | ||
fac41238 PB |
658 | if (insn == BB_END (bb)) |
659 | break; | |
660 | else | |
661 | continue; | |
662 | } | |
663 | ||
664 | set = single_set (insn); | |
665 | extract_insn (insn); | |
666 | if (! constrain_operands (1)) | |
667 | fatal_insn_not_found (insn); | |
668 | preprocess_constraints (); | |
669 | alt = which_alternative; | |
670 | n_ops = recog_data.n_operands; | |
671 | is_asm = asm_noperands (PATTERN (insn)) >= 0; | |
672 | ||
673 | /* Simplify the code below by rewriting things to reflect | |
674 | matching constraints. Also promote OP_OUT to OP_INOUT | |
675 | in predicated instructions. */ | |
676 | ||
677 | predicated = GET_CODE (PATTERN (insn)) == COND_EXEC; | |
678 | for (i = 0; i < n_ops; ++i) | |
679 | { | |
680 | int matches = recog_op_alt[i][alt].matches; | |
681 | if (matches >= 0) | |
682 | recog_op_alt[i][alt].cl = recog_op_alt[matches][alt].cl; | |
683 | if (matches >= 0 || recog_op_alt[i][alt].matched >= 0 | |
684 | || (predicated && recog_data.operand_type[i] == OP_OUT)) | |
685 | recog_data.operand_type[i] = OP_INOUT; | |
686 | } | |
687 | ||
688 | /* For each earlyclobber operand, zap the value data. */ | |
689 | for (i = 0; i < n_ops; i++) | |
690 | if (recog_op_alt[i][alt].earlyclobber) | |
691 | kill_value (recog_data.operand[i], vd); | |
692 | ||
693 | /* Within asms, a clobber cannot overlap inputs or outputs. | |
694 | I wouldn't think this were true for regular insns, but | |
695 | scan_rtx treats them like that... */ | |
696 | note_stores (PATTERN (insn), kill_clobbered_value, vd); | |
697 | ||
698 | /* Kill all auto-incremented values. */ | |
699 | /* ??? REG_INC is useless, since stack pushes aren't done that way. */ | |
700 | for_each_rtx (&PATTERN (insn), kill_autoinc_value, vd); | |
701 | ||
702 | /* Kill all early-clobbered operands. */ | |
703 | for (i = 0; i < n_ops; i++) | |
704 | if (recog_op_alt[i][alt].earlyclobber) | |
705 | kill_value (recog_data.operand[i], vd); | |
706 | ||
707 | /* Special-case plain move instructions, since we may well | |
708 | be able to do the move from a different register class. */ | |
709 | if (set && REG_P (SET_SRC (set))) | |
710 | { | |
711 | rtx src = SET_SRC (set); | |
712 | unsigned int regno = REGNO (src); | |
713 | enum machine_mode mode = GET_MODE (src); | |
714 | unsigned int i; | |
715 | rtx new_rtx; | |
716 | ||
717 | /* If we are accessing SRC in some mode other that what we | |
718 | set it in, make sure that the replacement is valid. */ | |
719 | if (mode != vd->e[regno].mode) | |
720 | { | |
721 | if (hard_regno_nregs[regno][mode] | |
722 | > hard_regno_nregs[regno][vd->e[regno].mode]) | |
723 | goto no_move_special_case; | |
724 | } | |
725 | ||
726 | /* If the destination is also a register, try to find a source | |
727 | register in the same class. */ | |
728 | if (REG_P (SET_DEST (set))) | |
729 | { | |
730 | new_rtx = find_oldest_value_reg (REGNO_REG_CLASS (regno), src, vd); | |
731 | if (new_rtx && validate_change (insn, &SET_SRC (set), new_rtx, 0)) | |
732 | { | |
733 | if (dump_file) | |
734 | fprintf (dump_file, | |
735 | "insn %u: replaced reg %u with %u\n", | |
736 | INSN_UID (insn), regno, REGNO (new_rtx)); | |
737 | changed = true; | |
738 | goto did_replacement; | |
739 | } | |
740 | } | |
741 | ||
742 | /* Otherwise, try all valid registers and see if its valid. */ | |
743 | for (i = vd->e[regno].oldest_regno; i != regno; | |
744 | i = vd->e[i].next_regno) | |
745 | { | |
746 | new_rtx = maybe_mode_change (vd->e[i].mode, vd->e[regno].mode, | |
747 | mode, i, regno); | |
748 | if (new_rtx != NULL_RTX) | |
749 | { | |
750 | if (validate_change (insn, &SET_SRC (set), new_rtx, 0)) | |
751 | { | |
752 | ORIGINAL_REGNO (new_rtx) = ORIGINAL_REGNO (src); | |
753 | REG_ATTRS (new_rtx) = REG_ATTRS (src); | |
754 | REG_POINTER (new_rtx) = REG_POINTER (src); | |
755 | if (dump_file) | |
756 | fprintf (dump_file, | |
757 | "insn %u: replaced reg %u with %u\n", | |
758 | INSN_UID (insn), regno, REGNO (new_rtx)); | |
759 | changed = true; | |
760 | goto did_replacement; | |
761 | } | |
762 | } | |
763 | } | |
764 | } | |
765 | no_move_special_case: | |
766 | ||
767 | any_replacements = false; | |
768 | ||
769 | /* For each input operand, replace a hard register with the | |
770 | eldest live copy that's in an appropriate register class. */ | |
771 | for (i = 0; i < n_ops; i++) | |
772 | { | |
773 | replaced[i] = false; | |
774 | ||
775 | /* Don't scan match_operand here, since we've no reg class | |
776 | information to pass down. Any operands that we could | |
777 | substitute in will be represented elsewhere. */ | |
778 | if (recog_data.constraints[i][0] == '\0') | |
779 | continue; | |
780 | ||
781 | /* Don't replace in asms intentionally referencing hard regs. */ | |
782 | if (is_asm && REG_P (recog_data.operand[i]) | |
783 | && (REGNO (recog_data.operand[i]) | |
784 | == ORIGINAL_REGNO (recog_data.operand[i]))) | |
785 | continue; | |
786 | ||
787 | if (recog_data.operand_type[i] == OP_IN) | |
788 | { | |
789 | if (recog_op_alt[i][alt].is_address) | |
790 | replaced[i] | |
791 | = replace_oldest_value_addr (recog_data.operand_loc[i], | |
792 | recog_op_alt[i][alt].cl, | |
793 | VOIDmode, insn, vd); | |
794 | else if (REG_P (recog_data.operand[i])) | |
795 | replaced[i] | |
796 | = replace_oldest_value_reg (recog_data.operand_loc[i], | |
797 | recog_op_alt[i][alt].cl, | |
798 | insn, vd); | |
799 | else if (MEM_P (recog_data.operand[i])) | |
800 | replaced[i] = replace_oldest_value_mem (recog_data.operand[i], | |
801 | insn, vd); | |
802 | } | |
803 | else if (MEM_P (recog_data.operand[i])) | |
804 | replaced[i] = replace_oldest_value_mem (recog_data.operand[i], | |
805 | insn, vd); | |
806 | ||
807 | /* If we performed any replacement, update match_dups. */ | |
808 | if (replaced[i]) | |
809 | { | |
810 | int j; | |
811 | rtx new_rtx; | |
812 | ||
813 | new_rtx = *recog_data.operand_loc[i]; | |
814 | recog_data.operand[i] = new_rtx; | |
815 | for (j = 0; j < recog_data.n_dups; j++) | |
816 | if (recog_data.dup_num[j] == i) | |
817 | validate_unshare_change (insn, recog_data.dup_loc[j], new_rtx, 1); | |
818 | ||
819 | any_replacements = true; | |
820 | } | |
821 | } | |
822 | ||
823 | if (any_replacements) | |
824 | { | |
825 | if (! apply_change_group ()) | |
826 | { | |
827 | for (i = 0; i < n_ops; i++) | |
828 | if (replaced[i]) | |
829 | { | |
830 | rtx old = *recog_data.operand_loc[i]; | |
831 | recog_data.operand[i] = old; | |
832 | } | |
833 | ||
834 | if (dump_file) | |
835 | fprintf (dump_file, | |
836 | "insn %u: reg replacements not verified\n", | |
837 | INSN_UID (insn)); | |
838 | } | |
839 | else | |
840 | changed = true; | |
841 | } | |
842 | ||
843 | did_replacement: | |
b5b8b0ac AO |
844 | if (changed) |
845 | { | |
846 | df_insn_rescan (insn); | |
847 | anything_changed = true; | |
848 | } | |
849 | ||
fac41238 PB |
850 | /* Clobber call-clobbered registers. */ |
851 | if (CALL_P (insn)) | |
852 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
853 | if (TEST_HARD_REG_BIT (regs_invalidated_by_call, i)) | |
854 | kill_value_regno (i, 1, vd); | |
855 | ||
856 | /* Notice stores. */ | |
857 | note_stores (PATTERN (insn), kill_set_value, vd); | |
858 | ||
859 | /* Notice copies. */ | |
860 | if (set && REG_P (SET_DEST (set)) && REG_P (SET_SRC (set))) | |
861 | copy_value (SET_DEST (set), SET_SRC (set), vd); | |
862 | ||
863 | if (insn == BB_END (bb)) | |
864 | break; | |
865 | } | |
866 | ||
b5b8b0ac | 867 | return anything_changed; |
fac41238 PB |
868 | } |
869 | ||
870 | /* Main entry point for the forward copy propagation optimization. */ | |
871 | ||
872 | static unsigned int | |
873 | copyprop_hardreg_forward (void) | |
874 | { | |
875 | struct value_data *all_vd; | |
876 | basic_block bb; | |
877 | sbitmap visited; | |
878 | ||
879 | all_vd = XNEWVEC (struct value_data, last_basic_block); | |
880 | ||
881 | visited = sbitmap_alloc (last_basic_block); | |
882 | sbitmap_zero (visited); | |
883 | ||
884 | FOR_EACH_BB (bb) | |
885 | { | |
886 | SET_BIT (visited, bb->index); | |
887 | ||
888 | /* If a block has a single predecessor, that we've already | |
889 | processed, begin with the value data that was live at | |
890 | the end of the predecessor block. */ | |
891 | /* ??? Ought to use more intelligent queuing of blocks. */ | |
b8698a0f | 892 | if (single_pred_p (bb) |
fac41238 PB |
893 | && TEST_BIT (visited, single_pred (bb)->index) |
894 | && ! (single_pred_edge (bb)->flags & (EDGE_ABNORMAL_CALL | EDGE_EH))) | |
895 | all_vd[bb->index] = all_vd[single_pred (bb)->index]; | |
896 | else | |
897 | init_value_data (all_vd + bb->index); | |
898 | ||
899 | copyprop_hardreg_forward_1 (bb, all_vd + bb->index); | |
900 | } | |
901 | ||
b8698a0f | 902 | sbitmap_free (visited); |
fac41238 PB |
903 | free (all_vd); |
904 | return 0; | |
905 | } | |
906 | ||
907 | /* Dump the value chain data to stderr. */ | |
908 | ||
909 | void | |
910 | debug_value_data (struct value_data *vd) | |
911 | { | |
912 | HARD_REG_SET set; | |
913 | unsigned int i, j; | |
914 | ||
915 | CLEAR_HARD_REG_SET (set); | |
916 | ||
917 | for (i = 0; i < FIRST_PSEUDO_REGISTER; ++i) | |
918 | if (vd->e[i].oldest_regno == i) | |
919 | { | |
920 | if (vd->e[i].mode == VOIDmode) | |
921 | { | |
922 | if (vd->e[i].next_regno != INVALID_REGNUM) | |
923 | fprintf (stderr, "[%u] Bad next_regno for empty chain (%u)\n", | |
924 | i, vd->e[i].next_regno); | |
925 | continue; | |
926 | } | |
927 | ||
928 | SET_HARD_REG_BIT (set, i); | |
929 | fprintf (stderr, "[%u %s] ", i, GET_MODE_NAME (vd->e[i].mode)); | |
930 | ||
931 | for (j = vd->e[i].next_regno; | |
932 | j != INVALID_REGNUM; | |
933 | j = vd->e[j].next_regno) | |
934 | { | |
935 | if (TEST_HARD_REG_BIT (set, j)) | |
936 | { | |
937 | fprintf (stderr, "[%u] Loop in regno chain\n", j); | |
938 | return; | |
939 | } | |
940 | ||
941 | if (vd->e[j].oldest_regno != i) | |
942 | { | |
943 | fprintf (stderr, "[%u] Bad oldest_regno (%u)\n", | |
944 | j, vd->e[j].oldest_regno); | |
945 | return; | |
946 | } | |
947 | SET_HARD_REG_BIT (set, j); | |
948 | fprintf (stderr, "[%u %s] ", j, GET_MODE_NAME (vd->e[j].mode)); | |
949 | } | |
950 | fputc ('\n', stderr); | |
951 | } | |
952 | ||
953 | for (i = 0; i < FIRST_PSEUDO_REGISTER; ++i) | |
954 | if (! TEST_HARD_REG_BIT (set, i) | |
955 | && (vd->e[i].mode != VOIDmode | |
956 | || vd->e[i].oldest_regno != i | |
957 | || vd->e[i].next_regno != INVALID_REGNUM)) | |
958 | fprintf (stderr, "[%u] Non-empty reg in chain (%s %u %i)\n", | |
959 | i, GET_MODE_NAME (vd->e[i].mode), vd->e[i].oldest_regno, | |
960 | vd->e[i].next_regno); | |
961 | } | |
962 | ||
963 | #ifdef ENABLE_CHECKING | |
964 | static void | |
965 | validate_value_data (struct value_data *vd) | |
966 | { | |
967 | HARD_REG_SET set; | |
968 | unsigned int i, j; | |
969 | ||
970 | CLEAR_HARD_REG_SET (set); | |
971 | ||
972 | for (i = 0; i < FIRST_PSEUDO_REGISTER; ++i) | |
973 | if (vd->e[i].oldest_regno == i) | |
974 | { | |
975 | if (vd->e[i].mode == VOIDmode) | |
976 | { | |
977 | if (vd->e[i].next_regno != INVALID_REGNUM) | |
978 | internal_error ("validate_value_data: [%u] Bad next_regno for empty chain (%u)", | |
979 | i, vd->e[i].next_regno); | |
980 | continue; | |
981 | } | |
982 | ||
983 | SET_HARD_REG_BIT (set, i); | |
984 | ||
985 | for (j = vd->e[i].next_regno; | |
986 | j != INVALID_REGNUM; | |
987 | j = vd->e[j].next_regno) | |
988 | { | |
989 | if (TEST_HARD_REG_BIT (set, j)) | |
990 | internal_error ("validate_value_data: Loop in regno chain (%u)", | |
991 | j); | |
992 | if (vd->e[j].oldest_regno != i) | |
993 | internal_error ("validate_value_data: [%u] Bad oldest_regno (%u)", | |
994 | j, vd->e[j].oldest_regno); | |
995 | ||
996 | SET_HARD_REG_BIT (set, j); | |
997 | } | |
998 | } | |
999 | ||
1000 | for (i = 0; i < FIRST_PSEUDO_REGISTER; ++i) | |
1001 | if (! TEST_HARD_REG_BIT (set, i) | |
1002 | && (vd->e[i].mode != VOIDmode | |
1003 | || vd->e[i].oldest_regno != i | |
1004 | || vd->e[i].next_regno != INVALID_REGNUM)) | |
1005 | internal_error ("validate_value_data: [%u] Non-empty reg in chain (%s %u %i)", | |
1006 | i, GET_MODE_NAME (vd->e[i].mode), vd->e[i].oldest_regno, | |
1007 | vd->e[i].next_regno); | |
1008 | } | |
1009 | #endif | |
1010 | \f | |
1011 | static bool | |
1012 | gate_handle_cprop (void) | |
1013 | { | |
1014 | return (optimize > 0 && (flag_cprop_registers)); | |
1015 | } | |
1016 | ||
1017 | ||
1018 | struct rtl_opt_pass pass_cprop_hardreg = | |
1019 | { | |
1020 | { | |
1021 | RTL_PASS, | |
1022 | "cprop_hardreg", /* name */ | |
1023 | gate_handle_cprop, /* gate */ | |
1024 | copyprop_hardreg_forward, /* execute */ | |
1025 | NULL, /* sub */ | |
1026 | NULL, /* next */ | |
1027 | 0, /* static_pass_number */ | |
1028 | TV_CPROP_REGISTERS, /* tv_id */ | |
1029 | 0, /* properties_required */ | |
1030 | 0, /* properties_provided */ | |
1031 | 0, /* properties_destroyed */ | |
1032 | 0, /* todo_flags_start */ | |
1033 | TODO_dump_func | TODO_verify_rtl_sharing /* todo_flags_finish */ | |
1034 | } | |
1035 | }; |