1 | /* Copy propagation on hard registers for the GNU compiler. |
2 | Copyright (C) 2000-2023 Free Software Foundation, Inc. |
3 | |
4 | This file is part of GCC. |
5 | |
6 | GCC is free software; you can redistribute it and/or modify it |
7 | under the terms of the GNU General Public License as published by |
8 | the Free Software Foundation; either version 3, or (at your option) |
9 | any later version. |
10 | |
11 | GCC is distributed in the hope that it will be useful, but WITHOUT |
12 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
13 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public |
14 | License for more details. |
15 | |
16 | You should have received a copy of the GNU General Public License |
17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ |
19 | |
20 | #include "config.h" |
21 | #include "system.h" |
22 | #include "coretypes.h" |
23 | #include "backend.h" |
24 | #include "rtl.h" |
25 | #include "df.h" |
26 | #include "memmodel.h" |
27 | #include "tm_p.h" |
28 | #include "insn-config.h" |
29 | #include "regs.h" |
30 | #include "emit-rtl.h" |
31 | #include "recog.h" |
32 | #include "diagnostic-core.h" |
33 | #include "addresses.h" |
34 | #include "tree-pass.h" |
35 | #include "rtl-iter.h" |
36 | #include "cfgrtl.h" |
37 | #include "target.h" |
38 | #include "function-abi.h" |
39 | |
40 | /* The following code does forward propagation of hard register copies. |
41 | The object is to eliminate as many dependencies as possible, so that |
42 | we have the most scheduling freedom. As a side effect, we also clean |
43 | up some silly register allocation decisions made by reload. This |
44 | code may be obsoleted by a new register allocator. */ |
45 | |
46 | /* DEBUG_INSNs aren't changed right away, as doing so might extend the |
47 | lifetime of a register and get the DEBUG_INSN subsequently reset. |
48 | So they are queued instead, and updated only when the register is |
49 | used in some subsequent real insn before it is set. */ |
50 | struct queued_debug_insn_change |
51 | { |
52 | struct queued_debug_insn_change *next; |
53 | rtx_insn *insn; |
54 | rtx *loc; |
55 | rtx new_rtx; |
56 | }; |
57 | |
58 | /* For each register, we have a list of registers that contain the same |
59 | value. The OLDEST_REGNO field points to the head of the list, and |
60 | the NEXT_REGNO field runs through the list. The MODE field indicates |
61 | what mode the data is known to be in; this field is VOIDmode when the |
62 | register is not known to contain valid data. */ |
63 | |
64 | struct value_data_entry |
65 | { |
66 | machine_mode mode; |
67 | unsigned int oldest_regno; |
68 | unsigned int next_regno; |
69 | struct queued_debug_insn_change *debug_insn_changes; |
70 | }; |
71 | |
72 | struct value_data |
73 | { |
74 | struct value_data_entry e[FIRST_PSEUDO_REGISTER]; |
75 | unsigned int max_value_regs; |
76 | unsigned int n_debug_insn_changes; |
77 | }; |
78 | |
79 | static object_allocator<queued_debug_insn_change> queued_debug_insn_change_pool |
80 | ("debug insn changes pool" ); |
81 | |
82 | static bool skip_debug_insn_p; |
83 | |
84 | static void kill_value_one_regno (unsigned, struct value_data *); |
85 | static void kill_value_regno (unsigned, unsigned, struct value_data *); |
86 | static void kill_value (const_rtx, struct value_data *); |
87 | static void set_value_regno (unsigned, machine_mode, struct value_data *); |
88 | static void init_value_data (struct value_data *); |
89 | static void kill_clobbered_value (rtx, const_rtx, void *); |
90 | static void kill_set_value (rtx, const_rtx, void *); |
91 | static void copy_value (rtx, rtx, struct value_data *); |
92 | static bool mode_change_ok (machine_mode, machine_mode, |
93 | unsigned int); |
94 | static rtx maybe_mode_change (machine_mode, machine_mode, |
95 | machine_mode, unsigned int, unsigned int); |
96 | static rtx find_oldest_value_reg (enum reg_class, rtx, struct value_data *); |
97 | static bool replace_oldest_value_reg (rtx *, enum reg_class, rtx_insn *, |
98 | struct value_data *); |
99 | static bool replace_oldest_value_addr (rtx *, enum reg_class, |
100 | machine_mode, addr_space_t, |
101 | rtx_insn *, struct value_data *); |
102 | static bool replace_oldest_value_mem (rtx, rtx_insn *, struct value_data *); |
103 | static bool copyprop_hardreg_forward_1 (basic_block, struct value_data *); |
104 | extern void debug_value_data (struct value_data *); |
105 | static void validate_value_data (struct value_data *); |
106 | |
107 | /* Free all queued updates for DEBUG_INSNs that change some reg to |
108 | register REGNO. */ |
109 | |
110 | static void |
111 | free_debug_insn_changes (struct value_data *vd, unsigned int regno) |
112 | { |
113 | struct queued_debug_insn_change *cur, *next; |
114 | for (cur = vd->e[regno].debug_insn_changes; cur; cur = next) |
115 | { |
116 | next = cur->next; |
117 | --vd->n_debug_insn_changes; |
118 | queued_debug_insn_change_pool.remove (object: cur); |
119 | } |
120 | vd->e[regno].debug_insn_changes = NULL; |
121 | } |
122 | |
123 | /* Kill register REGNO. This involves removing it from any value |
124 | lists, and resetting the value mode to VOIDmode. This is only a |
125 | helper function; it does not handle any hard registers overlapping |
126 | with REGNO. */ |
127 | |
128 | static void |
129 | kill_value_one_regno (unsigned int regno, struct value_data *vd) |
130 | { |
131 | unsigned int i, next; |
132 | |
133 | if (vd->e[regno].oldest_regno != regno) |
134 | { |
135 | for (i = vd->e[regno].oldest_regno; |
136 | vd->e[i].next_regno != regno; |
137 | i = vd->e[i].next_regno) |
138 | continue; |
139 | vd->e[i].next_regno = vd->e[regno].next_regno; |
140 | } |
141 | else if ((next = vd->e[regno].next_regno) != INVALID_REGNUM) |
142 | { |
143 | for (i = next; i != INVALID_REGNUM; i = vd->e[i].next_regno) |
144 | vd->e[i].oldest_regno = next; |
145 | } |
146 | |
147 | vd->e[regno].mode = VOIDmode; |
148 | vd->e[regno].oldest_regno = regno; |
149 | vd->e[regno].next_regno = INVALID_REGNUM; |
150 | if (vd->e[regno].debug_insn_changes) |
151 | free_debug_insn_changes (vd, regno); |
152 | |
153 | if (flag_checking) |
154 | validate_value_data (vd); |
155 | } |
156 | |
157 | /* Kill the value in register REGNO for NREGS, and any other registers |
158 | whose values overlap. */ |
159 | |
160 | static void |
161 | kill_value_regno (unsigned int regno, unsigned int nregs, |
162 | struct value_data *vd) |
163 | { |
164 | unsigned int j; |
165 | |
166 | /* Kill the value we're told to kill. */ |
167 | for (j = 0; j < nregs; ++j) |
168 | kill_value_one_regno (regno: regno + j, vd); |
169 | |
170 | /* Kill everything that overlapped what we're told to kill. */ |
171 | if (regno < vd->max_value_regs) |
172 | j = 0; |
173 | else |
174 | j = regno - vd->max_value_regs; |
175 | for (; j < regno; ++j) |
176 | { |
177 | unsigned int i, n; |
178 | if (vd->e[j].mode == VOIDmode) |
179 | continue; |
180 | n = hard_regno_nregs (regno: j, mode: vd->e[j].mode); |
181 | if (j + n > regno) |
182 | for (i = 0; i < n; ++i) |
183 | kill_value_one_regno (regno: j + i, vd); |
184 | } |
185 | } |
186 | |
187 | /* Kill X. This is a convenience function wrapping kill_value_regno |
188 | so that we mind the mode the register is in. */ |
189 | |
190 | static void |
191 | kill_value (const_rtx x, struct value_data *vd) |
192 | { |
193 | if (GET_CODE (x) == SUBREG) |
194 | { |
195 | rtx tmp = simplify_subreg (GET_MODE (x), SUBREG_REG (x), |
196 | GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x)); |
197 | x = tmp ? tmp : SUBREG_REG (x); |
198 | } |
199 | if (REG_P (x)) |
200 | kill_value_regno (REGNO (x), REG_NREGS (x), vd); |
201 | } |
202 | |
203 | /* Remember that REGNO is valid in MODE. */ |
204 | |
205 | static void |
206 | set_value_regno (unsigned int regno, machine_mode mode, |
207 | struct value_data *vd) |
208 | { |
209 | unsigned int nregs; |
210 | |
211 | vd->e[regno].mode = mode; |
212 | |
213 | nregs = hard_regno_nregs (regno, mode); |
214 | if (nregs > vd->max_value_regs) |
215 | vd->max_value_regs = nregs; |
216 | } |
217 | |
218 | /* Initialize VD such that there are no known relationships between regs. */ |
219 | |
220 | static void |
221 | init_value_data (struct value_data *vd) |
222 | { |
223 | int i; |
224 | for (i = 0; i < FIRST_PSEUDO_REGISTER; ++i) |
225 | { |
226 | vd->e[i].mode = VOIDmode; |
227 | vd->e[i].oldest_regno = i; |
228 | vd->e[i].next_regno = INVALID_REGNUM; |
229 | vd->e[i].debug_insn_changes = NULL; |
230 | } |
231 | vd->max_value_regs = 0; |
232 | vd->n_debug_insn_changes = 0; |
233 | } |
234 | |
235 | /* Called through note_stores. If X is clobbered, kill its value. */ |
236 | |
237 | static void |
238 | kill_clobbered_value (rtx x, const_rtx set, void *data) |
239 | { |
240 | struct value_data *const vd = (struct value_data *) data; |
241 | |
242 | if (GET_CODE (set) == CLOBBER) |
243 | kill_value (x, vd); |
244 | } |
245 | |
246 | /* A structure passed as data to kill_set_value through note_stores. */ |
247 | struct kill_set_value_data |
248 | { |
249 | struct value_data *vd; |
250 | rtx ignore_set_reg; |
251 | }; |
252 | |
253 | /* Called through note_stores. If X is set, not clobbered, kill its |
254 | current value and install it as the root of its own value list. */ |
255 | |
256 | static void |
257 | kill_set_value (rtx x, const_rtx set, void *data) |
258 | { |
259 | struct kill_set_value_data *ksvd = (struct kill_set_value_data *) data; |
260 | if (rtx_equal_p (x, ksvd->ignore_set_reg)) |
261 | return; |
262 | |
263 | if (GET_CODE (set) != CLOBBER) |
264 | { |
265 | kill_value (x, vd: ksvd->vd); |
266 | if (REG_P (x)) |
267 | set_value_regno (REGNO (x), GET_MODE (x), vd: ksvd->vd); |
268 | } |
269 | } |
270 | |
271 | /* Kill any register used in X as the base of an auto-increment expression, |
272 | and install that register as the root of its own value list. */ |
273 | |
274 | static void |
275 | kill_autoinc_value (rtx_insn *insn, struct value_data *vd) |
276 | { |
277 | subrtx_iterator::array_type array; |
278 | FOR_EACH_SUBRTX (iter, array, PATTERN (insn), NONCONST) |
279 | { |
280 | const_rtx x = *iter; |
281 | if (GET_RTX_CLASS (GET_CODE (x)) == RTX_AUTOINC) |
282 | { |
283 | x = XEXP (x, 0); |
284 | kill_value (x, vd); |
285 | set_value_regno (REGNO (x), GET_MODE (x), vd); |
286 | iter.skip_subrtxes (); |
287 | } |
288 | } |
289 | } |
290 | |
291 | /* Assert that SRC has been copied to DEST. Adjust the data structures |
292 | to reflect that SRC contains an older copy of the shared value. */ |
293 | |
294 | static void |
295 | copy_value (rtx dest, rtx src, struct value_data *vd) |
296 | { |
297 | unsigned int dr = REGNO (dest); |
298 | unsigned int sr = REGNO (src); |
299 | unsigned int dn, sn; |
300 | unsigned int i; |
301 | |
302 | /* ??? At present, it's possible to see noop sets. It'd be nice if |
303 | this were cleaned up beforehand... */ |
304 | if (sr == dr) |
305 | return; |
306 | |
307 | /* Do not propagate copies to the stack pointer, as that can leave |
308 | memory accesses with no scheduling dependency on the stack update. */ |
309 | if (dr == STACK_POINTER_REGNUM) |
310 | return; |
311 | |
312 | /* Likewise with the frame pointer, if we're using one. */ |
313 | if (frame_pointer_needed && dr == HARD_FRAME_POINTER_REGNUM) |
314 | return; |
315 | |
316 | /* Do not propagate copies to fixed or global registers, patterns |
317 | can be relying to see particular fixed register or users can |
318 | expect the chosen global register in asm. */ |
319 | if (fixed_regs[dr] || global_regs[dr]) |
320 | return; |
321 | |
322 | /* If SRC and DEST overlap, don't record anything. */ |
323 | dn = REG_NREGS (dest); |
324 | sn = REG_NREGS (src); |
325 | if ((dr > sr && dr < sr + sn) |
326 | || (sr > dr && sr < dr + dn)) |
327 | return; |
328 | |
329 | /* If SRC had no assigned mode (i.e. we didn't know it was live) |
330 | assign it now and assume the value came from an input argument |
331 | or somesuch. */ |
332 | if (vd->e[sr].mode == VOIDmode) |
333 | set_value_regno (regno: sr, mode: vd->e[dr].mode, vd); |
334 | |
335 | /* If we are narrowing the input to a smaller number of hard regs, |
336 | and it is in big endian, we are really extracting a high part. |
337 | Since we generally associate a low part of a value with the value itself, |
338 | we must not do the same for the high part. |
339 | Note we can still get low parts for the same mode combination through |
340 | a two-step copy involving differently sized hard regs. |
341 | Assume hard regs fr* are 32 bits each, while r* are 64 bits each: |
342 | (set (reg:DI r0) (reg:DI fr0)) |
343 | (set (reg:SI fr2) (reg:SI r0)) |
344 | loads the low part of (reg:DI fr0) - i.e. fr1 - into fr2, while: |
345 | (set (reg:SI fr2) (reg:SI fr0)) |
346 | loads the high part of (reg:DI fr0) into fr2. |
347 | |
348 | We can't properly represent the latter case in our tables, so don't |
349 | record anything then. */ |
350 | else if (sn < hard_regno_nregs (regno: sr, mode: vd->e[sr].mode) |
351 | && maybe_ne (a: subreg_lowpart_offset (GET_MODE (dest), |
352 | innermode: vd->e[sr].mode), b: 0U)) |
353 | return; |
354 | |
355 | /* If SRC had been assigned a mode narrower than the copy, we can't |
356 | link DEST into the chain, because not all of the pieces of the |
357 | copy came from oldest_regno. */ |
358 | else if (sn > hard_regno_nregs (regno: sr, mode: vd->e[sr].mode)) |
359 | return; |
360 | |
361 | /* If a narrower value is copied using wider mode, the upper bits |
362 | are undefined (could be e.g. a former paradoxical subreg). Signal |
363 | in that case we've only copied value using the narrower mode. |
364 | Consider: |
365 | (set (reg:DI r14) (mem:DI ...)) |
366 | (set (reg:QI si) (reg:QI r14)) |
367 | (set (reg:DI bp) (reg:DI r14)) |
368 | (set (reg:DI r14) (const_int ...)) |
369 | (set (reg:DI dx) (reg:DI si)) |
370 | (set (reg:DI si) (const_int ...)) |
371 | (set (reg:DI dx) (reg:DI bp)) |
372 | The last set is not redundant, while the low 8 bits of dx are already |
373 | equal to low 8 bits of bp, the other bits are undefined. */ |
374 | else if (partial_subreg_p (outermode: vd->e[sr].mode, GET_MODE (src))) |
375 | { |
376 | if (!REG_CAN_CHANGE_MODE_P (sr, GET_MODE (src), vd->e[sr].mode) |
377 | || !REG_CAN_CHANGE_MODE_P (dr, vd->e[sr].mode, GET_MODE (dest))) |
378 | return; |
379 | set_value_regno (regno: dr, mode: vd->e[sr].mode, vd); |
380 | } |
381 | |
382 | /* Link DR at the end of the value chain used by SR. */ |
383 | |
384 | vd->e[dr].oldest_regno = vd->e[sr].oldest_regno; |
385 | |
386 | for (i = sr; vd->e[i].next_regno != INVALID_REGNUM; i = vd->e[i].next_regno) |
387 | continue; |
388 | vd->e[i].next_regno = dr; |
389 | |
390 | if (flag_checking) |
391 | validate_value_data (vd); |
392 | } |
393 | |
394 | /* Return true if a mode change from ORIG to NEW is allowed for REGNO. */ |
395 | |
396 | static bool |
397 | mode_change_ok (machine_mode orig_mode, machine_mode new_mode, |
398 | unsigned int regno ATTRIBUTE_UNUSED) |
399 | { |
400 | if (partial_subreg_p (outermode: orig_mode, innermode: new_mode)) |
401 | return false; |
402 | |
403 | return REG_CAN_CHANGE_MODE_P (regno, orig_mode, new_mode); |
404 | } |
405 | |
406 | /* Register REGNO was originally set in ORIG_MODE. It - or a copy of it - |
407 | was copied in COPY_MODE to COPY_REGNO, and then COPY_REGNO was accessed |
408 | in NEW_MODE. |
409 | Return a NEW_MODE rtx for REGNO if that's OK, otherwise return NULL_RTX. */ |
410 | |
411 | static rtx |
412 | maybe_mode_change (machine_mode orig_mode, machine_mode copy_mode, |
413 | machine_mode new_mode, unsigned int regno, |
414 | unsigned int copy_regno ATTRIBUTE_UNUSED) |
415 | { |
416 | if (partial_subreg_p (outermode: copy_mode, innermode: orig_mode) |
417 | && partial_subreg_p (outermode: copy_mode, innermode: new_mode)) |
418 | return NULL_RTX; |
419 | |
420 | /* Avoid creating multiple copies of the stack pointer. Some ports |
421 | assume there is one and only one stack pointer. |
422 | |
423 | It's unclear if we need to do the same for other special registers. */ |
424 | if (regno == STACK_POINTER_REGNUM) |
425 | { |
426 | if (orig_mode == new_mode && new_mode == GET_MODE (stack_pointer_rtx)) |
427 | return stack_pointer_rtx; |
428 | else |
429 | return NULL_RTX; |
430 | } |
431 | |
432 | if (orig_mode == new_mode) |
433 | return gen_raw_REG (new_mode, regno); |
434 | else if (mode_change_ok (orig_mode, new_mode, regno) |
435 | && mode_change_ok (orig_mode: copy_mode, new_mode, regno: copy_regno)) |
436 | { |
437 | int copy_nregs = hard_regno_nregs (regno: copy_regno, mode: copy_mode); |
438 | int use_nregs = hard_regno_nregs (regno: copy_regno, mode: new_mode); |
439 | poly_uint64 bytes_per_reg; |
440 | if (!can_div_trunc_p (a: GET_MODE_SIZE (mode: copy_mode), |
441 | b: copy_nregs, quotient: &bytes_per_reg)) |
442 | return NULL_RTX; |
443 | poly_uint64 copy_offset = bytes_per_reg * (copy_nregs - use_nregs); |
444 | poly_uint64 offset |
445 | = subreg_size_lowpart_offset (GET_MODE_SIZE (mode: new_mode) + copy_offset, |
446 | GET_MODE_SIZE (mode: orig_mode)); |
447 | regno += subreg_regno_offset (regno, orig_mode, offset, new_mode); |
448 | if (targetm.hard_regno_mode_ok (regno, new_mode)) |
449 | return gen_raw_REG (new_mode, regno); |
450 | } |
451 | return NULL_RTX; |
452 | } |
453 | |
454 | /* Find the oldest copy of the value contained in REGNO that is in |
455 | register class CL and has mode MODE. If found, return an rtx |
456 | of that oldest register, otherwise return NULL. */ |
457 | |
458 | static rtx |
459 | find_oldest_value_reg (enum reg_class cl, rtx reg, struct value_data *vd) |
460 | { |
461 | unsigned int regno = REGNO (reg); |
462 | machine_mode mode = GET_MODE (reg); |
463 | unsigned int i; |
464 | |
465 | gcc_assert (regno < FIRST_PSEUDO_REGISTER); |
466 | |
467 | /* If we are accessing REG in some mode other that what we set it in, |
468 | make sure that the replacement is valid. In particular, consider |
469 | (set (reg:DI r11) (...)) |
470 | (set (reg:SI r9) (reg:SI r11)) |
471 | (set (reg:SI r10) (...)) |
472 | (set (...) (reg:DI r9)) |
473 | Replacing r9 with r11 is invalid. */ |
474 | if (mode != vd->e[regno].mode |
475 | && (REG_NREGS (reg) > hard_regno_nregs (regno, mode: vd->e[regno].mode) |
476 | || !REG_CAN_CHANGE_MODE_P (regno, mode, vd->e[regno].mode))) |
477 | return NULL_RTX; |
478 | |
479 | for (i = vd->e[regno].oldest_regno; i != regno; i = vd->e[i].next_regno) |
480 | { |
481 | machine_mode oldmode = vd->e[i].mode; |
482 | rtx new_rtx; |
483 | |
484 | if (!in_hard_reg_set_p (reg_class_contents[cl], mode, regno: i)) |
485 | continue; |
486 | |
487 | new_rtx = maybe_mode_change (orig_mode: oldmode, copy_mode: vd->e[regno].mode, new_mode: mode, regno: i, copy_regno: regno); |
488 | if (new_rtx) |
489 | { |
490 | /* NEW_RTX may be the global stack pointer rtx, in which case we |
491 | must not modify it's attributes. */ |
492 | if (new_rtx != stack_pointer_rtx) |
493 | { |
494 | ORIGINAL_REGNO (new_rtx) = ORIGINAL_REGNO (reg); |
495 | REG_ATTRS (new_rtx) = REG_ATTRS (reg); |
496 | REG_POINTER (new_rtx) = REG_POINTER (reg); |
497 | } |
498 | return new_rtx; |
499 | } |
500 | } |
501 | |
502 | return NULL_RTX; |
503 | } |
504 | |
505 | /* If possible, replace the register at *LOC with the oldest register |
506 | in register class CL. Return true if successfully replaced. */ |
507 | |
508 | static bool |
509 | replace_oldest_value_reg (rtx *loc, enum reg_class cl, rtx_insn *insn, |
510 | struct value_data *vd) |
511 | { |
512 | rtx new_rtx = find_oldest_value_reg (cl, reg: *loc, vd); |
513 | if (new_rtx && (!DEBUG_INSN_P (insn) || !skip_debug_insn_p)) |
514 | { |
515 | if (DEBUG_INSN_P (insn)) |
516 | { |
517 | struct queued_debug_insn_change *change; |
518 | |
519 | if (dump_file) |
520 | fprintf (stream: dump_file, format: "debug_insn %u: queued replacing reg %u with %u\n" , |
521 | INSN_UID (insn), REGNO (*loc), REGNO (new_rtx)); |
522 | |
523 | change = queued_debug_insn_change_pool.allocate (); |
524 | change->next = vd->e[REGNO (new_rtx)].debug_insn_changes; |
525 | change->insn = insn; |
526 | change->loc = loc; |
527 | change->new_rtx = new_rtx; |
528 | vd->e[REGNO (new_rtx)].debug_insn_changes = change; |
529 | ++vd->n_debug_insn_changes; |
530 | return true; |
531 | } |
532 | if (dump_file) |
533 | fprintf (stream: dump_file, format: "insn %u: replaced reg %u with %u\n" , |
534 | INSN_UID (insn), REGNO (*loc), REGNO (new_rtx)); |
535 | |
536 | validate_change (insn, loc, new_rtx, 1); |
537 | return true; |
538 | } |
539 | return false; |
540 | } |
541 | |
542 | /* Similar to replace_oldest_value_reg, but *LOC contains an address. |
543 | Adapted from find_reloads_address_1. CL is INDEX_REG_CLASS or |
544 | BASE_REG_CLASS depending on how the register is being considered. */ |
545 | |
546 | static bool |
547 | replace_oldest_value_addr (rtx *loc, enum reg_class cl, |
548 | machine_mode mode, addr_space_t as, |
549 | rtx_insn *insn, struct value_data *vd) |
550 | { |
551 | rtx x = *loc; |
552 | RTX_CODE code = GET_CODE (x); |
553 | const char *fmt; |
554 | int i, j; |
555 | bool changed = false; |
556 | |
557 | switch (code) |
558 | { |
559 | case PLUS: |
560 | if (DEBUG_INSN_P (insn)) |
561 | break; |
562 | |
563 | { |
564 | rtx orig_op0 = XEXP (x, 0); |
565 | rtx orig_op1 = XEXP (x, 1); |
566 | RTX_CODE code0 = GET_CODE (orig_op0); |
567 | RTX_CODE code1 = GET_CODE (orig_op1); |
568 | rtx op0 = orig_op0; |
569 | rtx op1 = orig_op1; |
570 | rtx *locI = NULL; |
571 | rtx *locB = NULL; |
572 | enum rtx_code index_code = SCRATCH; |
573 | |
574 | if (GET_CODE (op0) == SUBREG) |
575 | { |
576 | op0 = SUBREG_REG (op0); |
577 | code0 = GET_CODE (op0); |
578 | } |
579 | |
580 | if (GET_CODE (op1) == SUBREG) |
581 | { |
582 | op1 = SUBREG_REG (op1); |
583 | code1 = GET_CODE (op1); |
584 | } |
585 | |
586 | if (code0 == MULT || code0 == SIGN_EXTEND || code0 == TRUNCATE |
587 | || code0 == ZERO_EXTEND || code1 == MEM) |
588 | { |
589 | locI = &XEXP (x, 0); |
590 | locB = &XEXP (x, 1); |
591 | index_code = GET_CODE (*locI); |
592 | } |
593 | else if (code1 == MULT || code1 == SIGN_EXTEND || code1 == TRUNCATE |
594 | || code1 == ZERO_EXTEND || code0 == MEM) |
595 | { |
596 | locI = &XEXP (x, 1); |
597 | locB = &XEXP (x, 0); |
598 | index_code = GET_CODE (*locI); |
599 | } |
600 | else if (code0 == CONST_INT || code0 == CONST |
601 | || code0 == SYMBOL_REF || code0 == LABEL_REF) |
602 | { |
603 | locB = &XEXP (x, 1); |
604 | index_code = GET_CODE (XEXP (x, 0)); |
605 | } |
606 | else if (code1 == CONST_INT || code1 == CONST |
607 | || code1 == SYMBOL_REF || code1 == LABEL_REF) |
608 | { |
609 | locB = &XEXP (x, 0); |
610 | index_code = GET_CODE (XEXP (x, 1)); |
611 | } |
612 | else if (code0 == REG && code1 == REG) |
613 | { |
614 | int index_op; |
615 | unsigned regno0 = REGNO (op0), regno1 = REGNO (op1); |
616 | |
617 | if (REGNO_OK_FOR_INDEX_P (regno1) |
618 | && regno_ok_for_base_p (regno: regno0, mode, as, outer_code: PLUS, index_code: REG)) |
619 | index_op = 1; |
620 | else if (REGNO_OK_FOR_INDEX_P (regno0) |
621 | && regno_ok_for_base_p (regno: regno1, mode, as, outer_code: PLUS, index_code: REG)) |
622 | index_op = 0; |
623 | else if (regno_ok_for_base_p (regno: regno0, mode, as, outer_code: PLUS, index_code: REG) |
624 | || REGNO_OK_FOR_INDEX_P (regno1)) |
625 | index_op = 1; |
626 | else if (regno_ok_for_base_p (regno: regno1, mode, as, outer_code: PLUS, index_code: REG)) |
627 | index_op = 0; |
628 | else |
629 | index_op = 1; |
630 | |
631 | locI = &XEXP (x, index_op); |
632 | locB = &XEXP (x, !index_op); |
633 | index_code = GET_CODE (*locI); |
634 | } |
635 | else if (code0 == REG) |
636 | { |
637 | locI = &XEXP (x, 0); |
638 | locB = &XEXP (x, 1); |
639 | index_code = GET_CODE (*locI); |
640 | } |
641 | else if (code1 == REG) |
642 | { |
643 | locI = &XEXP (x, 1); |
644 | locB = &XEXP (x, 0); |
645 | index_code = GET_CODE (*locI); |
646 | } |
647 | |
648 | if (locI) |
649 | changed |= replace_oldest_value_addr (loc: locI, INDEX_REG_CLASS, |
650 | mode, as, insn, vd); |
651 | if (locB) |
652 | changed |= replace_oldest_value_addr (loc: locB, |
653 | cl: base_reg_class (mode, as, outer_code: PLUS, |
654 | index_code), |
655 | mode, as, insn, vd); |
656 | return changed; |
657 | } |
658 | |
659 | case POST_INC: |
660 | case POST_DEC: |
661 | case POST_MODIFY: |
662 | case PRE_INC: |
663 | case PRE_DEC: |
664 | case PRE_MODIFY: |
665 | return false; |
666 | |
667 | case MEM: |
668 | return replace_oldest_value_mem (x, insn, vd); |
669 | |
670 | case REG: |
671 | return replace_oldest_value_reg (loc, cl, insn, vd); |
672 | |
673 | default: |
674 | break; |
675 | } |
676 | |
677 | fmt = GET_RTX_FORMAT (code); |
678 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) |
679 | { |
680 | if (fmt[i] == 'e') |
681 | changed |= replace_oldest_value_addr (loc: &XEXP (x, i), cl, mode, as, |
682 | insn, vd); |
683 | else if (fmt[i] == 'E') |
684 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) |
685 | changed |= replace_oldest_value_addr (loc: &XVECEXP (x, i, j), cl, |
686 | mode, as, insn, vd); |
687 | } |
688 | |
689 | return changed; |
690 | } |
691 | |
692 | /* Similar to replace_oldest_value_reg, but X contains a memory. */ |
693 | |
694 | static bool |
695 | replace_oldest_value_mem (rtx x, rtx_insn *insn, struct value_data *vd) |
696 | { |
697 | enum reg_class cl; |
698 | |
699 | if (DEBUG_INSN_P (insn)) |
700 | cl = ALL_REGS; |
701 | else |
702 | cl = base_reg_class (GET_MODE (x), MEM_ADDR_SPACE (x), outer_code: MEM, index_code: SCRATCH); |
703 | |
704 | return replace_oldest_value_addr (loc: &XEXP (x, 0), cl, |
705 | GET_MODE (x), MEM_ADDR_SPACE (x), |
706 | insn, vd); |
707 | } |
708 | |
709 | /* Apply all queued updates for DEBUG_INSNs that change some reg to |
710 | register REGNO. */ |
711 | |
712 | static void |
713 | apply_debug_insn_changes (struct value_data *vd, unsigned int regno) |
714 | { |
715 | struct queued_debug_insn_change *change; |
716 | rtx_insn *last_insn = vd->e[regno].debug_insn_changes->insn; |
717 | |
718 | for (change = vd->e[regno].debug_insn_changes; |
719 | change; |
720 | change = change->next) |
721 | { |
722 | if (last_insn != change->insn) |
723 | { |
724 | apply_change_group (); |
725 | last_insn = change->insn; |
726 | } |
727 | validate_change (change->insn, change->loc, change->new_rtx, 1); |
728 | } |
729 | apply_change_group (); |
730 | } |
731 | |
732 | /* Called via note_uses, for all used registers in a real insn |
733 | apply DEBUG_INSN changes that change registers to the used |
734 | registers. */ |
735 | |
736 | static void |
737 | cprop_find_used_regs (rtx *loc, void *data) |
738 | { |
739 | struct value_data *const vd = (struct value_data *) data; |
740 | subrtx_iterator::array_type array; |
741 | FOR_EACH_SUBRTX (iter, array, *loc, NONCONST) |
742 | { |
743 | const_rtx x = *iter; |
744 | if (REG_P (x)) |
745 | { |
746 | unsigned int regno = REGNO (x); |
747 | if (vd->e[regno].debug_insn_changes) |
748 | { |
749 | apply_debug_insn_changes (vd, regno); |
750 | free_debug_insn_changes (vd, regno); |
751 | } |
752 | } |
753 | } |
754 | } |
755 | |
756 | /* Apply clobbers of INSN in PATTERN and C_I_F_U to value_data VD. */ |
757 | |
758 | static void |
759 | kill_clobbered_values (rtx_insn *insn, struct value_data *vd) |
760 | { |
761 | note_stores (insn, kill_clobbered_value, vd); |
762 | } |
763 | |
764 | /* Perform the forward copy propagation on basic block BB. */ |
765 | |
766 | static bool |
767 | copyprop_hardreg_forward_1 (basic_block bb, struct value_data *vd) |
768 | { |
769 | bool anything_changed = false; |
770 | rtx_insn *insn, *next; |
771 | |
772 | for (insn = BB_HEAD (bb); ; insn = next) |
773 | { |
774 | int n_ops, i, predicated; |
775 | bool is_asm, any_replacements; |
776 | rtx set; |
777 | rtx link; |
778 | bool changed = false; |
779 | struct kill_set_value_data ksvd; |
780 | |
781 | next = NEXT_INSN (insn); |
782 | if (!NONDEBUG_INSN_P (insn)) |
783 | { |
784 | if (DEBUG_BIND_INSN_P (insn)) |
785 | { |
786 | rtx loc = INSN_VAR_LOCATION_LOC (insn); |
787 | if (!VAR_LOC_UNKNOWN_P (loc)) |
788 | replace_oldest_value_addr (loc: &INSN_VAR_LOCATION_LOC (insn), |
789 | cl: ALL_REGS, GET_MODE (loc), |
790 | ADDR_SPACE_GENERIC, insn, vd); |
791 | } |
792 | |
793 | if (insn == BB_END (bb)) |
794 | break; |
795 | else |
796 | continue; |
797 | } |
798 | |
799 | set = single_set (insn); |
800 | |
801 | /* Detect noop sets and remove them before processing side effects. */ |
802 | if (set && REG_P (SET_DEST (set)) && REG_P (SET_SRC (set))) |
803 | { |
804 | unsigned int regno = REGNO (SET_SRC (set)); |
805 | rtx r1 = find_oldest_value_reg (REGNO_REG_CLASS (regno), |
806 | SET_DEST (set), vd); |
807 | rtx r2 = find_oldest_value_reg (REGNO_REG_CLASS (regno), |
808 | SET_SRC (set), vd); |
809 | if (rtx_equal_p (r1 ? r1 : SET_DEST (set), r2 ? r2 : SET_SRC (set))) |
810 | { |
811 | bool last = insn == BB_END (bb); |
812 | delete_insn (insn); |
813 | if (last) |
814 | break; |
815 | continue; |
816 | } |
817 | } |
818 | |
819 | /* Detect obviously dead sets (via REG_UNUSED notes) and remove them. */ |
820 | if (set |
821 | && !RTX_FRAME_RELATED_P (insn) |
822 | && NONJUMP_INSN_P (insn) |
823 | && !may_trap_p (set) |
824 | && find_reg_note (insn, REG_UNUSED, SET_DEST (set)) |
825 | && !side_effects_p (SET_SRC (set)) |
826 | && !side_effects_p (SET_DEST (set))) |
827 | { |
828 | bool last = insn == BB_END (bb); |
829 | delete_insn (insn); |
830 | if (last) |
831 | break; |
832 | continue; |
833 | } |
834 | |
835 | |
836 | extract_constrain_insn (insn); |
837 | preprocess_constraints (insn); |
838 | const operand_alternative *op_alt = which_op_alt (); |
839 | n_ops = recog_data.n_operands; |
840 | is_asm = asm_noperands (PATTERN (insn)) >= 0; |
841 | |
842 | /* Simplify the code below by promoting OP_OUT to OP_INOUT |
843 | in predicated instructions. */ |
844 | |
845 | predicated = GET_CODE (PATTERN (insn)) == COND_EXEC; |
846 | for (i = 0; i < n_ops; ++i) |
847 | { |
848 | int matches = op_alt[i].matches; |
849 | if (matches >= 0 || op_alt[i].matched >= 0 |
850 | || (predicated && recog_data.operand_type[i] == OP_OUT)) |
851 | recog_data.operand_type[i] = OP_INOUT; |
852 | } |
853 | |
854 | /* Apply changes to earlier DEBUG_INSNs if possible. */ |
855 | if (vd->n_debug_insn_changes) |
856 | note_uses (&PATTERN (insn), cprop_find_used_regs, vd); |
857 | |
858 | /* For each earlyclobber operand, zap the value data. */ |
859 | for (i = 0; i < n_ops; i++) |
860 | if (op_alt[i].earlyclobber) |
861 | kill_value (x: recog_data.operand[i], vd); |
862 | |
863 | /* Within asms, a clobber cannot overlap inputs or outputs. |
864 | I wouldn't think this were true for regular insns, but |
865 | scan_rtx treats them like that... */ |
866 | kill_clobbered_values (insn, vd); |
867 | |
868 | /* Kill all auto-incremented values. */ |
869 | /* ??? REG_INC is useless, since stack pushes aren't done that way. */ |
870 | kill_autoinc_value (insn, vd); |
871 | |
872 | /* Kill all early-clobbered operands. */ |
873 | for (i = 0; i < n_ops; i++) |
874 | if (op_alt[i].earlyclobber) |
875 | kill_value (x: recog_data.operand[i], vd); |
876 | |
877 | /* If we have dead sets in the insn, then we need to note these as we |
878 | would clobbers. */ |
879 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) |
880 | { |
881 | if (REG_NOTE_KIND (link) == REG_UNUSED) |
882 | { |
883 | kill_value (XEXP (link, 0), vd); |
884 | /* Furthermore, if the insn looked like a single-set, |
885 | but the dead store kills the source value of that |
886 | set, then we can no-longer use the plain move |
887 | special case below. */ |
888 | if (set |
889 | && reg_overlap_mentioned_p (XEXP (link, 0), SET_SRC (set))) |
890 | set = NULL; |
891 | } |
892 | |
893 | /* We need to keep CFI info correct, and the same on all paths, |
894 | so we cannot normally replace the registers REG_CFA_REGISTER |
895 | refers to. Bail. */ |
896 | if (REG_NOTE_KIND (link) == REG_CFA_REGISTER) |
897 | goto did_replacement; |
898 | } |
899 | |
900 | /* Special-case plain move instructions, since we may well |
901 | be able to do the move from a different register class. */ |
902 | if (set && REG_P (SET_SRC (set))) |
903 | { |
904 | rtx src = SET_SRC (set); |
905 | rtx dest = SET_DEST (set); |
906 | unsigned int regno = REGNO (src); |
907 | machine_mode mode = GET_MODE (src); |
908 | unsigned int i; |
909 | rtx new_rtx; |
910 | |
911 | /* If we are accessing SRC in some mode other that what we |
912 | set it in, make sure that the replacement is valid. */ |
913 | if (mode != vd->e[regno].mode) |
914 | { |
915 | if (REG_NREGS (src) |
916 | > hard_regno_nregs (regno, mode: vd->e[regno].mode)) |
917 | goto no_move_special_case; |
918 | |
919 | /* And likewise, if we are narrowing on big endian the transformation |
920 | is also invalid. */ |
921 | if (REG_NREGS (src) < hard_regno_nregs (regno, mode: vd->e[regno].mode) |
922 | && maybe_ne (a: subreg_lowpart_offset (outermode: mode, |
923 | innermode: vd->e[regno].mode), b: 0U)) |
924 | goto no_move_special_case; |
925 | } |
926 | |
927 | /* If the destination is also a register, try to find a source |
928 | register in the same class. */ |
929 | if (REG_P (dest)) |
930 | { |
931 | new_rtx = find_oldest_value_reg (REGNO_REG_CLASS (regno), |
932 | reg: src, vd); |
933 | |
934 | if (new_rtx && validate_change (insn, &SET_SRC (set), new_rtx, 0)) |
935 | { |
936 | if (dump_file) |
937 | fprintf (stream: dump_file, |
938 | format: "insn %u: replaced reg %u with %u\n" , |
939 | INSN_UID (insn), regno, REGNO (new_rtx)); |
940 | changed = true; |
941 | goto did_replacement; |
942 | } |
943 | /* We need to re-extract as validate_change clobbers |
944 | recog_data. */ |
945 | extract_constrain_insn (insn); |
946 | preprocess_constraints (insn); |
947 | } |
948 | |
949 | /* Otherwise, try all valid registers and see if its valid. */ |
950 | for (i = vd->e[regno].oldest_regno; i != regno; |
951 | i = vd->e[i].next_regno) |
952 | { |
953 | new_rtx = maybe_mode_change (orig_mode: vd->e[i].mode, copy_mode: vd->e[regno].mode, |
954 | new_mode: mode, regno: i, copy_regno: regno); |
955 | if (new_rtx != NULL_RTX) |
956 | { |
957 | /* Don't propagate for a more expensive reg-reg move. */ |
958 | if (REG_P (dest)) |
959 | { |
960 | enum reg_class from = REGNO_REG_CLASS (regno); |
961 | enum reg_class to = REGNO_REG_CLASS (REGNO (dest)); |
962 | enum reg_class new_from = REGNO_REG_CLASS (i); |
963 | unsigned int original_cost |
964 | = targetm.register_move_cost (mode, from, to); |
965 | unsigned int after_cost |
966 | = targetm.register_move_cost (mode, new_from, to); |
967 | if (after_cost > original_cost) |
968 | continue; |
969 | } |
970 | |
971 | if (validate_change (insn, &SET_SRC (set), new_rtx, 0)) |
972 | { |
973 | /* NEW_RTX may be the global stack pointer rtx, in which |
974 | case we must not modify it's attributes. */ |
975 | if (new_rtx != stack_pointer_rtx) |
976 | { |
977 | ORIGINAL_REGNO (new_rtx) = ORIGINAL_REGNO (src); |
978 | REG_ATTRS (new_rtx) = REG_ATTRS (src); |
979 | REG_POINTER (new_rtx) = REG_POINTER (src); |
980 | } |
981 | if (dump_file) |
982 | fprintf (stream: dump_file, |
983 | format: "insn %u: replaced reg %u with %u\n" , |
984 | INSN_UID (insn), regno, REGNO (new_rtx)); |
985 | changed = true; |
986 | goto did_replacement; |
987 | } |
988 | /* We need to re-extract as validate_change clobbers |
989 | recog_data. */ |
990 | extract_constrain_insn (insn); |
991 | preprocess_constraints (insn); |
992 | } |
993 | } |
994 | } |
995 | no_move_special_case: |
996 | |
997 | any_replacements = false; |
998 | |
999 | /* For each input operand, replace a hard register with the |
1000 | eldest live copy that's in an appropriate register class. */ |
1001 | for (i = 0; i < n_ops; i++) |
1002 | { |
1003 | bool replaced = false; |
1004 | |
1005 | /* Don't scan match_operand here, since we've no reg class |
1006 | information to pass down. Any operands that we could |
1007 | substitute in will be represented elsewhere. */ |
1008 | if (recog_data.constraints[i][0] == '\0') |
1009 | continue; |
1010 | |
1011 | /* Don't replace in asms intentionally referencing hard regs. */ |
1012 | if (is_asm && REG_P (recog_data.operand[i]) |
1013 | && (REGNO (recog_data.operand[i]) |
1014 | == ORIGINAL_REGNO (recog_data.operand[i]))) |
1015 | continue; |
1016 | |
1017 | if (recog_data.operand_type[i] == OP_IN) |
1018 | { |
1019 | if (op_alt[i].is_address) |
1020 | replaced |
1021 | = replace_oldest_value_addr (loc: recog_data.operand_loc[i], |
1022 | cl: alternative_class (alt: op_alt, i), |
1023 | VOIDmode, ADDR_SPACE_GENERIC, |
1024 | insn, vd); |
1025 | else if (REG_P (recog_data.operand[i])) |
1026 | replaced |
1027 | = replace_oldest_value_reg (loc: recog_data.operand_loc[i], |
1028 | cl: alternative_class (alt: op_alt, i), |
1029 | insn, vd); |
1030 | else if (MEM_P (recog_data.operand[i])) |
1031 | replaced = replace_oldest_value_mem (x: recog_data.operand[i], |
1032 | insn, vd); |
1033 | } |
1034 | else if (MEM_P (recog_data.operand[i])) |
1035 | replaced = replace_oldest_value_mem (x: recog_data.operand[i], |
1036 | insn, vd); |
1037 | |
1038 | /* If we performed any replacement, update match_dups. */ |
1039 | if (replaced) |
1040 | { |
1041 | int j; |
1042 | rtx new_rtx; |
1043 | |
1044 | new_rtx = *recog_data.operand_loc[i]; |
1045 | recog_data.operand[i] = new_rtx; |
1046 | for (j = 0; j < recog_data.n_dups; j++) |
1047 | if (recog_data.dup_num[j] == i) |
1048 | validate_unshare_change (insn, recog_data.dup_loc[j], new_rtx, 1); |
1049 | |
1050 | any_replacements = true; |
1051 | } |
1052 | } |
1053 | |
1054 | if (any_replacements) |
1055 | { |
1056 | if (! apply_change_group ()) |
1057 | { |
1058 | if (dump_file) |
1059 | fprintf (stream: dump_file, |
1060 | format: "insn %u: reg replacements not verified\n" , |
1061 | INSN_UID (insn)); |
1062 | } |
1063 | else |
1064 | changed = true; |
1065 | } |
1066 | |
1067 | did_replacement: |
1068 | if (changed) |
1069 | { |
1070 | anything_changed = true; |
1071 | |
1072 | /* If something changed, perhaps further changes to earlier |
1073 | DEBUG_INSNs can be applied. */ |
1074 | if (vd->n_debug_insn_changes) |
1075 | note_uses (&PATTERN (insn), cprop_find_used_regs, vd); |
1076 | df_insn_rescan (insn); |
1077 | } |
1078 | |
1079 | ksvd.vd = vd; |
1080 | ksvd.ignore_set_reg = NULL_RTX; |
1081 | |
1082 | /* Clobber call-clobbered registers. */ |
1083 | if (CALL_P (insn)) |
1084 | { |
1085 | unsigned int set_regno = INVALID_REGNUM; |
1086 | unsigned int set_nregs = 0; |
1087 | unsigned int regno; |
1088 | rtx exp; |
1089 | |
1090 | for (exp = CALL_INSN_FUNCTION_USAGE (insn); exp; exp = XEXP (exp, 1)) |
1091 | { |
1092 | rtx x = XEXP (exp, 0); |
1093 | if (GET_CODE (x) == SET) |
1094 | { |
1095 | rtx dest = SET_DEST (x); |
1096 | kill_value (x: dest, vd); |
1097 | set_value_regno (REGNO (dest), GET_MODE (dest), vd); |
1098 | copy_value (dest, SET_SRC (x), vd); |
1099 | ksvd.ignore_set_reg = dest; |
1100 | set_regno = REGNO (dest); |
1101 | set_nregs = REG_NREGS (dest); |
1102 | break; |
1103 | } |
1104 | } |
1105 | |
1106 | function_abi callee_abi = insn_callee_abi (insn); |
1107 | for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) |
1108 | if (vd->e[regno].mode != VOIDmode |
1109 | && callee_abi.clobbers_reg_p (mode: vd->e[regno].mode, regno) |
1110 | && (regno < set_regno || regno >= set_regno + set_nregs)) |
1111 | kill_value_regno (regno, nregs: 1, vd); |
1112 | |
1113 | /* If SET was seen in CALL_INSN_FUNCTION_USAGE, and SET_SRC |
1114 | of the SET isn't clobbered by CALLEE_ABI, but instead among |
1115 | CLOBBERs on the CALL_INSN, we could wrongly assume the |
1116 | value in it is still live. */ |
1117 | if (ksvd.ignore_set_reg) |
1118 | kill_clobbered_values (insn, vd); |
1119 | } |
1120 | |
1121 | bool copy_p = (set |
1122 | && REG_P (SET_DEST (set)) |
1123 | && REG_P (SET_SRC (set))); |
1124 | bool noop_p = (copy_p |
1125 | && rtx_equal_p (SET_DEST (set), SET_SRC (set))); |
1126 | |
1127 | /* If a noop move is using narrower mode than we have recorded, |
1128 | we need to either remove the noop move, or kill_set_value. */ |
1129 | if (noop_p |
1130 | && partial_subreg_p (GET_MODE (SET_DEST (set)), |
1131 | innermode: vd->e[REGNO (SET_DEST (set))].mode)) |
1132 | { |
1133 | if (noop_move_p (insn)) |
1134 | { |
1135 | bool last = insn == BB_END (bb); |
1136 | delete_insn (insn); |
1137 | if (last) |
1138 | break; |
1139 | } |
1140 | else |
1141 | noop_p = false; |
1142 | } |
1143 | |
1144 | if (!noop_p) |
1145 | { |
1146 | /* Notice stores. */ |
1147 | note_stores (insn, kill_set_value, &ksvd); |
1148 | |
1149 | /* Notice copies. */ |
1150 | if (copy_p) |
1151 | { |
1152 | df_insn_rescan (insn); |
1153 | copy_value (SET_DEST (set), SET_SRC (set), vd); |
1154 | } |
1155 | } |
1156 | |
1157 | if (insn == BB_END (bb)) |
1158 | break; |
1159 | } |
1160 | |
1161 | return anything_changed; |
1162 | } |
1163 | |
1164 | /* Dump the value chain data to stderr. */ |
1165 | |
1166 | DEBUG_FUNCTION void |
1167 | debug_value_data (struct value_data *vd) |
1168 | { |
1169 | HARD_REG_SET set; |
1170 | unsigned int i, j; |
1171 | |
1172 | CLEAR_HARD_REG_SET (set); |
1173 | |
1174 | for (i = 0; i < FIRST_PSEUDO_REGISTER; ++i) |
1175 | if (vd->e[i].oldest_regno == i) |
1176 | { |
1177 | if (vd->e[i].mode == VOIDmode) |
1178 | { |
1179 | if (vd->e[i].next_regno != INVALID_REGNUM) |
1180 | fprintf (stderr, format: "[%u] Bad next_regno for empty chain (%u)\n" , |
1181 | i, vd->e[i].next_regno); |
1182 | continue; |
1183 | } |
1184 | |
1185 | SET_HARD_REG_BIT (set, bit: i); |
1186 | fprintf (stderr, format: "[%u %s] " , i, GET_MODE_NAME (vd->e[i].mode)); |
1187 | |
1188 | for (j = vd->e[i].next_regno; |
1189 | j != INVALID_REGNUM; |
1190 | j = vd->e[j].next_regno) |
1191 | { |
1192 | if (TEST_HARD_REG_BIT (set, bit: j)) |
1193 | { |
1194 | fprintf (stderr, format: "[%u] Loop in regno chain\n" , j); |
1195 | return; |
1196 | } |
1197 | |
1198 | if (vd->e[j].oldest_regno != i) |
1199 | { |
1200 | fprintf (stderr, format: "[%u] Bad oldest_regno (%u)\n" , |
1201 | j, vd->e[j].oldest_regno); |
1202 | return; |
1203 | } |
1204 | SET_HARD_REG_BIT (set, bit: j); |
1205 | fprintf (stderr, format: "[%u %s] " , j, GET_MODE_NAME (vd->e[j].mode)); |
1206 | } |
1207 | fputc (c: '\n', stderr); |
1208 | } |
1209 | |
1210 | for (i = 0; i < FIRST_PSEUDO_REGISTER; ++i) |
1211 | if (! TEST_HARD_REG_BIT (set, bit: i) |
1212 | && (vd->e[i].mode != VOIDmode |
1213 | || vd->e[i].oldest_regno != i |
1214 | || vd->e[i].next_regno != INVALID_REGNUM)) |
1215 | fprintf (stderr, format: "[%u] Non-empty reg in chain (%s %u %i)\n" , |
1216 | i, GET_MODE_NAME (vd->e[i].mode), vd->e[i].oldest_regno, |
1217 | vd->e[i].next_regno); |
1218 | } |
1219 | |
1220 | /* Do copyprop_hardreg_forward_1 for a single basic block BB. |
1221 | DEBUG_INSN is skipped since we do not want to involve DF related |
1222 | staff as how it is handled in function pass_cprop_hardreg::execute. |
1223 | |
1224 | NOTE: Currently it is only used for shrink-wrap. Maybe extend it |
1225 | to handle DEBUG_INSN for other uses. */ |
1226 | |
1227 | void |
1228 | copyprop_hardreg_forward_bb_without_debug_insn (basic_block bb) |
1229 | { |
1230 | struct value_data *vd; |
1231 | vd = XNEWVEC (struct value_data, 1); |
1232 | init_value_data (vd); |
1233 | |
1234 | skip_debug_insn_p = true; |
1235 | copyprop_hardreg_forward_1 (bb, vd); |
1236 | free (ptr: vd); |
1237 | skip_debug_insn_p = false; |
1238 | } |
1239 | |
1240 | static void |
1241 | validate_value_data (struct value_data *vd) |
1242 | { |
1243 | HARD_REG_SET set; |
1244 | unsigned int i, j; |
1245 | |
1246 | CLEAR_HARD_REG_SET (set); |
1247 | |
1248 | for (i = 0; i < FIRST_PSEUDO_REGISTER; ++i) |
1249 | if (vd->e[i].oldest_regno == i) |
1250 | { |
1251 | if (vd->e[i].mode == VOIDmode) |
1252 | { |
1253 | if (vd->e[i].next_regno != INVALID_REGNUM) |
1254 | internal_error ("%qs: [%u] bad %<next_regno%> for empty chain (%u)" , |
1255 | __func__, i, vd->e[i].next_regno); |
1256 | continue; |
1257 | } |
1258 | |
1259 | SET_HARD_REG_BIT (set, bit: i); |
1260 | |
1261 | for (j = vd->e[i].next_regno; |
1262 | j != INVALID_REGNUM; |
1263 | j = vd->e[j].next_regno) |
1264 | { |
1265 | if (TEST_HARD_REG_BIT (set, bit: j)) |
1266 | internal_error ("%qs: loop in %<next_regno%> chain (%u)" , |
1267 | __func__, j); |
1268 | if (vd->e[j].oldest_regno != i) |
1269 | internal_error ("%qs: [%u] bad %<oldest_regno%> (%u)" , |
1270 | __func__, j, vd->e[j].oldest_regno); |
1271 | |
1272 | SET_HARD_REG_BIT (set, bit: j); |
1273 | } |
1274 | } |
1275 | |
1276 | for (i = 0; i < FIRST_PSEUDO_REGISTER; ++i) |
1277 | if (! TEST_HARD_REG_BIT (set, bit: i) |
1278 | && (vd->e[i].mode != VOIDmode |
1279 | || vd->e[i].oldest_regno != i |
1280 | || vd->e[i].next_regno != INVALID_REGNUM)) |
1281 | internal_error ("%qs: [%u] non-empty register in chain (%s %u %i)" , |
1282 | __func__, i, |
1283 | GET_MODE_NAME (vd->e[i].mode), vd->e[i].oldest_regno, |
1284 | vd->e[i].next_regno); |
1285 | } |
1286 | |
1287 | |
1288 | namespace { |
1289 | |
1290 | const pass_data pass_data_cprop_hardreg = |
1291 | { |
1292 | .type: RTL_PASS, /* type */ |
1293 | .name: "cprop_hardreg" , /* name */ |
1294 | .optinfo_flags: OPTGROUP_NONE, /* optinfo_flags */ |
1295 | .tv_id: TV_CPROP_REGISTERS, /* tv_id */ |
1296 | .properties_required: 0, /* properties_required */ |
1297 | .properties_provided: 0, /* properties_provided */ |
1298 | .properties_destroyed: 0, /* properties_destroyed */ |
1299 | .todo_flags_start: 0, /* todo_flags_start */ |
1300 | TODO_df_finish, /* todo_flags_finish */ |
1301 | }; |
1302 | |
1303 | class pass_cprop_hardreg : public rtl_opt_pass |
1304 | { |
1305 | public: |
1306 | pass_cprop_hardreg (gcc::context *ctxt) |
1307 | : rtl_opt_pass (pass_data_cprop_hardreg, ctxt) |
1308 | {} |
1309 | |
1310 | /* opt_pass methods: */ |
1311 | bool gate (function *) final override |
1312 | { |
1313 | return (optimize > 0 && (flag_cprop_registers)); |
1314 | } |
1315 | |
1316 | unsigned int execute (function *) final override; |
1317 | |
1318 | }; // class pass_cprop_hardreg |
1319 | |
1320 | static bool |
1321 | cprop_hardreg_bb (basic_block bb, struct value_data *all_vd, sbitmap visited) |
1322 | { |
1323 | bitmap_set_bit (map: visited, bitno: bb->index); |
1324 | |
1325 | /* If a block has a single predecessor, that we've already |
1326 | processed, begin with the value data that was live at |
1327 | the end of the predecessor block. */ |
1328 | /* ??? Ought to use more intelligent queuing of blocks. */ |
1329 | if (single_pred_p (bb) |
1330 | && bitmap_bit_p (map: visited, bitno: single_pred (bb)->index) |
1331 | && ! (single_pred_edge (bb)->flags & (EDGE_ABNORMAL_CALL | EDGE_EH))) |
1332 | { |
1333 | all_vd[bb->index] = all_vd[single_pred (bb)->index]; |
1334 | if (all_vd[bb->index].n_debug_insn_changes) |
1335 | { |
1336 | unsigned int regno; |
1337 | |
1338 | for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) |
1339 | { |
1340 | if (all_vd[bb->index].e[regno].debug_insn_changes) |
1341 | { |
1342 | struct queued_debug_insn_change *cur; |
1343 | for (cur = all_vd[bb->index].e[regno].debug_insn_changes; |
1344 | cur; cur = cur->next) |
1345 | --all_vd[bb->index].n_debug_insn_changes; |
1346 | all_vd[bb->index].e[regno].debug_insn_changes = NULL; |
1347 | if (all_vd[bb->index].n_debug_insn_changes == 0) |
1348 | break; |
1349 | } |
1350 | } |
1351 | } |
1352 | } |
1353 | else |
1354 | init_value_data (vd: all_vd + bb->index); |
1355 | |
1356 | return copyprop_hardreg_forward_1 (bb, vd: all_vd + bb->index); |
1357 | } |
1358 | |
1359 | static void |
1360 | cprop_hardreg_debug (function *fun, struct value_data *all_vd) |
1361 | { |
1362 | basic_block bb; |
1363 | |
1364 | FOR_EACH_BB_FN (bb, fun) |
1365 | if (all_vd[bb->index].n_debug_insn_changes) |
1366 | { |
1367 | unsigned int regno; |
1368 | bitmap live; |
1369 | |
1370 | live = df_get_live_out (bb); |
1371 | for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) |
1372 | if (all_vd[bb->index].e[regno].debug_insn_changes) |
1373 | { |
1374 | if (REGNO_REG_SET_P (live, regno)) |
1375 | apply_debug_insn_changes (vd: all_vd + bb->index, regno); |
1376 | |
1377 | struct queued_debug_insn_change *cur; |
1378 | for (cur = all_vd[bb->index].e[regno].debug_insn_changes; |
1379 | cur; cur = cur->next) |
1380 | --all_vd[bb->index].n_debug_insn_changes; |
1381 | all_vd[bb->index].e[regno].debug_insn_changes = NULL; |
1382 | if (all_vd[bb->index].n_debug_insn_changes == 0) |
1383 | break; |
1384 | } |
1385 | } |
1386 | |
1387 | queued_debug_insn_change_pool.release (); |
1388 | } |
1389 | |
1390 | unsigned int |
1391 | pass_cprop_hardreg::execute (function *fun) |
1392 | { |
1393 | struct value_data *all_vd; |
1394 | basic_block bb; |
1395 | |
1396 | all_vd = XNEWVEC (struct value_data, last_basic_block_for_fn (fun)); |
1397 | |
1398 | auto_sbitmap visited (last_basic_block_for_fn (fun)); |
1399 | bitmap_clear (visited); |
1400 | |
1401 | auto_vec<int> worklist1, worklist2; |
1402 | auto_vec<int> *curr = &worklist1; |
1403 | auto_vec<int> *next = &worklist2; |
1404 | bool any_debug_changes = false; |
1405 | |
1406 | /* We need accurate notes. Earlier passes such as if-conversion may |
1407 | leave notes in an inconsistent state. */ |
1408 | df_note_add_problem (); |
1409 | df_analyze (); |
1410 | |
1411 | /* It is tempting to set DF_LR_RUN_DCE, but DCE may choose to delete |
1412 | an insn and this pass would not have visibility into the removal. |
1413 | This pass would then potentially use the source of that |
1414 | INSN for propagation purposes, generating invalid code. |
1415 | |
1416 | So we just ask for updated notes and handle trivial deletions |
1417 | within this pass where we can update this passes internal |
1418 | data structures appropriately. */ |
1419 | df_set_flags (DF_DEFER_INSN_RESCAN); |
1420 | |
1421 | FOR_EACH_BB_FN (bb, fun) |
1422 | { |
1423 | if (cprop_hardreg_bb (bb, all_vd, visited)) |
1424 | curr->safe_push (obj: bb->index); |
1425 | if (all_vd[bb->index].n_debug_insn_changes) |
1426 | any_debug_changes = true; |
1427 | } |
1428 | |
1429 | /* We must call df_analyze here unconditionally to ensure that the |
1430 | REG_UNUSED and REG_DEAD notes are consistent with and without -g. */ |
1431 | df_analyze (); |
1432 | |
1433 | if (MAY_HAVE_DEBUG_BIND_INSNS && any_debug_changes) |
1434 | cprop_hardreg_debug (fun, all_vd); |
1435 | |
1436 | /* Repeat pass up to PASSES times, but only processing basic blocks |
1437 | that have changed on the previous iteration. CURR points to the |
1438 | current worklist, and each iteration populates the NEXT worklist, |
1439 | swapping pointers after each cycle. */ |
1440 | |
1441 | unsigned int passes = optimize > 1 ? 3 : 2; |
1442 | for (unsigned int pass = 2; pass <= passes && !curr->is_empty (); pass++) |
1443 | { |
1444 | any_debug_changes = false; |
1445 | bitmap_clear (visited); |
1446 | next->truncate (size: 0); |
1447 | for (int index : *curr) |
1448 | { |
1449 | bb = BASIC_BLOCK_FOR_FN (fun, index); |
1450 | if (cprop_hardreg_bb (bb, all_vd, visited)) |
1451 | next->safe_push (obj: bb->index); |
1452 | if (all_vd[bb->index].n_debug_insn_changes) |
1453 | any_debug_changes = true; |
1454 | } |
1455 | |
1456 | df_analyze (); |
1457 | if (MAY_HAVE_DEBUG_BIND_INSNS && any_debug_changes) |
1458 | cprop_hardreg_debug (fun, all_vd); |
1459 | std::swap (a&: curr, b&: next); |
1460 | } |
1461 | |
1462 | free (ptr: all_vd); |
1463 | return 0; |
1464 | } |
1465 | |
1466 | } // anon namespace |
1467 | |
1468 | rtl_opt_pass * |
1469 | make_pass_cprop_hardreg (gcc::context *ctxt) |
1470 | { |
1471 | return new pass_cprop_hardreg (ctxt); |
1472 | } |
1473 | |