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6fb5fa3c | 1 | /* Scanning of rtl for dataflow analysis. |
7adcbafe | 2 | Copyright (C) 2007-2022 Free Software Foundation, Inc. |
6fb5fa3c DB |
3 | Contributed by Kenneth Zadeck (zadeck@naturalbridge.com). |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it under | |
8 | the terms of the GNU General Public License as published by the Free | |
9dcd6f09 | 9 | Software Foundation; either version 3, or (at your option) any later |
6fb5fa3c DB |
10 | version. |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
6fb5fa3c DB |
20 | |
21 | ||
22 | #include "config.h" | |
23 | #include "system.h" | |
24 | #include "coretypes.h" | |
c7131fb2 | 25 | #include "backend.h" |
6fb5fa3c | 26 | #include "rtl.h" |
957060b5 | 27 | #include "predict.h" |
c7131fb2 | 28 | #include "df.h" |
6fb5fa3c | 29 | #include "regs.h" |
6fb5fa3c DB |
30 | |
31 | ||
6fb5fa3c DB |
32 | struct regstat_n_sets_and_refs_t *regstat_n_sets_and_refs; |
33 | ||
34 | /*---------------------------------------------------------------------------- | |
b8698a0f | 35 | REG_N_SETS and REG_N_REFS. |
6fb5fa3c DB |
36 | ----------------------------------------------------------------------------*/ |
37 | ||
dd5a833e | 38 | /* If a pass need to change these values in some magical way or the |
6fb5fa3c DB |
39 | pass needs to have accurate values for these and is not using |
40 | incremental df scanning, then it should use REG_N_SETS and | |
41 | REG_N_USES. If the pass is doing incremental scanning then it | |
42 | should be getting the info from DF_REG_DEF_COUNT and | |
43 | DF_REG_USE_COUNT. */ | |
44 | ||
45 | void | |
46 | regstat_init_n_sets_and_refs (void) | |
47 | { | |
48 | unsigned int i; | |
49 | unsigned int max_regno = max_reg_num (); | |
50 | ||
51 | timevar_push (TV_REG_STATS); | |
52 | df_grow_reg_info (); | |
53 | gcc_assert (!regstat_n_sets_and_refs); | |
54 | ||
1634b18f | 55 | regstat_n_sets_and_refs = XNEWVEC (struct regstat_n_sets_and_refs_t, max_regno); |
6fb5fa3c | 56 | |
36f52e8f | 57 | if (MAY_HAVE_DEBUG_BIND_INSNS) |
b5b8b0ac AO |
58 | for (i = 0; i < max_regno; i++) |
59 | { | |
60 | int use_count; | |
61 | df_ref use; | |
62 | ||
63 | use_count = DF_REG_USE_COUNT (i); | |
64 | for (use = DF_REG_USE_CHAIN (i); use; use = DF_REF_NEXT_REG (use)) | |
65 | if (DF_REF_INSN_INFO (use) && DEBUG_INSN_P (DF_REF_INSN (use))) | |
66 | use_count--; | |
67 | ||
68 | ||
69 | SET_REG_N_SETS (i, DF_REG_DEF_COUNT (i)); | |
70 | SET_REG_N_REFS (i, use_count + REG_N_SETS (i)); | |
71 | } | |
72 | else | |
73 | for (i = 0; i < max_regno; i++) | |
74 | { | |
75 | SET_REG_N_SETS (i, DF_REG_DEF_COUNT (i)); | |
76 | SET_REG_N_REFS (i, DF_REG_USE_COUNT (i) + REG_N_SETS (i)); | |
77 | } | |
6fb5fa3c DB |
78 | timevar_pop (TV_REG_STATS); |
79 | ||
80 | } | |
81 | ||
82 | ||
83 | /* Free the array that holds the REG_N_SETS and REG_N_REFS. */ | |
84 | ||
85 | void | |
86 | regstat_free_n_sets_and_refs (void) | |
87 | { | |
88 | gcc_assert (regstat_n_sets_and_refs); | |
89 | free (regstat_n_sets_and_refs); | |
90 | regstat_n_sets_and_refs = NULL; | |
91 | } | |
92 | ||
93 | ||
94 | /*---------------------------------------------------------------------------- | |
95 | REGISTER INFORMATION | |
96 | ||
725842d0 | 97 | Process REG_N_DEATHS, REG_N_CALLS_CROSSED, and REG_BASIC_BLOCK. |
6fb5fa3c DB |
98 | |
99 | ----------------------------------------------------------------------------*/ | |
100 | ||
101 | static bitmap setjmp_crosses; | |
102 | struct reg_info_t *reg_info_p; | |
103 | ||
104 | /* The number allocated elements of reg_info_p. */ | |
105 | size_t reg_info_p_size; | |
106 | ||
107 | /* Compute register info: lifetime, bb, and number of defs and uses | |
91dabbb2 | 108 | for basic block BB. LIVE is a scratch bitvector used here. */ |
6fb5fa3c DB |
109 | |
110 | static void | |
91dabbb2 | 111 | regstat_bb_compute_ri (basic_block bb, bitmap live) |
6fb5fa3c | 112 | { |
7839a073 | 113 | rtx_insn *insn; |
bfac633a | 114 | df_ref def, use; |
6fb5fa3c DB |
115 | bitmap_iterator bi; |
116 | unsigned int regno; | |
117 | ||
118 | bitmap_copy (live, df_get_live_out (bb)); | |
6fb5fa3c DB |
119 | |
120 | /* Process the regs live at the end of the block. Mark them as | |
121 | not local to any one basic block. */ | |
122 | EXECUTE_IF_SET_IN_BITMAP (live, 0, regno, bi) | |
123 | REG_BASIC_BLOCK (regno) = REG_BLOCK_GLOBAL; | |
124 | ||
125 | /* Process the artificial defs and uses at the bottom of the block | |
126 | to begin processing. */ | |
91dabbb2 | 127 | FOR_EACH_ARTIFICIAL_DEF (def, bb->index) |
292321a5 RS |
128 | if ((DF_REF_FLAGS (def) & DF_REF_AT_TOP) == 0) |
129 | bitmap_clear_bit (live, DF_REF_REGNO (def)); | |
6fb5fa3c | 130 | |
91dabbb2 | 131 | FOR_EACH_ARTIFICIAL_USE (use, bb->index) |
292321a5 RS |
132 | if ((DF_REF_FLAGS (use) & DF_REF_AT_TOP) == 0) |
133 | { | |
134 | regno = DF_REF_REGNO (use); | |
135 | bitmap_set_bit (live, regno); | |
292321a5 | 136 | } |
b8698a0f | 137 | |
6fb5fa3c DB |
138 | FOR_BB_INSNS_REVERSE (bb, insn) |
139 | { | |
bfac633a | 140 | struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn); |
6fb5fa3c | 141 | bitmap_iterator bi; |
6fb5fa3c | 142 | rtx link; |
b8698a0f | 143 | |
b5b8b0ac | 144 | if (!NONDEBUG_INSN_P (insn)) |
6fb5fa3c DB |
145 | continue; |
146 | ||
6fb5fa3c DB |
147 | link = REG_NOTES (insn); |
148 | while (link) | |
149 | { | |
150 | if (REG_NOTE_KIND (link) == REG_DEAD) | |
c3284718 | 151 | REG_N_DEATHS (REGNO (XEXP (link, 0)))++; |
6fb5fa3c DB |
152 | link = XEXP (link, 1); |
153 | } | |
154 | ||
155 | /* Process the defs. */ | |
156 | if (CALL_P (insn)) | |
157 | { | |
6fb5fa3c DB |
158 | bool set_jump = (find_reg_note (insn, REG_SETJMP, NULL) != NULL); |
159 | EXECUTE_IF_SET_IN_BITMAP (live, 0, regno, bi) | |
160 | { | |
161 | REG_N_CALLS_CROSSED (regno)++; | |
b8698a0f | 162 | |
6fb5fa3c DB |
163 | /* We have a problem with any pseudoreg that lives |
164 | across the setjmp. ANSI says that if a user variable | |
165 | does not change in value between the setjmp and the | |
166 | longjmp, then the longjmp preserves it. This | |
167 | includes longjmp from a place where the pseudo | |
168 | appears dead. (In principle, the value still exists | |
169 | if it is in scope.) If the pseudo goes in a hard | |
170 | reg, some other value may occupy that hard reg where | |
171 | this pseudo is dead, thus clobbering the pseudo. | |
172 | Conclusion: such a pseudo must not go in a hard | |
173 | reg. */ | |
174 | if (set_jump) | |
175 | bitmap_set_bit (setjmp_crosses, regno); | |
176 | } | |
177 | } | |
b8698a0f | 178 | |
6fb5fa3c DB |
179 | /* All of the defs except the return value are some sort of |
180 | clobber. This code is for the return. */ | |
bfac633a | 181 | FOR_EACH_INSN_INFO_DEF (def, insn_info) |
6fb5fa3c | 182 | { |
6fb5fa3c | 183 | if ((!CALL_P (insn)) |
91dabbb2 AM |
184 | || (!(DF_REF_FLAGS (def) |
185 | & (DF_REF_MUST_CLOBBER | DF_REF_MAY_CLOBBER)))) | |
6fb5fa3c DB |
186 | { |
187 | unsigned int dregno = DF_REF_REGNO (def); | |
b8698a0f | 188 | |
91dabbb2 AM |
189 | /* Kill this register if it is not a subreg store or |
190 | conditional store. | |
191 | ??? This means that any partial store is live from | |
192 | the last use in a basic block to the start of this | |
193 | basic block. */ | |
194 | if (!(DF_REF_FLAGS (def) | |
195 | & (DF_REF_PARTIAL | DF_REF_CONDITIONAL))) | |
196 | bitmap_clear_bit (live, dregno); | |
b8698a0f | 197 | |
6fb5fa3c DB |
198 | if (dregno >= FIRST_PSEUDO_REGISTER) |
199 | { | |
200 | REG_FREQ (dregno) += REG_FREQ_FROM_BB (bb); | |
8e6acdb8 SB |
201 | REG_FREQ (dregno) = |
202 | MIN (REG_FREQ (dregno), REG_FREQ_MAX); | |
203 | ||
6fb5fa3c DB |
204 | if (REG_BASIC_BLOCK (dregno) == REG_BLOCK_UNKNOWN) |
205 | REG_BASIC_BLOCK (dregno) = bb->index; | |
206 | else if (REG_BASIC_BLOCK (dregno) != bb->index) | |
207 | REG_BASIC_BLOCK (dregno) = REG_BLOCK_GLOBAL; | |
208 | } | |
6fb5fa3c DB |
209 | } |
210 | } | |
b8698a0f | 211 | |
bfac633a | 212 | FOR_EACH_INSN_INFO_USE (use, insn_info) |
6fb5fa3c | 213 | { |
6fb5fa3c DB |
214 | unsigned int uregno = DF_REF_REGNO (use); |
215 | ||
216 | if (uregno >= FIRST_PSEUDO_REGISTER) | |
217 | { | |
218 | REG_FREQ (uregno) += REG_FREQ_FROM_BB (bb); | |
8e6acdb8 SB |
219 | REG_FREQ (uregno) = |
220 | MIN (REG_FREQ (uregno), REG_FREQ_MAX); | |
221 | ||
6fb5fa3c DB |
222 | if (REG_BASIC_BLOCK (uregno) == REG_BLOCK_UNKNOWN) |
223 | REG_BASIC_BLOCK (uregno) = bb->index; | |
224 | else if (REG_BASIC_BLOCK (uregno) != bb->index) | |
225 | REG_BASIC_BLOCK (uregno) = REG_BLOCK_GLOBAL; | |
226 | } | |
6fb5fa3c DB |
227 | } |
228 | } | |
6fb5fa3c DB |
229 | } |
230 | ||
231 | ||
232 | /* Compute register info: lifetime, bb, and number of defs and uses. */ | |
233 | void | |
234 | regstat_compute_ri (void) | |
235 | { | |
236 | basic_block bb; | |
237 | bitmap live = BITMAP_ALLOC (&df_bitmap_obstack); | |
6fb5fa3c DB |
238 | unsigned int regno; |
239 | bitmap_iterator bi; | |
240 | ||
241 | /* Initialize everything. */ | |
242 | ||
243 | gcc_assert (!reg_info_p); | |
244 | ||
245 | timevar_push (TV_REG_STATS); | |
246 | setjmp_crosses = BITMAP_ALLOC (&df_bitmap_obstack); | |
247 | max_regno = max_reg_num (); | |
248 | reg_info_p_size = max_regno; | |
1634b18f | 249 | reg_info_p = XCNEWVEC (struct reg_info_t, max_regno); |
6fb5fa3c | 250 | |
11cd3bed | 251 | FOR_EACH_BB_FN (bb, cfun) |
6fb5fa3c | 252 | { |
91dabbb2 | 253 | regstat_bb_compute_ri (bb, live); |
6fb5fa3c DB |
254 | } |
255 | ||
256 | BITMAP_FREE (live); | |
6fb5fa3c | 257 | |
aeb9f7cf | 258 | /* See the setjmp comment in regstat_bb_compute_ri. */ |
6fb5fa3c DB |
259 | EXECUTE_IF_SET_IN_BITMAP (setjmp_crosses, FIRST_PSEUDO_REGISTER, regno, bi) |
260 | { | |
261 | REG_BASIC_BLOCK (regno) = REG_BLOCK_UNKNOWN; | |
b8698a0f L |
262 | } |
263 | ||
6fb5fa3c DB |
264 | timevar_pop (TV_REG_STATS); |
265 | } | |
266 | ||
267 | ||
268 | /* Free all storage associated with the problem. */ | |
269 | ||
270 | void | |
271 | regstat_free_ri (void) | |
272 | { | |
273 | gcc_assert (reg_info_p); | |
274 | reg_info_p_size = 0; | |
b8698a0f | 275 | free (reg_info_p); |
6fb5fa3c DB |
276 | reg_info_p = NULL; |
277 | ||
278 | BITMAP_FREE (setjmp_crosses); | |
279 | } | |
280 | ||
281 | ||
b8698a0f | 282 | /* Return a bitmap containing the set of registers that cross a setjmp. |
6fb5fa3c DB |
283 | The client should not change or delete this bitmap. */ |
284 | ||
285 | bitmap | |
286 | regstat_get_setjmp_crosses (void) | |
287 | { | |
288 | return setjmp_crosses; | |
289 | } | |
290 | ||
291 | /*---------------------------------------------------------------------------- | |
b8698a0f | 292 | Process REG_N_CALLS_CROSSED. |
6fb5fa3c DB |
293 | |
294 | This is used by sched_deps. A good implementation of sched-deps | |
cea618ac | 295 | would really process the blocks directly rather than going through |
6fb5fa3c DB |
296 | lists of insns. If it did this, it could use the exact regs that |
297 | cross an individual call rather than using this info that merges | |
298 | the info for all calls. | |
299 | ||
300 | ----------------------------------------------------------------------------*/ | |
301 | ||
302 | ||
303 | ||
0d52bcc1 | 304 | /* Compute calls crossed for BB. Live is a scratch bitvector. */ |
6fb5fa3c DB |
305 | |
306 | static void | |
307 | regstat_bb_compute_calls_crossed (unsigned int bb_index, bitmap live) | |
308 | { | |
06e28de2 | 309 | basic_block bb = BASIC_BLOCK_FOR_FN (cfun, bb_index); |
7839a073 | 310 | rtx_insn *insn; |
bfac633a | 311 | df_ref def, use; |
6fb5fa3c DB |
312 | |
313 | bitmap_copy (live, df_get_live_out (bb)); | |
314 | ||
315 | /* Process the artificial defs and uses at the bottom of the block | |
316 | to begin processing. */ | |
292321a5 RS |
317 | FOR_EACH_ARTIFICIAL_DEF (def, bb_index) |
318 | if ((DF_REF_FLAGS (def) & DF_REF_AT_TOP) == 0) | |
319 | bitmap_clear_bit (live, DF_REF_REGNO (def)); | |
6fb5fa3c | 320 | |
292321a5 RS |
321 | FOR_EACH_ARTIFICIAL_USE (use, bb_index) |
322 | if ((DF_REF_FLAGS (use) & DF_REF_AT_TOP) == 0) | |
323 | bitmap_set_bit (live, DF_REF_REGNO (use)); | |
b8698a0f | 324 | |
6fb5fa3c DB |
325 | FOR_BB_INSNS_REVERSE (bb, insn) |
326 | { | |
5e72bcc1 JJ |
327 | if (!NONDEBUG_INSN_P (insn)) |
328 | continue; | |
329 | ||
e6130412 | 330 | gcc_assert (INSN_UID (insn) < (int) DF_INSN_SIZE ()); |
bfac633a | 331 | struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn); |
6fb5fa3c | 332 | unsigned int regno; |
b8698a0f | 333 | |
6fb5fa3c DB |
334 | /* Process the defs. */ |
335 | if (CALL_P (insn)) | |
336 | { | |
337 | bitmap_iterator bi; | |
338 | EXECUTE_IF_SET_IN_BITMAP (live, 0, regno, bi) | |
a03c6d64 JH |
339 | { |
340 | REG_N_CALLS_CROSSED (regno)++; | |
a03c6d64 | 341 | } |
6fb5fa3c | 342 | } |
b8698a0f | 343 | |
6fb5fa3c DB |
344 | /* All of the defs except the return value are some sort of |
345 | clobber. This code is for the return. */ | |
bfac633a | 346 | FOR_EACH_INSN_INFO_DEF (def, insn_info) |
6fb5fa3c | 347 | { |
6fb5fa3c DB |
348 | if ((!CALL_P (insn)) |
349 | || (!(DF_REF_FLAGS (def) & (DF_REF_MUST_CLOBBER | DF_REF_MAY_CLOBBER)))) | |
350 | { | |
351 | /* Kill this register if it is not a subreg store or conditional store. */ | |
352 | if (!(DF_REF_FLAGS (def) & (DF_REF_PARTIAL | DF_REF_CONDITIONAL))) | |
353 | bitmap_clear_bit (live, DF_REF_REGNO (def)); | |
354 | } | |
355 | } | |
b8698a0f | 356 | |
bfac633a RS |
357 | FOR_EACH_INSN_INFO_USE (use, insn_info) |
358 | bitmap_set_bit (live, DF_REF_REGNO (use)); | |
6fb5fa3c DB |
359 | } |
360 | } | |
361 | ||
362 | ||
363 | /* Compute register info: lifetime, bb, and number of defs and uses. */ | |
364 | void | |
365 | regstat_compute_calls_crossed (void) | |
366 | { | |
367 | basic_block bb; | |
368 | bitmap live = BITMAP_ALLOC (&df_bitmap_obstack); | |
369 | ||
370 | /* Initialize everything. */ | |
371 | gcc_assert (!reg_info_p); | |
372 | ||
373 | timevar_push (TV_REG_STATS); | |
374 | max_regno = max_reg_num (); | |
375 | reg_info_p_size = max_regno; | |
1634b18f | 376 | reg_info_p = XCNEWVEC (struct reg_info_t, max_regno); |
6fb5fa3c | 377 | |
11cd3bed | 378 | FOR_EACH_BB_FN (bb, cfun) |
6fb5fa3c DB |
379 | { |
380 | regstat_bb_compute_calls_crossed (bb->index, live); | |
381 | } | |
382 | ||
383 | BITMAP_FREE (live); | |
384 | timevar_pop (TV_REG_STATS); | |
385 | } | |
386 | ||
387 | ||
388 | /* Free all storage associated with the problem. */ | |
389 | ||
390 | void | |
391 | regstat_free_calls_crossed (void) | |
392 | { | |
393 | gcc_assert (reg_info_p); | |
394 | reg_info_p_size = 0; | |
b8698a0f | 395 | free (reg_info_p); |
6fb5fa3c DB |
396 | reg_info_p = NULL; |
397 | } | |
398 | ||
532aafad SB |
399 | /* Dump the register info to FILE. */ |
400 | ||
401 | void | |
402 | dump_reg_info (FILE *file) | |
403 | { | |
404 | unsigned int i, max = max_reg_num (); | |
405 | if (reload_completed) | |
406 | return; | |
407 | ||
408 | if (reg_info_p_size < max) | |
409 | max = reg_info_p_size; | |
410 | ||
411 | fprintf (file, "%d registers.\n", max); | |
412 | for (i = FIRST_PSEUDO_REGISTER; i < max; i++) | |
413 | { | |
414 | enum reg_class rclass, altclass; | |
415 | ||
416 | if (regstat_n_sets_and_refs) | |
91dabbb2 AM |
417 | fprintf (file, "\nRegister %d used %d times", |
418 | i, REG_N_REFS (i)); | |
532aafad | 419 | else if (df) |
91dabbb2 AM |
420 | fprintf (file, "\nRegister %d used %d times", |
421 | i, DF_REG_USE_COUNT (i) + DF_REG_DEF_COUNT (i)); | |
532aafad SB |
422 | |
423 | if (REG_BASIC_BLOCK (i) >= NUM_FIXED_BLOCKS) | |
424 | fprintf (file, " in block %d", REG_BASIC_BLOCK (i)); | |
425 | if (regstat_n_sets_and_refs) | |
426 | fprintf (file, "; set %d time%s", REG_N_SETS (i), | |
427 | (REG_N_SETS (i) == 1) ? "" : "s"); | |
428 | else if (df) | |
429 | fprintf (file, "; set %d time%s", DF_REG_DEF_COUNT (i), | |
430 | (DF_REG_DEF_COUNT (i) == 1) ? "" : "s"); | |
431 | if (regno_reg_rtx[i] != NULL && REG_USERVAR_P (regno_reg_rtx[i])) | |
432 | fputs ("; user var", file); | |
433 | if (REG_N_DEATHS (i) != 1) | |
434 | fprintf (file, "; dies in %d places", REG_N_DEATHS (i)); | |
435 | if (REG_N_CALLS_CROSSED (i) == 1) | |
436 | fputs ("; crosses 1 call", file); | |
437 | else if (REG_N_CALLS_CROSSED (i)) | |
438 | fprintf (file, "; crosses %d calls", REG_N_CALLS_CROSSED (i)); | |
532aafad | 439 | if (regno_reg_rtx[i] != NULL |
cf098191 RS |
440 | && maybe_ne (PSEUDO_REGNO_BYTES (i), UNITS_PER_WORD)) |
441 | { | |
442 | fprintf (file, "; "); | |
443 | print_dec (PSEUDO_REGNO_BYTES (i), file, SIGNED); | |
444 | fprintf (file, " bytes"); | |
445 | } | |
532aafad SB |
446 | |
447 | rclass = reg_preferred_class (i); | |
448 | altclass = reg_alternate_class (i); | |
449 | if (rclass != GENERAL_REGS || altclass != ALL_REGS) | |
450 | { | |
451 | if (altclass == ALL_REGS || rclass == ALL_REGS) | |
452 | fprintf (file, "; pref %s", reg_class_names[(int) rclass]); | |
453 | else if (altclass == NO_REGS) | |
454 | fprintf (file, "; %s or none", reg_class_names[(int) rclass]); | |
455 | else | |
456 | fprintf (file, "; pref %s, else %s", | |
457 | reg_class_names[(int) rclass], | |
458 | reg_class_names[(int) altclass]); | |
459 | } | |
460 | ||
461 | if (regno_reg_rtx[i] != NULL && REG_POINTER (regno_reg_rtx[i])) | |
462 | fputs ("; pointer", file); | |
463 | fputs (".\n", file); | |
464 | } | |
465 | } | |
466 |