1 /* Scanning of rtl for dataflow analysis.
2 Copyright (C) 2007-2022 Free Software Foundation, Inc.
3 Contributed by Kenneth Zadeck (zadeck@naturalbridge.com).
5 This file is part of GCC.
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
9 Software Foundation; either version 3, or (at your option) any later
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
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/>. */
24 #include "coretypes.h"
32 struct regstat_n_sets_and_refs_t
*regstat_n_sets_and_refs
;
34 /*----------------------------------------------------------------------------
35 REG_N_SETS and REG_N_REFS.
36 ----------------------------------------------------------------------------*/
38 /* If a pass need to change these values in some magical way or the
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
46 regstat_init_n_sets_and_refs (void)
49 unsigned int max_regno
= max_reg_num ();
51 timevar_push (TV_REG_STATS
);
53 gcc_assert (!regstat_n_sets_and_refs
);
55 regstat_n_sets_and_refs
= XNEWVEC (struct regstat_n_sets_and_refs_t
, max_regno
);
57 if (MAY_HAVE_DEBUG_BIND_INSNS
)
58 for (i
= 0; i
< max_regno
; i
++)
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
)))
69 SET_REG_N_SETS (i
, DF_REG_DEF_COUNT (i
));
70 SET_REG_N_REFS (i
, use_count
+ REG_N_SETS (i
));
73 for (i
= 0; i
< max_regno
; i
++)
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
));
78 timevar_pop (TV_REG_STATS
);
83 /* Free the array that holds the REG_N_SETS and REG_N_REFS. */
86 regstat_free_n_sets_and_refs (void)
88 gcc_assert (regstat_n_sets_and_refs
);
89 free (regstat_n_sets_and_refs
);
90 regstat_n_sets_and_refs
= NULL
;
94 /*----------------------------------------------------------------------------
97 Process REG_N_DEATHS, REG_N_CALLS_CROSSED, and REG_BASIC_BLOCK.
99 ----------------------------------------------------------------------------*/
101 static bitmap setjmp_crosses
;
102 struct reg_info_t
*reg_info_p
;
104 /* The number allocated elements of reg_info_p. */
105 size_t reg_info_p_size
;
107 /* Compute register info: lifetime, bb, and number of defs and uses
108 for basic block BB. LIVE is a scratch bitvector used here. */
111 regstat_bb_compute_ri (basic_block bb
, bitmap live
)
118 bitmap_copy (live
, df_get_live_out (bb
));
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
;
125 /* Process the artificial defs and uses at the bottom of the block
126 to begin processing. */
127 FOR_EACH_ARTIFICIAL_DEF (def
, bb
->index
)
128 if ((DF_REF_FLAGS (def
) & DF_REF_AT_TOP
) == 0)
129 bitmap_clear_bit (live
, DF_REF_REGNO (def
));
131 FOR_EACH_ARTIFICIAL_USE (use
, bb
->index
)
132 if ((DF_REF_FLAGS (use
) & DF_REF_AT_TOP
) == 0)
134 regno
= DF_REF_REGNO (use
);
135 bitmap_set_bit (live
, regno
);
138 FOR_BB_INSNS_REVERSE (bb
, insn
)
140 struct df_insn_info
*insn_info
= DF_INSN_INFO_GET (insn
);
144 if (!NONDEBUG_INSN_P (insn
))
147 link
= REG_NOTES (insn
);
150 if (REG_NOTE_KIND (link
) == REG_DEAD
)
151 REG_N_DEATHS (REGNO (XEXP (link
, 0)))++;
152 link
= XEXP (link
, 1);
155 /* Process the defs. */
158 bool set_jump
= (find_reg_note (insn
, REG_SETJMP
, NULL
) != NULL
);
159 EXECUTE_IF_SET_IN_BITMAP (live
, 0, regno
, bi
)
161 REG_N_CALLS_CROSSED (regno
)++;
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
175 bitmap_set_bit (setjmp_crosses
, regno
);
179 /* All of the defs except the return value are some sort of
180 clobber. This code is for the return. */
181 FOR_EACH_INSN_INFO_DEF (def
, insn_info
)
184 || (!(DF_REF_FLAGS (def
)
185 & (DF_REF_MUST_CLOBBER
| DF_REF_MAY_CLOBBER
))))
187 unsigned int dregno
= DF_REF_REGNO (def
);
189 /* Kill this register if it is not a subreg store or
191 ??? This means that any partial store is live from
192 the last use in a basic block to the start of this
194 if (!(DF_REF_FLAGS (def
)
195 & (DF_REF_PARTIAL
| DF_REF_CONDITIONAL
)))
196 bitmap_clear_bit (live
, dregno
);
198 if (dregno
>= FIRST_PSEUDO_REGISTER
)
200 REG_FREQ (dregno
) += REG_FREQ_FROM_BB (bb
);
202 MIN (REG_FREQ (dregno
), REG_FREQ_MAX
);
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
;
212 FOR_EACH_INSN_INFO_USE (use
, insn_info
)
214 unsigned int uregno
= DF_REF_REGNO (use
);
216 if (uregno
>= FIRST_PSEUDO_REGISTER
)
218 REG_FREQ (uregno
) += REG_FREQ_FROM_BB (bb
);
220 MIN (REG_FREQ (uregno
), REG_FREQ_MAX
);
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
;
232 /* Compute register info: lifetime, bb, and number of defs and uses. */
234 regstat_compute_ri (void)
237 bitmap live
= BITMAP_ALLOC (&df_bitmap_obstack
);
241 /* Initialize everything. */
243 gcc_assert (!reg_info_p
);
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
;
249 reg_info_p
= XCNEWVEC (struct reg_info_t
, max_regno
);
251 FOR_EACH_BB_FN (bb
, cfun
)
253 regstat_bb_compute_ri (bb
, live
);
258 /* See the setjmp comment in regstat_bb_compute_ri. */
259 EXECUTE_IF_SET_IN_BITMAP (setjmp_crosses
, FIRST_PSEUDO_REGISTER
, regno
, bi
)
261 REG_BASIC_BLOCK (regno
) = REG_BLOCK_UNKNOWN
;
264 timevar_pop (TV_REG_STATS
);
268 /* Free all storage associated with the problem. */
271 regstat_free_ri (void)
273 gcc_assert (reg_info_p
);
278 BITMAP_FREE (setjmp_crosses
);
282 /* Return a bitmap containing the set of registers that cross a setjmp.
283 The client should not change or delete this bitmap. */
286 regstat_get_setjmp_crosses (void)
288 return setjmp_crosses
;
291 /*----------------------------------------------------------------------------
292 Process REG_N_CALLS_CROSSED.
294 This is used by sched_deps. A good implementation of sched-deps
295 would really process the blocks directly rather than going through
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.
300 ----------------------------------------------------------------------------*/
304 /* Compute calls crossed for BB. Live is a scratch bitvector. */
307 regstat_bb_compute_calls_crossed (unsigned int bb_index
, bitmap live
)
309 basic_block bb
= BASIC_BLOCK_FOR_FN (cfun
, bb_index
);
313 bitmap_copy (live
, df_get_live_out (bb
));
315 /* Process the artificial defs and uses at the bottom of the block
316 to begin processing. */
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
));
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
));
325 FOR_BB_INSNS_REVERSE (bb
, insn
)
327 if (!NONDEBUG_INSN_P (insn
))
330 gcc_assert (INSN_UID (insn
) < (int) DF_INSN_SIZE ());
331 struct df_insn_info
*insn_info
= DF_INSN_INFO_GET (insn
);
334 /* Process the defs. */
338 EXECUTE_IF_SET_IN_BITMAP (live
, 0, regno
, bi
)
340 REG_N_CALLS_CROSSED (regno
)++;
344 /* All of the defs except the return value are some sort of
345 clobber. This code is for the return. */
346 FOR_EACH_INSN_INFO_DEF (def
, insn_info
)
349 || (!(DF_REF_FLAGS (def
) & (DF_REF_MUST_CLOBBER
| DF_REF_MAY_CLOBBER
))))
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
));
357 FOR_EACH_INSN_INFO_USE (use
, insn_info
)
358 bitmap_set_bit (live
, DF_REF_REGNO (use
));
363 /* Compute register info: lifetime, bb, and number of defs and uses. */
365 regstat_compute_calls_crossed (void)
368 bitmap live
= BITMAP_ALLOC (&df_bitmap_obstack
);
370 /* Initialize everything. */
371 gcc_assert (!reg_info_p
);
373 timevar_push (TV_REG_STATS
);
374 max_regno
= max_reg_num ();
375 reg_info_p_size
= max_regno
;
376 reg_info_p
= XCNEWVEC (struct reg_info_t
, max_regno
);
378 FOR_EACH_BB_FN (bb
, cfun
)
380 regstat_bb_compute_calls_crossed (bb
->index
, live
);
384 timevar_pop (TV_REG_STATS
);
388 /* Free all storage associated with the problem. */
391 regstat_free_calls_crossed (void)
393 gcc_assert (reg_info_p
);
399 /* Dump the register info to FILE. */
402 dump_reg_info (FILE *file
)
404 unsigned int i
, max
= max_reg_num ();
405 if (reload_completed
)
408 if (reg_info_p_size
< max
)
409 max
= reg_info_p_size
;
411 fprintf (file
, "%d registers.\n", max
);
412 for (i
= FIRST_PSEUDO_REGISTER
; i
< max
; i
++)
414 enum reg_class rclass
, altclass
;
416 if (regstat_n_sets_and_refs
)
417 fprintf (file
, "\nRegister %d used %d times",
420 fprintf (file
, "\nRegister %d used %d times",
421 i
, DF_REG_USE_COUNT (i
) + DF_REG_DEF_COUNT (i
));
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");
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
));
439 if (regno_reg_rtx
[i
] != NULL
440 && maybe_ne (PSEUDO_REGNO_BYTES (i
), UNITS_PER_WORD
))
442 fprintf (file
, "; ");
443 print_dec (PSEUDO_REGNO_BYTES (i
), file
, SIGNED
);
444 fprintf (file
, " bytes");
447 rclass
= reg_preferred_class (i
);
448 altclass
= reg_alternate_class (i
);
449 if (rclass
!= GENERAL_REGS
|| altclass
!= ALL_REGS
)
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
]);
456 fprintf (file
, "; pref %s, else %s",
457 reg_class_names
[(int) rclass
],
458 reg_class_names
[(int) altclass
]);
461 if (regno_reg_rtx
[i
] != NULL
&& REG_POINTER (regno_reg_rtx
[i
]))
462 fputs ("; pointer", file
);