gcc/lra-int.h

   1 /* Local Register Allocator (LRA) intercommunication header file.
   2    Copyright (C) 2010-2024 Free Software Foundation, Inc.
   3    Contributed by Vladimir Makarov <vmakarov@redhat.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
   9 Software Foundation; either version 3, or (at your option) any later
  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
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef GCC_LRA_INT_H
  22 #define GCC_LRA_INT_H
  23
  24 #define lra_assert(c) gcc_checking_assert (c)
  25
  26 /* The parameter used to prevent infinite reloading for an insn.  Each
  27    insn operands might require a reload and, if it is a memory, its
  28    base and index registers might require a reload too.  */
  29 #define LRA_MAX_INSN_RELOADS (MAX_RECOG_OPERANDS * 3)
  30
  31 typedef struct lra_live_range *lra_live_range_t;
  32
  33 /* The structure describes program points where a given pseudo lives.
  34    The live ranges can be used to find conflicts with other pseudos.
  35    If the live ranges of two pseudos are intersected, the pseudos are
  36    in conflict.  */
  37 struct lra_live_range
  38 {
  39   /* Pseudo regno whose live range is described by given
  40      structure.  */
  41   int regno;
  42   /* Program point range.  */
  43   int start, finish;
  44   /* Next structure describing program points where the pseudo
  45      lives.  */
  46   lra_live_range_t next;
  47   /* Pointer to structures with the same start.  */
  48   lra_live_range_t start_next;
  49 };
  50
  51 typedef struct lra_copy *lra_copy_t;
  52
  53 /* Copy between pseudos which affects assigning hard registers.  */
  54 struct lra_copy
  55 {
  56   /* True if regno1 is the destination of the copy.  */
  57   bool regno1_dest_p;
  58   /* Execution frequency of the copy.  */
  59   int freq;
  60   /* Pseudos connected by the copy.  REGNO1 < REGNO2.  */
  61   int regno1, regno2;
  62   /* Next copy with correspondingly REGNO1 and REGNO2.  */
  63   lra_copy_t regno1_next, regno2_next;
  64 };
  65
  66 /* Common info about a register (pseudo or hard register).  */
  67 class lra_reg
  68 {
  69 public:
  70   /* Bitmap of UIDs of insns (including debug insns) referring the
  71      reg.  */
  72   bitmap_head insn_bitmap;
  73   /* The following fields are defined only for pseudos.  */
  74   /* Hard registers with which the pseudo conflicts.  */
  75   HARD_REG_SET conflict_hard_regs;
  76   /* Pseudo allocno class hard registers which cannot be a start hard register
  77      of the pseudo.  */
  78   HARD_REG_SET exclude_start_hard_regs;
  79   /* We assign hard registers to reload pseudos which can occur in few
  80      places.  So two hard register preferences are enough for them.
  81      The following fields define the preferred hard registers.  If
  82      there are no such hard registers the first field value is
  83      negative.  If there is only one preferred hard register, the 2nd
  84      field is negative.  */
  85   int preferred_hard_regno1, preferred_hard_regno2;
  86   /* Profits to use the corresponding preferred hard registers.  If
  87      the both hard registers defined, the first hard register has not
  88      less profit than the second one.  */
  89   int preferred_hard_regno_profit1, preferred_hard_regno_profit2;
  90 #ifdef STACK_REGS
  91   /* True if the pseudo should not be assigned to a stack register.  */
  92   bool no_stack_p;
  93 #endif
  94   /* Number of references and execution frequencies of the register in
  95      *non-debug* insns.  */
  96   int nrefs, freq;
  97   int last_reload;
  98   /* rtx used to undo the inheritance.  It can be non-null only
  99      between subsequent inheritance and undo inheritance passes.  */
 100   rtx restore_rtx;
 101   /* Value holding by register.  If the pseudos have the same value
 102      they do not conflict.  */
 103   int val;
 104   /* Offset from relative eliminate register to pesudo reg.  */
 105   poly_int64 offset;
 106   /* These members are set up in lra-lives.cc and updated in
 107      lra-coalesce.cc.  */
 108   /* The biggest size mode in which each pseudo reg is referred in
 109      whole function (possibly via subreg).  */
 110   machine_mode biggest_mode;
 111   /* Live ranges of the pseudo.  */
 112   lra_live_range_t live_ranges;
 113   /* This member is set up in lra-lives.cc for subsequent
 114      assignments.  */
 115   lra_copy_t copies;
 116 };
 117
 118 /* References to the common info about each register.  */
 119 extern class lra_reg *lra_reg_info;
 120
 121 extern HARD_REG_SET hard_regs_spilled_into;
 122
 123 /* Static info about each insn operand (common for all insns with the
 124    same ICODE).  Warning: if the structure definition is changed, the
 125    initializer for debug_operand_data in lra.cc should be changed
 126    too.  */
 127 struct lra_operand_data
 128 {
 129   /* The machine description constraint string of the operand.  */
 130   const char *constraint;
 131   /* Alternatives for which early_clobber can be true.  */
 132   alternative_mask early_clobber_alts;
 133   /* It is taken only from machine description (which is different
 134      from recog_data.operand_mode) and can be of VOIDmode.  */
 135   ENUM_BITFIELD(machine_mode) mode : 16;
 136   /* The type of the operand (in/out/inout).  */
 137   ENUM_BITFIELD (op_type) type : 8;
 138   /* Through if accessed through STRICT_LOW.  */
 139   unsigned int strict_low : 1;
 140   /* True if the operand is an operator.  */
 141   unsigned int is_operator : 1;
 142   /* True if the operand is an address.  */
 143   unsigned int is_address : 1;
 144 };
 145
 146 /* Info about register occurrence in an insn.  */
 147 struct lra_insn_reg
 148 {
 149   /* Alternatives for which early_clobber can be true.  */
 150   alternative_mask early_clobber_alts;
 151   /* The biggest mode through which the insn refers to the register
 152      occurrence (remember the register can be accessed through a
 153      subreg in the insn).  */
 154   ENUM_BITFIELD(machine_mode) biggest_mode : 16;
 155   /* The type of the corresponding operand which is the register.  */
 156   ENUM_BITFIELD (op_type) type : 8;
 157   /* True if the reg is accessed through a subreg and the subreg is
 158      just a part of the register.  */
 159   unsigned int subreg_p : 1;
 160   /* The corresponding regno of the register.  */
 161   int regno;
 162   /* Next reg info of the same insn.  */
 163   struct lra_insn_reg *next;
 164 };
 165
 166 /* Static part (common info for insns with the same ICODE) of LRA
 167    internal insn info. It exists in at most one exemplar for each
 168    non-negative ICODE. There is only one exception. Each asm insn has
 169    own structure.  Warning: if the structure definition is changed,
 170    the initializer for debug_insn_static_data in lra.cc should be
 171    changed too.  */
 172 struct lra_static_insn_data
 173 {
 174   /* Static info about each insn operand.  */
 175   struct lra_operand_data *operand;
 176   /* Each duplication refers to the number of the corresponding
 177      operand which is duplicated.  */
 178   int *dup_num;
 179   /* The number of an operand marked as commutative, -1 otherwise.  */
 180   int commutative;
 181   /* Number of operands, duplications, and alternatives of the
 182      insn.  */
 183   char n_operands;
 184   char n_dups;
 185   char n_alternatives;
 186   /* Insns in machine description (or clobbers in asm) may contain
 187      explicit hard regs which are not operands.  The following list
 188      describes such hard registers.  */
 189   struct lra_insn_reg *hard_regs;
 190   /* Array [n_alternatives][n_operand] of static constraint info for
 191      given operand in given alternative.  This info can be changed if
 192      the target reg info is changed.  */
 193   const struct operand_alternative *operand_alternative;
 194 };
 195
 196 /* Negative insn alternative numbers used for special cases.  */
 197 #define LRA_UNKNOWN_ALT -1
 198 #define LRA_NON_CLOBBERED_ALT -2
 199
 200 /* LRA internal info about an insn (LRA internal insn
 201    representation).  */
 202 class lra_insn_recog_data
 203 {
 204 public:
 205   /* The insn code.  */
 206   int icode;
 207   /* The alternative should be used for the insn, LRA_UNKNOWN_ALT if
 208      unknown, or we should assume any alternative, or the insn is a
 209      debug insn.  LRA_NON_CLOBBERED_ALT means ignoring any earlier
 210      clobbers for the insn.  */
 211   int used_insn_alternative;
 212   /* Defined for asm insn and it is how many times we already generated reloads
 213      for the asm insn.  */
 214   int asm_reloads_num;
 215   /* SP offset before the insn relative to one at the func start.  */
 216   poly_int64 sp_offset;
 217   /* The insn itself.  */
 218   rtx_insn *insn;
 219   /* Common data for insns with the same ICODE.  Asm insns (their
 220      ICODE is negative) do not share such structures.  */
 221   struct lra_static_insn_data *insn_static_data;
 222   /* Two arrays of size correspondingly equal to the operand and the
 223      duplication numbers: */
 224   rtx **operand_loc; /* The operand locations, NULL if no operands.  */
 225   rtx **dup_loc; /* The dup locations, NULL if no dups.  */
 226   /* Number of hard registers implicitly used/clobbered in given call
 227      insn.  The value can be NULL or points to array of the hard
 228      register numbers ending with a negative value.  To differ
 229      clobbered and used hard regs, clobbered hard regs are incremented
 230      by FIRST_PSEUDO_REGISTER.  */
 231   int *arg_hard_regs;
 232   /* Cached value of get_preferred_alternatives.  */
 233   alternative_mask preferred_alternatives;
 234   /* The following member value is always NULL for a debug insn.  */
 235   struct lra_insn_reg *regs;
 236 };
 237
 238 typedef class lra_insn_recog_data *lra_insn_recog_data_t;
 239
 240 /* Whether the clobber is used temporary in LRA.  */
 241 #define LRA_TEMP_CLOBBER_P(x) \
 242   (RTL_FLAG_CHECK1 ("TEMP_CLOBBER_P", (x), CLOBBER)->unchanging)
 243
 244 /* Cost factor for each additional reload and maximal cost reject for
 245    insn reloads.  One might ask about such strange numbers.  Their
 246    values occurred historically from former reload pass.  */
 247 #define LRA_LOSER_COST_FACTOR 6
 248 #define LRA_MAX_REJECT 600
 249
 250 /* Maximum allowed number of assignment pass iterations after the
 251    latest spill pass when any former reload pseudo was spilled.  It is
 252    for preventing LRA cycling in a bug case.  */
 253 #define LRA_MAX_ASSIGNMENT_ITERATION_NUMBER 30
 254
 255 /* The maximal number of inheritance/split passes in LRA.  It should
 256    be more 1 in order to perform caller saves transformations and much
 257    less MAX_CONSTRAINT_ITERATION_NUMBER to prevent LRA to do as many
 258    as permitted constraint passes in some complicated cases.  The
 259    first inheritance/split pass has a biggest impact on generated code
 260    quality.  Each subsequent affects generated code in less degree.
 261    For example, the 3rd pass does not change generated SPEC2000 code
 262    at all on x86-64.  */
 263 #define LRA_MAX_INHERITANCE_PASSES 2
 264
 265 #if LRA_MAX_INHERITANCE_PASSES <= 0 \
 266     || LRA_MAX_INHERITANCE_PASSES >= LRA_MAX_ASSIGNMENT_ITERATION_NUMBER - 8
 267 #error wrong LRA_MAX_INHERITANCE_PASSES value
 268 #endif
 269
 270 /* Analogous macro to the above one but for rematerialization.  */
 271 #define LRA_MAX_REMATERIALIZATION_PASSES 2
 272
 273 #if LRA_MAX_REMATERIALIZATION_PASSES <= 0 \
 274     || LRA_MAX_REMATERIALIZATION_PASSES >= LRA_MAX_ASSIGNMENT_ITERATION_NUMBER - 8
 275 #error wrong LRA_MAX_REMATERIALIZATION_PASSES value
 276 #endif
 277
 278 /* lra.cc: */
 279
 280 extern FILE *lra_dump_file;
 281 extern int lra_verbose;
 282
 283 extern bool lra_hard_reg_split_p;
 284 extern bool lra_asm_error_p;
 285 extern bool lra_reg_spill_p;
 286
 287 extern HARD_REG_SET lra_no_alloc_regs;
 288
 289 extern int lra_insn_recog_data_len;
 290 extern lra_insn_recog_data_t *lra_insn_recog_data;
 291
 292 extern int lra_curr_reload_num;
 293
 294 extern void lra_dump_bitmap_with_title (const char *, bitmap, int);
 295 extern hashval_t lra_rtx_hash (rtx x);
 296 extern void lra_push_insn (rtx_insn *);
 297 extern void lra_push_insn_by_uid (unsigned int);
 298 extern void lra_push_insn_and_update_insn_regno_info (rtx_insn *);
 299 extern rtx_insn *lra_pop_insn (void);
 300 extern unsigned int lra_insn_stack_length (void);
 301
 302 extern rtx lra_create_new_reg (machine_mode, rtx, enum reg_class, HARD_REG_SET *,
 303                                const char *);
 304 extern rtx lra_create_new_reg_with_unique_value (machine_mode, rtx,
 305                                                  enum reg_class, HARD_REG_SET *,
 306                                                  const char *);
 307 extern void lra_set_regno_unique_value (int);
 308 extern void lra_invalidate_insn_data (rtx_insn *);
 309 extern void lra_set_insn_deleted (rtx_insn *);
 310 extern void lra_delete_dead_insn (rtx_insn *);
 311 extern void lra_emit_add (rtx, rtx, rtx);
 312 extern void lra_emit_move (rtx, rtx);
 313 extern void lra_update_dups (lra_insn_recog_data_t, signed char *);
 314 extern void lra_asm_insn_error (rtx_insn *insn);
 315
 316 extern void lra_dump_insns (FILE *f);
 317 extern void lra_dump_insns_if_possible (const char *title);
 318
 319 extern void lra_process_new_insns (rtx_insn *, rtx_insn *, rtx_insn *,
 320                                    const char *);
 321
 322 extern bool lra_substitute_pseudo (rtx *, int, rtx, bool, bool);
 323 extern bool lra_substitute_pseudo_within_insn (rtx_insn *, int, rtx, bool);
 324
 325 extern lra_insn_recog_data_t lra_set_insn_recog_data (rtx_insn *);
 326 extern lra_insn_recog_data_t lra_update_insn_recog_data (rtx_insn *);
 327 extern void lra_set_used_insn_alternative (rtx_insn *, int);
 328 extern void lra_set_used_insn_alternative_by_uid (int, int);
 329
 330 extern void lra_invalidate_insn_regno_info (rtx_insn *);
 331 extern void lra_update_insn_regno_info (rtx_insn *);
 332 extern struct lra_insn_reg *lra_get_insn_regs (int);
 333
 334 extern void lra_free_copies (void);
 335 extern void lra_create_copy (int, int, int);
 336 extern lra_copy_t lra_get_copy (int);
 337
 338 extern int lra_new_regno_start;
 339 extern int lra_constraint_new_regno_start;
 340 extern int lra_bad_spill_regno_start;
 341 extern rtx lra_pmode_pseudo;
 342 extern bitmap_head lra_inheritance_pseudos;
 343 extern bitmap_head lra_split_regs;
 344 extern bitmap_head lra_subreg_reload_pseudos;
 345 extern bitmap_head lra_optional_reload_pseudos;
 346
 347 /* lra-constraints.cc: */
 348
 349 extern void lra_init_equiv (void);
 350 extern int lra_constraint_offset (int, machine_mode);
 351
 352 extern int lra_constraint_iter;
 353 extern bool check_and_force_assignment_correctness_p;
 354 extern int lra_inheritance_iter;
 355 extern int lra_undo_inheritance_iter;
 356 extern bool lra_constrain_insn (rtx_insn *);
 357 extern bool lra_constraints (bool);
 358 extern void lra_constraints_init (void);
 359 extern void lra_constraints_finish (void);
 360 extern bool spill_hard_reg_in_range (int, enum reg_class, rtx_insn *, rtx_insn *);
 361 extern void lra_inheritance (void);
 362 extern bool lra_undo_inheritance (void);
 363
 364 /* lra-lives.cc: */
 365
 366 extern int lra_live_max_point;
 367 extern int *lra_point_freq;
 368
 369 extern int lra_hard_reg_usage[FIRST_PSEUDO_REGISTER];
 370
 371 extern int lra_live_range_iter;
 372 extern void lra_create_live_ranges (bool, bool);
 373 extern lra_live_range_t lra_copy_live_range_list (lra_live_range_t);
 374 extern lra_live_range_t lra_merge_live_ranges (lra_live_range_t,
 375                                                lra_live_range_t);
 376 extern bool lra_intersected_live_ranges_p (lra_live_range_t,
 377                                            lra_live_range_t);
 378 extern void lra_print_live_range_list (FILE *, lra_live_range_t);
 379 extern void debug (lra_live_range &ref);
 380 extern void debug (lra_live_range *ptr);
 381 extern void lra_debug_live_range_list (lra_live_range_t);
 382 extern void lra_debug_pseudo_live_ranges (int);
 383 extern void lra_debug_live_ranges (void);
 384 extern void lra_clear_live_ranges (void);
 385 extern void lra_live_ranges_init (void);
 386 extern void lra_live_ranges_finish (void);
 387 extern void lra_setup_reload_pseudo_preferenced_hard_reg (int, int, int);
 388
 389 /* lra-assigns.cc: */
 390
 391 extern int lra_assignment_iter;
 392 extern int lra_assignment_iter_after_spill;
 393 extern void lra_setup_reg_renumber (int, int, bool);
 394 extern bool lra_assign (bool &);
 395 extern bool lra_split_hard_reg_for (void);
 396
 397 /* lra-coalesce.cc: */
 398
 399 extern int lra_coalesce_iter;
 400 extern bool lra_coalesce (void);
 401
 402 /* lra-spills.cc:  */
 403
 404 extern bool lra_need_for_scratch_reg_p (void);
 405 extern bool lra_need_for_spills_p (void);
 406 extern void lra_spill (void);
 407 extern void lra_final_code_change (void);
 408
 409 /* lra-remat.cc:  */
 410
 411 extern int lra_rematerialization_iter;
 412 extern bool lra_remat (void);
 413
 414 /* lra-elimination.c: */
 415
 416 extern void lra_debug_elim_table (void);
 417 extern int lra_get_elimination_hard_regno (int);
 418 extern rtx lra_eliminate_regs_1 (rtx_insn *, rtx, machine_mode,
 419                                  bool, bool, poly_int64, bool);
 420 extern void eliminate_regs_in_insn (rtx_insn *insn, bool, bool, poly_int64);
 421 extern int lra_update_fp2sp_elimination (int *spilled_pseudos);
 422 extern void lra_eliminate (bool, bool);
 423
 424 extern poly_int64 lra_update_sp_offset (rtx, poly_int64);
 425 extern void lra_eliminate_reg_if_possible (rtx *);
 426
 427 \f
 428
 429 /* Return the hard register which given pseudo REGNO assigned to.
 430    Negative value means that the register got memory or we don't know
 431    allocation yet.  */
 432 inline int
 433 lra_get_regno_hard_regno (int regno)
 434 {
 435   resize_reg_info ();
 436   return reg_renumber[regno];
 437 }
 438
 439 /* Change class of pseudo REGNO to NEW_CLASS.  Print info about it
 440    using TITLE.  Output a new line if NL_P.  */
 441 inline void
 442 lra_change_class (int regno, enum reg_class new_class,
 443                   const char *title, bool nl_p)
 444 {
 445   lra_assert (regno >= FIRST_PSEUDO_REGISTER);
 446   if (lra_dump_file != NULL)
 447     fprintf (lra_dump_file, "%s class %s for r%d",
 448              title, reg_class_names[new_class], regno);
 449   setup_reg_classes (regno, new_class, NO_REGS, new_class);
 450   if (lra_dump_file != NULL && nl_p)
 451     fprintf (lra_dump_file, "\n");
 452 }
 453
 454 /* Update insn operands which are duplication of NOP operand.  The
 455    insn is represented by its LRA internal representation ID.  */
 456 inline void
 457 lra_update_dup (lra_insn_recog_data_t id, int nop)
 458 {
 459   int i;
 460   struct lra_static_insn_data *static_id = id->insn_static_data;
 461
 462   for (i = 0; i < static_id->n_dups; i++)
 463     if (static_id->dup_num[i] == nop)
 464       *id->dup_loc[i] = *id->operand_loc[nop];
 465 }
 466
 467 /* Process operator duplications in insn with ID.  We do it after the
 468    operands processing.  Generally speaking, we could do this probably
 469    simultaneously with operands processing because a common practice
 470    is to enumerate the operators after their operands.  */
 471 inline void
 472 lra_update_operator_dups (lra_insn_recog_data_t id)
 473 {
 474   int i;
 475   struct lra_static_insn_data *static_id = id->insn_static_data;
 476
 477   for (i = 0; i < static_id->n_dups; i++)
 478     {
 479       int ndup = static_id->dup_num[i];
 480
 481       if (static_id->operand[ndup].is_operator)
 482         *id->dup_loc[i] = *id->operand_loc[ndup];
 483     }
 484 }
 485
 486 /* Return info about INSN.  Set up the info if it is not done yet.  */
 487 inline lra_insn_recog_data_t
 488 lra_get_insn_recog_data (rtx_insn *insn)
 489 {
 490   lra_insn_recog_data_t data;
 491   unsigned int uid = INSN_UID (insn);
 492
 493   if (lra_insn_recog_data_len > (int) uid
 494       && (data = lra_insn_recog_data[uid]) != NULL)
 495     {
 496       /* Check that we did not change insn without updating the insn
 497          info.  */
 498       lra_assert (data->insn == insn
 499                   && (INSN_CODE (insn) < 0
 500                       || data->icode == INSN_CODE (insn)));
 501       return data;
 502     }
 503   return lra_set_insn_recog_data (insn);
 504 }
 505
 506 /* Update offset from pseudos with VAL by INCR.  */
 507 inline void
 508 lra_update_reg_val_offset (int val, poly_int64 incr)
 509 {
 510   int i;
 511
 512   for (i = FIRST_PSEUDO_REGISTER; i < max_reg_num (); i++)
 513     {
 514       if (lra_reg_info[i].val == val)
 515         lra_reg_info[i].offset += incr;
 516     }
 517 }
 518
 519 /* Return true if register content is equal to VAL with OFFSET.  */
 520 inline bool
 521 lra_reg_val_equal_p (int regno, int val, poly_int64 offset)
 522 {
 523   if (lra_reg_info[regno].val == val
 524       && known_eq (lra_reg_info[regno].offset, offset))
 525     return true;
 526
 527   return false;
 528 }
 529
 530 /* Assign value of register FROM to TO.  */
 531 inline void
 532 lra_assign_reg_val (int from, int to)
 533 {
 534   lra_reg_info[to].val = lra_reg_info[from].val;
 535   lra_reg_info[to].offset = lra_reg_info[from].offset;
 536 }
 537
 538 /* Update REGNO's biggest recorded mode so that it includes a reference
 539    in mode MODE.  */
 540 inline void
 541 lra_update_biggest_mode (int regno, machine_mode mode)
 542 {
 543   if (!ordered_p (GET_MODE_SIZE (lra_reg_info[regno].biggest_mode),
 544                   GET_MODE_SIZE (mode)))
 545     {
 546       gcc_checking_assert (HARD_REGISTER_NUM_P (regno));
 547       lra_reg_info[regno].biggest_mode = reg_raw_mode[regno];
 548     }
 549   else if (partial_subreg_p (lra_reg_info[regno].biggest_mode, mode))
 550     lra_reg_info[regno].biggest_mode = mode;
 551 }
 552
 553 #endif /* GCC_LRA_INT_H */