gcc/lra-int.h

   1 /* Local Register Allocator (LRA) intercommunication header file.
   2    Copyright (C) 2010-2017 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 struct lra_reg
  68 {
  69   /* Bitmap of UIDs of insns (including debug insns) referring the
  70      reg.  */
  71   bitmap_head insn_bitmap;
  72   /* The following fields are defined only for pseudos.  */
  73   /* Hard registers with which the pseudo conflicts.  */
  74   HARD_REG_SET conflict_hard_regs;
  75   /* Call used registers with which the pseudo conflicts, taking into account
  76      the registers used by functions called from calls which cross the
  77      pseudo.  */
  78   HARD_REG_SET actual_call_used_reg_set;
  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   /* True if the pseudo crosses a call.  It is setup in lra-lives.c
  95      and used to check that the pseudo crossing a call did not get a
  96      call used hard register.  */
  97   bool call_p;
  98   /* Number of references and execution frequencies of the register in
  99      *non-debug* insns.  */
 100   int nrefs, freq;
 101   int last_reload;
 102   /* rtx used to undo the inheritance.  It can be non-null only
 103      between subsequent inheritance and undo inheritance passes.  */
 104   rtx restore_rtx;
 105   /* Value holding by register.  If the pseudos have the same value
 106      they do not conflict.  */
 107   int val;
 108   /* Offset from relative eliminate register to pesudo reg.  */
 109   int offset;
 110   /* These members are set up in lra-lives.c and updated in
 111      lra-coalesce.c.  */
 112   /* The biggest size mode in which each pseudo reg is referred in
 113      whole function (possibly via subreg).  */
 114   machine_mode biggest_mode;
 115   /* Live ranges of the pseudo.  */
 116   lra_live_range_t live_ranges;
 117   /* This member is set up in lra-lives.c for subsequent
 118      assignments.  */
 119   lra_copy_t copies;
 120 };
 121
 122 /* References to the common info about each register.  */
 123 extern struct lra_reg *lra_reg_info;
 124
 125 /* Static info about each insn operand (common for all insns with the
 126    same ICODE).  Warning: if the structure definition is changed, the
 127    initializer for debug_operand_data in lra.c should be changed
 128    too.  */
 129 struct lra_operand_data
 130 {
 131   /* The machine description constraint string of the operand.  */
 132   const char *constraint;
 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 there is an early clobber alternative for this operand.
 143      This field is set up every time when corresponding
 144      operand_alternative in lra_static_insn_data is set up.  */
 145   unsigned int early_clobber : 1;
 146   /* True if the operand is an address.  */
 147   unsigned int is_address : 1;
 148 };
 149
 150 /* Info about register occurrence in an insn.  */
 151 struct lra_insn_reg
 152 {
 153   /* The biggest mode through which the insn refers to the register
 154      occurrence (remember the register can be accessed through a
 155      subreg in the insn).  */
 156   ENUM_BITFIELD(machine_mode) biggest_mode : 16;
 157   /* The type of the corresponding operand which is the register.  */
 158   ENUM_BITFIELD (op_type) type : 8;
 159   /* True if the reg is accessed through a subreg and the subreg is
 160      just a part of the register.  */
 161   unsigned int subreg_p : 1;
 162   /* True if there is an early clobber alternative for this
 163      operand.  */
 164   unsigned int early_clobber : 1;
 165   /* The corresponding regno of the register.  */
 166   int regno;
 167   /* Next reg info of the same insn.  */
 168   struct lra_insn_reg *next;
 169 };
 170
 171 /* Static part (common info for insns with the same ICODE) of LRA
 172    internal insn info. It exists in at most one exemplar for each
 173    non-negative ICODE. There is only one exception. Each asm insn has
 174    own structure.  Warning: if the structure definition is changed,
 175    the initializer for debug_insn_static_data in lra.c should be
 176    changed too.  */
 177 struct lra_static_insn_data
 178 {
 179   /* Static info about each insn operand.  */
 180   struct lra_operand_data *operand;
 181   /* Each duplication refers to the number of the corresponding
 182      operand which is duplicated.  */
 183   int *dup_num;
 184   /* The number of an operand marked as commutative, -1 otherwise.  */
 185   int commutative;
 186   /* Number of operands, duplications, and alternatives of the
 187      insn.  */
 188   char n_operands;
 189   char n_dups;
 190   char n_alternatives;
 191   /* Insns in machine description (or clobbers in asm) may contain
 192      explicit hard regs which are not operands.  The following list
 193      describes such hard registers.  */
 194   struct lra_insn_reg *hard_regs;
 195   /* Array [n_alternatives][n_operand] of static constraint info for
 196      given operand in given alternative.  This info can be changed if
 197      the target reg info is changed.  */
 198   const struct operand_alternative *operand_alternative;
 199 };
 200
 201 /* LRA internal info about an insn (LRA internal insn
 202    representation).  */
 203 struct lra_insn_recog_data
 204 {
 205   /* The insn code.  */
 206   int icode;
 207   /* The alternative should be used for the insn, -1 if invalid, or we
 208      should try to use any alternative, or the insn is a debug
 209      insn.  */
 210   int used_insn_alternative;
 211   /* SP offset before the insn relative to one at the func start.  */
 212   HOST_WIDE_INT sp_offset;
 213   /* The insn itself.  */
 214   rtx_insn *insn;
 215   /* Common data for insns with the same ICODE.  Asm insns (their
 216      ICODE is negative) do not share such structures.  */
 217   struct lra_static_insn_data *insn_static_data;
 218   /* Two arrays of size correspondingly equal to the operand and the
 219      duplication numbers: */
 220   rtx **operand_loc; /* The operand locations, NULL if no operands.  */
 221   rtx **dup_loc; /* The dup locations, NULL if no dups.  */
 222   /* Number of hard registers implicitly used/clobbered in given call
 223      insn.  The value can be NULL or points to array of the hard
 224      register numbers ending with a negative value.  To differ
 225      clobbered and used hard regs, clobbered hard regs are incremented
 226      by FIRST_PSEUDO_REGISTER.  */
 227   int *arg_hard_regs;
 228   /* Cached value of get_preferred_alternatives.  */
 229   alternative_mask preferred_alternatives;
 230   /* The following member value is always NULL for a debug insn.  */
 231   struct lra_insn_reg *regs;
 232 };
 233
 234 typedef struct lra_insn_recog_data *lra_insn_recog_data_t;
 235
 236 /* Whether the clobber is used temporary in LRA.  */
 237 #define LRA_TEMP_CLOBBER_P(x) \
 238   (RTL_FLAG_CHECK1 ("TEMP_CLOBBER_P", (x), CLOBBER)->unchanging)
 239
 240 /* Cost factor for each additional reload and maximal cost reject for
 241    insn reloads.  One might ask about such strange numbers.  Their
 242    values occurred historically from former reload pass.  */
 243 #define LRA_LOSER_COST_FACTOR 6
 244 #define LRA_MAX_REJECT 600
 245
 246 /* Maximum allowed number of assignment pass iterations after the
 247    latest spill pass when any former reload pseudo was spilled.  It is
 248    for preventing LRA cycling in a bug case.  */
 249 #define LRA_MAX_ASSIGNMENT_ITERATION_NUMBER 30
 250
 251 /* The maximal number of inheritance/split passes in LRA.  It should
 252    be more 1 in order to perform caller saves transformations and much
 253    less MAX_CONSTRAINT_ITERATION_NUMBER to prevent LRA to do as many
 254    as permitted constraint passes in some complicated cases.  The
 255    first inheritance/split pass has a biggest impact on generated code
 256    quality.  Each subsequent affects generated code in less degree.
 257    For example, the 3rd pass does not change generated SPEC2000 code
 258    at all on x86-64.  */
 259 #define LRA_MAX_INHERITANCE_PASSES 2
 260
 261 #if LRA_MAX_INHERITANCE_PASSES <= 0 \
 262     || LRA_MAX_INHERITANCE_PASSES >= LRA_MAX_ASSIGNMENT_ITERATION_NUMBER - 8
 263 #error wrong LRA_MAX_INHERITANCE_PASSES value
 264 #endif
 265
 266 /* Analogous macro to the above one but for rematerialization.  */
 267 #define LRA_MAX_REMATERIALIZATION_PASSES 2
 268
 269 #if LRA_MAX_REMATERIALIZATION_PASSES <= 0 \
 270     || LRA_MAX_REMATERIALIZATION_PASSES >= LRA_MAX_ASSIGNMENT_ITERATION_NUMBER - 8
 271 #error wrong LRA_MAX_REMATERIALIZATION_PASSES value
 272 #endif
 273
 274 /* lra.c: */
 275
 276 extern FILE *lra_dump_file;
 277
 278 extern bool lra_reg_spill_p;
 279
 280 extern HARD_REG_SET lra_no_alloc_regs;
 281
 282 extern int lra_insn_recog_data_len;
 283 extern lra_insn_recog_data_t *lra_insn_recog_data;
 284
 285 extern int lra_curr_reload_num;
 286
 287 extern void lra_dump_bitmap_with_title (const char *, bitmap, int);
 288 extern hashval_t lra_rtx_hash (rtx x);
 289 extern void lra_push_insn (rtx_insn *);
 290 extern void lra_push_insn_by_uid (unsigned int);
 291 extern void lra_push_insn_and_update_insn_regno_info (rtx_insn *);
 292 extern rtx_insn *lra_pop_insn (void);
 293 extern unsigned int lra_insn_stack_length (void);
 294
 295 extern rtx lra_create_new_reg_with_unique_value (machine_mode, rtx,
 296                                                  enum reg_class, const char *);
 297 extern void lra_set_regno_unique_value (int);
 298 extern void lra_invalidate_insn_data (rtx_insn *);
 299 extern void lra_set_insn_deleted (rtx_insn *);
 300 extern void lra_delete_dead_insn (rtx_insn *);
 301 extern void lra_emit_add (rtx, rtx, rtx);
 302 extern void lra_emit_move (rtx, rtx);
 303 extern void lra_update_dups (lra_insn_recog_data_t, signed char *);
 304
 305 extern void lra_process_new_insns (rtx_insn *, rtx_insn *, rtx_insn *,
 306                                    const char *);
 307
 308 extern bool lra_substitute_pseudo (rtx *, int, rtx, bool);
 309 extern bool lra_substitute_pseudo_within_insn (rtx_insn *, int, rtx, bool);
 310
 311 extern lra_insn_recog_data_t lra_set_insn_recog_data (rtx_insn *);
 312 extern lra_insn_recog_data_t lra_update_insn_recog_data (rtx_insn *);
 313 extern void lra_set_used_insn_alternative (rtx_insn *, int);
 314 extern void lra_set_used_insn_alternative_by_uid (int, int);
 315
 316 extern void lra_invalidate_insn_regno_info (rtx_insn *);
 317 extern void lra_update_insn_regno_info (rtx_insn *);
 318 extern struct lra_insn_reg *lra_get_insn_regs (int);
 319
 320 extern void lra_free_copies (void);
 321 extern void lra_create_copy (int, int, int);
 322 extern lra_copy_t lra_get_copy (int);
 323 extern bool lra_former_scratch_p (int);
 324 extern bool lra_former_scratch_operand_p (rtx_insn *, int);
 325 extern void lra_register_new_scratch_op (rtx_insn *, int);
 326
 327 extern int lra_new_regno_start;
 328 extern int lra_constraint_new_regno_start;
 329 extern int lra_bad_spill_regno_start;
 330 extern bitmap_head lra_inheritance_pseudos;
 331 extern bitmap_head lra_split_regs;
 332 extern bitmap_head lra_subreg_reload_pseudos;
 333 extern bitmap_head lra_optional_reload_pseudos;
 334
 335 /* lra-constraints.c: */
 336
 337 extern void lra_init_equiv (void);
 338 extern int lra_constraint_offset (int, machine_mode);
 339
 340 extern int lra_constraint_iter;
 341 extern bool lra_risky_transformations_p;
 342 extern int lra_inheritance_iter;
 343 extern int lra_undo_inheritance_iter;
 344 extern bool lra_constrain_insn (rtx_insn *);
 345 extern bool lra_constraints (bool);
 346 extern void lra_constraints_init (void);
 347 extern void lra_constraints_finish (void);
 348 extern void lra_inheritance (void);
 349 extern bool lra_undo_inheritance (void);
 350
 351 /* lra-lives.c: */
 352
 353 extern int lra_live_max_point;
 354 extern int *lra_point_freq;
 355
 356 extern int lra_hard_reg_usage[FIRST_PSEUDO_REGISTER];
 357
 358 extern int lra_live_range_iter;
 359 extern void lra_create_live_ranges (bool, bool);
 360 extern lra_live_range_t lra_copy_live_range_list (lra_live_range_t);
 361 extern lra_live_range_t lra_merge_live_ranges (lra_live_range_t,
 362                                                lra_live_range_t);
 363 extern bool lra_intersected_live_ranges_p (lra_live_range_t,
 364                                            lra_live_range_t);
 365 extern void lra_print_live_range_list (FILE *, lra_live_range_t);
 366 extern void debug (lra_live_range &ref);
 367 extern void debug (lra_live_range *ptr);
 368 extern void lra_debug_live_range_list (lra_live_range_t);
 369 extern void lra_debug_pseudo_live_ranges (int);
 370 extern void lra_debug_live_ranges (void);
 371 extern void lra_clear_live_ranges (void);
 372 extern void lra_live_ranges_init (void);
 373 extern void lra_live_ranges_finish (void);
 374 extern void lra_setup_reload_pseudo_preferenced_hard_reg (int, int, int);
 375
 376 /* lra-assigns.c: */
 377
 378 extern int lra_assignment_iter;
 379 extern int lra_assignment_iter_after_spill;
 380 extern void lra_setup_reg_renumber (int, int, bool);
 381 extern bool lra_assign (void);
 382
 383
 384 /* lra-coalesce.c: */
 385
 386 extern int lra_coalesce_iter;
 387 extern bool lra_coalesce (void);
 388
 389 /* lra-spills.c:  */
 390
 391 extern bool lra_need_for_spills_p (void);
 392 extern void lra_spill (void);
 393 extern void lra_final_code_change (void);
 394
 395 /* lra-remat.c:  */
 396
 397 extern int lra_rematerialization_iter;
 398 extern bool lra_remat (void);
 399
 400 /* lra-elimination.c: */
 401
 402 extern void lra_debug_elim_table (void);
 403 extern int lra_get_elimination_hard_regno (int);
 404 extern rtx lra_eliminate_regs_1 (rtx_insn *, rtx, machine_mode,
 405                                  bool, bool, HOST_WIDE_INT, bool);
 406 extern void eliminate_regs_in_insn (rtx_insn *insn, bool, bool, HOST_WIDE_INT);
 407 extern void lra_eliminate (bool, bool);
 408
 409 extern void lra_eliminate_reg_if_possible (rtx *);
 410
 411 \f
 412
 413 /* Return the hard register which given pseudo REGNO assigned to.
 414    Negative value means that the register got memory or we don't know
 415    allocation yet.  */
 416 static inline int
 417 lra_get_regno_hard_regno (int regno)
 418 {
 419   resize_reg_info ();
 420   return reg_renumber[regno];
 421 }
 422
 423 /* Change class of pseudo REGNO to NEW_CLASS.  Print info about it
 424    using TITLE.  Output a new line if NL_P.  */
 425 static void inline
 426 lra_change_class (int regno, enum reg_class new_class,
 427                   const char *title, bool nl_p)
 428 {
 429   lra_assert (regno >= FIRST_PSEUDO_REGISTER);
 430   if (lra_dump_file != NULL)
 431     fprintf (lra_dump_file, "%s class %s for r%d",
 432              title, reg_class_names[new_class], regno);
 433   setup_reg_classes (regno, new_class, NO_REGS, new_class);
 434   if (lra_dump_file != NULL && nl_p)
 435     fprintf (lra_dump_file, "\n");
 436 }
 437
 438 /* Update insn operands which are duplication of NOP operand.  The
 439    insn is represented by its LRA internal representation ID.  */
 440 static inline void
 441 lra_update_dup (lra_insn_recog_data_t id, int nop)
 442 {
 443   int i;
 444   struct lra_static_insn_data *static_id = id->insn_static_data;
 445
 446   for (i = 0; i < static_id->n_dups; i++)
 447     if (static_id->dup_num[i] == nop)
 448       *id->dup_loc[i] = *id->operand_loc[nop];
 449 }
 450
 451 /* Process operator duplications in insn with ID.  We do it after the
 452    operands processing.  Generally speaking, we could do this probably
 453    simultaneously with operands processing because a common practice
 454    is to enumerate the operators after their operands.  */
 455 static inline void
 456 lra_update_operator_dups (lra_insn_recog_data_t id)
 457 {
 458   int i;
 459   struct lra_static_insn_data *static_id = id->insn_static_data;
 460
 461   for (i = 0; i < static_id->n_dups; i++)
 462     {
 463       int ndup = static_id->dup_num[i];
 464
 465       if (static_id->operand[ndup].is_operator)
 466         *id->dup_loc[i] = *id->operand_loc[ndup];
 467     }
 468 }
 469
 470 /* Return info about INSN.  Set up the info if it is not done yet.  */
 471 static inline lra_insn_recog_data_t
 472 lra_get_insn_recog_data (rtx_insn *insn)
 473 {
 474   lra_insn_recog_data_t data;
 475   unsigned int uid = INSN_UID (insn);
 476
 477   if (lra_insn_recog_data_len > (int) uid
 478       && (data = lra_insn_recog_data[uid]) != NULL)
 479     {
 480       /* Check that we did not change insn without updating the insn
 481          info.  */
 482       lra_assert (data->insn == insn
 483                   && (INSN_CODE (insn) < 0
 484                       || data->icode == INSN_CODE (insn)));
 485       return data;
 486     }
 487   return lra_set_insn_recog_data (insn);
 488 }
 489
 490 /* Update offset from pseudos with VAL by INCR.  */
 491 static inline void
 492 lra_update_reg_val_offset (int val, int incr)
 493 {
 494   int i;
 495
 496   for (i = FIRST_PSEUDO_REGISTER; i < max_reg_num (); i++)
 497     {
 498       if (lra_reg_info[i].val == val)
 499         lra_reg_info[i].offset += incr;
 500     }
 501 }
 502
 503 /* Return true if register content is equal to VAL with OFFSET.  */
 504 static inline bool
 505 lra_reg_val_equal_p (int regno, int val, int offset)
 506 {
 507   if (lra_reg_info[regno].val == val
 508       && lra_reg_info[regno].offset == offset)
 509     return true;
 510
 511   return false;
 512 }
 513
 514 /* Assign value of register FROM to TO.  */
 515 static inline void
 516 lra_assign_reg_val (int from, int to)
 517 {
 518   lra_reg_info[to].val = lra_reg_info[from].val;
 519   lra_reg_info[to].offset = lra_reg_info[from].offset;
 520 }
 521
 522 #endif /* GCC_LRA_INT_H */