gcc/lra-int.h

   1 /* Local Register Allocator (LRA) intercommunication header file.
   2    Copyright (C) 2010-2013 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 #include "lra.h"
  22 #include "bitmap.h"
  23 #include "recog.h"
  24 #include "insn-attr.h"
  25 #include "insn-codes.h"
  26 #include "insn-config.h"
  27 #include "regs.h"
  28
  29 #define lra_assert(c) gcc_checking_assert (c)
  30
  31 /* The parameter used to prevent infinite reloading for an insn.  Each
  32    insn operands might require a reload and, if it is a memory, its
  33    base and index registers might require a reload too.  */
  34 #define LRA_MAX_INSN_RELOADS (MAX_RECOG_OPERANDS * 3)
  35
  36 /* Return the hard register which given pseudo REGNO assigned to.
  37    Negative value means that the register got memory or we don't know
  38    allocation yet.  */
  39 static inline int
  40 lra_get_regno_hard_regno (int regno)
  41 {
  42   resize_reg_info ();
  43   return reg_renumber[regno];
  44 }
  45
  46 typedef struct lra_live_range *lra_live_range_t;
  47
  48 /* The structure describes program points where a given pseudo lives.
  49    The live ranges can be used to find conflicts with other pseudos.
  50    If the live ranges of two pseudos are intersected, the pseudos are
  51    in conflict.  */
  52 struct lra_live_range
  53 {
  54   /* Pseudo regno whose live range is described by given
  55      structure.  */
  56   int regno;
  57   /* Program point range.  */
  58   int start, finish;
  59   /* Next structure describing program points where the pseudo
  60      lives.  */
  61   lra_live_range_t next;
  62   /* Pointer to structures with the same start.  */
  63   lra_live_range_t start_next;
  64 };
  65
  66 typedef struct lra_copy *lra_copy_t;
  67
  68 /* Copy between pseudos which affects assigning hard registers.  */
  69 struct lra_copy
  70 {
  71   /* True if regno1 is the destination of the copy.  */
  72   bool regno1_dest_p;
  73   /* Execution frequency of the copy.  */
  74   int freq;
  75   /* Pseudos connected by the copy.  REGNO1 < REGNO2.  */
  76   int regno1, regno2;
  77   /* Next copy with correspondingly REGNO1 and REGNO2.  */
  78   lra_copy_t regno1_next, regno2_next;
  79 };
  80
  81 /* Common info about a register (pseudo or hard register).  */
  82 struct lra_reg
  83 {
  84   /* Bitmap of UIDs of insns (including debug insns) referring the
  85      reg.  */
  86   bitmap_head insn_bitmap;
  87   /* The following fields are defined only for pseudos.  */
  88   /* Hard registers with which the pseudo conflicts.  */
  89   HARD_REG_SET conflict_hard_regs;
  90   /* We assign hard registers to reload pseudos which can occur in few
  91      places.  So two hard register preferences are enough for them.
  92      The following fields define the preferred hard registers.  If
  93      there are no such hard registers the first field value is
  94      negative.  If there is only one preferred hard register, the 2nd
  95      field is negative.  */
  96   int preferred_hard_regno1, preferred_hard_regno2;
  97   /* Profits to use the corresponding preferred hard registers.  If
  98      the both hard registers defined, the first hard register has not
  99      less profit than the second one.  */
 100   int preferred_hard_regno_profit1, preferred_hard_regno_profit2;
 101 #ifdef STACK_REGS
 102   /* True if the pseudo should not be assigned to a stack register.  */
 103   bool no_stack_p;
 104 #endif
 105 #ifdef ENABLE_CHECKING
 106   /* True if the pseudo crosses a call.  It is setup in lra-lives.c
 107      and used to check that the pseudo crossing a call did not get a
 108      call used hard register.  */
 109   bool call_p;
 110 #endif
 111   /* Number of references and execution frequencies of the register in
 112      *non-debug* insns.  */
 113   int nrefs, freq;
 114   int last_reload;
 115   /* Regno used to undo the inheritance.  It can be non-zero only
 116      between couple of inheritance and undo inheritance passes.  */
 117   int restore_regno;
 118   /* Value holding by register.  If the pseudos have the same value
 119      they do not conflict.  */
 120   int val;
 121   /* These members are set up in lra-lives.c and updated in
 122      lra-coalesce.c.  */
 123   /* The biggest size mode in which each pseudo reg is referred in
 124      whole function (possibly via subreg).  */
 125   enum machine_mode biggest_mode;
 126   /* Live ranges of the pseudo.  */
 127   lra_live_range_t live_ranges;
 128   /* This member is set up in lra-lives.c for subsequent
 129      assignments.  */
 130   lra_copy_t copies;
 131 };
 132
 133 /* References to the common info about each register.  */
 134 extern struct lra_reg *lra_reg_info;
 135
 136 /* Static info about each insn operand (common for all insns with the
 137    same ICODE).  Warning: if the structure definition is changed, the
 138    initializer for debug_operand_data in lra.c should be changed
 139    too.  */
 140 struct lra_operand_data
 141 {
 142   /* The machine description constraint string of the operand.  */
 143   const char *constraint;
 144   /* It is taken only from machine description (which is different
 145      from recog_data.operand_mode) and can be of VOIDmode.  */
 146   ENUM_BITFIELD(machine_mode) mode : 16;
 147   /* The type of the operand (in/out/inout).  */
 148   ENUM_BITFIELD (op_type) type : 8;
 149   /* Through if accessed through STRICT_LOW.  */
 150   unsigned int strict_low : 1;
 151   /* True if the operand is an operator.  */
 152   unsigned int is_operator : 1;
 153   /* True if there is an early clobber alternative for this operand.
 154      This field is set up every time when corresponding
 155      operand_alternative in lra_static_insn_data is set up.  */
 156   unsigned int early_clobber : 1;
 157   /* True if the operand is an address.  */
 158   unsigned int is_address : 1;
 159 };
 160
 161 /* Info about register occurrence in an insn.  */
 162 struct lra_insn_reg
 163 {
 164   /* The biggest mode through which the insn refers to the register
 165      occurrence (remember the register can be accessed through a
 166      subreg in the insn).  */
 167   ENUM_BITFIELD(machine_mode) biggest_mode : 16;
 168   /* The type of the corresponding operand which is the register.  */
 169   ENUM_BITFIELD (op_type) type : 8;
 170   /* True if the reg is accessed through a subreg and the subreg is
 171      just a part of the register.  */
 172   unsigned int subreg_p : 1;
 173   /* True if there is an early clobber alternative for this
 174      operand.  */
 175   unsigned int early_clobber : 1;
 176   /* The corresponding regno of the register.  */
 177   int regno;
 178   /* Next reg info of the same insn.  */
 179   struct lra_insn_reg *next;
 180 };
 181
 182 /* Static part (common info for insns with the same ICODE) of LRA
 183    internal insn info. It exists in at most one exemplar for each
 184    non-negative ICODE. There is only one exception. Each asm insn has
 185    own structure.  Warning: if the structure definition is changed,
 186    the initializer for debug_insn_static_data in lra.c should be
 187    changed too.  */
 188 struct lra_static_insn_data
 189 {
 190   /* Static info about each insn operand.  */
 191   struct lra_operand_data *operand;
 192   /* Each duplication refers to the number of the corresponding
 193      operand which is duplicated.  */
 194   int *dup_num;
 195   /* The number of an operand marked as commutative, -1 otherwise.  */
 196   int commutative;
 197   /* Number of operands, duplications, and alternatives of the
 198      insn.  */
 199   char n_operands;
 200   char n_dups;
 201   char n_alternatives;
 202   /* Insns in machine description (or clobbers in asm) may contain
 203      explicit hard regs which are not operands.  The following list
 204      describes such hard registers.  */
 205   struct lra_insn_reg *hard_regs;
 206   /* Array [n_alternatives][n_operand] of static constraint info for
 207      given operand in given alternative.  This info can be changed if
 208      the target reg info is changed.  */
 209   struct operand_alternative *operand_alternative;
 210 };
 211
 212 /* LRA internal info about an insn (LRA internal insn
 213    representation).  */
 214 struct lra_insn_recog_data
 215 {
 216   /* The insn code.  */
 217   int icode;
 218   /* The insn itself.  */
 219   rtx insn;
 220   /* Common data for insns with the same ICODE.  Asm insns (their
 221      ICODE is negative) do not share such structures.  */
 222   struct lra_static_insn_data *insn_static_data;
 223   /* Two arrays of size correspondingly equal to the operand and the
 224      duplication numbers: */
 225   rtx **operand_loc; /* The operand locations, NULL if no operands.  */
 226   rtx **dup_loc; /* The dup locations, NULL if no dups.  */
 227   /* Number of hard registers implicitly used in given call insn.  The
 228      value can be NULL or points to array of the hard register numbers
 229      ending with a negative value.  */
 230   int *arg_hard_regs;
 231   /* Alternative enabled for the insn.  NULL for debug insns.  */
 232   bool *alternative_enabled_p;
 233   /* The alternative should be used for the insn, -1 if invalid, or we
 234      should try to use any alternative, or the insn is a debug
 235      insn.  */
 236   int used_insn_alternative;
 237   /* The following member value is always NULL for a debug insn.  */
 238   struct lra_insn_reg *regs;
 239 };
 240
 241 typedef struct lra_insn_recog_data *lra_insn_recog_data_t;
 242
 243 /* Whether the clobber is used temporary in LRA.  */
 244 #define LRA_TEMP_CLOBBER_P(x) \
 245   (RTL_FLAG_CHECK1 ("TEMP_CLOBBER_P", (x), CLOBBER)->unchanging)
 246
 247 /* Cost factor for each additional reload and maximal cost reject for
 248    insn reloads.  One might ask about such strange numbers.  Their
 249    values occurred historically from former reload pass.  */
 250 #define LRA_LOSER_COST_FACTOR 6
 251 #define LRA_MAX_REJECT 600
 252
 253 /* Maximum allowed number of constraint pass iterations after the last
 254    spill pass.  It is for preventing LRA cycling in a bug case.  */
 255 #define LRA_MAX_CONSTRAINT_ITERATION_NUMBER 30
 256
 257 /* The maximal number of inheritance/split passes in LRA.  It should
 258    be more 1 in order to perform caller saves transformations and much
 259    less MAX_CONSTRAINT_ITERATION_NUMBER to prevent LRA to do as many
 260    as permitted constraint passes in some complicated cases.  The
 261    first inheritance/split pass has a biggest impact on generated code
 262    quality.  Each subsequent affects generated code in less degree.
 263    For example, the 3rd pass does not change generated SPEC2000 code
 264    at all on x86-64.  */
 265 #define LRA_MAX_INHERITANCE_PASSES 2
 266
 267 #if LRA_MAX_INHERITANCE_PASSES <= 0 \
 268     || LRA_MAX_INHERITANCE_PASSES >= LRA_MAX_CONSTRAINT_ITERATION_NUMBER - 8
 269 #error wrong LRA_MAX_INHERITANCE_PASSES value
 270 #endif
 271
 272 /* lra.c: */
 273
 274 extern FILE *lra_dump_file;
 275
 276 extern bool lra_reg_spill_p;
 277
 278 extern HARD_REG_SET lra_no_alloc_regs;
 279
 280 extern int lra_insn_recog_data_len;
 281 extern lra_insn_recog_data_t *lra_insn_recog_data;
 282
 283 extern int lra_curr_reload_num;
 284
 285 extern void lra_push_insn (rtx);
 286 extern void lra_push_insn_by_uid (unsigned int);
 287 extern void lra_push_insn_and_update_insn_regno_info (rtx);
 288 extern rtx lra_pop_insn (void);
 289 extern unsigned int lra_insn_stack_length (void);
 290
 291 extern rtx lra_create_new_reg_with_unique_value (enum machine_mode, rtx,
 292                                                  enum reg_class, const char *);
 293 extern void lra_set_regno_unique_value (int);
 294 extern void lra_invalidate_insn_data (rtx);
 295 extern void lra_set_insn_deleted (rtx);
 296 extern void lra_delete_dead_insn (rtx);
 297 extern void lra_emit_add (rtx, rtx, rtx);
 298 extern void lra_emit_move (rtx, rtx);
 299 extern void lra_update_dups (lra_insn_recog_data_t, signed char *);
 300
 301 extern void lra_process_new_insns (rtx, rtx, rtx, const char *);
 302
 303 extern lra_insn_recog_data_t lra_set_insn_recog_data (rtx);
 304 extern lra_insn_recog_data_t lra_update_insn_recog_data (rtx);
 305 extern void lra_set_used_insn_alternative (rtx, int);
 306 extern void lra_set_used_insn_alternative_by_uid (int, int);
 307
 308 extern void lra_invalidate_insn_regno_info (rtx);
 309 extern void lra_update_insn_regno_info (rtx);
 310 extern struct lra_insn_reg *lra_get_insn_regs (int);
 311
 312 extern void lra_free_copies (void);
 313 extern void lra_create_copy (int, int, int);
 314 extern lra_copy_t lra_get_copy (int);
 315 extern bool lra_former_scratch_p (int);
 316 extern bool lra_former_scratch_operand_p (rtx, int);
 317
 318 extern int lra_new_regno_start;
 319 extern int lra_constraint_new_regno_start;
 320 extern bitmap_head lra_inheritance_pseudos;
 321 extern bitmap_head lra_split_regs;
 322 extern bitmap_head lra_optional_reload_pseudos;
 323 extern int lra_constraint_new_insn_uid_start;
 324
 325 /* lra-constraints.c: */
 326
 327 extern int lra_constraint_offset (int, enum machine_mode);
 328
 329 extern int lra_constraint_iter;
 330 extern int lra_constraint_iter_after_spill;
 331 extern bool lra_risky_transformations_p;
 332 extern int lra_inheritance_iter;
 333 extern int lra_undo_inheritance_iter;
 334 extern bool lra_constraints (bool);
 335 extern void lra_constraints_init (void);
 336 extern void lra_constraints_finish (void);
 337 extern void lra_inheritance (void);
 338 extern bool lra_undo_inheritance (void);
 339
 340 /* lra-lives.c: */
 341
 342 extern int lra_live_max_point;
 343 extern int *lra_point_freq;
 344
 345 extern int lra_hard_reg_usage[FIRST_PSEUDO_REGISTER];
 346
 347 extern int lra_live_range_iter;
 348 extern void lra_create_live_ranges (bool);
 349 extern lra_live_range_t lra_copy_live_range_list (lra_live_range_t);
 350 extern lra_live_range_t lra_merge_live_ranges (lra_live_range_t,
 351                                                lra_live_range_t);
 352 extern bool lra_intersected_live_ranges_p (lra_live_range_t,
 353                                            lra_live_range_t);
 354 extern void lra_print_live_range_list (FILE *, lra_live_range_t);
 355 extern void debug (lra_live_range &ref);
 356 extern void debug (lra_live_range *ptr);
 357 extern void lra_debug_live_range_list (lra_live_range_t);
 358 extern void lra_debug_pseudo_live_ranges (int);
 359 extern void lra_debug_live_ranges (void);
 360 extern void lra_clear_live_ranges (void);
 361 extern void lra_live_ranges_init (void);
 362 extern void lra_live_ranges_finish (void);
 363 extern void lra_setup_reload_pseudo_preferenced_hard_reg (int, int, int);
 364
 365 /* lra-assigns.c: */
 366
 367 extern void lra_setup_reg_renumber (int, int, bool);
 368 extern bool lra_assign (void);
 369
 370
 371 /* lra-coalesce.c: */
 372
 373 extern int lra_coalesce_iter;
 374 extern bool lra_coalesce (void);
 375
 376 /* lra-spills.c:  */
 377
 378 extern bool lra_need_for_spills_p (void);
 379 extern void lra_spill (void);
 380 extern void lra_final_code_change (void);
 381
 382
 383 /* lra-elimination.c: */
 384
 385 extern void lra_debug_elim_table (void);
 386 extern int lra_get_elimination_hard_regno (int);
 387 extern rtx lra_eliminate_regs_1 (rtx, enum machine_mode, bool, bool, bool);
 388 extern void lra_eliminate (bool);
 389
 390 extern void lra_eliminate_reg_if_possible (rtx *);
 391
 392 \f
 393
 394 /* Update insn operands which are duplication of NOP operand.  The
 395    insn is represented by its LRA internal representation ID.  */
 396 static inline void
 397 lra_update_dup (lra_insn_recog_data_t id, int nop)
 398 {
 399   int i;
 400   struct lra_static_insn_data *static_id = id->insn_static_data;
 401
 402   for (i = 0; i < static_id->n_dups; i++)
 403     if (static_id->dup_num[i] == nop)
 404       *id->dup_loc[i] = *id->operand_loc[nop];
 405 }
 406
 407 /* Process operator duplications in insn with ID.  We do it after the
 408    operands processing.  Generally speaking, we could do this probably
 409    simultaneously with operands processing because a common practice
 410    is to enumerate the operators after their operands.  */
 411 static inline void
 412 lra_update_operator_dups (lra_insn_recog_data_t id)
 413 {
 414   int i;
 415   struct lra_static_insn_data *static_id = id->insn_static_data;
 416
 417   for (i = 0; i < static_id->n_dups; i++)
 418     {
 419       int ndup = static_id->dup_num[i];
 420
 421       if (static_id->operand[ndup].is_operator)
 422         *id->dup_loc[i] = *id->operand_loc[ndup];
 423     }
 424 }
 425
 426 /* Return info about INSN.  Set up the info if it is not done yet.  */
 427 static inline lra_insn_recog_data_t
 428 lra_get_insn_recog_data (rtx insn)
 429 {
 430   lra_insn_recog_data_t data;
 431   unsigned int uid = INSN_UID (insn);
 432
 433   if (lra_insn_recog_data_len > (int) uid
 434       && (data = lra_insn_recog_data[uid]) != NULL)
 435     {
 436       /* Check that we did not change insn without updating the insn
 437          info.  */
 438       lra_assert (data->insn == insn
 439                   && (INSN_CODE (insn) < 0
 440                       || data->icode == INSN_CODE (insn)));
 441       return data;
 442     }
 443   return lra_set_insn_recog_data (insn);
 444 }
 445
 446 \f
 447
 448 struct target_lra_int
 449 {
 450   /* Map INSN_UID -> the operand alternative data (NULL if unknown).
 451      We assume that this data is valid until register info is changed
 452      because classes in the data can be changed.  */
 453   struct operand_alternative *x_op_alt_data[LAST_INSN_CODE];
 454 };
 455
 456 extern struct target_lra_int default_target_lra_int;
 457 #if SWITCHABLE_TARGET
 458 extern struct target_lra_int *this_target_lra_int;
 459 #else
 460 #define this_target_lra_int (&default_target_lra_int)
 461 #endif
 462
 463 #define op_alt_data (this_target_lra_int->x_op_alt_data)