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